[Doses of 147 to 167 mg of caffein per kilo were employed in these
experiments.]
_Rabbit 332. Belgian hare, female. Weight, 1,070 grams. Diet, oats._
March 25: 8.5 cc 2 per cent caffein (158 mg per kilo) injected
subcutaneously at 2.15 p. m.; 4 p. m., reflexes increased; 5.45 p. m.,
increases of reflexes still more marked.
March 26: Rabbit looked normal; no symptoms observed.
_Rabbit 331. Belgian hare, female. Weight, 1,170 grams. Diet, oats._
March 25: 2.15 p. m., 9 cc 2 per cent caffein (153 mg per kilo)
injected subcutaneously; 4 p. m., reflexes increased; 5.45 p. m.,
condition the same.
March 26: Rabbit looks normal; no symptoms observed.
_Rabbit 328. Belgian hare, female. Weight, 1,200 grams. Diet, oats._
March 25: 9 cc 2 per cent caffein injected subcutaneously (150 mg per
kilo); 4 p. m., reflexes increased; 5.45 p. m., reflexes increased but
not markedly.
March 26: No symptoms; rabbit looks normal.
_Rabbit 322. White female. Weight, 1,065 grams. Diet, oats._
March 17: 8 cc 2 per cent caffein (150 mg per kilo) injected
subcutaneously at 11.55 a. m.; 12.55 p. m., reflexes increased, but no
tetanus nor any other symptoms.
March 18: Rabbit running around in cage; condition apparently normal.
March 25: Condition of rabbit good.
_Rabbit 217. White. Weight, 1,355 grams. Diet, oats._
October 29: 10 cc 2 per cent caffein (147 mg per kilo) injected
subcutaneously at 1.51 p. m. 5.15 p. m., rabbit alive; survived.
_Rabbit 219. Maltese. Weight, 1,820 grams. Diet, oats._
October 29: 14 cc 2 per cent caffein injected subcutaneously at
1.40 p. m. (153 mg per kilo); 5.15, rabbit alive; survived.
_Rabbit 194. White female. Weight, 1,490 grams. Diet, oats._
October 14: 13 cc 2 per cent caffein (174 mg per kilo) injected
subcutaneously; increased reflexes and tremors were observed.
October 15: Condition of rabbit good; no symptoms.
_Rabbit 191. Brown male. Weight, 1,915 grams. Diet, oats._
October 14: 16 cc 2 per cent caffein (167 mg per kilo) injected
subcutaneously; reflexes increased and tremors present.
October 15: Condition of rabbit good.
A study of this series shows that about 150 mg of caffein per kilo
caused increased reflexes within one to two hours after injection.
When the dose was increased, as in rabbits 194 and 191, the symptoms
were more pronounced; 150 mg per kilo may be regarded as the minimum
dose which produces symptoms of nervous irritability when caffein is
injected subcutaneously. Experiments with larger doses were therefore
carried out in order to determine the minimum fatal dose.