Pathway to Japanese Literature

I

“The very origin of my resolve to invent the artificial heart dates back to my first year in medical school, when I heard the terms ‘artificial amoeba’ and ‘artificial heart’ during a general physiology lecture…”

Thus spoke Dr. A, the physiologist, addressing me. Dr. A was once a man who devoted himself with painstaking effort to creating artificial hearts—mechanically crafted replacements for natural ones—through which he sought to rescue humanity from myriad diseases, prolong life indefinitely, and ultimately achieve resurrection from death. Though this endeavor ruined his health and left him bedridden with severe illness, he persevered unwaveringly and temporarily achieved his goal. Yet after his wife’s death, for reasons unknown, he discarded this hard-won grand research like a worn-out shoe and ceased to regard it. I had asked him repeatedly about the reason, but the doctor would only smile wryly and firmly refuse to speak. However, one day when I visited Dr. A and happened to mention that Dr. Haber—the discoverer of atmospheric nitrogen fixation—would soon be visiting Japan, he, for reasons unknown, cheerfully declared, “Today I shall recount the full story of the artificial heart invention you’ve long desired to hear,” and began his tale. Let me pause here for a moment—I am a cultural affairs reporter for S Newspaper.

Both the artificial amoeba and artificial heart were devised to mimic amoebic and cardiac movements using inorganic materials—proof that biological motion constitutes no divine mystery but rather phenomena entirely explicable through mechanical principles. “You may not have observed an amoeba’s movements under a microscope—it’s a single-celled organism composed of semi-fluid protoplasm and nucleus,” he explained clinically. “When observing its crawling form,” he continued with academic precision, “at times it resembles a slug traversing a fence, other moments evoking how a tengu mask’s nose might gradually elongate.” If one takes a flat-bottomed glass dish containing twenty percent nitric acid, drips mercury globules within, and immerses potassium dichromate crystals at one edge, the dissolving crystals diffuse across the base until contacting mercury— whereupon droplets animate like silver spiders flexing metallic limbs. “This artificial amoeba,” he concluded, “through sustained observation reveals mercury replicating organic motion itself.”

"Next, the artificial heart," he continued. "The heart," he explained, "needless to say, rhythmically alternates between two movements: contraction and expansion." "We can skillfully mimic this rhythmic motion of the heart using mercury as well." "That is to say—if one places ten percent sulfuric acid in a watch glass, adds a minute quantity of potassium dichromate, deposits a mercury globule within, then lightly touches the droplet's surface with an iron needle—the globule immediately begins moving like a frog's heart, shrinking and expanding as it rapidly performs rhythmic motions comparable to what we call contraction and expansion."

Now, as for why the mercury droplet performs such lifelike movements—all liquids exhibit a type of force at the boundary where they contact foreign objects, which we commonly refer to as surface tension. Within a liquid’s interior, all molecules are pulled with equal force from above, below, left, right, front, and back. However, at the liquid’s surface, the molecules there are pulled from the inner side by the liquid’s own molecules and from the outer side by the molecules of the substance it contacts. When oil is dripped onto water, it spreads across the surface because water’s surface tension exceeds that of oil. Similarly, mercury forms spherical shapes when dripped into water due to its greater surface tension compared to water. If we hypothetically strengthen the water’s surface tension at its contact point with mercury beyond mercury’s own tension, or conversely reduce mercury’s tension, the weaker portion contracts less than the stronger portion, deforming the mercury sphere. Regarding the earlier artificial amoeba example: when potassium dichromate and mercury make contact within a nitric acid solution, mercury chromate forms at that interface, weakening mercury’s surface tension. This alters mercury’s shape temporarily—but since mercury chromate readily dissolves in nitric acid, the original surface tension restores itself. Naturally, the mercury’s shape reverts accordingly, and external observers recognize this as a single completed movement. Through repeated contact between fresh potassium dichromate and mercury in subsequent moments, the mercury continues performing amoeba-like motions without cessation.

Now, to explain how the phenomenon of the artificial heart occurs: when an iron needle touches mercury in sulfuric acid solution, contact electricity is generated due to the presence of the acidic liquid, and this electricity flows through both the metal and the liquid. At this point, electrolysis of the liquid occurs, and the decomposition product—positively charged hydrogen ions—adhere to the negatively charged mercury surface. As a result, the mercury's surface tension increases, causing the mercury to contract. When it contracts, it breaks contact with the iron needle and expands back to its original size; when it expands, it touches the needle again to generate electricity and contracts once more. Thus, as this motion rhythmically repeats, it appears—to an external observer—like the movement of a heart.

II

“You must find this lengthy explanation rather tedious, but since my motivation for conceiving the artificial heart lies precisely here, I have elaborated in detail about the artificial amoeba and artificial heart.” “However, needless to say, what I attempted to invent as an artificial heart was fundamentally different from the artificial heart I have just described.” “I will elaborate on that in due course. Now, in our General Physiology lectures, we were taught time and again—just as with the aforementioned artificial amoeba and artificial heart—that all life phenomena, no matter how complex, could be explained through purely mechanical principles.” “And thus, the conviction that life phenomena could be fully explained through the forces of physics and chemistry—without needing to posit any mysterious powers—became deeply ingrained in my mind.” “Looking back now, even if mercury performs movements resembling an amoeba’s, it remains mercury—not an amoeba—and likewise cannot be a heart. Yet when one is young, compromise is difficult in all matters, so I became an extreme adherent of the so-called mechanism theory.”

