158 CHEMICAL MEANS OF DEFENSE AGAINST POISONS 



immunized animals, which he attributes to an increased amount 

 of cholesterin, perhaps liberated by the corpuscles decomposed 

 by the injected poison, or perhaps produced in excess by the 

 tissues. Wohlgemuth 1 has also suggested that in the case of 

 poisoning with large amounts of substances which combine with 

 glycuronic acid (e. g., lysol), excessive quantities of this sub- 

 stance are formed by the cells and excreted into the blood, 

 where they neutralize the poisons in much the same manner as 

 the antitoxins neutralize toxins. 



But besides these scanty examples of tolerance to poisons the 

 body possesses a number of methods for opposing many other 

 poisons with more or less success ; and, poisons invariably act- 

 ing chemically, the defenses are in turn largely chemical. We 

 have elsewhere referred to the destructive action of the enzymes 

 of the digestive tract upon bacterial and similar poisons ; this 

 means of defense cannot apply to ordinary chemical substances, 

 because of their non-pro teid nature. But the acidity of the gas- 

 tric juice, the alkalinity of the bile and pancreatic juice, and the 

 precipitating effect of the hydrogen sulphide formed in intestinal 

 putrefaction are all factors that help to neutralize or prevent 

 the absorption of certain poisons, their total efficiency, however, 

 being on the whole very slight. After absorption of a poison a 

 large series of chemical reactions and physiological processes is 

 brought into play, and there are few poisons indeed whose harm- 

 ful influence is not more or less decreased by these means. 

 Robert 2 classifies these protective processes as follows : 



1. Rapid elimination, either before absorption by means of 

 diarrhea and vomiting, or by the same means after absorption 

 in case the poisons are excreted into the digestive tract ( e. g., 

 morphine, venoms, antimony, and many other metals). Many 

 poisons are very rapidly eliminated by other routes (e. g., 

 anesthetics, curare), in some instances causing harm, particularly 

 to the eliminating organ (e. g., kidneys in phenol poisoning, 

 intestines in riciii poisoning). The routes and conditions of 

 elimination of poison have been recently fully discussed by 

 Lewin. 3 



2. Deposition and Fixation in Single Organs or Tissues. 

 In this respect the liver is especially important, probably be- 

 cause of its location and function as a filter for all the blood 

 coming fresh from the alimentary tract. The manner and means 



1 Biochem. Zeitschr., 1906 (1), 134. 



2 " Lehrbuch der Intoxikationen," Stuttgart, 1902. 



8 Deut. med. Woch., 1906 (32), 169; see also Mendel et al., Amer. Jour. 

 Physiol., 1904 (11), 5; 1906 (16), 147 and 152. 



