

RECENT WORK IN AGRICULTURAL SCIENCE. 



CHEMISTRY. 



The determination of the fermentable substances present in 

 cereals, J. Effront (Monit. Sclent., 1897, p. 270; abs. in Ghem. Centbl., 



1897, I, No. 18, p. 950). — jSTumerous experiments have shown that treat- 

 ment with mineral acids in the cold gives results corresponding to the 

 actual amount of fermentable substances present. The results were 

 controlled by fermentation analyses. The failures recorded with the 

 latter must be ascribed to the fact that the nature of the yeast used 

 and the conditions of fermentation have been only superficially con- 

 sidered. The yeast used must be well characterized and the conditions 

 must be such as to exclude the development of foreign yeasts. The 

 starch may be accurately determined by solution in hydrochloric acid, 

 when the cereal is very finely ground ami the fat removed. Three 

 grams of the flour is treated with ether on a filter, dried one-half hour at 

 100°, transferred to a glass mortar, and mixed with 20 ec. concentrated 

 hydrochloric acid, which must be added in small quantities to avoid 

 the formation of lumps. The process must be completed in six minutes, 

 wlieu the action of the acid will be limited to the starch. The mix- 

 ture is transferred to a 100 cc. flask, containing some water, diluted to 

 the mark, and immediately filtered. Seventy-five cubic centimeters of 

 the filtrate is nearly neutralized, evaporated, redissolved, the solution 

 again made up to 75 cc. and filtered. It is then polarized and the dex- 

 trose determined with Fehling's solution. The excess in rotation is 

 calculated to dextrin. — w. h. kbug. 



A new synthesis in the sugar group, H. J. H. Fenton (Jour. 

 Ghem. Soc. [London], 71 (1897), No. 413, p. 375). — Dihydroxymaleic acid 

 which is formed by the oxidation of tartaric acid in tfie presence of iron 

 can be almost quantitatively decomposed into glycolylaldehyde and car- 

 bonic acid by heating with water. Glycolylaldehyde undergoes a pecu- 

 liar change when heated in vacuo, and is transformed into a sweet, solid 

 gum, having the composition 6 H 12 O 6 . This condensation product is 

 soluble in water, and reduces both Fehling's solution and ammoniacal 

 silver nitrate solution rapidly. It exhibits several characteristic sugar 

 reactions, and forms with phenylhydrazin a normal hexose C18H22X1O4, 

 melting at 168 to 170° C. It is optically inactive, is not fermented by 

 yeast, and on heating with water to If 0° C. gives furfurol. The purified 



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