834 EXPERIMENT STATION RECORD. 



The determination of the fat content of butter, II. Luhrig (Molk. Ztg., 

 19 (1905), No. 48. pp. 1217, 1218). — The author tested the method of E. Von 

 Waegenigh. 



In this 1 gm. of butter is shaken with 20 cc. of ether, and 0.5 gm. of powdered 

 tragacanth and 2.5 cc. of water are added to the mixture, which is then cen- 

 trifuged for 2 to 3 minutes. The ether layer containing the fat is separated, 

 the ether evaporated, and the fat weighed. The tragacanth is added for the 

 purpose of removing the water, proteids, milk sugar, and salt from the fat. 

 The method was found to be rapid, but not very accurate. It is considered 

 worthy of further study. 



New method for the detection of cocoanut oil in butter, U. P. Wusman and 

 Reijst (Ztschr. Untersuch. Nahr. k. Genussmtl., 11 {1906), To. 5, pp. 267-271; 

 Rev. Soc. Sci. Hyg. Aliment.. 2 {1905), Ao. 5, pp. 491-498). — This method is 

 based upon the precipitation of volatile fatty acids by silver nitrate. 



To the filtered and neutralized distillate obtained in the Reichert-Meissl method 

 is added 40 cc. of a decinormal solution of silver nitrate. This is filtered and 

 the precipitate washed until about 200 cc. of liquid is obtained, to which is 

 added 50 cc. of decinormal solution of sodium chlorid. The excess of sodium 

 chlorid is determined by titration with decinormal silver nitrate, potassium 

 chromate being used as an indicator. The difference between the total number 

 of cubic centimeters of silver nitrate employed and the number of cubic centi- 

 meters of sodium chlorid increased by 0.1 is called the first silver index. 



A second silver index is obtained by using 300 cc. of distillate from the 

 Reichert-Meissl method instead of 110, adding 40 cc. of a decinormal silver 

 nitrate to 250 cc of this liquid, filtering and washing until 350 cc. of liquid is 

 obtained. The number obtained as above is increased by one-fifth. The pres- 

 ence of cocoanut oil is indicated by an increase in the second silver index over 

 the first. 



On the value of Schiff 's reagent for the detection of formaldehyde in milk, 

 Utz (Milchw. Zentbl., 2 (1906), No. 1, pp. 12, IS). — The author concludes, as 

 the result of his investigations, that this reagent is not to be recommended for 

 the detection of formaldehyde in milk, and that the best method for this pur- 

 pose is that of Arnold and Mentzel (E. S. R„ 13, p. 1015).' 



The relation of cows' milk to Schiff's reagent and a test for formalin in 

 milk, Eichholz (Milchw. Zentbl., 1 (1905), Ao. 11. pp. J,99, 500).— This is a 

 criticism of the article by Seligmann previously noted (E. S. R., 16, p. 742). 



Separation of nitrogenous bodies in cheese, R. IIarcourt (Ann. Rpt. Ontario 

 Agr. Col. and Expt. Farm, SI {1905), pp. 70-76). — This report was presented 

 at the last meeting of the Association of Official Agricultural Chemists (E. S. R., 

 17, p. 432). 



Extracts from the proceedings of the Association of Official Agricultural 

 Chemists, 1905, edited by II. W. Wiley (V. 8. Dept. Agr.. Bur. Client. Cire. 26. 

 pp. 16). — This gives the recommendations of referees as adopted, motions, and 

 appointments affecting the work of the association for 190G. A summarized 

 account of the proceedings of this association in 1005 was given in a previous 

 number of the Record (E. S. R., 17, p. 423). 



Agricultural chemistry, A. Morgen and W. Zielstorff (Jahrb. Chem., 14 

 (1904), PP- 286-303). — This is a brief review of progress during 1004 in investi- 

 gations relating to air and water, soils, fertilizers, plant physiology, and animal 

 physiology, including also biographical and miscellaneous notes, 



