AGRICULTURAL CHEMISTRY. 811 



The estimation of total tartaric acid in tartar and wine lees, P. Carles 

 {Jour. I'hann. ft. Chini., G. svr., 25 (1007), Xo. 12. iip. 617-610). — Improvements 

 are suggested for the deteruiination of tartaric acid by the Goldeaberg and 

 Giromont method. 



Solubilities and extraction values of food colors, E. Gudeman (Jour. Amei\ 

 Vhcm. Soc, 2'J (1{)07), yo. 11, pp. 162V-16.iJi).— From a number of tests carried 

 ou with coal tar and vegetable colors, the author concludes that " the colors 

 extracted or dissolvetl by many solvents under varying conditions from neutral, 

 acid or alkaline solutions, give no conclusive data for deciding upon the char- 

 acter or class of the colors themselves. The differences in solubility and in 

 extractive values of vegetable colors compared with coal-tar colors are no 

 greater nor less than the differences found between the various colors them- 

 selves belonging to the same class of colors. 



" Comparative color intensities were also determined, and it was found that 

 only a very limited number of vegetable colors had a color intensity equal to 

 one-fourth that of a corresponding shade of coal-tar color and that the largest 

 number of vegetable colors had one-tenth or less color intensity than the cor- 

 responding coal-tar color of similar shade." 



The volumetric measurement of coloring- matter, L. Pelex and Y. Gartjti 

 (Bui. Soc. Viiud. Sci. Xat., 5. set:, .J5 {11)07), Xo. 158, pp. 1-38). — By the method 

 described by the authors certain basic coloring matters are measured vol- 

 umetrically bj- titration with acid coloring matter, the combination of the two 

 in the presence of hydrochloric acid forming a precipitate. Some other basic 

 coloring matters are likewise measured volumetrically by means of a solution 

 of iodin in potassium iodid. 



The detection and determination of benzoic acid in catsups, fruits, and 

 ciders, H. S. Eeed (Jour. Aimr. CJiciii. .Soc, 29 (1H07), X'). 11. pp. 1626-1629, 

 fiiJ. 1). — A modification of Mohler's method for detecting benzoic acid is de- 

 scribed and also a method for its quantitative determination. 



The author states that the method for the estimation of benzoic acid is based 

 ou the facts that chloroform very completely extracts benzoic acid from other 

 vegetable acids, such as malic, tartaric, oxalic, etc., in water solution and that 

 the calcium salt of benzoic acid is far. more soluble in cold water than the 

 calcium salts of the other acids mentioned. The method is time consuming but, 

 according to the author, gives satisfactory results, particularly when benzoic 

 acid is present in very small quantities. 



Methods of fat determinations in milk, A. V. Krarup {Ber. K. Vet. og Land- 

 hcJiojsholcs Lah. Laiulokoiiom. Forsog [Copenhagen], 61 {1907), pp. 23-43). — 

 Determinations of fat by the Gerber salt method agreed more closely with the 

 results of chemical analysis than did those by the Sichler 45 per cent sin-acid 

 method. The salt method was not quite so accurate as the regular Gerber 

 method (su]i)huric acid and amy] alcohol). 



Regarding formulas used in calculating total solids of milk, P. Gobekt and 

 M. BouiN {Rev. Gen. Lait, 6 {1907), Xo. 18, pp. //09-//i^).— The authors review 

 various formulas for calculating the quantity of total solids of milk, and con- 

 clude that those given in their previous discussion (E. S. R., 18, p. 1107) are 

 still to be recommended. 



The value of the specific gravity of the dry substance of milk in detecting 

 falsification, K. Teiciiekt {Landic. Vers. Stat., 67 (1907), Xo. 5-6, pp. .'i07- 

 .'il8). — In the author's opinion the analytical data obtained in an examination 

 of a considerable number of samples of fresh whole milk, whole milk diluted 

 with skim milk, and whole milk skimmed indicate that the estimation of the 

 si)ecific gravity of the dry substance according to Fleischmaun's formula does 



