As we shall presently see, ptomaines are essentially products formed during putrefactive fermentation. The toxic properties of extracts from the cadaveric fluids have long been known. Already in 1838 Panum[3] had met with these products in snake venoms. Bergmann and Schmiedberg[4] in 1868 isolated from septic pus a toxic substance which they named sepsin; and almost at the same time Zuelzer and Sonnenschein[5] reported having isolated from anatomical preparations an alkaloid possessing mydriatic properties. It is, however, due particularly to the researches of Selmi and Armand Gautier that we are now so well informed regarding these toxic principles.
The labors of Armand Gautier were first published in his Traité de Chimie Appliquée à la Physiologie; those of Selmi in the Actes de l'Académie de Bologne.
At first sight, there appears to be a great difference between these alkaloidal bases, the ptomaines and leucomaines, and the albuminoid toxins proper. The toxic bases of the first two groups are quite definite chemical products which can be generally obtained quite pure, and frequently in crystalline form. The toxins proper, on the other hand, are highly complex albuminoid substances which greatly resemble the true diastases in all their properties.
Nevertheless, between the toxic alkaloids, ptomaines and leucomaines, and the toxic albuminoids, or more properly toxins, there exists no absolutely sharp line of demarcation, but there is a gradual passage from the one to the other by every intermediary grade, as a result of the breaking down of the albuminoid molecule.
We shall see, moreover, as we proceed, that these substances are formed under coexistent circumstances, and that they are, hence, found together, whether it be in virus or in snake venom.
We will first consider the ptomaines, and then the leucomaines.
This name is more specially reserved to designate those alkaloidal substances, generally highly hydrogenized, that are formed outside the organism, from the fermentative action of anaerobic microbes on albuminoid substances.
These bases are generally volatile, with an intense and tenacious purulent odor; often, however, they possess a floral odor (aubépine, syringa), and even like that of musk. They combine readily with acids and with the chlorides of the heavy metals, yielding crystallizable salts.
The ptomaines afford no specific reaction whereby they may be readily identified; and their identification is effected only after a painstaking analysis.