RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICTJLTTJRAL CHEMISTRY— AGROTECHNY. 



The starches of the grain sorghums, C. K. Fbancis and O. C. Smith {Olcla- 

 Jwma Sta. Bui. 110 (1916), pp. SS8, figs. 2i).— This bulletin reports the results 

 of a detailed microscopical study of the grain sorghums. The apparatus and 

 methods used for making the photomicrographs are described in detail. A 

 new apparatus devised by the authors for the determination of the gelatin- 

 izing temperature of the starches by means of a thermo-slide is also described 

 in detail and illustrated by drawings. 



The quantity of starch found in the different sorghums was fairly uniform, 

 Kafir corn containing 63.6 per cent, White milo maize 64.8, Yellow milo maize 

 63.1, feterita 63.8, and darso 63.7 per cent. 



The following averages of triplicate determinations of the gelatinizing tem- 

 peratures of the various starches are submitted : White kaoliang, 78° O. ; 

 Brown kaoliang, 76.3° ; feterita, 75.5° ; Orange Cane sorghum, 72.4° ; Red Kafir 

 corn, 75° ; White Kafir corn, 72.2° ; Pink Kafir corn, 64.7° ; White milo maize, 

 74.1° ; Yellow milo maize, 76.9° ; darso, 72.9° ; and Sudan grass, 72.5°. The 

 results obtained by the new thermo-slide procedure checked very closely with 

 those obtained by the water-bath methods. 



Photomicrographs, together with detailed descriptions of the following char- 

 acteristic reactions of the starch grains are submitted: Chloral-hydrate iodin, 

 chromic acid, ferric chlorid, gentian violet, pyrogallic acid, and safranin re- 

 actions. The starches examined were those of the White, Red, and Pink Kafir 

 corn, White and Yellow milo maize. Brown and White kaoliang, feterita, darso, 

 Sudan grass. Orange Cane sorghum, corn, sweet potato, Irish potato, rice, 

 arrowroot, navy bean, and wheat. 



Tables submitting data of the comparative size of the starch granules of 

 the grain sorghums and the comparative staining values of various starches 

 are included. 



It is indicated that " feterita, tlie milos, and Kafir, containing about 64 per 

 cent starch, seem to be especially suitable as raw materials for the manufac- 

 ture of high-grade starch by the commercial processes, and if they are used 

 will require practically no change in the machinery now in common use for 

 manufacturing starch from corn." 



The variations of gluten, Maechadiee and Goujon (Ann. Sci. Agron., 4. ser., 

 jff (1915), No. 1-6, pp. 7-19). — The composition, changes, and variations in 

 amount of gluten in various flours are briefly discussed. 



It is indicated that when rye flour is added to wheat flour the amount of 

 gluten is diminished, while the acidity is greatly increased. Rye flour which 

 yields no gluten possesses a normal acidity ten times greater than that of 

 wheat flour. Acetic acid oxidizes and dehydrates gluten, and when a wheat 

 flour which yields a gluten-gliadin ratio of 1 : 3 is treated with this acid a 

 gluten with a ratio of 1 : 1 is obtained. 



Development of sugar and acid in grapes during ripening, W. B. Alwood 

 ET AL. {U. K. ncpt. Agr. Bui. SS5 {1916), p. 28).— Continuing the work previ- 

 ously noted (E. S. R., 25, p. 504) this bulletin embodies the results of a further 

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