THE RELATION BETWEEN THE ACTION AND CONCENTRATION OF ETHER AND CAMPHOR APPLIED TO THE HEART MUSCLE

¹ From the Pharmacological Department, The Egyptian University, Cairo

1. The curve connecting the concentration of ether or camphor, with its effect in diminishing the force of the beat of a toad's heart is very similar to the corresponding curve for alcohol, and quite different from that for acetyl-choline.

2. The curve connecting the concentration of ether or camphor with its effect in diminishing the surface tension at a water/air interface, is roughly similar to the curve for the effect of these drugs on the heart. In both cases, however, the curves diverge from one another in the same way.

3. The theory is proposed that the observed effect of these drugs is directly due to the mechanical force exerted by films of the drugs adsorbed on the surface of the heart cells. This theory accounts both for, the general similarity of the curves and for their divergence. It is supported by a calculation of the magnitude of the forces involved.