Carbonic Acid and Ammoniac 261 



gases, according to which, the equivalents of ammonia and mu^ 

 riatic acid are 17 and 37. * 



I have said that the results of my analyses of the sesquicar- 

 bonate of ammonia, agree as nearly as might be expected with 

 those of Dr Ure, and of Mr Richard Philips. They are exhi- 

 bited in the following table : — 



The gas was procured from 1 grain of the salt, allowance 

 having been made for absorption by the acid; and the chloride 

 was obtained from 5 grains. In each instance, the salt was 

 taken from a compact translucent mass, that had undergone no 

 change from exposure to the air. 



Calculating on these results, or 1.15 cubic inch of carbonic 

 acid gas at 60° (the minimum quantity) for 1 grain, or 115 

 for 100 grains, and on the mean of the quantities of chloride 

 of silver, namely 11.74 grs. or 234.8 per cent, it follows, on the 



•I may mention, that I have endeavoured to ascertain directly the pro- 

 portion of muriatic acid in salammoniac, by decomposing it in a graduated 

 tube over mercury, by sulphuric acid ; but, that I have not been able to 

 obtain perfectly satisfactory results, owing to the power of absorbing muria-^ 

 tic acid gas possessed by sulphuric acid. Sulphuric acid, of specific gravity, 

 1.85, absorbs very nearly ils own volume of muriatic acid gas, at CO' ; the ab- 

 sorption takes place slowly, even when agitation is employed. The acid gas 

 imparts to the suphuric acid its peculiar odour; and, if ammonia Is brought 

 near, fumes may be seen on the exposure of the acid to the open air. 



On the supposition, that salammoniac is an anhydrous salt, 3 grains of it 

 ought to afford 8.2 cubic inches of gas ; they actually afforded 7.5 cubic 

 inches ; and, in another instance, 1 grain which should have yielded 1.65 cu- 

 bic inch, gave 1.56 cubic inch. 



That Salammoniac is an anhydrous salt, even leaving out of consideration 

 the results in the text, appears to be proved by the circumstance, that, when 

 muriate of ammonia is formed by the direct union of the gases, and heat is 

 applied to the salt, the smallest quantity of water present is driven off, and 

 becomes visible, being condensed in the cool part of the vessel — Vide, Ni- 

 colson'8 Journal, voL xxxlv, p. 70. where I have described in experiment in 

 proof of this. 



