Chap. II.
657
1 236 100-00
Perchloride of Mercury , or Corrosive Sublimate , has an acrid nauseous taste; its .specificgravity is 5-2. It is soluble in twenty parts of water at a temperature of 60°; boilingwater takes up about half its weight, and as it cools quadrangular prismatic crystals areformed. It dissolves without decomposition in muriatic acid, but is insoluble in concentratednitric and sulphuric acids.
Chlorine - - - 2 - 72 - 26*47
1 272 10000
Ilistdpkuret of Mercury., Cinnabar , or Vermilion , may be manufactured by mixing 8 parts ofmercury in an iron pot with 1 of sulphur, and combining them at a moderate heat; this isput into a glass subliming vessel, and heated in a sand-bath to redness, after which it isrubbed down into a fine powder.
Sulphur - - -2 - 32 - 13*8
1 232 100-0
Silver occurs native, and crystallised in cubes and octohedra; pure it has a brilliantwhite colour, and when polished a bright lustre, is extremely ductile and malleable. At abright red heat it melts, and when pure absorbs oxygen, which as it cools it again evolves.The tarnish of silver is produced by the vapours of sulphur, and it is most apparent whenthe metal is alloyed with copper.
When the argentiferous sulphuret of lead is placed in the reverberatory furnace, and acurrent of air suffered to pass over its surface, the lead is converted into litharge, and thesilver is left in the metallic state.
The sulphurets of silver are reduced by amalgamation; when these ores are washed andground, they are mixed with common salt, and roasted; sulphate of soda and chloride ofsilver are thus formed; it is then reduced to a fine powder, and agitated with mercury,water, and iron filings; thus the chloride of silver is decomposed, and the chloride of ironbeing washed away, the silver and mercury combine into an amalgam, when the mercuryis partly pressed out, and the remainder driven off by distillation; the specific gravity ofsilver is 10*5.
Oxide of Silver is of a (fork olive hue, and when employed in glass or enamel painting,gives a yellow colour.
Silver
.
,
- 1
_
108
93*103
Oxygen -
*
-
- 1
-
8
6-897
1
116
100*000
Chloride of Silver is formed by adding to a solution of chlorine of muriatic acid orcommon salt a solution of nitrate of silver ; it is precipitated in the form of a heavypowder, of a white colour, which by exposure to light becomes black.
Silver - 1 - 108 - 75
Chlorine - ... 1 - 36 - 25
I 144 100
When found native, it is crystallised in cubes and octohedra.
Nitrate of Silver -Silver is readily dissolved with nitric acid, when diluted with three
parts of water. Nitrate of silver should be a clear and colourless solution ; by exposure tolight it becomes deep purple, and all animal substances, when tinged with it, are of a deepyellow colour. Ivory, marble, and other substances when soaked in this solution, andafterwards exposed to a strong light, become black.
Nitrate of silver is an anhydrous salt, and consists of
Oxide of silver - - - 1 116 - 68-23
Nitric acid - - - 1 - 54 - 31*77