FULMINATING MERCURT. 



action. The precipitate is to be immediately collected on a filter, 

 well washed with distilled water, and carefully f'.-ied in a heat not 

 much exceeding that of a water-bath. The immediate edulcoration 

 of the powder is material, because it is liable to the reaction of ni. 

 trie acid ; and, whilst any of that acid adheres to it, it is >ery sub- 

 ject to the influence of light. Let it also be cautiously remembered, 

 that the mercurial solution is to be poured upon the alcohol. 



" I have recomnv nded quicksilver to be used in preference to 

 an oxyd, because it seems to answer equally, and is less expensive; 

 otherwise, not only the pure red oxyd, but the red nitrous oxide, 

 and turpcth, may be substituted ; neither does it seem essential to 

 attend to the precise specific gravity of the acid, or the alcohol. 

 The rectified spirit of wine, and the nitrous acid of commerce, 

 never failed with me, to produce a fulminating mercury. It is in. 

 deed true, that the powder prepared without attention is produced 

 in different quantities, varieties in colour, and probably in strength. 

 From analogy, I am disposed to think the whitest is the strongest ; 

 for it is well known that the black precipitates of mercury ap- 

 proach nearest to the metallic state. The variation in quantity is 

 remarkable: the smallest quantity I ever obtained from 100 grains 

 of quicksilver beinjj 120 grains, and the largest 132 grains. Much 

 depends on very minute circumstances. The greatest product 

 seems to be obtained when a vessel is used which condenses and 

 causes most ether to return into the mother liquor ; besides which, 

 care is to be had in applying the requisite heat, that a speedy and 

 not a violent action be ellected. One hundred grains of an oxide 

 are not so productive as 100 grains of quicksilver. 



" As to the colour, it seems to incline to black when the action 

 of the acid of the alcohol is most violent, and vice versa. 



*' I need not observe, that the gasses which were generated dur- 

 ing the combustion of the powder in the glass globe, were neces- 

 sarily mixed with atmospheric air ; the facility with which the 

 electric fluid passes through a vacuum, made such a mixture un- 

 avoidable. 



" The cubical inch of gass received over water was not readily 

 absorbed by it; and, as it soon extinguished a taper without be- 

 coming red, or being itself inflamed, barytes water was let up to 

 the three cubical inches received over mercury, when a carbonate 

 of barytes was immediately precipitated. 



" The residue of several explosions, after the carbonic acid bad 

 VOL. vi. 



