Ricin possesses considerable activity. 0.00003 Gm. suffice to kill a rabbit when injected hypodermically; 0.2 Gm. are fatal to man. The action is not immediate, but follows a period of incubation. Ehrlich has shown that, exercising precaution, it is possible to create, as with abrin, a condition of tolerance or habituation, and in consequence to cause the formation of a specific antibody.
Robin.—This toxic albuminoid was obtained from the bark of an Acacia (Robinia Pseudacacia) by Power and Cambier,[59] by exhausting with water at a temperature of about 30° C., and precipitating the infusion with alcohol. The substance is analogous to ricin, and like this, possesses powerful toxic properties.
Toxicity of the Vegetable Diastases.—The diastases, which have been treated of in a volume of the Encyclopédie Léauté,[60] and to which we would refer the reader who is desirous of more complete details, develop powerfully energetic toxic properties when injected into the organism. Thus amylase causes, when injected subcutaneously, a considerable rise of temperature, but without any other toxic symptoms. Invertin or sucrase was studied by Roussy under the name pyretogenin, but it appears probable that this diastase was not the only substance present in the product, but that there were present reducing diastases, as we have already shown in the first volume of this collection, devoted to the phenomena of reduction within the living organism.
The pyretogenin of Roussy gives rise to an attack of violent fever, but it loses all activity when heated to 80-100° C.
Through his researches, Roussy clearly demonstrated,[61] for the first time, that the fever may cause the formation within the blood of a substance clearly belonging to the class of soluble ferments or zymases. Now, it is well known that within the animal economy there exist many ferments of this character; and experiment has shown that they can, at a given period and under various influences, leave the cells in which they are normally localized, pass into the blood plasma, and reach the nervous centers, where they cause serious effects. We have already dwelt upon the mechanism of autointoxication of the organism. The toxic action of certain digestive diastases has been shown by Hildebrandt, who has demonstrated that 0.1 Gm. of pepsin is capable of killing a rabbit in two or three days.
Mushrooms are alimentary substances of the highest order, causing a general stimulation of the entire organism. The substances met with belong, according to their composition, to different classes—celluloses, sugars, and amylaceous substances, alcohols, acids, fats, astringents, essential oils, resins, alkaloids, and albuminoids. The study of the last only, the albuminoids and diastases, interests us here. The most important of these albuminoid substances, phallin, was discovered in 1890 by Kobert. Pouchet also has isolated a whole series of other toxic albuminoids, particularly from Amanita muscaria (Fly Agaric).
There are alimentary as well as toxic species in every possible variety among mushrooms, some species consisting chiefly of the edible kind, others consisting of the poisonous variety.
In consequence of the toxicity of mushrooms, great attention must be given to the treatment to which they are subjected when it is desired to utilize them for alimentary purposes. Thus the toxic principles of several varieties can be removed, and the mushrooms rendered edible by very simple means.
Pouchet has made a very ingenious comparison between the ethereal, alcoholic, saline, and aqueous extracts of mushrooms, and bacterial cultures. The analogy is striking as to the presence of toxin, toxalbumose, and albumoses more or less toxic; it is moreover not exaggerated, since, according to the classification generally admitted, mushrooms are nothing more than the very advanced representatives of a group the more simple members of which constitute the bacteria.