On the Vrussic and Prussous Acids, 

 Table II. — (Continued.) 



199 



It is necessary to remark, that in the preceding table, as 

 wel) as in Table I, several of the nitrates and muriates were 

 slightly reddened, though not in a degree to be compared 

 with the oxy-sulphate of iron. I have not noticed this in 

 the table,, because I am not certain whether this effect was 

 not owing to a minute portion of oxide of iron which might 

 have been introduced into those solutions by the acids em- 

 ployed to make them, as both the nitric and muriatic acids 

 of commerce generally contain some; an excess of nitric 

 acid, even if pure, might also cause this effect, as Table I. 

 may convince us. The solutions with which this effect 

 occurred to me were those or' bismuth, silver, mercury, 

 lead, cobalt, gold, and platina. 



The liquid B is not altered by exposure to the air. 



Its effect on oxv-sulphate of iron is the same, whether 

 this sulphate is neutral, or contains an excess of acid, or is 

 supersaturated with carbonate of ammonia. 



Sulphuric acid destroys the colour produced on oxy-sul- 

 phate of iron, provided the three liquids are in a concen- 

 trated state. If there is. much water present, no change 

 ensues. 



Having obtained the tingeing principle B, separate from 

 N 4 the 