Mechanism theory, as I have just explained, is the doctrine that seeks to account for all life phenomena through purely mechanical principles. In opposition to this, vitalism—the so-called theory of vital forces—asserts that life phenomena cannot be explained without invoking a kind of unfathomable power beyond the reach of physics and chemistry. This conflict between mechanism theory and vitalism has been a subject of scholarly debate since antiquity—sometimes one prevailing, sometimes the other gaining dominance in alternating turns—and continues to be disputed even now.

To tentatively outline its history: in primitive times, people undoubtedly believed life was sustained by a kind of mystical force—this goes without saying. Given that people of that era could perceive things but not deeply contemplate them, it was only natural for them to believe phenomena like life and death were governed by the dominion of spirits when confronted with such matters. However, as knowledge gradually developed, people began to particularly contemplate the nature of life. I should clarify that the development of scientific thought in Japan is quite recent, and as ascertaining past ideological conditions proves difficult, I shall here describe examples from the West. Now, it was the Greeks who conducted relatively deep examinations of life, approximately 2,700 to 2,800 years ago. Namely, during that period, natural philosophers emerged in Greece who contemplated the origins of the universe and humankind, attributing the essence of all things to the four elements of earth, water, fire, and wind—thereby establishing what is called mechanism theory: the doctrine that all phenomena are formed through the separation and combination of these four elements.

However, later in that same Greece, figures like Plato and Aristotle emerged. Through their profound studies of humanity, they clearly distinguished spirit from body, establishing spirit as primary and body as subordinate. Since mental phenomena could not be mechanically explained from this perspective, vitalism consequently regained prominence. And so this vitalism, taking on religious overtones with the rise of Christianity, dominated people’s minds for approximately a millennium.

Then came the sixteenth century with its so-called Renaissance period, when pioneers of modern science emerged. As studies in human anatomy and physiology advanced, mechanism theory regained its victory, giving rise to extreme schools like the iatrophysical and iatrochemical factions that sought to explain all life phenomena solely through physics and chemistry. However, when the great physiologist Haller appeared at the end of the eighteenth century, identified phenomena unique to living organisms and absent in non-living matter, and began advocating vitalism, just then the great philosopher Cast emerged to champion the theory. Consequently, vitalism reached its zenith in the first half of the nineteenth century.

Then, in the latter half of the nineteenth century, natural sciences achieved astonishing development: Darwin’s theory of evolution emerged alongside cell theory, and Mechanism Theory was revived to persist to this day—though the great physiologist Du Bois-Reymond, who died some years ago, leaned more toward Vitalism. Thus, throughout various eras, Mechanism Theory and Vitalism have alternated victories in turn; yet even for a single scholar, one who adhered to Mechanism Theory during a certain period might well adopt Vitalism due to some motivation. “In fact, from my student days until completing the invention of the artificial heart, I had been an extreme proponent of Mechanism Theory—but upon finally applying it in practice, I abandoned it entirely. “And at the same time, I abandoned my research on artificial hearts.”

III “Now, after attending lectures on artificial amoebae and artificial hearts and becoming a believer in mechanism theory—when as a second-year student I began practical experiments with them—it suddenly struck me: couldn’t we artificially construct hearts for humans or animals to replace natural ones?” “When I attended lectures on specialized physiology, I learned the heart merely functions as a kind of pump.” “Yet despite this simplicity of purpose, no organ surpasses the heart in importance.” “So long as the heart beats, even someone lying unconscious cannot be pronounced dead.” “Thus I conceived that if—the moment a heart stopped—we immediately replaced it with an artificial counterpart, applied external energy to activate its pumping mechanism, and circulated blood through the body, we might resurrect the dead... perhaps even grant eternal life in some cases.” “The artificial heart operates on an elementary principle: receiving spent venous blood into its chamber before expelling it through a valve into the aorta.” “Since an electric motor could drive this valve’s mechanism indefinitely through geomagnetism’s ceaseless current—I even fantasized humans might achieve immortality lasting as long as Earth itself...”

What particularly drove me to pursue an artificial heart was the excruciatingly convoluted theories surrounding cardiac physiology. While meticulous examination constitutes academia's essential purpose, being bombarded with countless hypotheses during one's student years proves remarkably onerous. "Hearing academic disputes can prove fascinating in isolation," I explained, "but when they multiply unchecked, they grow intolerable." I had come to realize that physiology might better be termed an aggregate of competing doctrines, and that streamlining these theories would not only benefit students of the discipline but ultimately simplify human existence itself.

“As you may know, there are two theories regarding the origin of cardiac movement. One is called the muscle theory, which posits that the heart moves through excitation of its constituent muscles; the other holds that movement arises from excitation of the nerves embedded within those muscles. Even when excised from the body, the heart continues beating unimpeded provided appropriate methods are employed—so there remains no doubt that the force driving its movement originates from the heart itself. Yet whether this force arises from its muscles or the nerves embedded within remains undetermined to this day. To discover which holds true, countless scholars have conducted research on the hearts of various animals—some dedicating their entire precious lives to this study—and still no satisfactory resolution has been reached. One scholar took pride in having conclusively proven the nerve theory through research on rare creatures like horseshoe crabs, but narrow-minded academics proved reluctant to acknowledge it.”

It was then that I conceived an idea. Whether it be the muscle theory or the nerve theory, after all, it was because the heart existed that such troublesome theories arose. If an artificial heart were ever created, both the muscle theory and nerve theory would be shattered to smithereens. Since the electricity that turned the motor became its origin, all previous theories would be unified into the sole "electric theory." Moreover, no one could possibly raise any opposing theories against this electric doctrine. What a triumph! ...Though it may be called the folly of youth, I became engrossed in an exceedingly simplistic notion. Yet upon deeper reflection, if God had created our bodies, then all this clamor over muscle theories and nerve theories might appear even more absurd to His eyes than my imagined electric doctrine ever did to mine. In any case, I—no longer able to endure the complexity of cramming various theories into my head—resolved that once I graduated from university, I would complete the invention of the artificial heart at the earliest possible date.

