Of great importance in the hygienic standardization of toxic substances are special neurohistological studies which can, in a number of cases, reveal the effect of small concentrations of chemical substances in the central and peripheral nervous system. In such standardization the neurohistologist can also evaluate the degree of damage to the nervous system and help the hygienist discover the mechanism of the effect of these agents. Many scientists have indicated that against the background of the general reactions of the nervous system a unique, more intense response of one section of the nervous system is observed where pathological changes are especially pronounced. The work of M. V. Vendilo et al., dealing with the inhalation effect of aliphatic alcohols suggested a deeper study of the visual analyser. The study was conducted on 66 rabbits. The greatest changes were found in the path of the visual analyser. On the basis of results of neurohistological and histochemical studies of the action of aliphatic alcohols on the nervous system, it is suggested that future study be limited to the visual analyser and that part leading to it which lacks neurons.