1919] AGRICULTURAL CHEMISTRY — AGROTECHNY. 715 



Lemon oil. — I, Fractional distillation and critical temperature of solution, 

 G. Ajon {Ann. li. Staz. Sper. Agrumiv. e Fruttic. Acireale, ^ {1916-1918), pp. 

 209-218, figs. 2).— The critical temperature of solution in alcohol of a definite 

 strength of the products of the fractional distillation of lemon oil is con- 

 sidered, by the author, to be a more accurate index of adulteration of the oil 

 than the temperatures obtained in the fractional distillation of the oil. 



Data are furnished which rhow that the later fractions of an adulterated 

 oil have a lower critical temperature of solution in alcohol than the pure oil, 

 while there is but little variation in the distillation temperatures of the pure 

 and adulterated oils. 



The U. S. P. test for methyl alcohol in ethyl alcohol, .7 W. Ehman {Aincr. 

 Jour. Phann., 91 {1919), Xo. 9, pp. 594-597).— As the result of a series of ex- 

 periments undertaken to determine the cause of variable results obtained with 

 the CJ. S. Pharmacopoeia test for methyl alcohol the following modified pro- 

 cedure is recommended : 



The fuchsin-sulphurous acid is prepared by dissolving 0..'i gm. fuchsin in 

 300 cc. of warm water, cooling and adding 11.2 gm. sodium sulphite (90 per 

 cent) dissolved in 200 cc. of water, and finally adding 20 cc. hydrochloric acid. 

 The other reagents and the method of procedure are the same as in the oflicial 

 test, with the exception that the technique proposed involves running a blank 

 determination with pure 10 per cent ethyl alcohol and adjusting the tempera- 

 ture of both tubes to 25° C after the addition of each reagent. If the blank is 

 violet after ten minutes too high a temperature is indicated, while if a bright 

 red color persists, too low a temperature. In either case the temperature 

 should be varied and the test repeated. 



With quantities of methyl alcohol of 1 per cent or more, the color produced 

 is said to change from violet to purplif h red in a few minutes when viewed 

 either vertically or transversely, while with ethyl alcohol the solution is color- 

 less or a pale yellow. With smaller quantities of methyl alcohol (0.2.5 to 0.5 

 per cent), 10 or 15 minutes are required for the test. The final color is pale 

 violet when viewed from above under artificial light. Viewed transversely 

 by daylight the solution may appear to be colorless. 



Notes on the assay of h3rpochlorite solutions, F. X. IMoerk and R. R. Foran 

 {Ame7: Jour. Pharm., 91 {1919), No. 9, pp. 592, 5P3).— Difficulty in obtaining 

 definite end reactions in the assay of Dakin's solution and other hypochlorite 

 solutions by the directions given in the Ninth Revision of the U. S. Pharmacopoeia 

 is attributed to the use of acetic acid in place of hydrochloric acid. The sug- 

 gestion is made that for Dakin's solution the amount of acetic acid be increased 

 from 2 to 3 cc. and for Labarraque's solution from 5 to 10 cc, if immediate 

 titration is to be made. Other suggested possibilities of avoiding an indefinite 

 end point are to allow the prepared test to stand one hour before titrating, or 

 to replace the acetic acid by a diluted hydrochloric or sulphuric acid. 



The canning' of apples. — Preventing pinholing, W. D. Bigelow {Conner, 

 49 {1919), No. 15, p. Sf/). — The author states that pinlioling or perforation of 

 apple cans is caused by the action of malic acid in the apples on the tin plate, 

 and may be prevented by using cans with a heavy tin coating, by tight sealing, so 

 that external air will be absolutely excluded, by filling the cans completely, by 

 expelling the air from the apple cells with a vacuum pump or with sufficient 

 exhaust, and finally by allowing the cans to cool to the center before tbej' are 

 •stacked away. 



Alcoholic fermentation of banana must, R. Perotti and V. Rivera {Staz. 

 Sper. Agr. Ttal, 50 {1917), No. 9-10, pp. 4S3-450 ; abs. in Ahs. Bad., 2 {1918), 

 No. 6, p. 339). — A must obtained by the extraction of the skins and pulp of 