IV

When I became a third-year student and attended clinical department lectures—progressing to directly handle patients—I not only keenly felt modern medicine's impotence but also discovered that what we study as medical science ultimately amounts to nothing more than an accumulation of theories, far removed from practical application. If theories could be decisively settled one way or another, treatments might be administered with clarity accordingly—but given that theories remain mired in debate, medical practice inevitably becomes fragmentary. Among the multitude of diseases, those treatable with pharmaceuticals are so few they don't even require all fingers of one hand to count; for the rest, we merely administer drugs as palliatives and wait for nature to take its course. And then, when life becomes critically endangered—well now—they invariably end up administering camphor injections for every disease, as you well know. In Japan alone, over a million people die each year, most departing for the next world with camphor injections as their parting gift. This camphor needless to say being a cardiotonic—a medication strengthening cardiac function—it follows that medicine's ultimate aim might be said to lie in fortifying the heart. Whether acute or chronic, if only the heart continued working with undiminished strength, curable diseases would be cured while life persisted even with incurable conditions remaining. Even terrifying diseases like plague and cholera ultimately amount to death through cardiac failure—therefore medical researchers must devote their efforts not to probing pathogens but rather to strengthening hearts with iron-like fortitude—no, advancing further to devise steel-crafted artificial hearts. In that case there would be no need to individually research every disease or produce voluminous literature. Were even the artificial heart's invention completed, no disease would merit fear. Whenever I reflected on Pasteur's, Koch's and Ehrlich's achievements—while feeling gratitude for their contributions—I simultaneously lamented why these great minds hadn't devoted themselves to artificial heart development. Many have left significant marks in medical history, but had those individuals focused solely on artificial hearts, an ideal device would likely have been perfected long ago—a utopia undoubtedly created ages past. From humanity's cultural development perspective, our greatest flaw lay in needlessly complicating matters. It seems humans take perverse interest in wandering lost through self-built labyrinths—such being our nature. When matters grow complex, people naturally fixate on peripheral concerns while forgetting fundamentals. That is why Rousseau cried "Return to nature!" By this I came to understand not reversion to primitive states but rather discarding foliage to return to roots. That I must complete the artificial heart's invention posthaste and restore medicine to its foundations—this conviction surged through me.

As human culture developed and matters grew increasingly complex, with medicine coming to focus on peripheral concerns—the result was the emergence of a dreadful disease. That was, needless to say, pulmonary tuberculosis. Pulmonary tuberculosis does not arise solely from the tubercle bacillus; it occurs when human constitution becomes conducive to the bacillus’s proliferation. Moreover, since this susceptibility to tuberculosis was itself produced by the progress of human cultural development, pulmonary tuberculosis could ultimately be regarded as a form of divine irony directed at civilization itself. As proof of this, modern medicine held no authority against tuberculosis. Far from holding any authority, it stood by in a daze, watching helplessly as the chaos raged unchecked. To doctors, it might have been a prized rice bowl—but for patients, it was nothing but a nuisance.

Therefore, all who aspired to medicine turned their thoughts to tuberculosis treatment. I was indeed one of them, but I came to realize this problem too could be immediately resolved through the invention of the artificial heart. As I had previously stated that all disease treatments would be accomplished through artificial hearts, pulmonary tuberculosis would naturally fall within that scope. However, since the lungs as an organ hold a special relationship with the artificial heart, I wished to address this matter specifically here.

The lungs' primary function was needless to say blood gas exchange. That is to say, venous blood containing carbon dioxide that had circulated through the entire body would be sent from the heart to the lungs, where it would discard the carbon dioxide, absorb oxygen from external air, transform into arterial blood, return to the heart, and then be distributed throughout the body. Therefore, were one to create an artificial heart while attaching a device to absorb or release carbon dioxide from venous blood and simultaneously supply oxygen, the lungs would become entirely superfluous organs. In that case, no matter how severely tuberculosis ravaged the lungs, one would feel no discomfort whatsoever. Consequently, the tuberculosis problem would be resolved immediately. Moreover, when attaching what might be termed an artificial lung to the artificial heart beforehand, the surgery to install it into the human body became remarkably simple—truly killing two birds with one stone.

However, when attaching an artificial lung to the artificial heart and freeing the lungs from gas exchange duties, I conceived that a unique phenomenon would manifest here. To elaborate: if lung cells were liberated from gas exchange tasks, human food consumption could likely be drastically reduced. Therefore, I imagined that solving the artificial heart's challenges would not only save humanity from disease's torment but potentially rescue them from food shortages too—enabling all people to live like so-called immortals sustained by mist alone.

While there may have been scholars who had previously given some consideration to the invention of the artificial heart, I believed myself likely the first to conceive that liberating the lungs from their gas exchange function could enable drastic reductions in food consumption. I shall therefore offer a few words on this matter now.

