V. 
PTOMAINES AND TOXALBUMINS. 
Various basic substances containing nitrogen, and in chemical 
constitution resembling the vegetable alkaloids, have been isolated 
by chemists from putrefying material and from cultures of the bac- 
teria concerned in putrefaction, and also from -certain pathogenic 
species. Some of these ptomaines are non-toxic, and others are 
very poisonous in minute doses (toxines). The toxic substances 
sometimes developed in milk, cheese, sausage, etc., are also of this 
nature, and are doubtless produced by the action of microdrganisms. 
The pathogenic power of the bacteria which cause various infectious 
diseases in man and the lower animals has also been shown to result 
from the production of toxic ptomaines or of toxalbumins. Selmi first 
gave the name ptomaines to cadaveric alkaloids isolated by him, and 
Panum subsequently called attention to the fact that poisonous basic 
substances of this class are contained in putrefying material. LEx- 
tended researches with reference to the ptomaines have since been 
made by numerous chemists, the most important being those of Berg- 
mann, Schmiedeberg, Zuelzer and Sonnenschein, Hager, Otto, Sel- 
mi, Brieger, Gautier and Etard, and Vaughan. 
For a full account of the history and chemical composition of the 
ptomaines the reader is referred to the valuable work of Vaughan 
and Novy (‘‘ Ptomaines and Leucomaines,” Philadelphia, 1891). In 
the present volume we shall give a brief account only of some of the 
most important. 
NON-TOXIC PTOMAINES. 
Neuridin, C,H,,N,.—This is one of the most common of the al- 
kaloids of putrefaction and was isolated by Brieger in 1884. It is 
obtained most abundantly from tissues containing gelatin. Very 
soluble in water, but insoluble in ether and absolute alcohol. Has a 
disagreeable odor. 
Cadaverin, C,H,,N,.—Isomeric with neuridin ; has a very dis- 
agreeable odor ; forms a thick, transparent, syrupy liquid; is vola- 
tile, and can be distilled with steam without undergoing decomposi- 
tion. When exposed to the air the base absorbs carbon dioxide and 
