Preliminary experiments carried out on three guinea pigs, which
received 360, 300, and 290 mg of caffein per kilo subcutaneously have
shown that such doses were rapidly fatal. Two of the animals were
seized with convulsions half an hour after the introduction of caffein
and died during the attack. The other had tetanus two minutes after the
injection of caffein. Repeated attacks followed, which terminated in
the death of the animal two and a half hours later. The fatal and toxic
doses must therefore be considerably under 0.3 gram of caffein per kilo
when introduced by this path and smaller doses were therefore injected.
The results are shown in the experiments of the next series.