S38 



OS SOXfE CITEMICAL AGENCIES OF ELECTRICITY. 



Transference of inclined to believe, that this fs uniformly the case in'all ex. 

 certain consti- . , if x% i /-» /..... .",.,, 



periments carefully made. One of the instances in which I 



tuent parts of 

 bodies by elec- 

 tricity. 



conceived acid most likel}^ to be present, was in the transfer 

 of magnesia from sulphate of magnesia in the positive tube, 

 to distilled water in the negative tube. I examined the 

 case, taking care that the distilled water was never upon a 

 lowxr level than the saline solution : the process was con- 

 tinued for some hours, till a considerable quantity of mag. 

 nesia had appeared. The connecting amianthus was re- 

 moved, and muriatic acid poured into the tube: the satu- 

 rated solution did not precipitate solution of niuriate of 

 barytes. ' 



I endeavoured to ascertain the progress of the transfer, 

 and the course of the acid or alkaline matter in these decom- 

 positions, by using solutions of litmus and turmeric, and 

 papers coloured by these substances; and these trials led 

 to the knowledge of some singular and unexpected cir- 

 cumstances. 



Two tubes, one containing distilled water, the other so- 

 lution of sulphate of potash, were each connected by ami- 

 anthus with a small oz, measure filled with distilled water 

 tinged by litmus : the saline solution was negatively elec- 

 trified; and as it was natural to suppose, that the sulphu- 

 ric acid in passing through the water to the positive sid« 

 would redden the litmus in its course, some slips of mois- 

 tened paper tinged with litmus were placed above and below 

 the pieces of amianthus, directly in the circuit. The pro- 

 gress of the experiment was minutely observed; the first 

 effect of reddening took place immediately above the posi- 

 tiTe surface, where I had least expected it; the red tint 

 slowly diffused itself from the positive side to the middle of 

 the vessel, but no redness appeared above the amianthus, 

 or about it, on the negative side, and though it had hcen 

 constantly transmitting sulphuric acid, it remained unaf- 

 fected to the last. 



The order of the experiment was changed, and the saline 

 solution placed oh ihe positive side ; a solution and papers 

 .tinged with turmeric bein^ substituted for those tinged with 

 litmus. The effect was precisely analogous; the turmeric 

 became brownf ^st oear ific negative wire, and ao change 



took 



