2. Creatinic Leucomaines.—These have for their type guanidine; they differ from the xanthic bases in that they are not precipitated by copper acetate, but frequently are by ammoniacal silver nitrate. They yield double salts with the chlorides of zinc and cadmium. To this group belong glycocyanine, C3H7N3O2, and glycocyanidine, C3H7N3O, both very toxic; creatine, C4H9N3O2, only slightly toxic; creatinine, C4H7N3O; lysatine, which very easily decomposes to form urea; lysatinine, xanthocreatine; arginine, a vegetable base, etc.
3. Neurinic Leucomaines.—These have none of the characteristics of the preceding bases; their type is neurine, a highly toxic base found in the brain, nerves, and certain fish ova. These bases are sometimes normally produced by the animal economy, and are also frequently the result of microbic action. They are the result of the simple phenomena of fermentative hydrolyzation of protagons and lecithins. Among these bases are choline, a weak alkaloid, and betaine, which appears to be non-toxic.
The former has the formula C5H15NO2; it was discovered by Stocker. Wurtz synthesized it by combining trimethylamine and glycol-monochlorhydrine, and treating the resulting hydrochloride with silver oxide. Betaine, C5H11NO2, is found in beets; it was discovered by Scheibler. Neurine is, chemically, trimethylvinylammonium hydrate.
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 C5H14N2. 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 C5H15N5; protamine, from fish milt, was discovered by Micocher.[20]
[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.
It is due to the knowledge of these principles that we have learned that the infectious microbes, far from acting as they were believed to do only a few years ago, and which Pasteur strongly maintained to be by vital parasitism—such as would be the case with the carbonizing bacteria which, according to Pasteur, act by diverting the oxygen, or causing capillary embolisms—owe their pathogenic action to the toxic substances which are the products of their secretion, and which spread throughout the organism, even though the microbe frequently is localized in a very circumscribed spot, as in tetanus and in diphtheria.