CHEMISTRY. 



89 



Element* and purified by a subsequent crystallization. This 



salt is soluble in about four parts of water. 

 Chemistry. g p> g Sulphated Mercury. Of this salt there 

 ^^ 'V are tw > species, the sulphate and oxytulphate. 



1. Sulphate. This salt may be obtained by boil- 

 ing over mercury, sulphuric acid diluted with its own 

 bulk of water. Very little sulphurous acid gas is 

 disengaged. By evaporation the salt is obtained in 

 mall prismatic crystals. It dissolves in 500 parts of 

 cold water, and is not altered by exposure to the air. 

 The alkalies throw down a dark -coloured sub-sulphate 

 of mercury, when poured into a solution of this salt. 

 The sulphate of mercury is composed of 12 acid, 83 

 protoxide, and 5 water. 



2. Oxysulphate. When three parts of sulphuric 

 acid are boiled on two parts of mercury, the whole, 

 by continuing the heat, is converted into oiysulphate. 

 This salt crystallizes in small prisms. When neutral, 

 its colour is a dirty white ; but when in the state of 

 super-oxysulphate, it is of a fine white. The neutral 

 salt is not altered in the air, the super-oxysulphate 

 deliquesces. It is composed of 31.8 acid, 63.8 per- 

 oxide, 4.4 water. When water is poured upon this 

 salt, it is decomposed and converted into fU]jer-o.zy- 

 svlp/iate, which dissolves, and sub oxy sulphate, which 

 remains in the state of a beautiful yellow powder. 

 This sub-salt is used as a pigment, and was formerly 

 known by the name of turpcth mineral. It is com- 

 posed of 15 acid and 85 peroxide. 



Sp. +. Phosphate of Mercury. This salt may be 

 formed by mixing together the solutions of nitrate of 

 mercury and phosphate of soda. It is a white pow- 

 der, insoluble in water, lately introduced into medicine, 

 and composed of 28.5 acid, 71.5 peroxide. 



There seems to be no such salt as phosphite of mer- 

 cury. 



bp. 5. Carbonate of Mercury. A white insoluble 

 powder. 



Sp. 6. Fluate of Mercury. A white insoluble 

 powder. 



Sp. 7. Borote of Mercury. A yellow insoluble 

 powder. 



Sp. 8. Acelated Mercury. Of this salt there arc 

 two species, the acetate and o.racctalc. 



1 . Acetate. This salt may be obtained by mixing 

 together solutions of nitrate of mercury and acetate 

 of potash. Its crystals are plates of a silvery white- 

 ness. It has an acrid taste, ii insoluble in alcohol, 

 and scarcely soluble in water. 



2. Oxacetate. This salt may be formed by dissol- 

 ving red oxide of mercury in acetic acid. It is a yel- 

 low mass, which does not crystallize, and toon deli- 

 quesces in the air. 



Sp. 9. Succinate of Mercury. This salt crystal- 

 lizes, and is soluble in water. 



Sp. 10. Benzoate of Mercury. A white powder, 

 insoluble in water, and very sparingly soluble in al- 

 cohol. 



Sp. 11. Oxalate of Mercury. A white powder, 

 scarcely soluble in water, which blackens when ex- 

 posed to the light. It detonates when heated. 



Sp. 12. Mellate (if Mercury. A white powder. 



Sp. 13. Tarlrate of Mercury. An insoluble white 

 powder, becoming yellow when exposed to the air. 



vou vi. FAUX i. 



E!ement 

 of 



Sp. 14. Citrate of Mercury. A . white mass, 

 scarcely soluble in water. 



Sp. 15. Prussia! e of Mercury. This salt may be ^"^T 

 formed by boiling red oxide of mercury and prussian 

 blue in water. It crystallizes in four-sided prisms, 

 terminated by four-sided pyramids. Its taste is acrid 

 and metallic. It is white, and soluble in water. 



Sp. 16. Arseniate of Mercury. A yellow inso- 

 luble powder. 



Sp. 17. Molybdate of Mercury. A white flaky 

 powder. 



Sp. 18. Chromate of Mercury. An insoluble pow- 

 der, of a fine purple colour. 



G EN us V. Salts of Palladium. 



The salts of this metal are almost all soluble in wa- Sa ' ts / 

 ter, and the solution has a fine red colour. Pruasiate P* llad ' uni ' 

 of potash occasions a dirty yellowish brown precipi- 

 tate, hydrosulphuret of potash, and the alkalies, an 

 orange-yellow precipitate when poured into solutions 

 of these salts. Neither nitrate of potash nor sal am- 

 moniac occasions any precipitate in them. Nitric, 

 muriatic, and sulphuric acid, digested on palladium, ac- 

 quire a red colour. But the true solvent of that me- 

 tal is nitro-muriatic acid. The salts of palladium are 

 not yet sufficiently known to admit of a particular 

 description. 



GENUS VI. Salts of Rhodium. 



The solutions of these salts are red. Prussiate of Salu of 

 potash, hydrosulphuret of potash, sal ammoniac, and rhodium, 

 alkaline carbonates, occasion no precipitate in them. 

 But the pure alkalies throw down a yellow powder, 

 soluble in an excess of alkali. 



GENUS VII. Salts of Iridium. 



Thete salts are soluble in water. The solution is S* 1 '.' < rf 

 at first green, but becomes red when concentrated in irldium - 

 an open vessel. Neither prussiate of potash nor in* 

 fusion of nutgalls occasion any precipitate, but they 

 render the solutions of iridium colourless. 



* Salt* of 

 osmium. 



GENUS VIII. Salts of Osmium. 

 This genus of salts is still entirely unknown. 



GENUS IX. Saltt of Copper. 



Most of these salts are soluble in water. The so- Saltt of 

 lution is blue or green, or at least it acquires these 

 colours when exposed to the air. When ammonia is 

 poured into these solutions, they assume a deep blue 

 colour. Prussiate of potash occasions a greenish yel- 

 low precipitate, hydrosulphuret of potash a black 

 precipitate, and gallic acid a brown precipitate in 

 these solutions. A plate of iron or zinc put into these 

 solutions precipitates the copper in the metallic state. 



Sp. 1. Nitrate of Copper. Nitric acid attacks 

 copper with some violence, nitrous gas is emitted, and 

 the metal dissolved. By evaporation, the salt cry- 

 stallizes in parallelepipeds. It has a blue colour, iu 



