1917] AGRIOULTUEAL CHEMISTRY AGROTECHNY. 13 



after being dissolved from the lining of the can, Is continually removed from 

 solution by the proteins, carbohydrates, and other highly porous solid phases 

 in contact with the solution. The theory in regard to the adsorption of the 

 tin Ions is discussed. 



The seeds of red cherries, black cherries, black raspberries, strawberries, and 

 tomatoes were found to have adsorbed quantities of tin far in excess of the tin 

 found in solution. The physiological significance of this adsorption of the tin 

 by the seeds Is indicated, since the seeds are usually eliminated intact. It 

 is also noted that " it would appear that the amount of soluble tin salts, rather 

 than the total tin present in a can of food, should be limited, since it is the 

 part of the tin adsorbed which determines the physiological action." 



The detection of added water in milk in India, J. W. Leathek {Agr. Re- 

 search hist. Pusa Bui. 57 {J915), pp. 7). — Using the procedure described by 

 Beckmann (E. S. R., 6, p. 611), with some slight modifications, the author 

 determined the freezing point of milks of Indian cows and buffaloes, and from 

 the data has evolved a formula for determining the percentage of added 

 water by this procedure. A table showing the percentage of added water cor- 

 responding to the freezing point of the sample, ranging from —0.542° to 

 —0.247° C, is included. 



The nature of the reducing substances precipitated by lead subacetate in 

 the defecation of impure sugar solutions, H. Pellet {Ann. Chim. Analyt., 21 

 {1916), No. 11, pp. 217-223). — The author briefly reviews previous studies of 

 the precipitate produced by defecation with lead subacetate, and from the 

 results, together with his own experience, concludes that its use is unsatis- 

 factory. 



The use of normal lead acetate (30 per cent solution) and the removal of 

 the excess lead with a saturated solution of sodium carbonate is recommended 

 as being entirely satisfactory for defecation in the determination of reducing 

 sugars in cane products, foods, diabetic urine, etc. 



Notes upon oil testing, A. H. Gill {Jour. Indus, and Engin. Cliem., 9 {1917), 

 No. 2, p. 136). — A test for oils by salting out their soaps is described, and some 

 analytical data, expressed in grams of sodium chlorid per gram of oil, for 

 several oils, a .sample of oleomargarin, and a sample of butter are submitted. 

 A test for gelatinous matter in linseed oils and its use are also described. 



Color tests for oils.— Palm oil, A. H. Gill {Jour. Indus, and Engin. Chem., 

 9 {1917), No. 2, pp. 136-139).— The Halphen and Becchi tests for cottonseed oil, 

 the Baudouln test for sesame oil, the Liebermann-Storch test for rosin oil, and 

 the Crampton-Simons test for palm oil are briefly discussed and some analytical 

 data on the Crampton-Simons test submitted. 



From the data the test is considered to be no longer available for use in 

 connection with the testing of oleomargarin (to determine the presence of 

 palm oil) because of Its unreliability, due to the difficulty in interpretation. 

 The test is one for carotin rather than palm oil and may be given by butter, 

 oleo oil, or sesame oil. Ingredients ordinarily found In oleomargarin. As com- 

 monly applied, it Is also untrustworthy on account of the presence of Interfer- 

 ing oils, as sesame, which are not washed out. 



The work reported Is considered preliminary and the subject Is being further 

 studied. 



A new method of steam distillation for the determination of the volatile 

 fatty acids, including a series of colorimetric qualitative reactions for their 

 identification, D. C. Dyee {Jour. Biol. Chem., 2S {1917), No. 2, pp. 445-473, pi. 

 1, fig. 1). — A method of steam distillation for the determination of volatile 

 fatty acids, which depends on the maintenance of the aqueous solution contain- 

 ing the acids at a constant volume throughout the course of the distillation, 



