672 SILVER. 



applied or the temperature allowed to rise, then the metal 

 dissolves with violent effervescence from the escape of nitric 

 oxide. The nitrate of silver crystallizes on cooling in colourless 

 tables, which are anhydrous. It is soluble in I part of cold, in 

 i part of hot water, and in 4 parts of boiling alcohol. The 

 solution of this salt does not redden litmus paper, like most 

 metallic salts, but is exactly neutral. Nitrate of silver fuses at 

 426 and forms a crystalline mass on cooling ; it is cast into 

 little cylinders for the use of surgeons. It is sometimes 

 adulterated in this state with nitrate of potash, which may 

 be detected by the alkaline residue which the salt then leaves, 

 when heated before the blowpipe, or with nitrate of lead, when 

 the solution of the salt is precipitated by iodide of potassium, 

 of a full yellow colour. When applied to the flesh of animals, 

 it instantly destroys the organization and vitality of the part. 

 It forms insoluble compounds with many kinds of animal 

 matter, and is employed to remove it from solution. When 

 organic substances, to which a solution of nitrate of silver has 

 been applied, are exposed to light, they become black from the 

 reduction of the oxide of silver to the metallic state. A solution 

 of nitrate of silver in ether is employed to dye the hair black. 

 It forms also the indelible marking ink used to write upon 

 linen. The part of the linen to be marked should be first 

 wetted with a solution of carbonate of soda and dried, and the 

 writing should be exposed to the light of the sun. For this 

 ink, which is expensive, another liquid has been substituted by 

 bleachers, namely coal tar, made sufficiently thin with naphtha 

 to write with, which is found to resist chlorine and to answer 

 welj as a marking ink. A strong solution of nitrate of silver 

 absorbs two equivalents of ammoniacal gas, and gives the 

 crystallizable Ammoniacal nitrate of silver, Ag O, NO 5 + 2NH 3 . 

 The dry nitrate in powder absorbs three atoms of ammonia, NgO, 

 NO 5 + 3NH 3 . 



Nitrate of silver forms a double salt with nitrate of the red 

 oxide of mercury, which crystallizes in prisms, Nitrate of silver 

 and cyanide of mercury also form a double salt, when hot solu- 

 tions of them are mixed ; Ag Q, NO 5 -f 2Hg Cy -f 8HO. Cyanide 

 of silver is soluble in a boiling solution of nitrate of silver, and 

 gives a crystalline compound, Ag O, NO 5 4-2 Ag Cy, which is 

 decomposed by water. 



Nitrite of silver, Ag O,NO 3 1928.6 or 154.54. Nitrate of 



