METHYL SALICYLATE III. 85 
but from the fact that the hydrogen atom para to the hydroxyl group is 
fixed, this seems clear. 
Salicylic acid is oxidized by potassium persulphate in alkaline solution 
to a product which gives gentisic acid on boiling with acids.* 
The literature concerning the oxidation products of more complicated 
benzene derivatives is exceedingly confused. For example, the compara- 
O 
| 
(Y)-08 
tively simple compound || is described as varying in color from brown 
I 
O 
to biack. It has been prepared by Piria®” by the oxidation of salicylic 
aldehyde in the air, by Woskressensky“ from the oxidation of quinone 
in the air in caustic alkali solutions, by Btichner™ from tannic acid, 
and by Sarouw™ from the action of mono brom quinone and ammonium 
hydroxide. The methyl ester C.H:0..0CH; prepared by Will, Bechhold,” 
and Muhlhauser™ is evidently more easily handled and has been secured 
in the pure state as fine, yellow needles. 
EXPERIMENTAL. 
METHYL SALICYLATE AND SALICYLIC ACID. 
Almost all of the tests hereinafter described were performed 
in sealed tubes of about 30 cubic centimeters capacity. The 
glass was thin and an investigation of its absorption spectrum 
proved that it was permeable to light of wave-length shorter 
than 285 pp which is considerably beyond the limit of the sun’s 
spectrum. 
The first experiments, described in Table I, consisted of a 
series of tubes containing methyl salicylate, various aqueous 
solutions, and atmospheric air. 
Duplicates of each mixture were prepared and treated exactly 
the same except that each of the duplicates was wrapped in tin 
“Beilstein, Handb. der organ. Chem. Hamburg (1903), Erg. II. 885. 
D. R. P. 81, 297. 
* Ann. d. chem. (Liebig) (1839), 30, 167. 
* Journ. f. prakt. Chem. (1845), 34, 251. 
* Ann. d. Chem. (Liebig) (1845), 53, 373. 
* Ibid. (1881), 209, 107. 
* Ber. d. deutschen chem. Ges. (1888), 21, 605. 
“Tbid. (1889), 22, 2381. 
** Ann. d. Chem. (Liebig) (1881), 207, 251. 
