AGRICULTURAL CHEMISTRY — AGROTECHNY. 617 



oil was dried on both glass and aluminum plates 4 by 7 in. in size, with a sur- 

 face ruled off for drying 3 by 6 in., giving an area of 18 sq. in. for spreading 

 oil for drying; 0.187 gm. of oil was spread out on this surface, giving a uni- 

 form thickness of film of approximately yz\-^ of an inch. Air was drawn 

 into the box at an average rate of one-half liter per minute."' The ai»paratus 

 used is illustrated. 



"From the results it may be seen that with the conditions named in these 

 experiments raw linseed oils reach their maximum gain in drying very close 

 around SO hours and boiled oils around 24 hours. Also 10 per cent adulteration 

 of raw linseed oil by rosin, soy-bean, and other semidrying oils may be de- 

 tected, as their presence retards the time of drying of linseed oil by a good 

 margin." 



The detection of adulteration in linseed oil, G. D. Elsdon and H. Hawley 

 (Analyst, 38 {1913), No. U2, pp. 3-7, fig. l).—lt was found that a close relation 

 existed between the iodin number and the quantity of ether extract obtained 

 from a partially dried linseed oil. This is especially noticeable when the 

 iodin number and the extract are platted against one another. The amount 

 of ether extract from linseed oils dried for 2 hours (10 samples) varied from 

 14 to 19 per cent and the iodin value from 176 to 192. 



Linseed oils containing 20 per cent of either colza, whale, cotton-seed, or 

 seal oil gave iodin values which varied from 176 to 185 and ether extracts from 

 ie.4 to 31.6. 



" The following equation has been calculated from the curve for the maxi- 

 mum extract of a linseed oil. If I is the iodin value, then the maximum 

 permissible extract for that oil is — Extract=S1.9— 0.35 /. 



" It is suggested that the routine examination of linseed oils be restricted 

 to the determination of the iodin value and the extract as described above, by 

 which means decisive information as to the purity or otherwise of any sample 

 may be obtained." 



Detection of the adulteration of linseed oil, R. W. Darner (North Dakota 

 Sta. Spec. BuL, 2 (1913), No. 21, pp. 369, 310, fig. i).— This is an application of 

 the method described in the abstract above to the detection of soy-bean oil and 

 other semidrying oils in linseed oil. Five samples of linseed oil examined by 

 the method showed extreme values for the ether extracts from 14.34 to 18 

 per cent. 



Soy-bean oil with an iodin value of 132 and sunflower-seed oil with an iodin 

 value of 129 were used in the tests. When the results were platted, the adul- 

 terated oils were found to lie to the left of the line within the sphere of pure 

 oil. This result seemed to indicate that the method could not be used with 

 certainty for the detection of the adulteration of linseed oil by semidrying 

 oils of high iodin value. 



Grape seed oil, R. W. Darner (North Dakota Sta. Spec. Bui, 2 (1913), No. 

 21, pp. 310-312). — After reviewing the literature in this regard (E. S. R., 29, 

 p. 13), the results of an analysis of an oil obtained from the seeds of grapes 

 grown in California are given. The golden yellow oil, when subjected to pro- 

 longed heating at 180° C. changes first to green and then to brown. The spe- 

 cific gravity at 15.5° was 0.9224, the refractive index at 20° was 1.475, iodin 

 number 131.9, saponification number 192.6, unsaponifiable matter 0.88 per cent, 

 acid number 1.11, acetyl value 81.09, Reichert-Meissl number 0.81. heat of 

 bromination 22°, and MaumenS test 82.5". According to this the acetyl value 

 of 144.5 reported by Horn needs confirmation. 



Very small amounts of volatile acids, i. e., caproic, butyric, valeric, and 

 caprylic, as evidenced by the Reichert-Meissl number, are present in grape seed 

 oil. The Hehner number or insoluble acids was 93.9 per cent and the soluble 