V

For some time, I had long harbored doubts regarding the existence of such vast quantities of nitrogen in the air. Indeed, nitrogen constitutes four-fifths of the entire volume of air, yet it is considered to be of no benefit whatsoever to human survival. Interpreting all phenomena through teleology may be dangerous, but I became convinced that this nitrogen in the air must undoubtedly be beneficial to human survival, just like oxygen. The oxygen in this same air is absolutely indispensable for human survival even momentarily, yet how can we reconcile this with nitrogen—four times its quantity—passing through our bodies without purpose? No matter how I considered it, this seemed contradictory. Therefore, I concluded that nitrogen does not pass through the human body without purpose. I concluded that what seems meaningless merely stems from humanity’s failure to recognize nitrogen’s value.

As you are aware, the chemical substance that constitutes the most vital tissues of the human body is protein. Since this protein is a compound centered on nitrogen, nitrogen compounds are something the human body cannot go without for even a day. Typically, we take in these nitrogen compounds through food, but considering that while nitrogen in compound form remains indispensable to the human body, nitrogen in gaseous form stays entirely unused by it, I concluded that even God had committed a grave oversight. And at the same time, I came to believe this was by no means an oversight by God—that He had indeed prepared free nitrogen to be usable—but that humankind simply failed to notice this fact. Now, you may dislike the term 'God,' but I think it's easier to understand than 'the Creator' or such phrases, so please bear with me.

Now then, in which organ of the human body had God bestowed the function to utilize free nitrogen? That, needless to say, must be the lungs through which nitrogen constantly passes in and out. While nitrogen utilization might be partially conducted through the skin—just as oxygen utilization is carried out via what's called skin respiration—I concluded that nitrogen utilization should primarily occur in the lungs, much like how oxygen utilization is principally performed there.

“Are you aware that a type of bacteria dwelling in the earth possesses nitrogen-fixing properties—that is, the ability to transform free nitrogen into nitrogen compounds?” “When even the most lowly organisms like bacteria have been endowed with such exquisite capabilities, how could humanity’s cells—belonging to Earth’s most advanced creatures—possibly lack this same faculty?” “Thus I concluded that lung cells must inherently possess this nitrogen-fixing function, mirroring soil bacteria’s natural capacity.”

However, because lung cells bear the crucial responsibility of gas exchange, they must naturally lack capacity for nitrogen fixation. Moreover, since nitrogen compounds essential for human survival are replenished through food intake, lung cells have no particular need to function. Yet if one were to cease food consumption and enter a state of starvation, the lungs' nitrogen fixation function would undoubtedly intensify. That is to say, rather than the digestive tract, the lungs would seek to govern bodily nutrition. The phenomenon of surviving weeks on mere water during starvation fasts must indisputably stem from pulmonary nitrogen fixation. When voluntarily undergoing starvation, recumbent experimenters prolong fasting because reduced gas exchange from stillness conversely heightens nitrogen fixation—this interpretation seems most appropriate. Furthermore, tuberculosis patients' severe emaciation and need for protein supplementation should be understood as resulting from tubercle bacilli impairing pulmonary nitrogen fixation.

Therefore, if the lungs were relieved of gas exchange duties, they would undoubtedly devote their full capacity to nitrogen fixation. And if the body’s nutrients were replenished through that nitrogen fixation, would there not likely be any further need to ingest protein as food through the mouth? There were those who calculated that the human body required merely two grams of protein per kilogram of body weight daily, but I believed that if all lung cells were to devote themselves to nitrogen fixation, producing that amount of nutrients would be easily achievable. If one were to complete the invention of the artificial heart and substitute the lungs’ gas exchange function with an attached artificial lung, human food consumption could be greatly reduced; moreover, should research advance further, humans might eventually live without food altogether. ……And so I would fantasize in those days, yearning to graduate from university as soon as possible and devote myself to inventing the artificial heart.

VI

Upon finally graduating from university, I was permitted to join the physiology department and, having obtained the head professor's authorization, commenced my research on artificial hearts. Due to personal circumstances, I had married while still enrolled in university, but since commuting from home would have squandered precious time, I secured permission from the head professor for my wife and me to lodge in a room within the laboratory premises. My wife developed a profound interest in my research and assisted me as my laboratory aide. We labored from daybreak until deep into the night.

Though situated in the city, the nights within the vast university grounds were serenely quiet; the light of gas lamps reflecting in the high-ceilinged laboratory evoked an indefinable loneliness. Yet whenever we exchanged smiles with eyes shining with hope across our experimental animals, we were always immersed in immeasurable joy. When experiments progressed unfavorably, I would often work through the night with a stern expression, but during such times my wife too would stay up all night, striving tirelessly to lift my spirits. Time and again I faced repeated failures, and just as I was about to sink into the abyss of despair, it was my wife who rescued and encouraged me. Had my wife not been there, I could not possibly have completed the invention of the artificial heart. That wife of mine is no longer dead now. And due to my wife’s death, I was forced to abandon the invention I had worked so hard to complete. What a strange fate this was. When I think of the hardships and joys of that time, even now I feel my heart race.

Ah, I unwittingly digressed. Now, when I set out to invent the artificial heart, I realized its completion was nowhere near as straightforward as I had imagined during my student days. And so I came to consider that while people had likely conceived the idea of inventing artificial hearts up to that point, their failure to realize it meant no records whatsoever existed in the literature.

In standard physiological experiments, it is customary to first conduct trials on readily available frogs; however, for artificial heart experiments, frogs proved too small and difficult to manipulate, so I decided to perform the experiments on domestic rabbits. Oh, how many domestic rabbits I killed. We conducted all experiments under anesthesia for the rabbits, yet even though these were endeavors meant to save humanity, I now find myself feeling profoundly apologetic toward those rabbits. Some people in society seem to believe that scientists are heartless and cruel individuals who take perverse interest in killing experimental animals, but not all of us are necessarily such people. The very reason I considered abandoning the experiment multiple times midway was indeed because I could not bear to torment the domestic rabbits.

