Brown-Séquard asserted, in 1889, that testicular extracts (from young animals) exerted marked stimulating powers on the nervous system when injected subcutaneously. His statements were confirmed by numerous observers. No bad effects resulted, but certain local manifestations suggested the separation of the base spermin, present in the testicular extract, and the use of the base alone. Parke, Davis, and Co., in America, and Prof. Poehl, in St. Petersburg, have prepared this spermin. It is an organic base which forms a well-defined crystalline salt with phosphoric acid. The crystals of this salt appear to be identical in form and composition with the crystals found by Charcot in the spleen and in the blood of leukaemia; in the marrow of bones in the same disease (Neumann); and in the expectoration of asthmatics (Leyden). Schreiner, in 1878, separated these same crystals from semen and from various organs of the body, and determined the chemical formula of the salt. Kobert, experimenting with spermin, declared it to be non-poisonous. Prof. Tarchanow, however, experimenting with the hydrochlorate of spermin, prepared by Prof. Poehl, found an increased force of the heart's contraction and a rise of blood pressure; other observers have confirmed his results. Kobert, objecting, maintains that in those diseases in which spermin is found in excessive quantity, the stimulant effects described are lacking. The firm of E. Schering has of late introduced a preparation to which they gave the name spermin in the first instance, but have now replaced it by “Piperazidin.” This body has been investigated by A. W. V. Hofmann, who finds it to be diæthyl-diamine. Experiments with this body give very divergent results as compared with those of Tarchanow, for no stimulant action can be recognized after subcutaneous injection in rabbits. Piperazidin, therefore, does not suggest usefulness as a nervine or cardiac stimulant, though it remains to be seen whether this body is identical with that previously experimented with under the name of spermin. One interesting property belongs to piperazidin; it has a great solvent action on uric acid, far surpassing that of lithia. Failing, then, its use as a nervine tonic, piperazidin may yet prove serviceable in another way.—“Therap. Monatsh.,” p. 88, Jan., 1891.