EXPERIMENTS ON BABBITS. 



13 



Series III. 



In these experiments the urine was obtained 15 to 20 minutes 

 after the injection of caffein. By reference to the table it will be 

 noticed that none was found at this time in the urine of the rabbits 

 which were fed oats, while only a little more than a trace was detected 

 in the urine of the rabbits fed on carrots. The elimination of caffein 

 does not begin,, therefore, so soon as this after its subcutaneous injec- 

 tion as in the case of other alkaloids, like strychnin. The examina- 

 tion of the urine of rabbit No. 651 shows, however, that 1.04 per 

 cent of caffein was recovered from the urine passed 40 minutes after 

 injection. During the next 40 minutes this rabbit eliminated 1.25 

 per cent more caffein, making a total of 2.25 per cent in 80 minutes, 

 while rabbit No. 652 of the same group eliminated slightly more than 

 2 per cent in 95 minutes and rabbit No. 653 eliminated 1.86 per cent 

 in 75 minutes. 



The rate of elimination of caffein also differed but little during the 

 next twenty-six hours in these cases, being 5.11 per cent for No. 651, 

 5.33 per cent for No. 652, and 4 per cent in No. 653. Analysis of 

 the urine of the following twenty-four hours shows that elimination 

 of caffein has been completed at this time, since no caffein was found. 

 The total amounts of caffein eliminated in the case of the rabbits 

 which were fed carrots was 11.63 per cent at the end of forty-two 

 hours, while in the urine of the next twenty-four hours 1.65 per cent 

 of caffein was found. 



SERIES III. Experiment A. Oats diet, 150 mg of caffein per kilo injected. 



Rabbit No. 651. Weight, 1,635 grams. Received 12 cc of 2 per cent caffein sub- 

 cutaneously on June 8, 10.35 a. m. 



