20 THE TOXICITY OF CAFFEIN. 



observed, but no other symptoms; 4.15 p. m., rabbit had tremors, was handled but 

 this failed to induce tetanus, 10 minutes later tetanus of short duration with recovery 

 occurred. 



March 19: 9 a. m., found dead. 

 Rabbit 119. Yellow white female. Weight, 1,060 grams. Diet, oats. 



April 17: 10 cc 2 per cent caffein (188 mg per kilo) injected subcutaneously at 

 2.10 p. m. 



April 18: Rabbit found dead. 

 Rabbit 195. White female. Weight, 1,300 grams. Diet, carrots, since October 7. 



October 14: 13 cc 2 per cent caffein (0.2 gram per kilo) injected subcutaneously at 

 11.15 a. m.; 2.25 p. m., rabbit had convulsions and died. Note: Ulceration of 

 rectum was noticed. 



Rabbit 208. Gray. Weight, 1,068 grams. Diet, carrots, October 7-15, inclusive. 



October 15: 10 cc 2 per cent caffein injected subcutaneously at 11 a. m.; 1 p. m., 

 increased reflexes and tremors observed; 3.45 p. m., tremors were marked when 

 rabbit was handled. 



October 16: Rabbit found dead. Note: Looked poorly nourished. 

 Rabbit 247. Belgian hare, female. Weight, 1,295 grams. Diet, oats last 10 days before 

 experiment. 



November 10: 11 a. m., urine obtained from the bladder was acid to litmus and 

 did not contain sugar or albumen, 13 cc 2 per cent caffein was injected subcutaneously ; 

 1.30 p. m., 15 cc urine obtained was markedly alkaline to litmus and reduced Fen- 

 ling's solution; 2.30 p. m., reduction of urine considerable, marked tremors observed 

 but no tetanus. 



November 11: 10.30 a. m., 95 cc urine collected gave moderate reduction of Feh- 

 ling's solution, no symptoms, condition of rabbit seemed to be good. 

 Rabbit 248. Belgian hare, female. Weight, 1,305 grams. Diet, oats the last 10 days 

 before the experiment. 



November 10: 11 a. m., urine markedly acid to litmus, no albumen, no sugar; 

 13 cc 2 per cent caffein injected subcutaneously; 1.30 p. m., urine was slightly alka- 

 line to litmus, no reduction of Fehling's solution; 2 p. m., reflexes increased; 2.30 

 p. m., 2 cc urine obtained from bladder, sugar abundant; 4.45 p. m., reflexes in- 

 creased as before, but no tetanus. 



November 11: 10.30 a. m., urine collected showed slight reduction of Fehling's 

 solution; otherwise condition of rabbit was good; rabbit did not show any effects 

 of caffein. 



Rabbit 337. Belgian hare. Weight, 1,040 grams. Diet, carrots, March 31 to April 6, 

 inclusive. 



April 6: 3 p. m., 11 cc 2 per cent caffein injected subcutaneously in the back 

 (0.211 per kilo); 4.30 p. m., reflexes much exaggerated. 



April 7: 8.15 a. m.; condition good, no symptoms. 



Rabbit 336. Belgian hare. Weight, 1,040 grams. Diet, carrots, March 31 to Apnl 6, 

 inclusive. 



April 6: 3 p. m., 11 cc 2 per cent caffein injected subcutaneously into tissues of 

 the back. 



April 7: 8.15 a. m., no symptoms, condition good. 



Although symptoms appeared in rabbits of Group I (see table, page 25) about the 

 same time after the administration of caffein as in the rabbits of the preceding series 

 all of them terminated fatally 2 hours to 24 hours after its administration. Two 

 of these rabbits (Nos. 195 and 208) were fed carrots for several days before the injec- 

 tion of caffein, the others were fed oats. Since symptoms and death appeared in 

 these two rabbits about the same time as in the rest of this group it may be concluded 

 that caffein is not less toxic when carrots are fed than when oats form the exclusive 

 diet. But since rabbit No. 208 was poorly nourished and ulceration of the rectum 

 was observed in No. 195 it is quite possible that caffein might be less toxic in 

 normal rabbits on this diet. This was tested in rabbits Nos. 336 and 337, both of 

 which seemed to be free from abnormality and were well nourished. Since these 

 rabbits survived and manifested mild symptoms only of intoxication it would seem 

 that a carrot diet decreases the toxicity of caffein. 



It was suggested, however, that another factor might be the cause of the greater 

 resistance to caffein in these two rabbits, namely, race. This was tested in rabbits 247 

 and 248, both Belgian hares. Since the toxicity of caffein in these two rabbits was the 



