1 826.] and Naphthaline, and on a new Acid produced. 20T: 



the water present in the oil of vitriol originally used, being suffi- 

 cient to cause a separation of a part^ but not of the whole. ^ 



2. Salts formed by the peculiar Jcid with Bases, 



These compounds may be formed, either by acting on the 

 bases or their carbonates by the pure acid, obtained as already 

 described ; or the impure acid in solution may be used, the 

 salts resulting being afterwards freed from sulphates, by solution 

 in alcohol. It is, however, proper to mention, that another 

 acid, composed of the same elements, is at the same time formed 

 with the acid in question, in small, but variable proportions. 

 The impure acid used, therefore, should be examined as to the 

 presence of this body, in the way to be directed when speaking 

 of the barytic salts ; and such specimens as contain very httle or 

 none of it should be selected. 



Potash forms with the acid a neutral salt, soluble in water 

 and alcohol, forming colourless solutions. These yield either 

 transparent or white pearly crystals, which are soft, slightly 

 fragile, feel slippery between the fingers, do not alter by expo- 

 sure to air, and are bitter and saline to the taste. They are not 

 very soluble in water ; but they undergo no change by repeated 

 solutions and crystallizations, or by long-continued ebullition. 

 The solutions frequently yield the salt in acicular tufts, and 

 they often vegetate, as it were, by spontaneous evaporation, the 

 salt creeping over the sides of the vessel, and running to a great 

 distance in very beautiful forms. The solid salt heated in a tube 

 gave off a little water, then some naphthaline ; after that a little 

 carbonic and sulphurous acid gases arose, and a black ash 

 remained, containing carbon, sulphate of potash, and sulphuret 

 of potassium. When the salt was heated on platinum foil, in the 

 air, it burnt with a dense flame, leaving a slightly alkaline sul- 

 phate of potash. 



Soda yields a salt, in most properties resembling that of 

 potash; crystaUine, white, pearly, and unaltered in the air, 

 I thought that, in it, the metallic taste which frequently 

 occurred with this acid and its compounds was very decided. 

 The action of heat was the same as before. 



Ammonia formed a neutral salt imperfectly crystalline, not 

 deliquescent, but drying in the atmosphere. Its taste was 

 saline and cooling. It was readily soluble in water and alcohol; 

 When heated on platinum foil it fused, blackened, burnt with 

 flame, and left a carbonaceous acid-sulphate of ammonia, which 

 by further heat was entirely dissipated. Its general habits were 

 those of ammoniacal salts. When its solutions, though pre- 

 viously rendered alkaline, were evaporated to dryness at common 

 temperatures, and exposed to air, the salt became strongly acid 

 to litmus paper. This, however, is a property common to all 

 soluble ammoniacal salts, I believe, without exception. 



