524 EXPERIMENT STATION EECOED. 



Estimating cellulose, lignin, and kutin in crude fiber, J. Konig (Ztschr. 

 TJ titers iich. ^ahr. w. Geiiussmtl, 12 {1906). No. 7. pp. 385-395).— An extension 

 of work previously noted (E. S. R., 17, p. 436). 



The optical rotation of gliadin in certain organic solvents, W. E. Mathew- 

 SON (Juiir. Amcr. Vhvm. Hoc. 28 (1906). No. 10, pp. J.'/S„^-.?.'/S5).— The optical 

 rotation of purified gliadin was studied, methyl, etbyl, and propyl alcohols of 

 different strengths, phenol, paracresol, glacial acetic acid, and benzyl alcohol 

 being used as solvents. 



The attempt was also made to estimate the gliadin present in flour by diges- 

 tion with phenol and polarization of the filtered extract. " The results obtained 

 seem to indicate that a quite complete extraction of the gliadin is effected. It 

 is possible, however, that more or less glutenin also dissolves in the phenol. 

 The chief difticulty encountered is in the filtration of the mixtures." 



"The fact that gliadin is soluble iu phenol would seem to render possible an 

 approximate determination of its molecular weight by the freezing-point 

 method." 



The technique of the quantitative estimation of albumen by means of the 

 precipitin reaction, A. Schulz ^Ztschr. riitcrsiich. Xahr. ii. GeinissmtL. 12 

 (1906), No. 5, pp. 257-266). — The author's investigations led to the conclusion 

 that proteids may be estimated quantitatively in food analysis by biological 

 methods — that is, by means of the precipitin reaction. He describes in some 

 detail his method of procedure and gives a summary of references to other 

 articles on the subject. 



Fermentation changes occurring in Muscovado sugars, F. Watts and H. A. 

 Tkmpany (Wrst India II BiiL. 7 {1906). No. .?, pp. 226-236, (Igiii. 1).— The inves- 

 tigations showed that Muscovado sugar is liable to fermentative changes whereby 

 the polarization is first increased and then decreased. These changes are con- 

 sidered due to micro-organisms. The rise iu the polarization is due in part to 

 the destruction of levulose and the subsequent fall to the destruction of dextrose 

 and sucrose. 



The estimation of cocoanut oil in butter fat, F. W. Harris {Analpst. 31 

 (1906), No. 368, pp. 353-360).— The presence on the market of cocoanut oil 

 devoid of odor and practically neutral makes the determination of this sub- 

 stance of considerable importance. Different methods for this purpose have 

 been tested in the author's laboratory for the past year. 



According to the results obtained, the Bomer phytosterin acetate test (E. S. 

 R., IG, p. 18) can not be used to distinguish between the adulteration of butter 

 with cocoanut oil and with raargarin. The method is exi)ensive and tedious 

 and is valual)le only as a confirmatory test. 



The Juckenaek and Pasternack method (E. S. K., 10, p. .3;i2) does not per- 

 mit the detection with any certainty of less than 15 per cent of cocoanut oil. 



By the Polenske method (E. S. R., 15, p. 850), which was subjected to care- 

 ful and extensive examination, it is quite possible, in the opinion of the author, 

 to detect the admixture of 10 per cent of cocoanut oil with a relative degree of 

 certainty and to estimate fairly accurately an addition of 15 per cent. This 

 method, which is simple and permits the determination of both the Polenske 

 and Reichert-lNIeissl numbers in one operation, is recommended for general 

 adoption. 



The detection of cocoanut oil in butter, II. LiJHRiG {Ztschr. Untersuch. 

 Nahr. ii. Gcnnssnitl., 12 (1906), No. 10, pp. .588-592).— Studies were made of 

 the method of Wijsmann and Reijst (E. S. R.. 17, p. 8B4). With pure Imtter 

 the second silver index was often lower than the first. The author therefore 

 concludes that the method is of no value. 



