Unspecific drug action. The effects of a homologous series of primary alcohols.

Experimental results relating to the unspecific depressant action of normal primary alcohols from methanol to octanol on four separate biological systems are presented. It was found that the log-concentration action curves of alcohols on all four systems were straight over most of their range and, for any one system, parallel throughout the series. With arithmetic increase in the alcohol chainlength the concentration required to produce a given effect diminished logarithmically. The rate of this decrease varied in different biological systems, and was always less than the rate of decrease of solubility with chainlength. In two of the systems investigated alcohols beyond octanol failed to show any activity (cut-off phenomenon). The implications of these findings are discussed, with reference to the mechanism of action of unspecific depressants. Ferguson's principle of using thermodynamic activity instead of concentration as an index of activity was applied to the present results. In an appendix, the results are compared with predictions according to Mullins' hypothesis of narcotic action, and found not to agree well.