328 Chemical Society. 



The table of galvanometric deflections is suspended in the labora- 

 tory of the London Institution. Professor Grove furnished Mr. Walker 

 with a copy for the Society ; it contains the deflections for twenty- 

 four arrangements. The negative element, also a suggestion of 

 Mr. Grove's, is platinized silver gauze for Smee's battery ; he has 

 found the advantage from using cuprized copper, and has only 

 delayed adopting the silver from the difficulty of obtaining such 

 an article. The Secretary recommended platinized, plated-copper 

 gauze. 



5th. " On certain Phenomena connected with the Spark from a 

 secondary Coil." By J. P. Gassiot, Esq., F.R.S., M.E.S., &c. 



The wires of the coil were placed side by side, sometimes parallel, 

 at other times at a considerable angle. In all cases the spark ap- 

 peared at the cathode. With a coil containing twelve miles of wire, 

 the secondary spark, in the flame of a spirit-lamp, was three-fourths 

 of an inch long. 



6th. " An Account of a Method of Electro-gilding and Electro- 

 plating at the expense of a Gold or a Silver Anode." By Charles 

 V.Walker, Esq., Hon. Sec. 



This object is usually effected at the expense of a gold or silver 

 solution, forming one of the exciting liquids in a single cell ; and its 

 strength is maintained by adding from time to time fresh supplies 

 of the salt. It is obviously not the wisest principle to employ the 

 salt if the metal itself can be used ; but as the former plan has been 

 so generally adopted, Mr. Walker suspected some physical difficulty 

 might exist in the other mode. To satisfy himself, he went through 

 a series of experiments, the results of which were, that from cyanide 

 of silver, when electrolysed with a silver anode, an anion will be re- 

 leased that will combine with the anode, and that the like result 

 attends the electrolysis of the cyanide of gold. The author em- 

 ployed a silver plate, which was considerably consumed ; and a gold 

 wire, which was also much acted upon. He recommends this as a 

 surer, a more simple, and a much more ceconomical method ; and 

 conceives that by this means the expense of each operation is reduced 

 to a minimum. The communication extended to some length, and 

 contained a description of a " Regulating Apparatus," to be em- 

 ployed when rich deposits are required, and instructions as to the 

 management and preparation of the apparatus, &c. 



Mr. Weekes's Monthly Register was then placed on the table, and 

 the Society adjourned. 



CHEMICAL SOCIETY OF LONDON. 



[Continued from vol. xviii. p. 520.] 



May 11, 1841. — " On a Simple and Cheap Method of preparing 

 Hydrochloric Acid absolutely pure, and of any required strength," 

 by Wm. Gregory, M.D. Professor, &c, King's College, Aberdeen. 



Much difficulty is experienced in procuring pure and concentrated 

 hydrochloric acid for chemical purposes, the common commercial 

 acid containing various impurities, particularly sulphuric and sulphu- 



