AGRICULTURAL CHEMISTRY, 



811 



consists ill trciitinfr tho niiliv with inci-ciii-ic iiilrato iiiul titratin;^ against B^h- 

 liiig's solution. 



The application of cryoscopy to the analysis of milk, 10. Grunku (Ann. 

 1st. Ai/r. [Milan], (> (1901-t!>05), pp. 21-50). — The freezing point of fresh cow's 

 milk varies, according to the author, between — O.o^^r) and — 0.580° C. The 

 variations for mixed milk are usually within —0.5.5 and — 0.57. The freezing 

 point was not influenced hy the age of the animals, the stage of lactation, or 

 the feeding stuffs used. A slight iiiMuence, however, was attributed to tlic breed. 

 The freezing point was not materially affected by the composition of the milk. 

 Taken in connection with chemical analysis the determination of the freezing 

 point is believed to afford valuable data in detecting the adulteration of milk 

 with water. 



The detection of added water in milk, ('. Kevis (Jour. Roi/. Inst. Pub. 

 llrulth. J.') (1907). No. 1. pp. J.9-//.3).— The author calls attention to the fact 

 that when genuine milk is deficient in solids-not-fat the deficiency is due to an 

 abnormally low i)ercentage of milk sugar. In endeavoring to ascertain the 

 cause of deficiency in the jierceiitage of solids-not-fat in milk, it is. therefore, 

 considered desirable to determine the amount of sugar. The difficulty lies in 

 making the analysis before much of the milk sugar is decomposed. Adultera- 

 tion with water is indicated when the amount of sugar is approximately \\ 

 of the solids-not-fat, the total amount being less than 8.5 per cent. When the 

 amount of sugar is considerablj^ less than if of the solids-not-fat. the reduc- 

 tion in solids-not-fat is apparently due to natural causes. 



Contribution to the refractometric detection of added water in milk, E. 

 AcKtJii.M.v.XxN (Ztschr. liitcrsncli. \(ihr. ii. (Jcniisisuitl.. 1.3 (1907), Wo. J/, pp. 

 18G-1S8, fifi. 1). — The value of determining the refractometer number of milk as 

 a means of detecting adulteration with water is pointed out. In the author's 

 method the serum is prepared by adding 0.25 cc. of a calcium chlorid solution 

 (si)ecific gravity, l.i;^75) to ;J0 ce. of milk. This is thoroughly mixed and heated 

 in a water bath for 15 minutes. The loss of water in the sample is j)revented 

 by means of a return-flow condenser. 



AVith normal milk the author obtains constant numbers with the Zeiss immer- 

 sion refractometer varying between 38.5 and 40.5. The addition of 5 to 50 per 

 cent of water caused, according to the results reported, a reduction in this 

 number of from 1.3 to 8.1. 



The temperature correction of the Zeiss butyro-refractometer, II. D. 

 RicH.Mo.M) (An(ili/.'<t. S2 (1907), No. 371. pfi. .'I'l-'i'!)- — 'fbe following are offered 

 as the most probable corrections : 



The Tolman and Munson factor 0.000305 for correcting refractive indices is. 

 therefore, considered inaccurate. The author gives directions for the construc- 

 tion of a correction chart which it is claimed will give very accurate readings 

 for all refractive flgin'(>s and all temperatures. 



A means of distinguishing cocoanut oil from butter and other fats and 

 oils, J. llANUs (Ztsrhr. L'ntcrsiirh. Xahr. u. G("»».s'swf/., 13 (1907), .Vo. 1, pp. 



