342 GALVANISM. 



regular deposition that precedes crystallization,* which ope- 

 rates on the light in a manner similar to that of an extended 

 plane surface, disposed nearly in a vertical position ; and the 

 rising sun appears to disturb and elevate this mass. But by 

 what laws these causes and their effects may be governed, 

 must be explained by more frequent and minute observation, 

 and, perhaps, from the analogy of experiment. 



IX. 



Letter from Dr. Wilkinson, respecting the supposed Pro- 

 duction of Muriatic Acid from Water hi) Gahardsm, 



To Mr. NICHOLSON. 

 Dear Sir, 



A^ 



^T the period Pacchioni's experiments were published^ re- 

 lative to the production of muriatic acid from the galvanic 

 disnxigenation of water, I was engaged in some lectures at 

 Dublin. I employed my extensive apparatus with a view of as- 

 certaining this curious circumstance : my friend Dr. Barker, 

 lecturer on chemistry in that university, provided me with 

 Four ounces of some pure distilled water, the purity of which was ascertained 

 drams bT-aN^ ^^ ^^'^ ^*^^^ means with the muriate of barytes and the nitrate 

 vanisiiisf and of silver : about four ounces of this water was subjected to 



theremaiDtler j. jj^fluence of 800 plates for thirty hours : about two drams 

 shewed mun- r ./ 



atic acid. of the water had disappeared : into the residual water, a solu- 



tion of the nitrate of silver was introduced, the white cloudy 

 precipitation, evincing the existence of muriatic acid, imme- 

 diately followed. The appearance surprized us much : not- 

 withstanding this, I doubted the accuracy of the experiment, 

 and suspected that muriatic acid had, some how or other. 

 In anotlier ev- crept into the water. Upon reflection, it appeared to me pro- 

 periment, per- jjably to arise from the acid mixture which is employed in the 

 foi-medwith •' -it i l 



extreme cau- galvanic arrangements. When at Limenck, 1 repeated the 

 tion, no acid 

 Mas produced. . „ . . ^ ., i t. v 



* Could it have been m frozen plates? Even if so, the Italia^ 



phenomenon could hard!^ have becii at so low a teaiperature. 



experl- 



