506 EXPERIMENT STATION RECORD. [Vol. 41 



For blood sugar determinations tlie method is said to be applicable to 1 cc. 

 or smaller amounts. Detailed instructions are given for the preparation of tlie 

 various solutions required and for the technique of the procedure when 1 cc. 

 and 0.2 cc. of blood, respectively, is used. 



The picric acid method for the estimation of sugar in blood and a compari- 

 son of this method with that of Maclean, O. L. V. De Wesselow {Biochem. 

 Jour., 13 (1919), No. 2, pp. 148-152, fig. 1). — A comparison of the method of 

 Maclean noted above and the picric acid method of Benedict (E, 8. R., 39, p. 112) 

 is reported. 



The Benedict method was found to give results from 30 to 50 per cent in 

 excess of those obtained by the Maclean method. 



" The high results appear to be chiefly due to the presence of an interfering 

 substance or substances mainly concentrated in the corpuscles but present to 

 some extent in the plasma also ; this substance reacts with the picric solution 

 at an early stage of the heating. Creatinin probably plays a large part in this 

 reaction. On account of the influence of this interfering factor the accurate 

 estimation of sugar in whole blood by the picric acid method as described by 

 Benedict is impossible." 



Notes on the determination of water solubles in leather, R. W. Fkey and 

 I. D. Clakke (Jour. Amer. Leather Chem. Assoc, IJf (1919), No. 9, pp. 488- 

 499). — Data obtained at the Bureau of Chemistry, U. S. Department of Agricul-. 

 ture, are presented indicating the influence of various factors on the determi- 

 nation of water solubles in leather, and the recommendation is made that the 

 Oflicial Method should be revised and standardized. 



The industries of the farm, A. Laebaleteier (Les Industries de la Fernie. 

 Paris: Libr. Larousse, 2. ed., pp. 216, figs. 160). — The industries treated in this 

 volume are milling, baking, starch, sugar, wine, cider, beef, distilled beverages, 

 vinegar, oils, milk, butter, cheese, and preserves. 



Methods of preservation of fruits and vegetables, A. Manabesi (Metodi di 

 Conservazione del Frutti e Degli Ortaggi. Casale Monferrato, Italy: Mares- 

 calchi Bros., 1915, pp. XVII-\-555). — This volume contains general directions for 

 the preservation of fruits and vegetables by inert substances, cold, desiccation, 

 antiseptics, and heat. Special directions are given for certain products under 

 each class, and a bibliography is included for each section. 



Fruit preserves prepared in the cold without the addition of sugar, alco- 

 hol, or antiseptics, G. Beetrand (Compt. Retid. Acad. ScL [Paris], 168 (1919), 

 No. 23. pp. 1162-1164). — The author reports that out of 47 jars of different 

 fruits canned in cold water, after a preliminary washing but with no further 

 treatment. 17 were in perfect condition at the end of 11 mouths. In the other 

 jars there Avas greater or less indication of alcoholic fermentation but no 

 evidence of other changes. As a result of this study the author concludes that 

 it is possible to preserve fruits by the elimination of air in flasks filled with 

 water without the necessity of adding sugar or any other substance, or of 

 heating the fruit. 



The mechanism of the preservation of fruits in cold water. G. Bertbanu 

 (Compt. Rend. Acad. Sci. [Paris], 168 (1919), No. 25, pp. 1285-1288) .—The 

 theory is advanced that the preservation of fruit by the method noted above is 

 due to the action upon the dissolved oxygen originally present of diastases 

 present in the fruits, thus rendering the medium anaerobic and preventing fer- 

 mentation. The chances of success in the use of this method are consequently 

 thought to depend upon the number, nature, and degree of vitality of the or- 

 ganisms present in the flask, upon the acidity of the fruits, and above all upon 

 the intensity of the biochemical processes which bring about the disappearance 

 of the dissolved oxygen. Cut fruits are apparently better suited to this proc- 



