116 British Association for the Advancement of Science. 



up the chimney. When carburetted hydrogen passes in, the fact 

 is discovered by numerous small explosions, and the whole glass 

 work is thrown into vibrations which emit a loud and shrill sound, 

 audible at a great distance. 



On a small Voltaic hattery of extraordinary energy by W. R. 

 Grove, Esq. In a letter published in the Philos. Mag. Feb. 

 1839, I stated, (said the author,) some reasons for hoping that by 

 changes in the constituents of voltaic combinations of four ele- 

 ments, we might greatly increase their energy. At that period I 

 sought in vain for improvements, which a fair induction convin- 

 ced me were attainable ; but being in the country, all my experi- 

 ments were with copper as a negative metal. I was constantly 

 unable to use concentrated nitric acid as an electrolyte, and its 

 importance never occurred to me until forced upon my notice by 

 an experiment which I made at Paris for a diJEferent object. This 

 was an endeavor to prove the dissolution of gold in nitro-muriatic 

 acid to be an electrical phenomenon ; or rather, that this (and, as 

 I believe with Sir H. Davy, every other chemical phenomenon,) 

 could be resolved into an electrical one by operating on masses 

 instead of molecules. The experiment was this : the extremities 

 of two strips of gold leaf were immersed, the one in nitric, the 

 other in muriatic acid ; contact between the liquids being permit- 

 ted, but mixture prevented, by an interposed porous diaphragm. 

 In this case, the gold remained undissolved for an indefinite period, 

 but the circuit being completed by metallic contact, either medi- 

 ate or immediate, the strip of gold in the muriatic acid was in- 

 stantly dissolved. Thus, it seems, that the affinity of gold for 

 chlorine is not able alone to decompose muriatic acid; but when 

 it is aided by that of oxygen for hydrogen, the decomposition is 

 effected. The phenomenon bears much analogy to ordinary 

 cases of double decomposition. The two gold strips in the ex- 

 periment being connected with a galvanometer, occasioned a 

 considerable deflexion ; and it now occurred to me, coupling this 

 experiment with my previous observations, that these same liquids, 

 with the substitution of zinc and platinum for the gold leaf, would 

 produce a combination of surpassing energy. My expectations 

 were fully realized ; and on the 15th of April, M. Becquerel pre- 

 sented to the Institute a small battery of my construction, consist- 

 ing of seven liqueur glasses, containing the bowls of common 

 tobacco-pipes, the metals zinc and platinum, and the electrolytes 



