From the researches of Schaeffer, Roos, and Sigmund Fraenkel[92] it results that the active principle of the gland is not a toxin, but a purely chemical substance, a true leucomaine, which has received the name _thyroantitoxin_. [92] _Wiener Med. Blätter_, No. 48; and _Gesellsch. d. Aerzte in Wien_, Nov. 22, 1895. On the other hand, Baumann quite recently extracted from the thyroid gland an iodized substance, which he named _thyroiodine_.[93] [93] _Zeitschr. f. Physiol. Chem._, XXI, pp. 319 and 481; and XXII, p. 1. ARMAND GAUTIER: Chimie Biologique, 2d edit., pp. 330-332. Masson, publ. The suprarenal capsules also possess properties that have often attracted the attention of physiologists during the last few years. They are considered as being, just like the thyroid gland, producers of antitoxins; they destroy, or seem to destroy, toxins that are artificially introduced into the circulation. 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] [94] ALBANÈSE: Recherches sur les fonctions des capsules surrénales. _Arch. Italiennes Biol._, 1892. [95] BOINET: _Compt. rend. Soc. de Biol._, Mch. 1896. [96] See _Compt. rend. de Biol. et Arch. Physiologie_, 1891-1897. [97] LANGLOIS: Thèse de doctorat en Méd., Paris, 1897. [98] GUIEYSSE: _Les capsules surrénales du cobaye_, Thèse, Paris, 1901. [99] Encyclopédie Léauté, CCCXIV, Masson, publ., Paris, 1904. 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_.