70 



to which the colour is due. But bichlorate of potash and bicome- 

 namate of iron likewise exhibit no change of colour on dilution, 

 though such must ensue, if they be converted into neutral salt and 

 free acid. On the other hand, the red potassio-oxalate of chromium 

 varies in intensity of colour on the addition of water, and the different 

 double chlorides of copper undergo the same change as the simple 

 salt. If hydrochlorate of terchloride of gold be added to the terbro- 

 mide of that metal, a reduction in colour ensues, and an analogous 

 result is obtained when the double sulphate of copper and potash 

 acts on the acetate of copper facts which point to a decomposition 

 of the double salt in solution. Indeed it is evident that some double 

 salts are resolved more or less into their components by water, while 

 others are not so affected. 



The general tendency of my observations has led me to the opinion, 

 that water does not act upon a salt dissolved in it in a manner analo- 

 gous to that of the hydracids, but I hesitate to draw any conclusion 

 as to the rational constitution of a dissolved salt. 



II. " On the Molecular Properties of Antimony." By GEORGE 

 GORE, Esq. Communicated by Dr. TYNDALL, F.R.S. 

 Received December 10, 1857. 



(Abstract.) 



Antimony may be readily deposited by the electro-process from 

 either of the following liquids : 5 parts of tartar-emetic and 5 parts 

 of tartaric acid dissolved in a mixture of 2 parts of hydrochloric acid 

 and 30 parts of water ; or 3 or 4 parts of tartar-emetic dissolved 

 in 1 part of the ordinary chloride of antimony. 



The metallic deposits obtained from these two liquids differ greatly 

 in appearance, in structure, and in physical properties : that obtained 

 from the first liquid has a silver-grey colour and frosted surface, is 

 hard in texture, and has a beautiful radiating crystalline structure ; 

 whilst that obtained from the second liquid has the colour and ap- 

 pearance of highly polished steel, and has a bright metallic amor- 

 phous fracture. The specific gravity of the former is 6 '5 5, whilst 

 that of the latter is 5*78, both being somewhat variable in this 

 respect. The electro-chemical equivalent of the crystalline variety, 



