AGRICULTURAL CHEMISTRY — AGROTECHNY. 209 



that of invert sugar which can be readilj- detected iu honey which has never 

 been subjected to heat." 



Browne's test (E. S. R., 19, p. 1058) may serve as an aid but is not con- 

 sidered infallible. 



Estimation of the fat content of milk with the aid of trichlorethylene, 

 D. P. Koss VAN Lennep and J. D. Ruys {Chem. ^Vcekh^., (1912), No. 32, pp. 

 654-607; uhs. in Chem. Zentbh, 1912, II, No. 11, p. 962).— The method is as 

 follows: Boil 10 gm., or 9.7 cc, of milk for 2 minutes with 10 cc. of hydro- 

 chloric acid (specific gravity 1.19) ; cool, add 50 cc. of trichlorethylene, shake, 

 allow the curd to settle, and draw off the supernatant trichlorethylene layer; 

 and filter through a dry filter. Twenty-five cc. of the filtrate is evaporated 

 in a tare<l beaker, and the residue dried for 45 minutes at 100° C. and weighed. 



The properties of watered milk, E, W. Tx)ng and C. E. May (Jour. Indus, 

 and Etij/in. Chem., 5 (1913), No. 7, pp. 573-575).— The results indicate that the 

 Zeiss inunersion refractometer method for examining milk serum is very prac- 

 tical for the detection of added water, but that when used alone it is not infalli- 

 ble. For every 10 per cent of water added to milk, the serum when prepared 

 by the acetic acid metho<l gives a refractometer reading about 2.9" lower than 

 the uuwatered milk, but the addition of 1 gm. of granulated sugar to 100 cc. of 

 milk, watered or unwatered, will raise the refractometer reading of the serum 

 about 4°. The adulteration of milk by watering and sugaring can therefore be 

 carried on by adjusting the amounts of the adulterants and adding them to 

 milk that is well above the standard in solids and fat. It therefore seems that 

 " m examining commercial samples of milk it is well worth the chemist's 

 trouble to look out for tlie presenr(> of this form of adulteration." 



The examination of the sediment obtained in the leucocyte test, with a 

 description of a new leucocyte tube, V. Bkudny (Osterr. Molk. Ztg., 21 (1914), 

 No. 1, pp. 1-3, fig. 1; ahs. in Cream, and Milk Plant Mo., 2 (191 4), No. 6, pp. 

 25, 26). — Milk samples which yield more than 0.1 per cent of sediment should 

 be titrated for acidity, because it often happens that samples of this kind 

 contain precipitated casein. The alizarol test of Morres is best for this pur- 

 pose. It is also well to consider the presence of tubercle bacilli in the sediment 

 and to make an animal test for the purpose of differentiating between non- 

 pathogenic and pathogenic acid-fast bacteria. The presence of streptococci 

 should also be considered, but it is often difllcult to differentiate the pathogenic 

 from the nonpathogenic forms. 



The leucocyte test is considered the only simple method which we have for 

 detecting mastitis in cows, but when noting the leucocytes the epithelial cells 

 must not be counted as leucocytes. 



A description and illustration are given of a special form of sedimentation 

 tube, provided with a clamp which holds a removable cover at each end of the 

 tube. This allows for the proper cleaning of the tube, especially at its capillary 

 end. 



Is the reductase test a valuable method for controlling the milk supply? 

 H. M. HoYBERG (Ztschr. Fleisch u. Milchhyg., 2k (1913), No. 5, pp. 107-112).— 

 The test is not considered one with which the bacterial content of a milk can 

 be determined with any degree of accuracy. The reduction of the dyes may be 

 due to the formation, by abnormal or pathologic cellular metabolism, of certain 

 substances which are secreted with the milk. 



The fluidity of butter fat and its substitutes, G. F. White and R. H. 

 Twining (Jour. Indus, and Engin. Chem., 5 (1913), No. 7, pp. 568-573, figs. 4). — 

 In this article are presented the results of a series of viscosity measurements 

 of various butter and oleomargarine samples and of mixtures of known com- 

 position. In addition to this the iodiu number, saponification number, and 



