SMITH ON THE OXIDATION OF ETHYLIC ETC. VIII.-On the Oxidation of Ethy lie and Methylie Benzoates. By R. H. SMITH,F.C.S. AT the suggestion of Mr. Chapman I wag induced to under-take the following investigation :- 132 SJIITH ON THE OXIDATI@K OF ETI-ITLIC ETC. Pure ethylic benzoate was digested with excess of a 12 per cent. solution of potassic dichromate and dilute sulphuric acid at the temperature of 100" C. for 9 or 10 hours. The tube was then removed from the water-bath and left to stand all night. In the morning beautiful white crystals were observed and the tube on opening gave little or no carbonic acid but there was a strong smell of acetic acid. The white crystals thus produced were dissolved in a large quantity of hot water and a solution of argentic nitrate added.The whole was then hent'ed and set aside to crystallise. After another crystallisation the sdt was submitted to analysis. 0.1355 grm. of the silver-salt was precipitated with hydro- chloric acid and the resulting argentic chloride washed dried and ignited. The argentic chloride weighed 0-085 grm. whence the percentage of silver is 47.15 agreeing closely with the theo- retical percenta,ge of silver in argentic berizoate- C,H,AgO, which is 47.16. The liquid also found in the tube was carefully distilled until it no longer retained sulphuric acid. A portion of this was heated with alcohol and sulphuric acid when the well known smell of ethylic acetate was obtained. The remaining portion was then treated with baric carbonate which dissolved freely ; an excess was added and the liquid boiled and filtered.The resulting clear solution was evaporated to dryness in the water- bath and the residue dried at 11O*C. I. 0*0970 grm. of the barium-salt was precipitated with dilute sulphuric acid and the baric mlphate ignited. It weighed 0.0885 grm. Percentage of barium 53-60 11. 0.1140 grm. gave 0.1040 grm. of bark sulphate. Per-centage of barium 53-59. These numbers agree very nearly with the theoretical per- centage of barium in baric acetate Ba''(C2H3Q2)2, viz. 53.72. In one experiment the carbonic acid was determined with the following result :-1.7990 grm. of etliylic benzoate gave 0*0020grm. of carbonic acid. This is only a trace. It is quite possible therefore to produce benzoic and acetic acids from ethylic benzoate without carbonic acid a result which is in harmony with theory.CHrlPilUN OK h NEW SYXTHESZS OF FORillIC ACID. 133 After having tried the action of potassic dichrornate of ethylic benzoate I was induced to try it on the methyl-compound. Methylic benzoate is decomposed by potassic dichromate in a eimilar manner. A quantity of this compound (prepared by the distillation of benzoic acid wit>h woad-spirit and sulphuric acid) was introduced into a tube with an 8 % solution of the potassir dichromate and the tube after being sealed was digested in the water-bath for several hours. It was then allowed to cool when the benzoic acid made its appearance entirely filling the tube with white crystals On opening the tube carbonic acid escaped; the contents of the tube were thrown upon a filter by which most of the benzoic acid was separated from the liquid.The liquid was then distilled the distillate converted into barium salt and the barium determined which gave a percentage agreeing very closely to that required by formate of bariuni. The benzoic acid was converted into the silver-salt and the percentage of silver determined which also agreed with that required by argentic benzoate. Methylic benzoate is therefore resolved as might be expected into benzoic acid carbonic acid and more or less formic acid. It will be seen from the foregoing results that benzoic acid and probably the acids of the benzoic series will resist the power of oxidising agents as well as those of the acetic series as shown by Messrs Chapman and Thorp. These experiments were performed in the laboratory of the East London Soap Works.