The experimental procedure was as follows: first secure a domestic rabbit supine on a specialized platform, administer anesthesia, open the thoracic cavity at the cardiac region, then incise the pericardium, and finally attach the pump we had devised in place of the heart. Stating it that way makes it sound deceptively simple, but let me emphasize—that surgical procedure was anything but easy. Initially we attempted to excise the rabbits' hearts and replace them with pumps, but this caused such severe hemorrhaging that achieving our objective proved utterly impossible. We later settled on leaving the hearts intact while attaching relatively long tubes to the pumps and connecting these to appropriate major blood vessels.

Initially, without devising an artificial lung, we focused our research solely on the artificial heart; however, using only the artificial heart proved more laborious due to requiring connections between the pump's tubes and both the pulmonary artery and pulmonary vein, leading us to realize it would be more practical to develop an artificial heart integrated with an artificial lung. As you are aware, since the heart comprises four chambers, an artificial heart—that is, a pump—must naturally be equipped with four chambers; however, when integrated with an artificial lung, only two chambers at the valve—or effectively a single chamber—are necessary, resulting in a remarkably straightforward configuration.

Initially, we used thick-walled glass for the pump material and hard rubber for the valves. This was to observe blood flow externally, but later we changed both pump and valves to steel. Through experience, we found steel more suitable than glass for artificial hearts.

Now I must explain the structure of the pump; however, before that, I will discuss the principle of the artificial lung. Though I call it a principle, it was quite simple: remove carbonic acid gas from venous blood arriving through the superior and inferior vena cavae, then supply oxygen instead and send it into the aorta. However, while supplying oxygen merely required connecting to an oxygen tube, removing carbonic acid gas proved quite troublesome. The difficulty lay not in removing carbonic acid gas itself, but in eliminating large quantities of it instantaneously. By collecting venous blood in a fixed container equipped with a device generating strong negative pressure, we could remove some carbonic acid gas, but eliminating all of it from rapidly flowing blood remained extremely challenging. After much deliberation, I concluded that reducing carbon dioxide levels in venous blood circulating through the body might overcome this obstacle. To achieve this, I theorized that accelerating circulation of oxygen-rich blood beyond normal rates—by tripling or quadrupling valve operation frequency compared to heartbeats—would suffice. When tested, this approach dramatically reduced venous carbon dioxide levels, resolving the artificial lung problem relatively easily.

Thus, the component of the artificial lung that removes carbonic acid gas was directly connected to the vena cava; the blood from which carbonic acid gas had been removed entered the artificial heart—that is, the pump—proceeded through a valve installed in the mechanism, was propelled by said mechanism, received oxygen supplied through an attached tube, transformed into what we call arterial blood, and entered the aorta. At first glance, you might imagine an artificial heart with an attached artificial lung would be quite bulky, but through gradual improvements and refinements, we succeeded in reducing it to approximately one and a half times the size of the experimental animal's original heart. In other words, by using steel as the material, we were able to reduce the artificial heart’s volume. I should mention that the valves were driven by an electric motor of course, and we later implemented electrical power generation for creating the negative pressure required to remove carbonic acid gas.

When I explain it this way, it may seem as though we advanced through the experiments with great simplicity, but devising and refining them up to this point had truly been no easy task. There were many occasions when both my wife and I literally forgot to eat or sleep as we worked. Even once the machine was completed, connecting it to a domestic rabbit’s vena cava and aorta proved the most formidable of challenges. Initially, we directly joined the steel tubes and blood vessels using threads called catgut sutures, but since steel lacked flexibility, we later resolved to insert rubber tubes of fixed rigidity between them. Yet even then, whenever pressure regulation failed unevenly, the seams would gape open—in an instant, hemorrhaging would claim the rabbits.

Among the unpleasant phenomena encountered during surgery was blood coagulation. As you know, blood coagulates immediately upon leaving blood vessels, but should even a fragment of this coagulated blood enter the bloodstream, it would cause embolisms in small vessels and lead tissues to necrosis; thus there remained no alternative but to devise methods to prevent coagulation. I therefore decided to use a substance called hirudin extracted from frogs' oral cavities to prevent coagulation during surgery. Yet even when surgeries concluded successfully, clots readily formed on the inner surfaces where major blood vessels connected to rubber tubes, and we still experienced repeated failures. However, through increasing the valves' operating speed - a method we discovered prevented coagulation - coupled with refinements to the artificial lung, we managed to surmount this critical obstacle.

The next phenomenon deserving consideration as unpleasant was bacterial suppuration. However, if one carefully sterilized instruments and performed so-called aseptic surgery, suppuration could be avoided due to domestic rabbits' blood possessing relatively strong bactericidal power; but above all else, performing the surgery swiftly remained paramount in preventing suppuration. To eliminate not just suppuration but all other unpleasant phenomena as well, conducting the surgery within the shortest possible time constituted the most critical requirement. Through the sacrifice of numerous rabbits, I had fortunately become able to complete the entire procedure in a mere ten minutes. Though it involved merely opening the thoracic cavity to attach the artificial heart before sealing it again, I felt a certain pride in accomplishing this within ten minutes. Needless to say, the artificial heart itself remained outside the thoracic cavity. While ideally it would have been preferable to house it within the cavity, with our apparatus as previously described, this hope proved utterly unattainable. "You may assume a steel-made heart requires periodic oiling," I addressed the reporter, "but fortunately blood's inherent fat content rendered such maintenance unnecessary."

