1S2G.] Sulpho-Naphthalic Acid. 193 



exposure to air slowly acquired oxygen, and a portion of per- 

 salt was found. 



Zinc was readily acted upon by the acid, hydrogen evolved, 

 and a salt formed. The same salt resulted from the action of 

 the acid upon the moist oxide. It was moderately soluble 

 in hot water, the solution on cooling affording an abundant 

 crop of acicular crystals. The salt was white and unchangeable 

 in the air ; its taste bitter. It burnt with flame, and gave the 

 usual results by heat. 



Lead. The salt of this metal was white, solid, crystalline, 

 and soluble in water and alcohol. It had a bitter metallic 

 taste, with very little sweetness. The results by heat were 

 such as might be expected. 



Manganese. The protoxide of this metal formed a neutral 

 crystalline salt with the acid. It had a slightly austere taste, 

 was soluble in water and alcohol, and was decomposed by heat, 

 with the general appearances already described. 



Copper. Hydrated peroxide of copper formed an acid salt 

 with the acid, and the solution evaporated in the air left radi- 

 ated crystalline films. The dry salt when heated fused, burnt 

 with flame, and exhibited the usual appearances. 



Nickel. The salt of this metal was made from the moist 

 carbonate. It was soluble, crystalline, of a green colour, and 

 decomposed by heat in the usual manner. In one instance an 

 insoluble subsalt was formed. 



Silver. Moist carbonate of silver dissolved readily in the 

 acid, and a solution, almost neutral, was quickly obtained. It 

 was of a brown colour, and a powerful metallic taste. By 

 evaporation it gave a splendent, white, crystalline salt ; not 

 changing in the air except when heated, but then burning 

 with flame and ultimately leaving pure silver. When the solu- 

 tion of the salt was boiled for some time, a black insoluble 

 matter was thrown down, and a solution obtained, which by 

 evaporation gave abundance of a yellow crystalline salt. The 

 changes which took place during the action of heat in the moist 

 way were not minutely examined. 



Mercury. Moist protocarbonate of mercury dissolved in 

 the acid, forming a salt not quite neutral, crystallizing feebly in 

 the air, white, of a metallic taste, not deliquescent, and decom- 

 posed with various phenomena by heat. By re-solution in 



o 



