This last passage from Fanny Hill clearly indicates the direction which Enlightenment writers would take in their refitted use of classical medical beliefs, and points to another set of beliefs about the value of semen and its effects, namely, the aura seminalis as productive of masculinity itself. In the overall economy of bodily fluids (blood, lymph, milk, menses, sweat, tears, urine, phlegm), seed had always been ranked highly, placed on a par with animal spirits. Part of the reason for this was that semen was viewed as an especially concentrated liquid whose powerful presence (or excessive loss) was not to be underestimated. Recounting earlier theories, De Graaf noted that “Some even think that a single drachm of semen is the equivalent of twenty of blood” (44). The sexologies made greater claims: “if we believe Avicenna,” Venette would explain, one unit of seed is the equivalent of “forty times the quantity of blood” (172); predictably enough, Tissot’s anti-masturbation tract would repeat the more exaggerated claim, reminding the reader “that physicians of all ages have been unanimously of opinion, that the loss of an ounce of this humour would weaken more than that of forty ounces of blood” (2). For the seventeenth and eighteenth century medical experts, however, male seed would hold precedence as a fluid also because it was a chemical agent of maleness itself. As “the heaviest humour in the human body,” according to Albrecht von Haller’s First Lines of Physiology (1747), seed’s function went beyond creative discharge, being “absorbed again into the blood, where it produces wonderful changes.”32 It was the aura seminalis, after all, which explained the journey from boyhood to virile manhood, altering the voice and skin, producing body hair, giving rise to physical strength and courage. Described at times as almost a world-soul or fiery emanation of divine-like spirit, semen was also a concentrated, essentialized masculinity—each drop a distilled and heated liquid carrying within it the potential code, as it were, of a male identity.
Indeed, one of the striking features of Enlightenment medical narratives is that it is not the yard or testicles but the seed which evoked an overall heightening of rhetoric. An important cause of this medico-scientific wonder is surely the improvement of microscopes and the discovery of sperm in the 1670s by Ham and Leeuwenhoek, the latter an acquaintance of De Graaf (both lived in Delft).33 As Marjorie Nicolson and John Harley Warner have demonstrated, the larger cultural effects which microscopic visions had on the collective imagination ought not to be underestimated,34 and in the case of Leeuwenhoek’s animalcules, homunculi, or spermatic worms (see Figure 1)—“spermatozoa” would not be used until the 1820s—the imaginative appeal is particularly noteworthy given the fact that it was not the animalculist but the ovist school of preformationist thought which dominated embryology from the late seventeenth until well into the eighteenth century.35 That is, although the miniature human was thought by most to reside within the egg, where its unfolding and growth would somehow be triggered by male semen, and, although a majority of the medico-scientific community was skeptical of animalculist arguments, the idea of the sperm as homunculus or preformed human-ness (particularly maleness) nevertheless held a wide imaginative appeal throughout the same period, showing up not only in animated debates published in the Philosophical Transactions,36 but also in accounts of intense personal curiosity by non-scientists such as Charles II, who in the mid-1680s commanded Robert Hooke, Curator of the Royal Society, to demonstrate these animalcula, or by the twenty-nine year-old Pope, who with his mother visited one Mr. Hatton “who is … curious in microscopes and showed my mother some of the semen masculinum, with animascula [sic] in it” (Corr. 1: 465, Pope to Caryll, 18 February 1717/18). Popular versions of sperm-as-man showed up in print as well, most famously in the first two chapters of Tristram Shandy, but also in novels such as The History of the Human Heart (1749) or in “Sir” John Hill’s spoof of sperm-catching machines in Lucine sine Concubitu (1750). The reasons for this appeal are not simply the new imaginative venue provided by the microscope, however; the image of the teeming seminal fluid—each drop containing the compacted human being, usually imagined male—also maintained the larger ideological construct of a superior male creativity not just at the macro levels of art, politics, and material sway, but now also at the micro level of the nearly invisible processes of life-giving itself. What microscopes brought to discourses about sperm was visible proof of maleness in its smallest constituent form. These conceptual images—sperm as male spirit, animalcule as tiny man—gave dramatic substance to the idea that masculinity and male identity itself were directly dependent on the man’s genitals and, by extension, that in the mysterious and spiritous inner workings of the organs of generation could be found an essential truth about the male mind.
But in seventeenth and eighteenth century medical models, no theory about sperm was more important than the brain-testicles homology, which functioned not as a direct but an inverse relationship. The origins of the homology can be explained partly as the legacy of classical medical theorists, the majority of whom believed that semen originated in the brain,37 and that excessive seminal loss would therefore debilitate the brain. Tissot’s anti-masturbatory tract cites this model of inverse relationship as a historic remnant of classical thought: “Hippocrates thought it was extracted from all the body, and particularly the head…. Galen is of this opinion … [that] When a person loses his seed … he loses at the same time the vital spirit: so that it is not astonishing that too frequent coition should enervate, as the body is thereby deprived of the purest of its humours” (48–49). Venette, likewise, would acknowledge the literalism of the ancients’ notion of a balanced fluid economy, reporting that “The brain … has been diminished to that degree in some lascivious men, according to Galen, that it has not been bigger than one’s fist” (162–63). The force of the older model is evident in other sexologies, as well, which sometimes appear to accept the classical theory without modification, as does Marten’s Gonosologium Novum in accounting for one of the causes of impotence:
Figure 1 Leeuwenhoek’s drawings of spermatozoa, “Observations Di. Anthonii Leewenhoeck, de prognatis è Semine genitali Animalculis,” Philosophical Transactions, No. 142, 1678. Courtesy of The Wellcome Library, London.
So will a man’s being wounded behind the Ears … whereby certain branches of the Jugular Veins and Arteries that are there have been cut; so that after those Vessels have been cicatriz’d, there follows an interception of the Seminal Matter downwards, and also of the community, which ought of necessity to be between the Brain and the Testicles; so that when the Conduits or Passages are stopp’d, the Stones or Testicles cannot any more receive either Matter or lively Spirits from the Brain in so great quantity, as it was wont. (41)
As these passages suggest, the older thesis survived in the sexologies, which offered readers a simplistic literal version of the brain-sperm connection: interrupt the downward flow from brain to testicles and sperm would be deficient; discharge too much sperm and suffer a brain-drain (usually figured as lassitude, headache, blurred vision, dizziness, stupidity; sometimes as madness or death, as in the anti-masturbation diatribes). But the brain-testes homology was also intensified by newer studies in reproductive physiology such as De Graaf’s which, having explained the confection of semen as a refinement of blood within the testes (see his Tractatus 29–32) rather than of nervous fluid or blood within the brain, were now more keenly interested in the physiological dynamics by which blood and animal spirits were shared by brain and testicles. One result was that the literalism of the classical linkage of brain and sperm was replaced by a homology in which brain and testicles were seen to have a correspondence of structure and function—that is, the brain produced animal spirits from the blood just as the testicles produced semen from the blood. As Jean Baptiste Verduc put it in A Treatise of the Parts of a Human Body