AGRICULTURAL CHEMISTRY AGROTECHNY. 109 



Determining the dry matter content of potatoes, H. Bjorn-Andersen 

 (Tidsskr. Landhr. Plantcavl., 17 {I'JIU), No. 3, pi). 5 10-528) .—This, is a critical 

 study of tlie methods of Heideprim, Holdefleiss, Adesser, Maercker, and A. J. 

 Hansen for obtaining tlie percentage of dry matter in potatoes from tlie specific 

 graAity, and supplemented by the author's worlc, which included determinations 

 of both the diy matter and specific gravity of a large number of samples of 15 

 different varieties of potatoes. The conclusion is reached that an error of at 

 least 1 per cent is frequently made by calculating the dry matter content from 

 the specific gravity of the potatoes, and that where greater accuracy is called 

 for, direct determinations of dry matter should be made. 



The chemistry of bee honey, A. Hasterlik {Leipzig. Bicnen Ztg., 26 (1911), 

 Nos. 2, pp. 2Jf-28; 3, pp. .'lO, J/l). — This is a review of the progress made in the 

 chemistry of bee honey during 1910. 



Honey and its analysis, F. Muttelet (Ami. Fahif., 3 (1910), No. 26, pp. 

 50,i-.')l3). — A general discussion of honey standards and the adulteration of 

 honeys, particularly those honeys obtained by feeding bees with sugar and 

 giving Fiehe's reaction (E. S. R., 20, pp. 612, 909, 1009). The author makes it a 

 practice to conduct his honey examinations organolepticallj-, microscopically, 

 polariscopically, and chemically. 



Analysis of honey, G. Curtel (Ann. Falsif., 3 (1910), No. 26, pp. Jt97-502).— 

 A description of the usual juethods for estimating and standards for pi'otein, 

 invert sugar, moisture total solids, acidity, ash, and chlorids, as well as of 

 Lund"s method for albmnin (E. S. R., 21, p. 308), Fiehe's reaction. Ley's reac- 

 tion, the polarization before and after inversion, and tests for glucose and 

 dextrin. 



Determination of gum in gum. sirups, Bellieb (Ann. Falsi/., 3 (1910), No. 

 26, pp. 528, 529). — This method is based on the principle of precipitating the 

 gum with alcohol in the presence of such salts as barium chlorid, magnesium 

 chlorid, and calcium chlorid. Preference is given to the calcium salt. 



The shell and germ content of cocoa products, H. Huss (Ztschr. TJnter- 

 such. Nahr. u. Oenussmtl., 21 (1911), No. 2, pp. 94-101). — After reporting the 

 results of factory tests in regard to freeing cocoa products from the shell and 

 germ, the author propounds the question as to what would be a fair limit for 

 these substances. He lays particular stress on the elimination of such terms 

 as traces, small amounts, etc., and sets the limit for cocoa mass at 2 per cent, 

 for chocolate at 1 per cent, and for cocoa at 8 per cent. 



A microscopic method is also described for obtaining approximate quantitative 

 figures for the shell and germ content of these products. This is based on the 

 fact that the mucus cells of the shell and the germ tissue do not take a stain com- 

 posed of (1) Congo red 1 gm. and water 100 gm. ; (2) brilliant blue 1 gm., 

 glycerin 20 gm., and water 80 gm. ; and (3) Sudan glycerin, consisting of 

 Sudan III 0,1 gm., glycerin 50 gm., and alcohol (95 per cent) 50 gm. The 

 samples which are to be examined are compared with other authentic samples 

 of known shell and germ content. Milk fat and other normal substances which 

 may be present are stained by these reagents. 



Estimation of citric acid in citrates and lemon juices, M. Spica (Chem. 

 Ztg., 34 (1910), No. 128, pp. lUl, ll-'i2, figs. 2; abs. in Analyst, 35 (1910), No. 

 JflT, p. 519). — The method is based upon the precipitation of citric acid as 

 calcium citrate, heating this with sulphuric acid, and measuring the carbon 

 dioxid which is driven off. The carbon dioxid has a direct relation to the 

 amount of citric acid present. 



A new method for the analysis of wine, Fbidebich (Monit. 8ci., 4- scr., 24 

 (1910), II, No. 827, pp. 705-710, figs. 7). — After discussing the physical-chemical 



