126 Report of Schimmel 3 Co. April 1913. 



J. C. Umney and C. T. Bennett 1 ) have made experiments in the quantitative 

 acetylation of citronellal, and have found, in confirmation of the earlier investigations 

 conducted by us 2 ), that accurate results are obtained from a period of acetylation 

 extending over two hours if 2 grams of anhydrous sodium acetate are used for 10 cc. 

 of oil. According to the results obtained by the English chemists, it is a matter of 

 indifference whether 10, 15 or 20 cc. acetic anhydride are used. But if under other- 

 wise equal experimental conditions a larger proportion of sodium acetate is used, the 

 results obtained are too high in proportion to the greater quantity of sodium acetate 

 employed. When using 2,5 grams sodium acetate to 10 cc. oil and acetic anhydride 

 we (loc. dt.) had obtained 103,8 and 104,4 p. c. citronellal, whereas Umney and Bennett 

 obtained as much as 109 p. c. when acetyling with 10 cc. citronellal, 20 cc. acetic 

 anhydride and 5 grams sodium acetate. 



J. Allan and C. W. Moore 3 ) have carried out a series of similar estimations. They 

 found that in the case of geraniol (10 cc), varying proportions of acetic anhydride 

 (10, 15 and 20 cc.) and sodium acetate (1, 2 and, 3 grams) did not affect the quantitative 

 result of the acetylation 4 ) whereas in the case of citronellal, according to the experimental 

 conditions, divergent values were obtained. From the results as set forth in table-form 

 (although these results are in part mutually contradictory and therefore do not admit 

 of the formation of an entirely positive judgment), so much at any rate may be con- 

 cluded that, generally speaking, concordant results are obtained when for two hours' 

 acetylation from 10 to 15 grams acetic anhydride and 2 grams sodium acetate per 

 10 grams citronellal are used. 



O. Tunmann 5 ) calls attention to the fact that among the bodies which occur in 

 resins, cinnamic acid affords the most beautiful sublimates, and that this property may 

 be utilised with advantage for its detection by microchemical means. He gives the 

 following method for microsublimation 6 ): On an asbestos-slab measuring 12X12 cm., 

 by 2 mm. thickness, place a small piece of a recipient, upon which place the substance 

 under examination. At a distance therefrom of from 2 to 3 cm. on the asbestos-slab 

 is a small wooden stick, 3 to 4 mm. high and from 6 to 8 cm. long. A recipient for 

 the sublimate is now placed over the substance under examination in such a way that 

 one end rests upon the asbestos-slab and the other upon the wooden stick, care being 

 taken that the recipient does not touch the lower piece of glass. When these conditions 

 are observed the sublimation-space measures from 1 to 1,5 mm. in height. The asbestos 

 slab rests upon an iron ring. Heat is conveyed by means of a spirit lamp of which 

 the flame just touches the underside of the asbestos slab, and which can be held 

 from 2 to 5 cm. high as required. After the commencement of the heating the 

 recipients must be frequently changed, because otherwise, owing to the gradually 

 increasing heat of the recipient, an escape of the sublimation-vapours is to be feared. 

 The length of the wooden stick is of importance in order to make easy the exchange 

 of the glasses. 



Cinnamic acid readily sublimes upon the asbestos slab without decomposition. 

 The crystals begin to separate out after a short time and polarise vigorously. They 

 consist mostly of very characteristically shaped leaflets, several of which are often 

 found grown together. When a drop of potassium permanganate solution is added 



x ) Perfum. and Essent. Oil Record 3 (1912), 251. — 2 ) Report April 1910, 156. — 3 ) Perfum. and Essent. 

 Oil Record 4 (1913), 13. — *) Only from 84,7 to 85,6 p. c. was obtained, probably because the preparation was 

 not quite pure. — 5 ) Pharm. Zentralh. bi (1913), 133. — 6 ) Apotheker Ztg. 72 (1912), 497, 507. 