Now, I thought you could well imagine how immense our joy was when we finally completed the invention of the artificial heart. The electric motor rotated with a sound like the buzzing of horseflies madly darting among leaves in the late autumn sunshine, its valves operating at blinding speed, and when we saw the domestic rabbit—having awakened from anesthesia yet remaining bound to the platform—continue living unperturbed for five hours, then ten, we embraced each other and choked with joy. The motor’s noise, along with the sounds of removing carbonic acid gas and supplying oxygen, may have been unpleasant for the domestic rabbits themselves, but I thought that if they had hearts capable of empathy, even they would share in our joy at having broken through the first major obstacle in artificial heart research—a feat no one had accomplished since humanity’s emergence on this earth. Moreover, I thought that if we could advance our research further to install artificial hearts in once-dead bodies and restore life to them, even the domestic rabbits would feel genuine gratitude. Since we had already surmounted the first critical obstacle, this second one should prove relatively easy to overcome. And so, shortly thereafter, we embarked upon this next phase of research, but here, an unforeseen obstacle arose.

VII

"There’s a saying that ‘no good deed goes unpunished,’ but truly, nothing ever proceeds as I intend. It was on a night about a week after having overcome that first critical obstacle that I suddenly hemorrhaged blood."

I completed the first stage of artificial heart research approximately a year and a half after joining the physiology department, though I had already begun experiencing occasional mild coughing fits about six months prior. I likely had some degree of fever during that period, but being utterly absorbed in my research, I had no capacity to attend to it, and this reckless overexertion must have taken its toll. I was finally struck by hemoptysis and was forced to temporarily halt my research. One might call it the folly of youth—my failure to conduct research with composure and my persistent rushing ahead were my undoing. Now that I have fortunately recovered my health, I have come to realize that the greater the undertaking, the more one must proceed with research slowly and deliberately.

Now, when I coughed up blood, the chief professor earnestly urged me to undergo hospital treatment, but I simply could not bring myself to leave the vicinity of the laboratory; we converted our lodging room directly into a sickroom, and my wife became my nurse to care for me. Initially, I coughed up approximately ten grams of blood, so I immediately lay down on the bed. When I had a friend working in internal medicine come examine me, he first administered a hemostatic injection and advised absolute bed rest; therefore, I remained lying on my back without moving.

Suddenly, when I awoke at midnight, I felt an itchy, ticklish sensation in my chest. The moment I became aware, a violent cough erupted the next instant, and still-warm blood surged violently into my mouth. Coughing, again coughing—my wife brought a cup, but in the blink of an eye, it filled with crimson. My startled wife brought a washbasin to catch it. I lay on my left side and coughed, but the excess blood was forced out through my nasal cavity as well, smearing the lower half of my face with a viscous substance. My chest made a sound like a beehive being prodded, then immediately rumbled like thunder. The washbasin was nearly half filled in an instant, and I thought I might cough up every last drop of blood in my body like this. Crimson-black stains of varying sizes bloomed across the white sheets, and my wife’s hands supporting the washbasin trembled incessantly. The gas lamp hissed; the night fell dead silent. As I coughed up blood, I was seized by a solemn thought.

However, fortunately, that hemoptysis ceased. The feeling following the cessation of hemoptysis could not be described even slightly. My head became momentarily crystal clear. But after a while, I began to feel dazed. But that too was fleeting—and then a kind of anxiety fiercely assailed me.

Terror. Unbearable terror. I was assailed by a terror unlike any I had felt since birth until then. Needless to say, it was terror born from the certainty that hemoptysis would soon begin anew. That might indeed have been the terror of 'death'. Yet for some reason, I myself thought it a terror surpassing death itself. Because of this, I could no longer sleep thereafter. Too terrified to sleep. The conviction that sleep would inevitably bring fresh hemorrhaging kept me rigidly awake. Once blood vessels rupture within the lungs, there exists no means of external intervention. Doctors merely stand as silent witnesses; hemostatic agents prove utterly futile. Leaving ruptured vessels untreated... What manner of terror is this? Until that moment, even when examining patients, I had never once contemplated their fear. There I keenly realized for the first time: a doctor who has never themselves been ill lacks all qualification to treat patients. I came to believe that were we but to eliminate the terror accompanying hemoptysis, the bleeding itself would amount to nothing. Thus I attained this understanding: medicine's paramount duty lies not in curing disease itself, but in eradicating the fear of disease.

To dispel the unease of sleeplessness, I had my wife administer a morphine injection. Convinced a standard dose couldn’t alleviate this terror, I asked her to inject a slightly larger amount. Then something remarkable occurred: within less than an hour, that dreadful anxiety had vanished completely. Before I knew it, I was drifting along a pleasant dream-path. “Have you ever taken morphine?” I asked. “Or read Confessions of an English Opium-Eater? Regardless—when you take morphine, it pulls you into a blissful realm where dream and reality merge. That world contains no trace of fear. It’s a pleasure garden transcending time and space.”

Suddenly becoming aware, I heard a droning buzz resembling a horsefly near my ear. Wondering at this, I strained to listen and caught a hissing sound like water gushing—shu, shu. I imagined myself strolling through XX Park with my wife, listening to a waterfall’s roar while basking in autumn sunlight, yet upon reflection realized I lay in bed. Thinking this strange, I turned to see a motor whirring vigorously beside me, the negative pressure generator and oxygen supply device both in active operation.

Artificial heart! That’s right—I had them install an artificial heart. The comfort of an artificial heart! An artificial heart that knows no fear! The artificial heart alone can utterly eliminate fear of illness! The artificial heart alone lets people bask in paradise! What a serene world this is!

