414 Tramactions. — ( 'hemiHtrij. 



or oily matter which may be present iu the solutiou to which such test is 

 applied. This can generally be accomplished by shaking such solution 

 with a little pure hard fat, at its fusing-point, and removing the crust which 

 forms on cooling. 



In conclusion, I would desire to point out to you that by some of the 

 facts above stated may be explained that difference which has arisen between 

 Eeynoso and Schiff respecting the character of the precipitate produced by 

 adding water to alcohol in which has long been dissolved mercuro-iodide ; 

 the former has stated it to be red ; the latter, to be yellow — a discrepancy 

 which is readily susceptible of explanation upon the very likely assumption 

 that in the case where such precipitate is yellow, an oil was present iu the 

 alcohol used. 



Aet. LXVI. — On the Decomposition of Argentic-oxide by Mercury. By 

 William Skey, Analyst to the Geological Survey Department. 

 [Read before the Wellington Philoso2}hical Society, 21st Februanj, 1880.] 

 Upon tbe authority of Fisher it is now supposed that argentic-oxide is not 

 decomposed by mercury ; but I find that, when these two substances are 

 kept for some weeks in contact, whether in light or not, a considerable 

 quantity of silver amalgamates with the mercury, and a crust of yellow 

 mercuro-oxide is formed, demonstrating that this silver compound is di- 

 vested of its oxygen by mercury, but at a very slow rate of speed. The 

 same decomposition takes place if the two substances are kept immersed in 

 caustic potash. 



