Electrical effects accompanying the decomposition of organic compounds

Abstract

The results of recent researches in electro-physiology have familiarised us with the view that any physiological process accompanied by chemical changes involves an associated electrical change. Haacke and Klein have shown that electrical currents in plants are essentially a manifestation of vital phenomena, and that differences in electric potential are connected both with respiration and carbon assimilation. Waller's investigations have also shown that the excitation of living vegetable protoplasm gives electrical response no less than that of animal protoplasm. He has demonstrated that leaves in a condition of active metabolism give an instant electrical response to the influence of sunlight, which was modified under conditions affecting protoplasmic activity. Apparently almost immediately upon the perception of the stimulus of light, electrical energy begins to be absorbed in the process of photosynthesis. Waller approaches very suggestively the existence of two opposing forces in the presence of analytic and synthetic processes, and recognises that the function of assimilation and respiration might be mutually antagonistic as regards visible electric effects. His conception that "the product of dissociation …. gives current from the focus of dissociation, whereas a product of association, during its formation, gives rise to a current in the opposite direction," is of great interest. The line of enquiry now followed lies in the direction only of dissociation, and is a study of electrical effects accompanying fermentation or putrefaction under the influence of micro-organisms such as Saccharomyces or bacteria. The special physiological character of fungi or bacteria demands the disintegration of organic compounds as a necessary source of energy, and where there has been absorption of energy in a synthetic process one must look for its liberation when the change is of an analytic nature. The evolution of caloric energy during fermentation or putrefaction is commonly recognised, and that electrical energy is also liberated during these processes is a conception of considerable interest. In this preliminary communication some experiments are described which were undertaken to determine whether any E. M. F. is developed when organic compounds are broken down through the fermentative activity of yeast and other organisms. Cultures of Saccharomyces cerevisiæ and certain species of bacteria were grown in nutrient media, and the chemical action of their vital processes was utilised to develop electrical energy in a manner parallel to the production of E. M. F. by means of the ordinary galvanic cell.