396 Chapter XII 



[416] seized and absorbed almost immediately by the leucocytes 1 . This 

 result has been confirmed by Lombard 2 by another series of experi- 

 ments. After injecting very large quantities of sulphate of atropin 

 into rabbits and guinea-pigs, he bled these animals and separated 

 out the elements of their blood. Instead of introducing these 

 elements into the brain of rabbits, he injected them into cats, 

 animals very sensitive to atropin. The cats which received the red 

 corpuscles and the plasma exhibited very insignificant symptoms of 

 poisoning. Those, on the other hand, which were injected with a 

 corresponding quantity of leucocytes, had much graver symptoms of 

 intoxication, such as photophobia with maximal pupillary dilatation, 

 dysphagia and persistent diarrhoea. 



It is, therefore, to the absorption of the atropin by the leucocytes 

 that naturally refractory animals owe their immunity, an immunity 

 which is very marked in spite of the susceptibility of the nervous 

 elements of these animals. We have been able to obtain this result 

 thanks to the delicate physiological reactions obtained with certain 

 alkaloids. As regards arsenic the demonstration could be pushed 

 even further, for the absorption of this mineral poison by the 

 leucocytes has been established by chemical analysis. 



When engaged in my researches on the leucocytic phenomena in 

 intoxications I succeeded 3 in showing that in rabbits subjected to 

 rapidly fatal doses of arsenious acid, there is a marked diminution in 

 the number of white corpuscles in the blood. On the other hand, 

 in rabbits habituated to arsenic, the same doses which brought about 

 hypoleucocytosis and death of the control rabbits, induced a con- 

 siderable rise in the number of leucocytes. Later, Besredka 4 made 

 continuous and detailed researches upon this subject and obtained 

 most interesting results. In order to simplify the conditions of 

 experiment, he studied the reaction of the organism of the animal 



[417] after the introduction of a red trisulphide of arsenic 5 , a not very 



1 The rapid disappearance of poisons from the blood is proved also by the ex- 

 periments of von Behring, Donitz, Decroly and Rousse (Arch, internal, de Pharma- 

 codyn., Gand et Paris, 1899, t. vi, p. 211) on snake venom and diphtheria and tetanus 

 toxins, as likewise by those of Heymans and Masoin (Ibid., 1901, t. vm, p. 1) on the 

 malonic and pyrotartaric nitrites. These poisons, within a few minutes of their 

 injection into the veins, are absorbed by the cell elements. 



2 " Contribution a 1'etude physiologique du leucocyte," Paris, 1901, p. 39. 



3 Ann. de TInst. Pasteur, Paris, 1894, t. vm, p. 719. 



4 Ann. de Vlnst. Pasteur, Paris, 1899, t. xm, pp. 49, 209. 



6 See Besredka, op. cit., p. 50, for its approximate composition and distinction 

 from ordinary yellow trisulphide. 



