Wit] AGRICULTURAL CHEMISTRY — AGROTECHNY. 507 



Contribution to the study of the Adamkiewicz reaction and of the trans- 

 formation of glyoxylic acid into formaldehyde, E. Voisknkt illnl. Soc. f'liim. 

 France, j. »er., 23 [1918), No. 8, pp. 861-869; abs. in Analyst, k8 (.1918), No. 

 ~>I2, p. 38(>). — Experiments arc described which indicate that the violet colora- 

 tion in the Adamkiewicz reaction is due to formaldehyde rather than to 



glyoxyllc acid. In place of glyoxyllc acid, rec mended by Hopkins and Cole 



(B. S. EL, 13, p. 522), the author suggests the use of formaldehyde in a 1 

 per cent solution with sulphuric or hydrochloric acid, followed by the addition 

 of a drop of 1 per cent nitrite solution. 



The determination of lactose, E5. IIildt (Comfit. Rend. Acad. Set. [I'<uix\, 

 till (1918), No. 21, pp. 756-759). — The author recommends the use of a cata- 

 lyzer such as benzene sulphonic acid for hydrolysis of the lacto-serum in the 

 procedure for determining lactose in lacto-serum by the reducing power after 

 inversion. The time required for complete hydrolysis is said to be less than 

 when mineral acids are employed as catalyzers, and the danger of destruction 

 of the galactose and glucose Conned on hydrolysis is ivoided. 



Determination of lactose in mixtures with sucrose and invert sugar, J. 

 Gbos8fielo (Ztschr. Untersuch. Nahr. u. Genussmtl., 35 {1018). No. 7-8, pp. 249- 

 %56).t u The author has derived formulas and constructed tables by means of 

 which lactose and sucrose can be determined in the same sample from the 

 values obtained on polarization and reduction after inversion. The method is 

 said to be applicable to the analysis of sweetened and condensed milk and 

 other milk products. 



The determination of fructose in the presence of aldoses, A. Hekzfkld and 

 G. Lenabt (Ztschr. Ver. Deut. Zuekerindus., No. 7J,'J, II (1918), pp. 227-284).— 

 This is an application to the determination of fructose in sugar beets and beet 

 juices of the procedure described by Wilson and Atkins (E. S. It., 37, p. 10) 

 for the estimation of mixtures of four or more carbohydrates by quantitative 

 oxidation with bromin. 



It was found that the lead acetate used for clarifying the solution to be 

 tested apparently acted as a catalyzer, reducing the oxidation period to within 

 24 hours. 



Determination of acidity and titrable nitrogen in wheat with the hydro- 

 gen electrode, C. O. Swanson and E. L. Tagtte (Jour. Ayr. Research [I . 8.1, 

 Id (1919), No. 1. pp. 1-13, figs. 6).— This paper presents the results of a study 

 at the Kansas Experiment Station of the H-ion concentration of extracts of 

 ground wheat at different temperatures and periods of time. Determinations 

 were also made of the amino nitrogen by the Sorensen formaldehyde method 

 and of the total and inorganic phosphorus. 



Fifty gm. of finely ground Kansas hard wheat was weighed into a quart 

 Mason jar and heated to the temperature used in the extraction. Five hun- 

 dred cc. of carbon dioxid-free water, previously heated to the temperature 

 employed, was then added with 5 cc. of toluene as a preventive of bacterial 

 action. The whole was thoroughly shaken, placed in a thermostat, and the 

 shaking repeated at frequent intervals during the time of extraction, at the 

 end of which time the contents of the jar were centrifuged and filtered. The 

 filtrate was used for determinations by means of the hydrogen electrode of the 

 H-ion concentration or the pH value of the extract, the amount of N/20 

 Ba(OH) 2 used to titrate to the absolute neutral point of pll=7, to the point 

 of color change for phenolphthalein or pII=S.S, to the point of color change 

 for thymolphthalein or pH=9.3; the amount of alkali necessary to reneutralize 

 after the addition of neutral formaldehyde; the total phosphorus in the extract; 

 and the phosphorus precipitated by magnesia mixture. Extractions were made 



114S7S — No. 6—19 2 



