GROUP II.
PTOMAINES OF KNOWN MICROBIAL ORIGIN.
a. Ptomaines extracted from microbial cells.
b. Ptomaines from pathological urines.
We will not here enter upon a detailed study of the bases belonging to each of these groups. This subject is a vast one, requiring for its treatment a volume devoted to it alone. We will here simply touch upon the principal properties of several of the bases of each of the subgroups named.
Bases of Group I.
a. Amines.—Among these we find nearly all the fatty amines, such as the methylamines and the cyclic alkaloids such as pyridine. They are formed particularly by the putrefaction of fish.
Certain of these bases are very toxic, for instance trimethylene diamine, the collidines, and the parvolines.
b. Guanidines.—Among the products of ordinary putrefaction there has been found so far only methylguanidine, C2H7N3. This is a highly toxic base of which 0.2 Gm. is fatal to a guinea-pig.
c. Oxamines.—Under this designation the following bases are comprised: 1. Neurine bases; 2. oxygenized aromatic bases; 3. bases of unknown constitution. Amongst them we find neurine and choline, which are toxic, and betaine, which is innocuous. They are found particularly in putrid fish.