430 Mr. R. Phillips on Nitric Acid 



pai'e nitric acid of the greatest strength, I mixed in a retort 

 70 parts of nitrate of potash with an equal weight of sulphuric 

 acid of sp. gr. l-84'4'2 at 60''. The heat was continued for 

 eight hours ; during the latter four of which, the contents of 

 the retort were in complete fusion, and in the quarter of an 

 hour previous to discontinuing the operation, only one drop 

 of nitric acid was obtained. 



The nitric acid procured was of a yellow colour, with a tint 

 of red ; it weighed 46*13 parts, and the salt remaining in the 

 retort amounted to 92-87 parts, showing that one part only 

 of the 140 of nitre and sulphuric acid employed was lost du- 

 ring the operation. 



The sp. gr. of the nitric acid at 60° was T.'iOSS, and I found 

 by one experiment that 615"4 grains of it decomposed 456*8 

 of carbonate of lime ; and by another 586*8 decomposed 435*6 

 of the same substance. These results agree almost precisely, 

 and show, that 46*1 3 parts, the wholequantity of acid produced 

 from 70 of niti*e, would dissolve 34*24 parts of carbonate of 

 lime. An atom of nitre being represented by 102, the atom 

 of acid 54, which it contains, is equivalent to 50 or one atom 

 of carbonate of lime; the acid contained in 70 of nitre should 

 therefore dissolve 34*31 of this substance, from which, if we 

 deduct 34*24, the solvent power of the acid actually obtained, 

 there will be a deficiency of only 00*07 of a part, — a loss which, 

 considering the nature of the operation, will be considered as 

 very small. As 50 of carbonate of lime are equivalent to 54 

 real nitric acid, 34*24 the quantity dissolved by 46*13 of the 

 liquid acid, indicate 36*98 of real acid, the product therefore 

 consists of 



Real nitric acid . . . 36*98 or 80*16 

 Water 9*15 19*84 



46*13 100*00 

 Supposing this acid to be a definite compound of 2 atoms 

 of acid 108, and 3 of water 27, it would consist of 



Real acid 36*90 or 80 



Water 9*23 20 



46*13 100 

 I have mentioned that the bisulphate of potash remaining 

 in the retort weighed 92*87 parts: now 102 or one atom of 

 nitre decomposed by two atoms of sulphuric acid 80, would 

 yield 128 one atom of anhydrous bisulphate of potash, or 

 if combined with 9, one atom of water, it would be 137 ; as 

 then 102: 137:: 70: 94 — exceeding the quantity I obtained 



by 