The instant I became aware, a raucous cough erupted, and once again the hemoptysis began. Paradise underwent a sudden transformation into the depths of hell. What I had mistaken for the artificial heart's motor was merely the abdominal gurgling sounds caused by hemoptysis. That gurgling sound had merely been something I was led by morphine’s effects to misperceive as a peaceful world arising from the artificial heart. The hemoptysis ceased after about three cupfuls, but terror once more assailed me violently. That is, because the morphine’s effects had worn off.

Lying on my back in stillness, I deeply yearned for the artificial heart. I came to believe the artificial heart would undoubtedly deliver us from disease's terror, exactly as I had envisioned in my dream. Though I had originally conceived the artificial heart's invention to rescue humanity from death and achieve life extension, after experiencing hemoptysis' terror surpassing even fear of death, I resolved that completing this device was imperative - if only to eradicate the "terror of disease."

It was precisely then that I recalled Lange's theory from a psychology lecture I had attended years prior. To illustrate Lange's theory—it posits that we experience terror precisely because we make fearful expressions when frightened. To put it plainly: We don't feel terror because our hair stands on end and faces blanch; rather, our hair stands on end and faces blanch first, thereby creating terror—an extreme manifestation of mechanism theory, if you will. Even after my hemoptysis episode, I—still clinging to mechanism theory—recognized how neatly Lange's theory explained why artificial hearts could eliminate fear. That is to say, during terror, the heartbeat slows or even ceases entirely. This means nothing more than that slowed or stopped heartbeats induce terror. Therefore, were we to install an artificial heart maintaining constant rhythm, sensations of terror could never manifest.

Thinking thus, I wanted to recover as quickly as possible and begin the second stage of research on the artificial heart. Fortunately, the hemoptysis ceased after five episodes, the subsequent course progressed smoothly, and after approximately a month and a half of convalescence, I was able to rise and work again. The friend who had been treating me persistently recommended a change of climate for convalescence, but I stubbornly refused to listen, and my wife, sympathizing with my resolve, joined me in resuming our artificial heart research.

When I look back now, I feel nothing but profound regret—if only I had heeded my friend's advice at that time. The change of climate convalescence was necessary not so much for my sake as for my wife’s. It seems my wife’s lungs had already been considerably affected by the time she was nursing me, but being as stubborn as I was, she never showed the slightest sign of it to me.

VIII

The second stage of artificial heart research—reviving once-deceased animals using artificial hearts—proved not as difficult as anticipated. I administered various poisons to domestic rabbits to induce death, waited for their hearts' final beats to cease, immediately opened their thoracic cavities, installed artificial hearts and conducted experiments. I discovered that if we commenced the procedure within five minutes postmortem, we could restore the rabbits' consciousness. However, allowing more than five minutes to pass rendered revival impossible. Let alone reviving a corpse that had grown cold—such a feat remained beyond our wildest hopes. Yet when we first succeeded in reviving a domestic rabbit that had once died—though almost disappointed by how anticlimactic it felt—we danced about the laboratory in exhilaration. Of course, while this sounds straightforward in explanation, the number of rabbits we sacrificed was truly considerable. The selection of poisons used to kill the domestic rabbits proved particularly challenging. We couldn't wait for natural deaths, necessitating artificial termination, but some toxins altered blood properties in ways that complicated our efforts. Moreover, success with one poison didn't guarantee success with others, compelling us to test numerous variants—a truly monumental undertaking.

Since the artificial heart's original purpose was to save humanity from terror, once successful in domestic rabbits, it became necessary to apply this to humans.—Though I stated that saving humanity from terror was the goal, after experiencing hemoptysis, I found myself with no time to consider other matters—I came to think that if we could save humanity from terror, we could form a paradise. A world without fear! What a joyous world that would be!—And so, as the next step, I decided to test the artificial heart on dogs larger than domestic rabbits. For dogs, it was simply a matter of using a larger pump—the surgical procedure itself held no particular differences—the only distinction from the domestic rabbit cases was the increased electricity required. Of course, with dogs, I only attempted experiments to revive them once they had died, and as a result, I found that with dogs, the objective could be achieved if I commenced within ten minutes postmortem. In other words, I found that with larger animals, it didn’t matter if the artificial heart attachment was somewhat delayed. I thought this was probably due to differences in blood coagulability. The blood of smaller animals coagulates more quickly. After death, needless to say, blood coagulates, but once the blood has coagulated, the artificial heart is no longer of any use. In any case, operating under the estimation that with animals larger than dogs, the time from immediately after death until commencing attachment of the artificial heart could be extended further without issue, I selected a sheep of equivalent weight to a human and conducted an experiment. Indeed, even when beginning the procedure over fifteen minutes postmortem, I succeeded in definitively reviving it. Now it was humans. Just when I thought of somehow conducting experiments on humans—what a cruel irony of fate! The first person on whom I experimented with the artificial heart was none other than my wife Fusako, who had assisted in its invention.

One day, my wife suddenly collapsed in the laboratory. I immediately lifted her up onto the bed and gave her red wine; she soon regained consciousness. But when I touched her forehead, it burned like fire. Placing a thermometer revealed—to my shock—a fever of 41.5°C. I hastily prepared an ice pack to cool her down and summoned that physician friend. The feeling I had upon hearing his diagnosis still chills me to this day. He pronounced it a full-blown case of miliary tuberculosis. Miliary tuberculosis! It differed little from a death sentence. My wife’s lungs had long been ravaged—through sheer stubborn endurance she had concealed it until plunging beyond salvation. I sank into boundless grief yet sensed an improbable thread of hope. The hope—needless to say—that through the artificial heart I might yet save her.

