ON T H E ELECTRICAL CONDUCTIVITY OF URINE IN RELATION TO ITS CHERICAL COflPOSITION.' Rr J . H. L o x + . 1 i e c e i " L i i !!#I>
3".
1909.
A J I O , ~the ~ ; newer applications of the methods of modern physical chemistry some of the most important are certainly those employed in the solution of problems i n physiology and physiological chemistry. A t first sight one of the least promising of these methods is that of the determination of electrical conductivity as applied to the fluids of the body, but the labors of Iioth,' Stewart," Bugarszky and Tangl,* and others have shown the possibilities of the method in the examination of blood seriim. In respect to inorganic constituents blood serum is much more constant than is urine, and the variations in the conductivitl. of the latter appear at first sight so irregular as to bc he!-ond simple formulation. This notion. hoivever, is not quite corrcct. Tt has been shown by l!ugarszl;!.~ that certain general relatioi?r are casily observe(!, anti among othcrs the connection hetwcen t!;c total ash and the conductivity. Tt must be reniemberetl that t h r coiiductivit!- of the urine is practically due to the mineral salts present only. T h e most abundant of all the urinary constituents, the urea. is so near a non-conductor in solution that its effect may he safely neglectcd. Even the low value given by TriibsbachG is probably high, as shown hy some of m y own observations with c a r e i d l y prepared urea. The creaticin, aminonia, xanthin bodie?. uric acid and urates have all but a slight conductivity and their effect in lowering the conductivity of the mineral salts is estremely small. For investigations of this liintl it is exceedingly difficult to obtain Lir
