Electro-deposited Antimony. 453 



upper part of the solution, composed of tartar-emetic and dilute 

 hydrochloric acid ; the remainder were deposited from the tar- 

 taric-acid liquid, Nos. 9 and 10 being formed very slowly. The 

 greater specific gravity of the crystalline metal appears worthy 

 of consideration in connexion with similar differences of density 

 of amorphous and crystalline sulphide of antimony*. 



47. The densities of both varieties changed to that of ordi- 

 nary antimony by fusion ; several specimens were fused under 

 tersulphide of antimony, also under cyanide of potassium, and 

 their specific gravities were as follows: — 6'67 ; 6*694; 6'71 at 

 76° F. ; 6-75 at 73'' F. ; and 6-83 at 75° F. 



48. I have endeavoured to determine the electi-o-chemical equi- 

 valent, or equivalents, of the two deposits ; and by repeated expe- 

 riments with two perfectly similar batteries, one for depositing 

 the metal, and the other for determining the loss of zinc by ordi- 

 nary chemical action, and deducting the average loss of zinc in 

 the cells of the idle Ijattery from that occurriDg in those of the 

 working one, and excluding, as far as possible, f.U other sources 

 of error, I found in one experiment that for every 32*6 parts of 

 zinc dissolved, 43'38 parts of amorphous antimony were depo- 

 sited in the solution of tartar-emetic and dilute hydrochloric 

 acid; ia a second experiment 43'61 parts of antimony were de- 

 posited; and in a third experiment 43-71 parts; and of gray 

 antimony, from the tartaric-acid solution, 41-1 parts. 



To exclude the possibility of difference of local action in the 

 two batteries, I arranged three depositing liquids in succession : 

 viz. 1st, the saturated solution of chloride of antimony [i. e. sa- 

 turated with antimony by means of a battery) ; 2nd, a solution 

 composed of 4 parts of sulphate of copjicr, dissolved in a mixture 

 of 1 ])art of pure sulphuric acid and 20 parts of distilled water ; 

 and 3rd, the tartaric-acid solution of tartar-emetic. A current 

 from twelve pairs of zinc and silver batteries was ])asscd through 

 these liquids by suitable electrodes of copper and antimony, and 

 the weights of the respective deposits, after washing and drying, 

 ascertained ; and 1 found in the following experiments that for 

 31-7 parts of copper deposited in the sulphate solution, the weight 

 of perfect crystalline deposit varied from 40-41 to 10-797 parts, 

 and of perfect amorphous deposit, from 42-304' to 43-813 parts. 



