134 On the manufacturing some Oxides of Mercury . 



the mercurial oxide, he sntFered the whole to cool, and 

 diluted it. He then decanted the mercury, and coUecied the 

 whole which adhered to the neck of the matrass : its total 

 weight was 0"81. The receiver which had served to collect 

 the oxysrcn gas was obscure, and indicated that a small 

 quantitv of mercury taken from the gaseous state was con- 

 densed un its interior sides. To force the oxygen gas to 

 abandon all the iiietallic particles which it might contain, 

 he surrounded the receiver with pounded ice; and when the 

 receiver had cooled for an hour he couvevcd the gas into 

 another vessel, and collected with care the whole of the mer- 

 curial oxide which lined the inside of the vessel. Slight 

 friction with the finger agauist the glass was sufficient to 

 effect the reduction of it, and to collect it in globules in a 

 brilliant state. Its weight was 0*02, which with the 0*81 

 found in the matrass gave 0*83. The neck of the latter 

 vessel exhibited small white crystals, which he collected 

 with care: their weight amounted to about 0-01 ; and their 

 taste and other chemical properties convinced him that they 

 were hyper-oxygenated muriate of mercury. A reddish 

 powder inclining to brown lined also a part of the dome of 

 the matrass, which it was necessary to break before it could 

 be collected. When carefully examined he found in it the 

 characters and properties of this new combination, already 

 mentioned in the beginning of this memoir, and which he 

 calls muriate of mercurv with excess of oxide: its weight 

 was 0*03. By these results it is seen that the quantity of 

 oxygen was 0-13. The same experiments being repeated 

 several times in succession, the resuiis were always the 

 same as the preceding. 



A hundred parts of red oxide of mercury, very brilliant 

 and well crystallized, and prepared with nitric acid free 

 from muriatic acid, were treated in the same manner as in 

 the preceding experiments : the reduction of the oxide was 

 complete, and the products were exactly 0*82 of mercury 

 and O'lS of oxygen. 



M. Paysse treated in the same manner red oxides of mer- 

 cury prepared in the Dutch manufactories and those he ob- 

 tained by his own trials : the proportions of the principles 

 which constituted these oxides, all very brilliant, exhibited 

 variations very litlle sensible. They amounted only to nearly 

 a hundiedth put; so that it may be considered as certain 

 that crystallized red oxides of mercury are indebted for this 

 state to a combination of oxygen with the mercury, the 

 proportions of the former being always between 18 and 19, 



while 



