To determine the toxicity of caffein more accurately, especially for
comparison with animals of other species, the subcutaneous method
of administration was also used. The injections were made with a
syringe of 20 cc capacity, the contents of which were introduced into
contiguous areas. The results of experiments on six dogs indicate that
approximately 150 to 160 mg per kilo is the minimum fatal dose, since
such doses proved fatal to two out of the three animals receiving this
amount, while three others which received doses of from 143 to 160 mg
per kilo survived.