44 THE TOXICITY OF CAFFEIN. 



to 1 hour after the first manifestations of symptoms. Two others died during the 

 night, while one lived 25 hours after the injection of caffein. Even 2 decigrams 

 caffein per kilo weight might therefore be fatal to the guinea pig. Experiments 

 carried out later have shown, however, that the resistance to caffein is appreciably 

 greater in some guinea pigs. This is indicated by the following experiments, in which 

 doses of 0.2 to 0.24 gram caffein per kilo were administered by the same path. 



SERIES C. 



Guinea pig 66. Yellow and dark brown male. Weight, 510 grams. Diet, oats. 



October 4: 5 cc 2 per cent caffein (0.2 gram per kilo) injected subcutaneously in 

 the back at 3 p. m.; 5 p. m., no symptoms. 



October 5: 9 a. m., alive; condition good. 



October 9: Found dead. Autopsy: Congestion of liver, kidney, and small intestine. 

 Guinea pig 65. White and black male. Weight, 510 grams. Diet, oats. 



October 4: 5 cc 2 per cent caffein (0.2 gram per kilo) injected subcutaneously in 

 the back at 3 p. m.; 5 p. m., no symptoms. 



October 5: 9 a. m., condition good. 

 Guinea pig 60. White and gray female. Weight, 320 grams. Diet, oats. 



October 3: 2.25 p. m., 3.5 cc 2 per cent caffein ((0.219 gram per kilo) injected sub- 

 cutaneously in the back; 3.40 p. m., convulsion with recovery; 3.50 p. m., frequent 

 spasms with paralysis, especially of anterior extremities; 5.30 p. m., tetanus when 

 removed from cage and put on floor. 



October 4: 8.50 a. m., found dead. Autopsy: Congestion of small intestines, lungs, 

 liver. 

 Guinea pig 57. White and gray female. Weight, 350 grams. Diet, oats. 



October 3: 2.15 p. m., 3.5 cc 2 per cent caffein injected subcutaneously in the back 

 (0.2 gram per kilo); 3.40 p. m., convulsions with recovery; 5.30 p. m., no marked 

 symptoms. 



October 4: 8.50 a. m., alive, active. 



October 6: Found dead at 9 a. m. Autopsy: Congestion of lungs and liver; kidneys 

 petechiated; severe gastro-enteritis. 

 Guinea pig 68. Yellow male. Weight, 785 grams. Diet, oats. 



October 6: 11.35 a. m., 7.8 cc 2 per cent caffein (0.2 gram per kilo) injected subcu- 

 taneously; 12 noon, reflexes increased markedly; 4.20 p. m., reflexes the same as at 

 12 noon. 



October 7: 9 a. m., dead. Autopsy: Lungs congested; liver congested and fatty; 

 spleen congested, kidney showed hemorrhagic spots; gastric mucosa necrotic; small 

 portion of small intestine inflamed. 

 Guinea pig 69. White male. Weight, 585 grams. Diet, oats. 



October 6: 11.40 a. m., 5.8 cc 2 per cent caffein injected subcutaneously; 12 noon, 

 reflexes increased, but not as much as in No. 68; 4.20 p. m., guinea pig hypersensitive, 

 reflexes increased more than at 12 noon. 



October 7: 9 a. m., alive. 



October 15: 9 a. m., found dead. 

 Guinea pig 61. Brown and black female. Weight, 330 grams. Diet, oats. 



October 3: 4 p. m., 4 cc 2 per cent caffein (240 mg per kilo) injected subcutaneously; 

 5.30 p. m., reflexes increased; runs, but drags posterior extremities. 



October 4: 8.50 a. m., found dead. 

 Guinea pig 62. White, yellow, and black female. Weight, 335 grams. Diet, oats. 



October 3: 4.05 p. m., 4 cc 2 per cent caffein (238 mg per kilo) injected Bubcu- 

 taneously in the back; 5 p. m., convulsions; 5.20 p. m., convulsions, alternating with 

 paralysis of anterior and posterior extremities. 



October 4: 8.50 a. m.,, found dead. 

 Guinea pig 70. White and brown male. Weight, 545 grams. Diet, oats. 



October 7: 3 p. m., 6.5 cc 2 per cent caffein (238 mg per kilo) aqueous solution 

 injected subcutaneously; 3.50 p. m., reflexes increased. 



October 9: 9 a. m., found dead. 

 Guinea pig 71. Brown and white male. Weight, 540 grams. Diet, oats. . 



October 7: 3 p. m., 6.5 cc 2 per cent caffein solution (0.24 gram per kilo) injected 

 eubcutaneously; 3.45 p. m., reflexes increased, tetanus. 



October 9: 9 a. m., found dead. 



