on the Haloid Compounds of Mercury. 433 
existence as a constituent at all, and which the relative quantities of the other ele- 
ments would appear to exclude. It is therefore necessary to examine whether any 
other method of arrangement is more suitable. 
From Dumas’ researches on oxamide, benzamide, &c. it follows, that by the ac- 
tion of ammonia on an oxide, there may be formed water anda compound of the body 
NH’, with the basis of the oxide. If we consider this to have taken place in white 
precipitate, we should have the formula (2 Ch + Hg) + (2 NH’ + Hg), giving— 
Hg 202,80 or 79,73 
Ch 35,42 13,93 
NH? 16,15 6,34 
254,37 100,00 
And this compound should give by decomposition 6,73 per cent. of ammonia. 
I should not wish to adopt too positively the opinion that white precipitate is a 
compound of deuto-chloride and deutamide of mercury, although the non-existence 
by experiment of oxygen as a constituent, renders it extremely probable. In addition, 
the decomposition of white precipitate by iodide of potassium appears to afford a pre- 
sumption that the mercury is not oxydized, as red oxide of mercury does not de- 
compose iodide of potassium ; on the other theory, the reaction is at once explained. 
Thus— 
4 f1+K} + 4 (@Ch+ Ha) +(2NH'+He)t ie 
a21+Hg)+2(Ch+K)+2(NH?+K). 
and 2(NH?+K)+2H = 2K+2NH’. 
The question whether ammonia, in acting on metallic oxides, forms water and me- 
tallic amides, is one of the most interesting now beginning to be examined ; but, 
notwithstanding the bearing which the results just described, have on the question, I 
do not wish to come to any positive conclusion, until a more extensive basis for in- 
duction is obtained. The atomic weight of mercury is so large, and preponderates 
so much on the other constituents, as to make small differences in their quantities fall 
within the limits of necessary error; and hence, I shall leave the two explanations 
until, by experiments on the compounds of a metal of a smaller combining number, I 
shall have an opportunity of seeing them diverge at a greater angle. 
To conclude, the white precipitate yields, as the mean results of my analyses, 
Mercury 78,60 
Chlorine 13,85 
Ammonia 6,77 ¢ 100,00 
Hygrometric water, ial 0,78 
and oxygen 
