74 . % THE TOXICITY OF CAFFEIN. 



Rabbit 391. Belgian. 

 Given 1 cc of 1 per cent caffein to each 100 grams through 



stomach tube. 



i Not fed. 



2 Poor condition. 



August 30, found dead 9 a. m. Autopsy: Heart injected; lungs normal; liver affected 

 slightly with coccidiidea; stomach normal in appearance; small intestines normal, 

 but colon considerably inflamed; kidneys slightly engorged; other organs normal. 

 Rabbit 402. Black female. 



Given 1 cc of 1 per cent caffein to each 100 grams. 



i Not fed. 



September 2, found dead 9 a. m. Autopsy: The lungs were badly congested, the 

 posterior lobe of the right lung showing hepatization; the liver was considerably 

 enlarged and congested; the mucous membrane of the stomach and small intestines 

 was congested and showed numerous hemorrhagic spots; the kidneys showed slight 

 congestion; all other organs normal. 



SERIES D. 



The evidence brought forth in the preceding pages regarding cumulation of caffein 

 naturally suggests the question whether or not the body acquires a tolerance for it. 

 This question has already been answered in the affirmative by Gourewitch, 28 but 

 owing to the method he used for the identification of caffein and the few experiments 

 made his results are not conclusive. The experiments of series A, B, and C might 

 be regarded as indicating that tolerance for caffein is not acquired by the rabbit. It 

 was noticed, however, that the rabbit apparently does tolerate increasingly larger 

 doses under certain conditions, as the following experiments show: 



Rabbit 223. Belgian hare, male. 



October 22: Weight, 1,520 grams; 15 cc 2 per cent caffein injected subcutaneously 

 at 2 p. m. 



November 1: 10.30 a. m., weight, 1,510 grams; 17 cc 2 per cent caffein injected 

 subcutaneously (225 mg per kilo), reflexes observed, but no tetanus. 



November 4: 10.30 a. m., weight 1,535 grams; 19 cc 2 per cent caffein injected 

 subcutaneously at 2.40 p. m.; 4.40 p. m., no symptoms. 



November 8: Weight, 1,425 grams; 20 cc 2 per cent caffein (285 mg per kilo) injected 

 at 11.45 p. m.; 5 p. m., no symptoms. 



November 17: Weight, 1,325 grams; 22 cc 2 per cent caffein injected at 2.55 p. m. 

 .(329 mg per kilo), no symptoms. 



November 18: Rabbit in good condition. 



