Abstract
It has been known that p-hydroxy-camphor has a cardio-stimulating action. This drug used for the author's experiment has been prepared from campherol, being separated from the urine of a dog taking camphor. The drug seemed to have the action to get rabbits sleep naturally by this experiment. In the case in which it was used with a barbiturate such as evipal, the author found it to be certain that, as the former would have the antagonistic action in part against the : latter, the paralytic action diminished and consequently sleep came on naturally in rabbits with the simultaneous application of both drugs. In the case in which these two drugs were administered together to the human body in the same way as bebore, it seemed certainly that they would act also antagonistically to each other at the site of action, so that their side actions diminished and they, therefore, caused sleep more naturally their synergistic action on the other hand. It may be said that sleep would come on with change of the state of two centers, sleeping and awaking; p-hydroxy-camphor excites the sleeping center, while barbiturates inhibit the awaking center, so that the human being would be taken in the natural sleep if he used these two drugs together.
