191G] AGRICULTURAL CHEMISTRY AGROTECHNY. 415 



oped in the bean during the process of fermentation. It is concluded that 

 " the presence of these enzyms undoubtedly influences the character of the 

 fermentation and that temperature control during fermentation is necessary in 

 order that they may not be destroyed." 



Standard methods of sampling- and analysis and standard samples, W. F. 

 HiLLEBRAND (Jour. ludus. and Engin. Chem., 8 {1916), No. 5, pp. 466-469). — 

 This aricle reviews the subject in brief and gives the standard methods recog- 

 nized by courts of law in the United States, the methods not having legal 

 recognition but approved by scientific or technical organizations, and the meth- 

 ods in use in laboratories of certain industrial establishments. 



A diagram for the calibration of volumetric apparatus and the reduction 

 of the volumes of liquids to a standard temperature of 20° C, H. C. Deming 

 {Jour. Indus, and Engin. Chem., 8 (1916), No. 5, pp. 451-453, figs. 3). — This 

 article describes in detail the construction and use of the diagram which the 

 author has devised for the rapid calibration of volumetric apparatus and the 

 reduction of volumes of liquids to standard temperatures. 



The admissibility of ammonium-mag'nesium phosphate as a form in "which 

 to weigh phosphoric acid, W. Jones (Jour. Biol. Chem., 25 (1916), No. 1, pp. 

 87-91). — Analytical data submitted indicate that in the quantitative determi- 

 nation of phosphoric acid the conversion of ammonium-magnesium phosphate 

 into magnesium pyrophosphate is superfluous, since accurate and concordant 

 results can be obtained by direct weighing of the crystalline precipitate. When 

 dry the ammonium-magnesium phosphate can be easily and completely removed 

 from the filter paper. 



Estimation of carbon dioxid as barium carbonate applied to the Marr 

 method for determination of carbonates in soil, C. J. Schollenberger (Jour. 

 Indus, and Engin. Chem., 8 (1916), No. 5, pp. 427, 428). — Experimental data 

 obtained at the Ohio Experiment Station from a series of six soils by boiling 

 with 1 : 10 hydrochloric acid at atmospheric pressure and by several modifica- 

 tions of the Marr method (E. S. R., 22, p. 511) are submitted. 



A comparison of the permanganate methods for the determination of 

 required oxygen, J. H. Sachs (Jour. Indus, and Engin. Chem., 8 (1916), No. 5, 

 pp. 404-4O6). — Analytical data obtained from a study of the various modifica- 

 tions for the determination of required oxygen in water are submitted. The 

 method described by Thresh (E. S. R., 29, p. 506) of titrating in an acid medium 

 after incubating at 37° C. is considered to be the best. 



The analysis of proteins. — I, The estimation of arginin by decomposition 

 with alkali, R. H. A. Plimmer (Biorhem. Jour., 10 (1916), No. 1, pp. 115- 

 119). — Experimental data indicate that arginin can be accurately estimated by 

 boiling with 20 per cent sodium hydroxid instead of 50 per cent, as originally 

 recommended by Van Slyke (E. S. R., 26, p. 22). The loss of determinations 

 through the action of the alkali on the glass is thus avoided. Copper flasks 

 were not found satisfactory, especially in the presence of histidin, as under 

 these conditions the histidin undergoes considerable decomposition. Boiling in 

 a glass flask causes a slight decomposition of histidin, but the error is practi- 

 cally negligible. It has been found to be more convenient to add an equal 

 volume of 40 per cent NaOH than to weigh the correct amount of solid reagent. 

 By using a solution of alkali a larger volume of liquid is contained in the 

 flask, which obviates the subsequent distillation after the reaction is complete, 

 as is necessary in the original procedure. 



For the determination of the total nitrogen of the bases it is recommended 

 to use a fresh portion of the solution of the bases rather than the residue 

 from the arginin estimation, on account of the unavoidable bumping and con- 

 sequent loss of nitrogen. 



