Albanèse[94] maintains that the function of the suprarenal capsules is to neutralize neurine, the toxic product of the disassimilation of the nervous system; this view, however, is opposed by Boinet[95] and Langlois.[96] On the contrary, it has been definitely proven that the suprarenal glands exert a specific action on the poisons of muscular origin. Abelous and Langlois[97] have in fact demonstrated that the alcoholic extract of the muscle of a decapsulated animal has the same properties as the extract of tetanized muscle; the decapsulated animal gives ergographic tracings analogous to those afforded by tetanized animals. The removal of the suprarenal capsule from an animal brings results, hence, analogous to those of fatigue—that is to say, that the toxic substances which accumulate as a result of the decapsulation resemble those that result from muscular exertion. The suprarenal capsules exert their action furthermore on other toxic products as well, as Guieysse[98] has shown, and particularly on the exogenous poisons. In conclusion, it may be said that the matter concerns a most important rôle, and we cannot do better in this respect than to refer the reader to the memoir presented by Sergent and Bernard to the Académie de Médecine in 1902 and entitled l'Insuffisance Surrénale.[99]
[CHAPTER IV.]
THE MICROBIAL TOXINS.
There is but one way of characterizing the toxic poisons secreted by microbes, and that is to apply to them the name of the microbes generating them; thus the soluble and toxic poison of the tetanus bacilli has received the name tetanus toxin.
In toxic microbial cultures it is necessary to distinguish the toxins proper from the toxic alkaloids (ptomaines) which generally accompany them; this is easily accomplished by evaporating the solution in a vacuum at about 30°C., and then treating with alcohol and ether, in which the alkaloids are soluble, while the true toxins are insoluble. By fractional precipitation with alcohol it is easy to isolate the peptones and true toxins.
The microbial toxins possess two essential properties; one the pyogenic property, thanks to which the toxins first attract, then destroy the white blood corpuscles or leucocytes, and transform them into pus, and the other the pyretogenic property, which appears to belong only quite indirectly to the pyogenic substance. The toxins in general retard the heart action.
We will not speak of the distinctions it has been sought to establish between the substances which possess these different properties, but will at once take up the discussion of several of the microbial toxins.
Anthrax Toxin[100] (from Bacillus Anthracis).—We will describe the preparation of this toxin as a type.
The cultures of the bacillus are made in Liebig's bouillon, to which has been added 0.1% of fibrin, the whole being carefully sterilized for a long time at 110° C. The cultures medium is inoculated with a drop of blood taken from the heart or spleen of an animal that has died of anthrax. At the end of a week, the culture is filtered, and the filtrate acidulated with a little acetic acid and precipitated by adding powdered ammonium sulphate. The flocculent precipitate is collected, washed, dissolved in distilled water, and dialyzed. The dialyzed solution is concentrated in vacuo at 40-45° C., and precipitated by adding to it alcohol. The precipitate formed is then collected and dried.[101]
In this manner there is obtained a grayish-white substance which is soluble in water, and which is fatal in large doses, but which, given in repeated small doses, confers immunity against anthrax.