AGRICULTURAL CHEMISTRY — AGROTECHNY. 613 



679-€87; aba. In Analyst, 37 {1912), No. 438, p. 403).— "The following per- 

 centage quantities of insoluble bromin compounds were obtained on subjecting 

 various oils and fats to the process described by Hehner and Mitchell : I^inseed 

 oil, 28.9; candlenut oil, 8.8; hempseed oil, 8.82; walnut oil, 2.22; soy-bean oil, 

 3.62 ; sesame oil, 0.14 ; mustard oil, 1.30 ; rape oil, 1.92. Poppy-seed oil, sun- 

 flower-seed oil, maize oil, cotton-seed oil, castor oil, tea oil, earthnut oil, coco- 

 nut oil, palm oil, palm-kernel oil, cacao butter, stillingia tallow, tulucuna fat, 

 dika fat, and malukang butter did not yield an insoluble bromin compound. 

 In the case of shea butter, different specimens of the fat yielded from 5.2 to 

 8.6 per cent of bromin compound, while mowrah butter gave 0.82 per cent, 

 enkabang tallow 0.17 per cent, and adjab fat 2.2 per cent. As regards the four 

 last mentioned fats, the bromin compound api>ears to be formed from the un- 

 saponifiable matters present, the fatty acids derived from the fats yielding no 

 bromin compound after they have been freed from unsaponifiable matter." 



A new oxygen absorption method for oils, L. P. Wilson and G. S. Heaven 

 (Jour. 8oc. Chem. Indus., 81 (1912), No. 12, pp. 565-568; abs. in Analyst, 37 

 (1912), No. 438, p. 4/2).— The method is as follows: 



About 0.2 gm. of the oil in question is mixed with 1 gm. of infusorial earth 

 (kieselguhr) in a 250-cc. flask having a side neck. After cooling to a fixed 

 temperature the side tube of the flask is sealed. The flask is then heated at 

 100° C. for 1 hour, cooled, and connected by means of the side tube to gradu- 

 ated levelling tubes filled with water. After noting the height of the water the 

 seal is broken and the height read again. The difference between the 2 read- 

 ings represents the oxygen absorbed by the oil, which is calculated to 100 

 parts of oil. 



" The following percentage amounts of oxygen were absorbed by various oils 

 examined : Linseed oil, 17.2 to 21.2 ; poppy-seed oil, 17.4 ; cotton-seed oil, 11.1 ; 

 sesame oil, 5.8 ; olive oil, none." 



Infl.uence of peptones on the estimation of reducing sugars by Fehling's 

 solution, A. Bernard: (Biochem. Ztschr., 41 (1912), No. 1-2, pp. 160-164; 

 abs. in Analyst, 37 (1912), No. 437, p. 367). — "Although peptones do not reduce 

 Fehling's solution, their presence in sugar solutions causes more cuprous oxid 

 to be precipitated than is due to the reducing action of the sugar alone. In 

 cases, therefore, where sugar has to be estimated in solutions containing pep- 

 tones, the latter should be removed by means of phosphotungstic acid previous 

 to the estimation of the sugar." 



Rapid and accurate determination of traces of iron in cane and beet sugar 

 factory and refinery products, J. J. Eastick, J. P. Ogilvie, and J. H. Linfield 

 (Internat. Sugar Jour., 14 (1912), No. 164, PP- 428-435; abs. in Jour. Soc. Chem. 

 Indus., 31 (1912), No. 17, pp. 831, 832).— It is of the greatest importance to con- 

 trol the amount of iron in the material during the various stages of the process 

 of manufacturing beet or cane sugar. For this purpose the authors recommend 

 the colorimetric sulphid method, which is conducted as follows : 



"A standard solution of iron is prepared by dissolving crystallized ferrous 

 sulphate in distilled water, adding a few drops of sulphuric acid, and diluting, 

 so that 1 cc.=0.00002 gm. of iron. In the case of light-colored products, 3 to 10 

 gm. of the sample is dissolved in water in a Nessler cylinder and made up to the 

 100 cc. mark. Into a series of Nessler cylinders are placed increasing amounts 

 of the standard solution of iron, and the volumes in each are likewise com- 

 pleted to 100 cc. To each cylinder, 2 cc. of ammonium sulphid (freshly pre- 

 pared) is added, the contents stirred, and allowed to stand for 10 minutes. 

 Comparison of the test with the standard tubes then gives the iron content. 



" If the sugar, massecuite, sirup, etc., be too dark, 3 to 10 gm. of the product 

 must first be incinerated, using sulphuric acid, the ash being dissolved in the 



