38 THE TOXICITY OF CAFFEINE 



100 to 114 mg caffein per kilo, and another (No. 292) received 141 mg of caffein per 

 kilo. The death of rabbits Nos. 294 and 556 may be regarded therefore as a case of 

 exceptionally low resistance to caffein. 



SERIES B. 



Doses of 160 to 200 mg caffein per kilo were employed in these experiments. The 

 rate of injection was 1 cc per minute, with the exception of Experiment 254, in 

 which 10.8 cc 2 per cent caffein were introduced in 17 minutes and 25 seconds. 

 Rabbit 562. Gray female. Weight, 1,650 grams. Diet, oats. 



February 1: Injection began at 3 p. m., injected 10 cc in 12 minutes; 3.01 p. m. 

 to 3.09 p. m., 3 cc injected, convulsions; 3.09 p. m. to 3.14 p. m., 3 cc injected, fol- 

 lowed by violent convulsions, marked opisthotonos; 4.30 p. m., rabbit died; total 

 quantity injected, 16 cc. 

 Rabbit 561. Gray female. Weight, 1,450 grams. Diet, oats. 



February 1: Injection began at 11.40 a. m.; 11.48, rabbit struggled, 7 cc 2 per cent 

 caffein injected; 11.50, convulsions, 10 cc 2 per cent caffein total amount injected; 

 11.55 a. m., injections stopped; injections resumed 11.58, violent convulsions, injec- 

 tions discontinued, total quantity received, 14.5 cc 2 per cent caffein solution; 1.30 

 p. m., found dead, did not urinate, 25 cc urine found in the bladder. 

 Rabbit 560. Gray male. Weight, 1,620 grams. Diet, oats. 



February 1: Injection began 11 a. m.; 11.10 a. m., 7 cc 2 per cent caffein injected, 

 rabbit struggled; 1 cc was injected during the next three minutes, rabbit struggled 

 but there were no convulsions, injection stopped; resumed at 11.15 a. m. and 

 continued 10 minutes, 8 cc 2 per cent caffein introduced during this time; total 

 amount caffein injected, 16 cc; reflexes markedly increased; 12 noon, tetanic con- 

 vulsions off and on until 2 p. m., then remained stretched out on abdomen, extremi- 

 ties extended. 



February 2: 9 a. m., found dead. 

 Rabbit 559. Gray female. Weight, 1,875 grams. Diet, oats. 



January 31: 4 p. m., convulsions after injection of 9 cc 2 per cent caffein in 14 

 minutes; 4.08 p. m., convulsions after injection of 7 cc caffein in 8 minues; 4.10 to 

 4.12 p. m., injected 2 cc more, rabbit lying stretched out on abdomen, extremities 

 extended; total amount of caffein injected, 18 cc (190 mg per kilo). 



February 1: 2 p. m., condition good, walked about, appetite good, passed 155 cc 

 dark, reddish-brown urine since 5.30 p. m. previous day. 

 Rabbit 279. Gray and white female. Weight, 1,820 grams. 



February 24: 10.09 a. m., 6 cc 2 per cent caffein passed rapidly into jugular vein; 

 10.15 a. m., involuntary twitching of muscles of legs, but no other symptoms; 10.23 

 to 10.26, 3 cc of 2 per cent caffein injected; 10.27 to 10.28, 2 cc 2 per cent caffein 

 injected, convulsions; 10.29, convulsions stopped; 10.32, convulsions; 11 a. m., rab- 

 bit lying on its Bide, anterior extremities paralyzed, posterior extremities contracted, 

 no clonic convulsions, breathed deeper and more slowly than normal; 11.10 a. m., 

 rabbit died, had no convulsions immediately before death; amount of caffein injected, 

 11 cc 2 per cent solution, or 0.166 gram per kilo. 

 Rabbit 254. Belgian hare, female. Weight, 1,285 grams. Diet, oats. 



November 12: 1.30J to 1.47f p. m., received 10.8 cc 2 per cent caffein from burette 

 into ear vein, after injection of 6.2 cc dyspnoea, 6.7 cc struggling, convulsions; at 

 1.50J p. m., released from holder, paralysis especially marked in the anterior extremi- 

 ties; 1.50 p. m., recovered, survived; total amount injected, 10.8 cc 2 per cent 

 caffein in 17 minutes and 25 seconds, or 0.16 gram caffein per kilo. 

 Rabbit 255. Belgian hare, male. Weight, 1,105 grams. Diet, oats. 



November 12:^2.311^0 2.35J p. m., received 3.7 cc; from 2.37 to 2.46 p. m., 5 cc 

 injected; after injection of 6.1 cc convulsions followed by dyspnoea, then contin- 

 uous struggling; when 8.3 cc were injected rabbit had another convulsion; 2.47 p. m.. 

 tonic contraction of anterior extremities; amount injected, 8.7 cc (158 mg per kilo) 

 in 15 minutes and 35 seconds. 

 Rabbit 567. Gray female. Diet, oats. 



February 6: Injection began at 4.11 p. m.; 4.18, convulsions after injection of 

 5 cc 2 per cent caffein; 4.21, convulsion after total injection of 8 cc; 4.24 p. m., injec- 

 tion resumed and 2 cc more introduced; 4.28 p. m., convulsions, injected 2 cc more; 

 total caffein injected, 12 cc, or 162 mg per kilo; 4.40 p. m., rabbit paralyzed in pos- 

 terior extremities; 5 p. m., found dead. 



