The toxicity of caffein was studied in a large number of individuals.
The experiments were conducted on full-grown animals and were carried
out at different seasons of the year in a variety of ways. Special
attention was given to diet as a possible factor influencing resistance
to caffein, and the effect of different modes of administration on
toxicity. Some animals were therefore fed oats, some carrots, others
received both hay and oats. Caffein was introduced subcutaneously,
intraperitoneally, and by mouth.