WHY SOAP CLENSES.

King Country Chronicle, Volume V, Issue 385, 9 August 1911, Page 6

WHY SOAP CLENSES.

It has been stated that the cleansing properties of soap are due to its combination with the soiling substance, but this only halt explains the question as to how soap acts. An -explanation is still required as to why it disappears after having taken ap and entered into combination with the dirt, or, in other words, why the compound is removed. M. W. Spring, a Belgian chemist, after studying the action of soap upon various soiling substances, such as lampblack, clay, red chalk, silica, cellulose, &e., comes to the conclusion that the cleansing of an object consists in a process of substitution. There is brought about a colloidal combination of the soap an.l the soiling substance, which, by reason of its constitution, no longer lias the power of. fixing itself by absorption on to the solid body, with the result that it is easily carried away by the water.

Thus in washing with soao one puts it in contact with one's soiling substances, these latter having a greater affinity for the former tha - : for one's skin. The process does not end here, foi rioap in its turn has even a greater affinity for one's akin than for tin, substances, which it proceeds to replace and to set free to be taken 115: by the water and removed. The dirty substances have a chemical action on the fresh solution of soap and water, resulting in the formation of an acid salt, with which they agglutinate themselves.—The '"•Hospital."