AGRICULTURAL CHEMISTRY— AGROTECHNY. 11 



determination of starch. Among the tltrimetric methods that of Sachsse is to 

 1)0 given preference. No definite conclusion could be drawn for the polari- 

 nietrie method. 



A rapid method for hydrolyzing' starch, G. A. Olson {Jour. Indus, and 

 Engin. Vlicm., 1 {I'Mi)), Xo. 7, pp. Uo-.'/.'p; abs. in Chem. Ztg., 33 {1909), No. 

 103, Repcrt., p. M6). — Owing to the length of time required in the Sachsse 

 method the author proposes the following, which can be done in 4 minutes : 

 Place 1 gm. of the finely ground sami)le in a 500 cc. Kjeldahl flask with 10 cc. of 

 (lislilled water, add 6 cc. of concentrated sul]ihnric acid (specific gravity 1.84), 

 and heat with shaking over the free flame until the solution is transparent. 

 Then add 10 to 15 cc. of distilled water, heat with shaking until the mixture 

 boils, cool, neutralize with sodium hydroxid, transfer to a 250 cc. flask and fill 

 to the mark with water. Determine dextrose in aliquot. 



The estimation of starch in feeds and foodstuffs, A. Scholl {Ztschr. 

 Unicrsiich. Xahr. u. GenusHmtl., 18 {1909), No. 1-2, pp. 157-166).— In the analy- 

 sis of potatoes for starch content by the liintner and Ewers method the author 

 found considerable dirticulty in clarifying the solution with phosphotungstic 

 acid. A method is described which eliminates the phosphotungstic acid from 

 the process. The method is reconnnended for feeds and foodstuffs in general. 



The indirect determination of alcohol in raspberry sirup, E. Gijnzel 

 (Zt.schr. Untcrsuch. Nahi: u. GcnussintL, 18 {190U), .Vo. 3, pp. 206-211).— 

 Determining alcohol indirectly by the specific gravity without diluting gives 

 higher results than those obtained l)y the distillation method. If, however, 

 both the original and the dealcoliolized sirups are diluted the results agree well 

 with the distillation method. Diluting the portion to be dealcoholized and em- 

 ploying the original undiluted docs not give good results. 



The determination of volatile org'anic acids in tobacco, II. Kisslino (Chem. 

 Ztg., 33 (1909), No. 79, pp. 719, 720).— This is a criticism of Toth's method for 

 determining the volatile organic acids of tobacco and an answer to T6th in 

 reference to the volatilizing of oxalic acid. 



The value of the nitrate reaction in milk, S. Eothenfusseb (Ztschr. Un- 

 tcrsuch. Nahr. u. Genussmtl., 18 (1909), No. 0, pp. 353-363).— The author con- 

 cludes from a large series of tests with milk and water from known sources 

 and milk purposely i)olluted with nitrates, that the nitrate reaction is a very 

 valuable means to judge milks from a .sanitary standpoint, and that it is possi- 

 ble to detect by this method milks of poor quality having a small addition of 

 water. The author made some 300 barn tests of milk and found in no instance 

 cither a nitrite or nitrate reaction. Milk from pastured animals also did not 

 give the nitrate reaction. 



The estimation of the dirt content of milk. H. Weller (Ztschr. Untcrsuch. 

 Nahr. u. Genussmtl., 18 (1909), No. 5, pp. 309-313).— A criticism of the method 

 of Fendler and Kuhn and the standard established by them. Examples are 

 presented to show that the Weller method is more reliable. 



The influence of heating upon butter fat, A. Behre (Pharni. Zcntralhnllc, 

 50 (1909), No. 8, p. 158; abs. in Ztschr. Untersvch. Nahr. u. Genussmtl., 18 

 (1909), No. 3, pp. 233, 23^).— In butter fat which was heated for 3 hours for 

 the removal of water over an open flame the acidity ran between 3.5 and 3.75. 

 The Reichert-Meissl number at the beginning was 27.06 and at the end 27.44. 

 The saponification number at first was 226.2 and finally 227.1. It is evident 

 from these figures that heating causes no appreciable change in these constants. 



The Polenske method for the detection of animal fats in a mixture of 

 other animal fats, L. Laband (Ztschr. Untcrsuch. Nahr. u. Genussmtl., 18 

 (1909), No. 5, pp. 289-299). — The author concludes that the Polenske method 

 (by dift'erence between the melting and solidifying points) is only applicable 



