157 



the yellow powder analyzed by Grouvelle. Dr. Kane finds 

 that this powder always retains an equivalent of water, that 

 its formula is HO.NO5 +2 h^2-0) and that the grey subnitrates 

 which have been noticed by some chemists, are impure mix- 

 tures of black oxide and the yellow powder. Dr. Kane 

 considers the nitrates of the black oxide of mercury to be 

 thus related : 



First crystallized, zr h^2-0-N03-[- 2ho. 

 Yellow powder, — HO.NO5 + 2h^.2.o. 



Second crystalHzed, zi 2 NO5 +3 Hg.2.0 -f- 3iio. A double salt. 



Great difficulty was found in determining what specimen 

 of Hahneman's mercury should be considered as pure and fit 

 for analysis. Considering that the most important sources of 

 error tend to throw the value of mercury too high, Dr. Kane 

 derives his formula from the lowest number which he ob- 

 tained by analysis, and these numbers were given always 

 by the blackest and purest looking portions. He finds, 

 on these grounds, for the ammonia subnitrate of the black 

 oxide, the formula NH3.NO5 + ^ H^.2.0. which is related to 

 the water subnitrate in a similar manner to what holds in 

 the corresponding compounds of the red oxide. ' 



Thus, in this paper, two propositions are developed : 

 1 st. Increased evidence of the formation of metallic amides. 

 2nd. That ammonia as amide of hydrogen is capable of 

 replacing oxide of hydrogen in its various functions in the 

 quicksilver salts. 



Professor Apjohn read a paper ** on the Properties of 

 a new Voltaic Combination," by Thomas Andrews M.D,, 

 Professor of Chemistry in the Belfast Institution. 



The object of the author in this paper is to extend the 

 results which he has already obtained on the influence of 

 voltaic circles upon the solution of the metals in nitric acid to 

 the case of concentrated sulphuric acid. When a plate of 



