CHEMISTRY SINCE TIME OF DALTON 



posite tube; but I soon ascertained that the muriatic 

 acid owed its existence to the animal or vegetable 

 matters employed ; for when the same fibres of cotton 

 were made use of in successive experiments, and washed 

 after every process in a weak solution of nitric acid, 

 the water in the apparatus containing them, though 

 acted on for a great length of time with a very strong 

 power, at last produced no effects upon nitrate of 

 silver. 



" In cases when I had procured much soda, the glass 

 at its point of contact with the wire seemed consider- 

 ably corroded ; and I was confirmed in my idea of re- 

 ferring the production of the alkali principally to this 

 source, by finding that no fixed saline matter could be 

 obtained by electrifying distilled water in a single agate 

 cup from two points of platina with the Voltaic bat- 

 tery. 



" Mr. Sylvester, however, in a paper published in Mr. 

 Nicholson's journal for last August, states that though 

 no fixed alkali or muriatic acid appears when a single 

 vessel is employed, yet that they are both formed when 

 two vessels are used . And to do away with all objections 

 with regard to vegetable substances or glass, he con- 

 ducted his process in a vessel made of baked tobacco- 

 pipe clay inserted in a crucible of platina. I have no 

 doubt of the correctness of his results ; but the conclu- 

 sion appears objectionable. He conceives that he ob- 

 tained fixed alkali, because the fluid after being heated 

 and evaporated left a matter that tinged turmeric 

 brown, which would have happened had it been lime, 

 a substance that exists in considerable quantities in all 

 pipe-clay ; and even allowing the presence of fixed al- 



49 



