Mr. Noad on the Action of Nitric Acid on CymoL 25 



grant liquid, having an odour closely resembling that of cin- 

 namic or benzoic aether, and a pungent and slightly bitter 

 taste. It boils at 228° C, uhich temperature may perhaps 

 be one or two degrees too high, the determination having been 

 made before the last traces of the nitrogenous aether had been 

 removed ; still it exhibits a new confirmation of the obser- 

 vation of H. Kopp, that the difference in the boiling-points of 

 two analogous compounds, which differ by two equivalents of 

 carbon and two of hydrogen, is 19° C. Benzoic jether, the 

 composition of which is C4 H^ O, CuH^O, boils at 209°. 

 Unfortunately I had not a sufficient quantity of the liquid 

 after purification for a second determination. 



The following salts I have examined qualitatively only, 

 considering the composition and atomic weight of the acid 

 well-enough established by the preceding analyses. 



Toluylate of Potash, formed by exactly neutralizing the 

 acid with caustic potash, is a very soluble salt, crystallizing 

 with great difficulty in small needles. 



Toluylate of Soda is still more soluble than the preceding. 

 I could not obtain it in the crystalline state. 



Toluylate of Ammonia crystallizes in small prisms. 



Toluylate of Lime crystallizes out of a concentrated aqueous 

 solution in long shining needles. 



Products of the Decomposition of Toluylic Acid. 



Nitrotoluylic Acid. — I have already observed that on treat- 

 ing cymol with concentrated and fuming nitric acid violent 

 action ensues, and that by repeated distillations a crystalline 

 acid containing nitrogen is obtained. I must now describe 

 this action more in detail. The nitric acid employed should 

 be concentrated and fuming, otherwise there v.ill be a con- 

 siderable formation of another crystalline substance, which is 

 in its chemical character neutral, and which is not easily con- 

 verted into nitrotoluylic acid. The properties and composi- 

 tion of this new product will be fully considered hereafter. 

 The distillation must be continued as long as nitrous fumes 

 continue to be evolved, and the retort then allowed to cool, 

 upon which a considerable quantity of crystalline matter is 

 deposited, and on adding cold water a copious precipitate 

 takes place. The whole is now thrown on a filter and washed 

 with cold water till all the nitric acid is removed ; the pre- 

 cipitate is then digested with ammonia, the greater part 

 dissolves ; a portion however collects at the bottom of the 

 vessel in the form of a red oil, which is to be separated. The 

 ammoniacal salt is next decomposed by hydrochloric acid, the 

 acid collected on a filter and well-washed Avith cold water, in 



