20 THE ELIMINATION OF CAFFEIN. 



EXPERIMENTS ON CATS AND DOGS. 



Experiments on the elimination of caffein were also carried out on 

 cats and dogs. The results show the interesting fact that the elimi- 

 nation in these animals is much less than in rabbits or in guinea pigs. 

 Only 1.3 per cent was recovered in the urine of a dog during twenty- 

 four hours, and the same amount was recovered in the urine and the 

 gastrointestinal canal of cats. It might also be added that small 

 quantities of caffein were found in the urine and bile of dogs two or 

 three hours after its intravenous injection. Moreover, the amounts 

 found were the same in the bile as in the urine, thus indicating that soon 

 after its introduction into the blood stream the liver is as efficient an 

 organ for the elimination of caffein as are the kidneys. 



Caffein Elimination in Dogs. 



Dog No. 83. — Weight, 5.6 kilos; had been given 1.6 grams caffein intravenously 

 in the course of a blood-pressure experiment; gall bladder contents, 15 cc, 0.9 mg of 

 caffein recovered; bladder contents, 15 cc, 1.0 mg of caffein recovered. 



Dog No. 84- — female fox terrier; weight, 5.250 kilos. 



November 22, 2.15 p. m., received 26 cc of 2 per cent caffein subcutaneously or 100 

 mg per kilo; 4.15 p.m., catheterized, obtained 15 cc urine ; total urine, 215 cc, in which 

 0.65 per cent of the caffein was recovered; had vomited and defecated during this 

 interval. 



November 23, 2.15 p. m., catheterized, urine 20 cc; total urine 95 cc, in which 

 0.65 per cent of the caffein was recovered. 



November 24, 2.15 p. m., urine collected, amount 300 cc, showing a trace only of 

 caffein; total caffein recovered was 1.30 per cent. 



Dog No. 85.— Weight, 21.5 kilos; had been given 1.5 grams caffein intravenously 

 in the course of a blood pressure experiment; gall bladder contents, 25 cc, contained 

 2 mg of caffein; bladder contents, 75 cc, contained 1 mg of caffein. 



Caffein Elimination in Cats when 100 mg were Injected Subcutaneously 



(Nov. 12, 1911). 



No. 87. — Weight, 2,645 grams; meat eaten, 100 grams; water, 15 cc; urine, 45 cc. 

 No. 98. — Weight, 2.855 grams; meat eaten, none; water, none; urine, 15 cc. 

 No. 99. — Weight, 2,920 grams; meat, 50 grams; water, 15 cc; urine, 50 cc. 



Caffein recovered twenty-four hours after injection, from composite sample. 



Per cent. 



Urine (7.5 mg) 0. 888 



Feces (2.1 mg) 247 



Stomach (1.2 mg) 140 



Intestines (1.2 mg) 140 



Bile 000 



Total 1. 415 



The gall bladders of the three animals gave 25 cc of bile; the stomach of cat No. 87 

 was full; the stomachs of the other cats were empty. 



