AGRICULTURAL CHEMISTRY AGROTECHNY. 11 



decoiupose the glycogen in organs. The losses when using such dilnte alkali 

 for dissolving organs for glycogen determination are explained by the fact that 

 the dilnte alkali, in contradistinction to 30 per cent alkali, does not so change 

 the protein as to allow a couii)lete precipitation of the glycogen. 



Influence of the time of heating- with strong alkali on glycogen determi- 

 nation, V. Hessen (Uhcr den Eliifluss, den die Zeit der Eriiitzung niit Slarker 

 Kalihnii/e aiif die Qnaulitalire Annhjse des CUykogenes Auxiibt. Inaug. Dins., 

 Univ. Bern, 1909, pp. ^5). — With an alkali concentration of 30 per cent the 

 f-anie results were obtained on heating for *, 1, 2. or 3 hours. It is, therefore, 

 considered evident that heating glycogen-containing organs for h hour suffices 

 for their complete solution. The only precaution which is necessary is to 

 lemove the flask from the water bath every 5 or 10 minutes and agitate it. 



The quantitative estimation of formic acid, H. Franzen and G. Greve {Jour. 

 J'rakt. CJiciii., n. ser., SO {1909), pp. SGS-SSD : ahs. in Ztselir. Angew. Chem., 23 

 I 1910). A'o. 5, p. 22)). — A method is described in which the formic acid in 

 bacterial culture solutions is extracted by distillation, and the estimation 

 made by a gravimetric method based on the observation that the formates 

 have the property of redncing mercuric salts to the mercurous state. 



Albert's method for soil acidity, H. Sijchting and T. Arnd {Zischr. Angew. 

 Chem., 23 {1910), Xo. 3, pp. 103-106). — As the result of making comparative 

 tests between Albert's rapid method and that of Tacke-Siichting (E. S. R., 21, 

 I). 9) the authors conclnde that Albert's method is not reliable. It is further 

 stated that the reason Albert obtained unfavorable results with the Tacke- 

 Siiehting method (E. S. R., 20, p. 1113) was because of an error in titrating 

 the carbon dioxid according to the method of Winkler. 



[Albert's method for soil acidity], Albert {Ztsclir. Angeio. Chem., 23 

 {1910), No. 3. pp. 106, 107). — This is a reply to the above, in which it is 

 stated that the results obtained with the author's method are as reliable as 

 those obtained by that of Tacke and Suchting. The author draws attention 

 to the fact that care must be exercised with his method not to use an excess of 

 annnonium salt and barium hydroxid solution. His researches are to be con- 

 tinued. 



Pentosans in soil, O. Schreiner and E. C. Shorey {Abs. in Seience, n. ser., 

 SI {1910), No. 191, pp. 308, 309). — Ten soils containing various amounts of 

 organic matter were submitted to the oflScial method of pentosan determination. 



The results obtained lay between 0.005 and 0.275 per cent. There was no 

 relation between the total carbon and pentosan carbon evident. From the soil 

 containing 0.275 per cent of pentosans the authors obtained, on precipitating 

 the sodium hydrate soil extract with alcohol, a dark gummy substance which 

 yielded a iientose sugar on hydrolysis. 



Examination of water, W. P. Mason {New York, 1910, Jf. ed., rer., pp. 

 V-hlin, pis. 3, figs. 10, maps 2). — This is the fourth edition of this work 

 (E. S. R., 18, p. 7), and contains both chemical and bacteriological methods. 

 The preface states that a special effort has been made to have the methods 

 conform to those proposed by the American Public Health Association. 



lodo-eosin as a test for free alkali in dried-up plant tissues, A. C. IIoe 

 (liio-Chcm. Jour., J, {1909), No. 3-//, pp. 115, 116; abs. in Zentbl. Gesam. 

 I'IniKiol n. Path. Stoffioeehsels, n. ser., // {1909), No. 23. p. 911).— The author rec- 

 ommends a solution of iodo-eosin in ether as an indicator of the presence of free 

 alkali. 



Judging of corn and its products, .1. Sciiin»i.kr (Ztsclir. Landir. ]'(rsiiclisir. 

 Osterr.. 12 (1909). Nos. 11, pp. 121-1.'>6; 12. pi. 1).—\ discussion of corn and 

 corn products, with special reference to their use as food. Methods of analysis 