My wife, seeing the expressions on my and the friend’s faces, seemed to have already perceived her fate, and once the friend had left, “I’m not going to recover, am I?”

she asked.

I was at a loss for a reply and silently shook my head. “I understand full well,” she said. “But I’m not the least bit afraid of dying.” Her voice was so brimming with hope that I involuntarily—

“Huh?” I said, staring at her face.

“There’s the artificial heart after all. Listen—when I die, have it attached immediately. I will surely revive.” “Don’t say such things—it pains me.” “You must stay composed.” “You’re the one who needs composure.” “After all these accumulated experiments, human trials are essential—otherwise everything amounts to nothing.” “When we succeeded with rabbits, I resolved that even without falling ill, I would intentionally die and have you experiment on my body.”

I involuntarily grasped her hand and kissed her lips.

“So you’ll conduct the experiment?” “Oh, you will? How wonderful!” “Until now, the experiments have only been on rabbits and dogs—no one could describe what survival with an artificial heart truly feels like.” “I want to experience it myself.” “I firmly believe a tranquil world will be realized just as you say.” “When I think of that, I feel like wanting to die soon.” “Tell me—when do you think I’ll die?”

I grew increasingly sad.

“Well… it’s fine…” “That’s not good, you know. It would be tragic if we’re too late—you must prepare everything quickly!” That’s it! If she truly cannot be saved, then fulfilling her wish through the artificial heart would be the kindest thing I could do for my wife! Thinking this, I found time amid nursing duties to prepare the artificial heart. Normally, as my wife and I would do this together, my heart would fill with courage—but this time, I found myself overcome with dark thoughts.

IX

The morning after completing preparations for the artificial heart, my wife’s condition worsened. Friends rushed over, but my wife detained only the Chief Professor and the friend serving as her attending physician, dismissing the others. She then requested of them: “Once I have passed away, I wish for my husband to conduct the artificial heart experiment on me. Please ensure he faces no legal repercussions for this.” Tears glistened in the Chief Professor's eyes. Then my wife had the two of them leave the room and asked me to show her the artificial heart. When I picked it up and showed her, my wife smiled gently—but at that very moment, her throat emitted a sudden sound, and she quietly closed her eyes.

Snapping back to my senses, I informed the people outside that my wife had stopped breathing, requested that no one enter during the surgery, and quickly began the operation.

The sensation when the scalpel touched her chest skin—that is something I still cannot forget. Quickly opening the thoracic cavity, I attached the artificial heart. The procedure commenced nine minutes after her death and concluded in thirteen minutes. When I twisted the switch with bloodstained hands, the motor began rotating with its characteristic sound. One minute, two minutes, three minutes—as I examined her pulse, I gazed into her eyes. The valve moved at a rate of two hundred fifty times per minute, making it impossible to count the pulse, but I could clearly perceive that the blood was circulating without issue.

Five minutes! Her lips regained their color while her eyelids trembled faintly. I involuntarily tried to shout for joy. Because I had first witnessed this eyelid tremor during my experiments with dogs and sheep.

Seven minutes! Both her eyeballs began rotating side to side. I forced myself to suppress the joy that threatened to burst forth and gazed at her.

Nine minutes! She opened her eyes wide, gazed into space, and moved her lips.

Eleven minutes! Her gaze focused on my face.

Thirteen minutes! She let out a deep sigh and said, “Ah…” I involuntarily shouted.

“Fusako! Do you understand? You’ve come back to life!” However, she did not smile.

“Fusako!” “The artificial heart succeeded.” “You must be happy?”

“I’m happy,” she uttered mechanically.

“Are you happy? “I’m happy too.” “You’ve gained new life!” “Oh!” she said, her face still mask-like. “I just said I was happy.” “But I can’t feel happy.” I started. Then I suddenly kissed her.

“Oh, please forgive me!” “I don’t feel the slightest bit nostalgic.” I was even more startled. “You—I’m sorry. “Even if I try to laugh, I can’t.” “Even if I try to feel happy, I can’t.” “Living like this amounts to nothing!”

The despair I felt in that moment! I involuntarily buried my face in the bed.

“You! “No good! “Please remove the artificial heart quickly. “There’s no feeling in dying or coming back to life!”

Two years of research were shattered into splinters by this single utterance. We who had focused solely on eliminating fear failed to notice that the artificial heart would also strip away pleasure and all other emotions. Remorse! Shame! My wife cannot even feel that now. The artificial heart was ultimately nothing more than an artificial existence.

Click! I resolutely twisted the switch to stop the motor. “Oh, I’ve gone on quite a lengthy tangent, haven’t I? My bitter experience may perhaps have substantiated Lange’s theory, but ever since then, I have harbored an unsatisfied feeling toward what is called mechanism theory. Mechanism theory ultimately crushes human hope. It may be precisely because there is fear, there is disease, there is death that humans find life worth living.”

“Thus, with my wife’s death, I abandoned my research on the artificial heart once and for all. However, regarding the nitrogen-fixing function of the lungs I mentioned earlier—I intend to continue researching it when the time is right—but since rushing tends to lead to mistakes, I plan to proceed at a leisurely pace.”

“No—since you mentioned Dr. Haber, the inventor of nitrogen fixation, visiting Japan, I ended up recounting my life’s confession. In the end, perhaps we physiologists would find it far more reassuring to keep ourselves occupied by creating mercury-based ‘artificial hearts’—ha ha ha ha ha.”