12 EXPERIMENT STATION EECOED. 



sity of setting up a uniform procedure for determiuiuj; tlie reaction of the 

 soil, and calls attention to some inaccuracies in the method in which phenol- 

 phthalein is used. The value of estimating the amount of water-soluble salts 

 in soils by the electrical conductivity method (E. S. R., 24, p. 210) is discussed 

 and accompanied by the results of tests with Swedish soils. 



The methods of soil analysis employed at the Passoeroean Sug'ar Experi- 

 ment Station [Java] {Jaarver. Proefstat. Ja^a SuikcrUnlus., 1909, p. 89). — 

 A description of the methods and reagents required. 



A biochemical reaction for detecting pollution in water supplies, A. W. 

 Sellakds and E. Bartow {Amcr. Jour. I'lib. llijg., 20 (JOIO), No. 3, pp. 682- 

 688). — A bacteriological-chemical method is described, with which it is possible 

 to tell the source of the ammonia in water and also the significance of the free 

 ammonia estimation in sanitary water analysis. 



Some considerations on colorimetry, and a new colorimeter, N. Roberts 

 {Pub. Health and Mar. Hosp. Serv. U. 8., Eyg. Lab. Bui. 66, pp. 79-93, figs. 

 5). — ^A description of a simple colorimeter for use in the sanitary anaylsis of 

 water. Methods for using the apparatus in general colorimetry are also 

 described. 



Method for the analysis of fat, David (Compt. Rend. Acad. 8ci. [Paris], 

 lot {1910), No. SI, pp. 756, 757).— The method depends on the fact that the 

 ammoniacal salts of the solid fatty acids are completely insoluble in an excess 

 of ammonia. These are collected and decomposed on the filter with hydro- 

 chloric acid and weighed directly as fatty acid. 



In rega.rd to the Kumagawa-Suto method for fat, Y. Shimidzu {Biochem. 

 Ztschr., 28 {1910), No. 3-^, pp. 237-273).— The method,* according to the author, 

 gives reliable results when fresh tissues and organs are employed, but low 

 results are obtained if large quantities of the fresh tissues are dried on the 

 water-bath prior to extracting the fat. Aiding the drying process with 

 alcohol did not seem to remedy this. The loss in some cases where drying was 

 resorted to with alcohol was as high as 10 per cent, while with small quantities 

 of material when drying was assisted w-ith alcohol the loss was under 1 per cent. 

 The loss of fat is attributed to the oxidization of the fatty acids, and when 

 tissues are to be dried this should be done in a dry vacuum without heat. 

 The method did not give good results with blood. 



Determination of fat in foods, E. Polenske {Arb. E. Gstidhtsamt., S3 

 {1910), No. 3, pp. 563-579). — After discussing the comparative value of the 

 usual hot extraction method and the shaking out method for estimating fat in 

 foods, the author describes a new shaking out method for determining fat in 

 plant substances. In this method the material is first treated with hydi'ochloric 

 acid in a boiling water bath, and after cooling the fat is extracted by shaking 

 wath ether and petroleum ether. The results with the method and various 

 cereals, legumes, meat, and dairy products are given. 



About banana flour and its microscopic examination, T. F. Hanausek 

 {Ztschr. Untersuch. Nahr. v. Gcnussmtl., 20 {1910), No. 4, pp. 215-220, figs. 2).— 

 A general discussion in regard to the uses of banana flour and its histology. 



Determination of solids in vinegar, R. T. Mohan {Pure Products, 7 {1911), 

 No. 1, pp. 22, 23, fig. 1). — The author points out that the official method for 

 estimating the total solids in vinegar by evaporation is faulty, because some of 

 the volatile acid is not driven off. In its stead he recommends using sensitive 

 standardized hydrometers for determining the specific gravity of the vinegar, 

 and presents a correction table for use with such instruments. 



o Biochem. Ztschr., 8 (1908), p. 212. 



