Proceedings of the Royal Society. 199 



of Dumas and Peligot) under voltaic agency, and those which he 

 had previously observed in regard to alcohol ; a coincidence which 

 was to be expected, from the interesting analogy existing between 

 these two liquids in other respects. 



The pyroxylic spirit, after three distillations from quicklime, had 

 a specific gravity of 801 at 62° F., and boiled in contact with mer- 

 cury at 140° F., under a pressure of 29.6 inches. The leading 

 facts observed were the following : — 



Minute quantities of acid, alkaline, and saline bodies, when dis- 

 solved with rectified pyroxylic spirit, favoured the voltaic action, 

 by increasing the conducting power of the liquid. When it held 

 in solution =1^ of pure potash, and was submitted to the agency of 

 thirty-six pairs of four-inch plates in a tube with parallel platinum 

 foil poles, hydrogen was given off from the negative pole, while no 

 gas proceeded from the positive pole. A ten thousandth part of 

 potash had a marked effect in promoting this action. 



When the pure spirit was submitted in a similar tube to the 

 agency of seventy-two pairs of four-inch plates, hydrogen was in 

 like manner evolved, although in smaller quantity. 



When the same electric current was passed through the spirit and 

 through water, each holding dissolved ^^^ part of potash, the quan- 

 tity of hydrogen evolved from both negative poles was the same. 



Besides the evolution of elastic fluid, there M'ere found in the 

 liquid acted on small quantities of such substances as often result 

 from the oxidation of analogous liquids, such as resinous matter ; 

 and, where the quantity of dissolved potash was considerable, a 

 speedy precipitation of carbonate of potash ensued, the liquid at 

 the same time acquiring a red colour from the formation of resinous 

 matter. 



In the whole circumstances it was concluded, as had been done 

 in regard to alcohol, that water, entering as such into the constitu- 

 tion of pyroxylic spirit, is resolved under voltaic agency into its 

 elements, its hydrogen being evolved at the negative pole, and its 

 oxygen employed in giving rise to the secondary effects of oxida- 

 tion. 



As pyroxylic ether (hydrate of methyline of D. and P.) bears 

 the gaseous form, no galvanic experiments were attempted with it ; 

 but, as the author had formerly observed no evidence of the pre- 

 sence of water in sulphuric ether under electric agency, he is dis- 

 posed to adopt the analogous view as in rega«<l t(» alcohol, and to 

 consider pyroxylic spirit as a hydrate of pyroxylic ether, ^vhieh lat- 



