16 EXPERIMENT STATION RECORD. 



Fitch's salt analysis, a rapid method for the estimation of salt in butter, 

 A. Vivian ( Wiscomin Sta. Rpt. 1900, pp. 98-101). — A method for tlie deteriiiinati(jn 

 of salt in l^utter, designed for factory use. A' standard solution of silver nitrate is 

 made by dissolving 2 tablets prepared for this purpose in 100 cc. of water. The 

 tablets as j^ut up by a Chicago firm contain 0.0509 gm, of silver nitrate in combina- 

 tion with potassium nitrate and gum acacia. The indicator is prepared by dissolv- 

 ing 1 gm. of potassium chromate in 1 liter of water. The sample of butter, weighing 

 3.5 gm., is treated with 180 cc. of boiling water, and 17.6 cc. of the mixture, when 

 cool, is taken for titration. The quantities used are such that each cubic centimeter 

 of the standard solution corresijonds to 0.1 per cent of sodium chlorid. The number 

 of cubic centimeters of the standard silver nitrate solution used divided by 10 gives, 

 therefore, the percentage of salt in the butter. Comparative determinations by this 

 method and the official method gave closely corresponding results. 



A quick method for estimating sodium chlorid in meat, F. Glage (ZlsrJir. 

 Flei.^rlt u. Mikhhiji)., 11 {1901), Xo. 4, pp- 111-114)-— -'^ practical method for obtain- 

 ing quick results by the use of an ammoniacal solutitjn of silver nitrate. 



A comparison of the calculated Tvith the analytical results in estimating 

 the solids of milk, H. Ldhrig {Molk. Ztg., 14 {1900), Xos. 50, jjp. 869-871; 51, pp. 

 889-891). — Results with milk from various sources and different degrees of freshness. 



The estimation of dry matter, fat, and ash in milk, H. Timpe {Ztschr. Oeffentl. 

 Chem., 5 {1899), p. 413; abs. in Hyg. Rundsduiu, 10 {1900), No. 15, p. 748).— In milk 

 analysis the use of asbestos as an absorbent material is advocated in lieu of sand or 

 filter ])aper. 



Estimation of fat in milk, R. Leze {Repert. Fliarui. el Jour. C'him. Med., S. ser., 13 

 {1901), p. 1; abs. In Chem. Ztg., ;J5 {1901), Xo. 16, p. 5^).— A practical application of 

 Ramchen's method, employing a solution of potash, ammonia, ethyl and amyl alco- 

 hols for separating the fat. 



The guiac test for pasteurized and unpasteurized milk, F. Glage {Milch 

 Ztg., 30 {1901), No. 12, pp. 182, 183).— k. large number of tests were made of the 

 color reaction produced in milk by the addition of guiac tincture. It was found that 

 in pasteurized milk no blue color was produced. In the unpasteurized milk the 

 results were variable. In some cases a dark-blue color was produced, in some a very 

 light-blue color, and in others no color at all. Different prejmrations of the tincture 

 were tested. 



A modification of Ritthausen's method for the determination of albumi- 

 noid nitrogen, F. Barxsteix {Landw. Vers. Stat., 54 {1900), No. 5-6, pp. 3^7-336). — 

 The modilication proposes the addition of a known quantity of soda solution after 

 the addition of copi)er suljihate to the heated nuxture to be tested. The operation 

 is carried out as follows: To 1 to 2 gm. of the substance in 50 cc. of water heated on the 

 water bath there is added 25 cc. of a cojiper sulphate solution made up of 60 gm. of 

 crystallized copper sulphate and 1 liter of water. After stirring, 25 cc. of soda solu- 

 tion of the strength 12.5 to 1,000 is added. After settling, the suisernatent liquid is 

 run through a filter, the i)recipitate washed by decanting, l)rought on the filter and 

 washed with warm water until the filtrate gives no precipitate with barium chlorid. 



By this method of adding soda solution in excess the copper is thrown down as a 

 hydrate and not as a basic salt. Quite a number of comparative analyses of differ- 

 ent substances are shown of the method proposed and of the method of Stutzer. 

 The results show a higher average nitrogen content in tlie proposed modification. 



Tables for use in Kjeldahl method for determination of nitrogen, A. Vivian 

 ( Wisconsin Sla. Rpt. 1900, pp. 261-265). — Tables are given showing the percentage of 

 nitrogen corresponding to any titration and for the conversion of nitrogen into 

 ammonia and protein. 



The chemistry of proteids, A. Cohenhei.m {Chemie der Eriveisskorper. Bruns- 

 uicJc: F. Vieireg d- Sou, 1900; rev. in Oesierr. Chem. Ztg., 3 {1900), No. 21, p. 518). — 

 The chemical properties and behavior of albumen toward reagents, micro-organisms, 

 metabolic processes, etc., are discussed. 



