1919] AGRICULTURAL CHEMISTRY AGROTECHNY. 113 



Estimation of cyanogen compounds in concentrated ammonia liquor, P. E. 

 Spielmann and H. Wood {Jour. Soc. Chem. Indus., 38 (1919), No. 4, pp. 43T- 

 J^5T). — The basis of the scheme of analysis outlined is (1) the conversion of the 

 ammonium thiocyanate iuto ferric thiocyanate and measurement in a tint- 

 ometer of the depth of color obtained, and (2) the interaction of a further 

 quantity of the original liquid witli ammonium polysulphid, which converts 

 the ammonium cyanid originally present into ammonium thiocyanate, and the 

 estimation of the total anmionium thiocyanate as ferric thiocyanate. The dif- 

 ference between the results obtained in (1) and (2) is a measure of the 

 quantity of cyanid originally present. 



The method is described in detail, including the preparation of standard 

 colors and the use of the Lovibond tintometer. 



Fat extraction apparatus, E. Geiffiths- Jones {Analyst, Jfli {1919), No. 515, 

 pp. 45-47, fig. 1). — The apparatus, which was designed for use when the ordi- 

 nary Soxhlet apparatus is not available, consists of an ordinary vertical con- 

 denser, the lower end of which passes through two corks, the upper one to 

 serve as a connection for the extraction flask and the lower one for the recep- 

 tion of the extraction thimble. A side tube passes just through the upper 

 cork, upward and parallel with the condenser, and then down the condenser 

 tube to approximately the level of the water intake. The material to be ex- 

 tracted is placed in an ordinary extraction thimble covered with a plug of 

 cotton wool and fitted over the lower cork. The condenser is then connected 

 with an extraction flask containing the solvent and the extraction carried 

 out over an electrically heated sand bath. 



The extraction is said to be moi'e rapid than with the ordinary type of 

 Soxhlet and to require less of the solvent. 



Acidimetric titration of grain extracts and amino acids in the presence of 

 alcohol, V. BiECKNEK {Jour. Biol. Chem., 38 {1919), No. 2, pp. 245-254, figs. 2).— 

 A study at the Bureau of Chemistry, U. S. Department of Agriculture, of the 

 cause of the change in acidity of grain extracts on the addition of alcohol led 

 to the conclusion that the increased acidity noted is due to the fact that 

 amino acids, which in aqueous solution are nearly neutral to phenolphthalein, 

 react distinctly acid in the presence of alcohol. It is pointed out that this fact 

 should be taken into account when making acidimetric titrations in alcoholic 

 liquids containing amino compounds, such as various animal or vegetable ex- 

 tracts. 



Meat extracts, their composition and identification, J. A. Emery and R. R. 

 Henley {Jour. Agr. Research [U. /S.], 17 {1919), No. 1, pp. i-i7).— This investi- 

 gation was conducted at the Bureau of Animal Industry, U. S. Department of 

 Agriculture, to obtain information regarding differences in composition of 

 meat extracts prepared from muscle tissue, livers, spleens, hearts, cured-meat 

 cook water, roast-beef soak water, and bones, all of which materials have been 

 used in recent years in the commercial manufacture of beef-extract. 



The extracts used in the investigation were prepared in the meat extract 

 department of a large commercial establishment according to the method ordi- 

 narily used, and also in the laboratory on a smaller scale but as far as possible 

 in the same way. The extracts prepared in the laboratory were identical in 

 physical appearance and organoleptic properties with those obtained by the 

 commercial process. The methods employed in the analysis of the extracts 

 were essentially those of Sti'eet et al. previously noted (E. S. R., 20, p. 959). 



The quantitative results, which are presented in tabular form, show the 

 following characteristic differences depending upon the nature of the extract : 



" Liver extracts are low both in total nitrogen and ' meat-base ' nitrogen, 



