298 DIGESTION. 



nexion with this point. Possibly also we should place in this 

 category certain poisons, which, like the protein-bodies, cannot be 

 directly resorbed by the blood-vessels, but must be first so changed 

 by the gastric and intestinal juices, that after being absorbed by the 

 lacteals they pass as innoxious matters into the blood. Diastase 

 and emulsin are substances which in many points of view are very 

 closely allied to the protein-bodies, although we cannot place them 

 in this class. We know that emulsin undergoes the same changes 

 during digestion as the true protein-bodies ; for it has been shown 

 by the experiments of Magendie and Bernard,* that pure amyg- 

 dalin exerts no injurious effects upon the health or the life of 

 animals, either when swallowed or when directly introduced into 

 the blood ; if, however, emulsin be simultaneously introduced into 

 the stomach or into the blood, decomposition is set up in the 

 amygdalin, and the prussic acid which is formed destroys the life 

 of the animal. I allowed rabbits to eat sweet almonds, and injected 

 amygdalin into the jugular vein, 1, 2, 4, and 6 hours after they had 

 fed ; the animals remained perfectly vigorous. I then reversed 

 the experiment, and injected emulsin into the vein, while I intro- 

 duced a solution of amygdalin into the stomach of the animal ; 

 symptoms of poisoning by prussic acid very soon presented them- 

 selves. Since, however, we cannot demonstrate in this manner 

 that the emulsin has actually been metamorphosed by the digestive 

 fluids, and has consequently lost its influence on the amygdalin, and 

 since it is conceivable that emulsin, like gum, might be incapable 

 of resorption, and passed off unchanged with the excrements, I 

 collected the excrements of a rabbit which had been fed for 48 

 hours on almonds, and mixed amygdalin with them ; but I could 

 detect no trace of any evolution of prussic acid ; indeed no decom- 

 position of the amygdalin was induced even by the ceecal contents 

 of the same animal. 



A number of other bodies, which have certainly been less 

 accurately investigated, but which coincide in their quantity of 

 nitrogen, in their insolubility in spirit, and in their solubility in 

 water, comport themselves in an analogous manner with emulsin. 

 Of all these substances, curarine has probably been most accurately 

 examined, thanks to the labours of Boussingault and Roulin.f 

 This substance, when introduced into the stomach and intestines, 

 does not induce the slightest morbid phenomenon, whilst if it be 

 conveyed into the blood, it causes the almost instantaneous death 



* Arch. gen. do Med. 4 Ser. T. 16, p. 79. 

 t Ann. do Cliim. ot de Phys. T. 39, p. 24. 



