The ultramicroscopic structure of soaps

Abstract

In 1912, Bachmann published, with Zsigmondy, beautiful pioneer descriptions of the ultramicroscopic appearance and behaviour of soaps. In view of our present greatly extended knowledge of the constitution of soap solutions, sols, gels, and curds, it was highly desirable to extend these morphological observations, and to correlate the various phenomena observed by Zsigmondy and Bachmann with the known constituents of these systems. It was also of great importance to find out to which state, whether sol, gel, or curd, the various phenomena were to be attributed. A further interest lay in the development of the technique of such investigations as, for instance, in the application of the cinematograph to the study of the life-history of an ultramicroscopie particle or formation in its genesis and subsequent transformations. The present paper contains some novel information with regard to Brownian movement and the distinction between sols, gels, and curds, the three different states which are possible for soaps. Although we have given a year to this work, in each experiment with the ultramicroscope we still find some new detail. We have endeavoured to record only those observations which appear reproducible and characteristic.