4. =Undetermined Leucomaines.=--Among these bases several are important in more than one respect. For instance _spermine_, which is found in the sperm, is a strong base possessing a powerfully dynamic and tonic action on the nerves. It acts as an oxidizer. Spermine was first obtained by Schreiner[17] from the sperm of mammifers in which it occurs as a phosphate. It has the formula C{5}H{14}N{2}. It was physiologically studied by Poehl, Tarchanoff, Weljaminoff, and Joffroy.[18] _Plasmaine_, a toxic base found in the blood and discovered by R. Wurtz,[19] has the formula C{5}H{15}N{5}; _protamine_, from fish milt, was discovered by Micocher.[20] [17] _Liebig's Ann. der Chemie_, CXCIV, p. 68. [18] _Journ. Soc. Phys. Chim. Russe_, 1893, No. 2; and _Bull. Soc. Chim._ (3), XII, p. 243. [19] _Leucomaines du Sang Normal_, Thèse, Paris, 1889. [20] _Joh reab. de Thiérchen_, 1874, p. 341; Picard, _Ibid._, p. 355. CHAPTER II. TOXINS AND ANTITOXINS. We have already seen, in the preceding chapter, that the microbes and the cells of various organisms are capable of secreting definite products of a toxic nature to which the names "ptomaines" and "leucomaines" have been given. Researches, which were begun scarcely twenty years ago, have shown that, besides these crystallizable and definite products, we meet with basic non-crystallizable substances of unknown composition, possessing special toxic properties, sometimes even of extreme violence. These substances have been named "toxins." At first this generic name was extended toward indefinite basic organic products that could be isolated from tissues and tumors both normal and abnormal; later on, however, the name was applied to toxic substances, equally indefinite, isolated from the culture media of microbes and the active constituent of various venoms. It is only since 1885, when Charrin called attention to them, that investigations began to be made regarding them. In 1888 Roux and Yersin,[21] in their beautiful researches on diphtheria, pointed out the diastatic nature of the properties of the active albuminoid matter existing in the cultures of the specific bacilli of this disease. From that period, these products began to take a more and more prominent place, from year to year, in the study of pathological affections, and, by developing the knowledge of immunity, they have opened a new path to the investigations of therapeutic technic. [21] ROUX and YERSIN; Mémoire sur Diphtérie. _Ann. Inst. Pasteur_, 1888-1889.