1919] AGRICULTURAL CHEMISTRY — AGROTECHNY. Ill 



wool, and leaves aucl flowers of wild and cultivated British plants capable of 

 dyeing aluminum-mordanted cotton. 



Chemical analyses of Logan blackberry (loganberry) juices, R. S. Hol- 

 LiNGSHEAD {U. S. Dcpt. A(jr. Bill. 113 {1919), pp. 12).— The uses of the logan- 

 berry, the manufacture of the juice for commercial purposes, and the results of 

 a number of analyses are reported. 



It is pointed out that because of its pleasant flavor, loganberry juice is popu- 

 lar as a beverage, while the berry is also used for making jams, jellies, and for 

 soda fountain service. The juice is naturally so sour that it is considered nec- 

 essary to dilute and sweeten it when used as a beverage, since the addition of 

 sufficient sugar to mask the acid makes the product too sirupy to drink unless 

 diluted. "The flavor and color of Logan blackberry juice permit a dilution 

 with from 2 to 3 parts of water, and the addition of 1 part of sugar. As a 

 rule, the sirups prepared for soda-fountain use are made by adding sugar to un- 

 diluted juices, the composition running from about 1 part of juice and 1 part of 

 sugar to, roughly, 3 parts of juice and 1 part of sugar." 



In discussing the analyses it is stated that the Washington and Oregon juices 

 differ considerably from those from California-grown berries. 



Tentative limits are proposed for Washington and Oregon-grown juice of 

 minimum and maximum nonsugar solids of 2.8 and 3.92 per cent, ash 0.25 and 

 0.43 per cent, and acids, as citric, of 1.42 and 2.33 per cent. For Cahfornia 

 Juice the corresponding limits suggested are 3.06 and 3.74 per cent for nonsugar 

 solids, 0.43 and 0.63 per cent for ash, and 1.06 and 1.96 per cent for acids, as 

 citric. 



The distribution of urease in the seeds of cereals, A. NSmec {Biochem. 



■ Ztschr., 91 {1918), No. 1^2, pp. i2e-i.?0).— Analytical data are given to prove 



the presence of the enzym lu'ease in grains sucli as wheat, rye, barley, and oats, 



and the connection between the presence of urease and proteins yielding arginln 



on hydrolysis is pointed out. 



Agglutination, R. E. Buchanan {Jour. Bad., 4 {1919), No. 2, pp. 13-105, 

 figs. 3). — In this address delivered before the Society of American Bacteriolo- 

 gists, December 27, 1918, the author discusses bacterial agglutination as essen- 

 tially a colloidal phenomenon that can best be studied in the light of the modern 

 work on colloidal and physical chemistry. An extensive list of literature refer- 

 ences is appended. 



The oxidation of ammonia, W. S. Landis {Chem. and Mctallurg. Engin., 20 

 {1919), No. 9, pp. JtlO-Jftl, figs. 5). — A r§sum6 is given of the early investigations 

 on the commercial oxidation of ammonia, followed by a discussion of the 

 development of the cyanamid process as adopted in the Government nitrate 

 plant at Muscle Shoals, Ala, 



Commercial oxidation of ammonia to nitric acid, C. L. Paksons {Jour. 

 Indus, and Engin. Chem., 11 {1919), No. 6, pp. 5^1-552, figs. 13). — This paper 

 deals with past and present methods and apparatus for the oxidation of am- 

 monia to nitric oxid for the production of nitric acid, including references to 

 the method noted above. In particular the development of the LT. S. Bureau of 

 Mines converter is discussed, and tables are given showing its efficiency. The 

 principle of the converter is the catalytic action of four cylindrical super- 

 imposed layers of platinum gauze so arranged inside the fire-brick lining of 

 the converter that the inside surface is always reflecting against another red 

 hot surface, no outside heat being required except that generated by the re- 

 action itself. The results obtained in 160 determinations indicate that a 92 per 

 cent efficiency with 10.5 per cent ammonia and with 200 cu. ft. per minute ca- 

 pacity can be easily reached with this converter. 



