22 Mr. Noad on the Action of Nitric Acid on Cymol. 



and with consideration of the atomic weight as deduced from 

 the analysis of the silver and baryta salts, lead to the follow- 

 ing formula, HO, C,6 H7 O3, as may be seen by the follow- 

 ing comparison : — 



Mean of the three 

 Theory. last experiments. 



16 equivs. Carbon . . 96 70'58 70*20 



8 ... Hydrogen . 8 5'88 5-97 



4 r.. Oxygen . . 32 23-54 

 1 ... Toluylic acid l36 100*00 

 This acid thus becomes isomeric with hydride of anisyle 

 and benzoate of oxide of methyle. 



Properties of Toluylic Acid. 



From an aqueous solution of any of its salts toluylic acid is 

 precipitated by nitric or hydrochloric acid as a snow-white 

 curdy mass, which under the microscope resolves itself into a 

 great number of small acicular crystals: it is soluble to a 

 considerable extent in boiling water, out of which it crystal- 

 lizes on cooling in small needles ; in alcohol, aether and pyr- 

 oxylic spirit it is soluble almost to any extent ; when heated 

 it fuses and sublimes without decomposition in beautiful 

 needles : in its state of perfect purity it is inodorous and taste- 

 less, but the impure acid has a peculiar and sickening smell, 

 somewhat resembling that of oil of bitter almonds. When 

 boiled for some time with concentrated nitric acid, it loses an 

 atom of hydrogen, in the place of which an atom of hyponi- 

 tric acid enters, nitrotoluylic acid being formed ; and when 

 heated with caustic lime or baryta it is decomposed into car- 

 bonic acid and toluol. 



In the formation of toluylic acid from cymol four equivalents 

 of carbon and six equivalents of hydrogen are eliminated in 

 the form of oxalic and carbonic acids and water. In several 

 preparations large quantities of oxalic acid were found. There 

 exists a striking similarity in the manner in which nitric acid 

 acts upon cymol and oil of anise, an oil in its composition 

 closely connected with cymol, and which gives rise to anisylic 

 acid, between which and toluylic acid there is also a marked 

 resemblance. The composition of oil of anise being C^q Hjj O^, 

 we may consider it as cymol which has lost two equivalents 

 of hydrogen and taken two of oxygen. The composition of 

 the acids formed by the action of nitric acid on these two oils 

 is as follows : — 



Toluylic acid .... HO, C.^. H7 O3 

 Anisylic acid .... HO, C,6 H7 O5. 



