----+--------+-------+-----------+------------------------------------ | |Caffein| | No.| Weight.| per | Results. | Remarks. | | kilo. | | ----+--------+-------+-----------+------------------------------------ |_Kilos._|_Gram._| | 8 | 3.10 | 0.354 |Found dead |Vomited in 4 hours after feeding; | | | next day | restlessness, loss of appetite, | | | | thirst, incoordination of muscles, | | | | convulsions. 9 | 3.15 | .350 |Survived |Muscular incoordination and | | | | stiffness, restlessness, vomited 1 | | | | hour after caffein was given. 10 | 1.60 | .350 |Died in |Convulsion; no vomiting. | | | 3 hours | 11 | 1.26 | .200 |Found dead |Salivation; convulsions. | | | next day | 12 | 1.28 | .200 |Survived |No symptoms. 15 | 1.20 | .250 | do. |Subcutaneous injection. 16 | 3.50 | .300 |Died in |Convulsions 45 minutes after caffein | | | 1 hour | was fed. ----+--------+-------+-----------+------------------------------------ CHRONIC CAFFEIN INTOXICATION. The object of this study was to ascertain the effect of repeated dosage when caffein was given daily or at longer intervals. The experiments were tried on rabbits and on dogs. As in the experiments on acute intoxication, the animals were under observation for some time in the laboratory before the administration of caffein was begun in order to ascertain the presence or absence of abnormality. The relation of diet to toxicity received some attention, but the question was not studied exhaustively in the present investigation. EXPERIMENTS ON RABBITS. Full-grown adult as well as young rabbits were employed. The diet consisted either of carrots or of oats; water was given ad libitum. The rabbits were kept in metal cages in a well-lighted and well-ventilated room. Unnecessary handling or any other procedure tending to fatigue or to cause discomfort to the animals was very carefully avoided, since we had found that such treatment was likely to decrease the resistance of the rabbit to caffein. The caffein was administered by feeding by mouth and through a stomach tube, or by the subcutaneous method. In a good many cases it was given daily, in some at longer intervals. SERIES A.