Research in the analysis of human eroticism involves ethical limitations which can be partially avoided by the utilization of natural and accidental changes in human sexual structure and function. This paper utilizes the opportunity of studying the sexual effects of drugs, particularly the drug, Ismelin (guanethidine sulphate), used for the treatment of high blood pressure. Human male eroticism has four distinct components: erection, glandular secretion, ejaculation, and detumescence. Although they are ordinarily synchronized and coordinated, each component is separate; erection, glandular secretion, and ejaculation can occur independently of one another (Money and Hirsch, 1965). Orgasm is preceded by the secretion of seminal fluids and sperms into the upper urethra; the ejaculatory process then expels the fluid out the penis. Ejaculation is achieved by spasmodic muscular contractions of the musculature of the perineum and penis. Semans and Langworthy (1938) have shown that, in the male cat, the secretion of seminal fluid into the upper urethra is an event separate and distinct from the ejaculation of this fluid out of the penis. In a detailed neurologic study of male paraplegics, Kuhn (1950) concluded that the same distinction between secretion and ejaculation is applicable to man. Ejaculatory contractions are accompanied by intensified erotic sensations, and these sensations, together with the muscular response, comprise the orgasm. The cognitional content and subjective feelings, associated with orgasm can occur without the ejaculation of fluid. This is the phenomenon referred to as a dry-run orgasm. In the dryrun orgasm, the glandular secretion fails, whereas the muscular contractions of ejaculation do not. The result is an orgasm-complete