1917] AGRICULTURAL CHEMISTRY AGROTECHNY. 7H 



The industrial importance of mannan in tiie production of ethyl alcohol 

 from sulphite liquor and by the hydrolysis of sawdust with catalyzers is 

 pointed out. 



The mannan was determined by precipitation of the mannose formed on 

 hydrolysis as mannose hydrazone. 



The effects of exposure on some fluid bitumens, C. S. Reeve and II. H. 

 Lewis (Jour. Indus, and Enyin. Chem., 9 (1917), No. 8, pp. 74S-746, fig. 1). 



The importance of uniform culture media in the bacteriological examina- 

 tion of disinfectants, J. H. Wkight (Jour. Bad., 2 (1911), No. 4, pp. S15-34G. 

 figs. 4)- — The results of the study reported show that variations in culture 

 media are the cause of the majority of the discrepancies obtained in the 

 bacteriological examination of disinfectants. The hydrogen ion concentration 

 of the culture medium was found to exert important influences on its compo- 

 sition and on its suitability for the growth of the typhoid organism. A marked 

 relationship between the hydrogen ion concentration of the culture medium and 

 the resistance of the test organism to the action of disinfectants was observed. 



" The most satisfactory and uniform results have been obtained witfi a 

 culture medium in which the Pjj value falls between 6 and 7. This condition 

 is easily obtained with a medium containing 10 gm. of Witte's peptone, 3 gm. 

 of Liebig's meat extract, and 5 gm. of salt, boiled 15 minutes, filtered, tubed, 

 and sterilized, with no attempt to adjust the acidity." 



The experimental data are submitted in tabular anxi graphical form. 



A simple ultramicroscope, C. C. Kiplingek (Jour. Am^r. Chem. Soc, S9 

 (1917), No. 8, p. 1616, figs. 2). — A simple apparatus, which has yielded good re- 

 sults in practice, and its manipulation are described. 



Sampling tubes for manure, alfalfa, or other organic materials, A. D. 

 Shamel (Mo. Bui. Com. Hort. Cal., 6 (1917), No. 7, pp. 225-228, figs. 4).— A 

 device for sampling organic materials is described and illustrated. 



" The apparatus . . . consists of a tube somewhat similar in arrangement 

 and appearance to the King soil tube. Two different sizes of sampling tubes 

 have been made, one for use in sampling car load or other large lots of manure, 

 and the other for sampling bales of alfalfa, bean straw, cornstalks, or other 

 similar materials. The manure sampling tube is about 6 ft. in length and 

 about 2 in. in diameter. One end is made with a sharp sawtooth-like cutting 

 edge so arranged as to cut do^vn through the manure somewhat on the principle 

 of the knives commonly used for cutting hay in the stack. At the other end 

 of the tube an extra ring of metal is welded onto the tube in order to give it 

 added support. A hole is cut through this ring and the tube so that a handle 

 can be pushed through it for use in twisting the tube when the sample is 

 being taken." 



A sampling press, W. B. Clark (Jour. Indus, and Engin. Chem., 9 (1917), 

 No. 8, pp. 788-790, figs. 4). — An apparatus for the sampling of roots, tubers, 

 melons, and such fruits as are easily separated from the seeds and skins, which 

 consists essentially of a plunger and a cylinder, the latter having a stout sieve 

 bottom, and its manipulation are described. 



The apparatus has also been found to be well adapted for obtaining raw 

 cultures of finely divided substance which is sterile except for such inoculations 

 as may already exist in the interior of the material. It is indicated that, while 

 this work has not been fiilly developed as yet, very satisfactory results have 

 been obtained with ordinary precautions. 



A new filter flask, J. A. Shaw (Jour. Indus, and Engin. Chem., 9 (1917), No. 

 8, p. 79S, fi,g. 1). — An apparatus which is considered equal to the ordinary filter 

 flasks and superior to the use of a bell jar for suction filtration and its manipu- 



