206 EXPERIMENT STATION EECORD. 



raent fixation method with a specific antiserum is considered the best pro- 

 cedure, as markedly specific quantitative results can be" obtained with samples 

 w^hich contain only a small amount of the seeds. Miessner's method (E. S. R., 

 25, p. 683), and the Miessner and Rehwald conglutination procedure are not 

 deemed reliable. 



Milk testing, C. W. Wai^ker-Tisdale (London, 1911, 2. ed., pp. S^, figs. 

 2S). — This practical handbook was gotten up for the milk producer, dairy 

 farmer, creamery manager, and estate agent. It deals chiefiy with European 

 methods for examining milk, e. g., Gerber's test for fat, etc. 



A rapid and exact method for counting leucocytes and bacteria in milk, 

 O. Skar (Milchic. Zentbh, Jfl {1912), Nos. 15, pp. 454-461, fids. 2; 23, pp. 

 705-712). — The method consists of counting the stained organisms on a special 

 slide with the aid of an ocular micrometer. It could be used for milk showing 

 acidity which corresponds to 14 Soxhlet-Henkel degrees, and also for colostrum 

 and mastitis milks. 



In this method 0.4 cc. of a 2 per cent carbol-methylene blue solution is placed 

 in a test tube, and 10 cc. of milk from a pipette is added ; the mixture is shaken 

 thoroughly and warmed in a water bath (highest temperature 70° C.) for from 

 5 to 10 minutes. With a capillary pipette 1/50 cc. of colored milk is withdrawn 

 and spread on the slide with the aid of a very fine platinum needle up to the 

 limit of a square (20 by 24 mm.) drawn on the glass. The preparation is 

 allowed to dry in the air, and is not fixed, nor is the fat removed. Then a 

 drop of emersion oil is brought directly on the preparation and examined with 

 a 1/12 lens, using the No. 1 eyepiece. Canada balsam and a cover glass can be 

 used, but they are deemed of doubtful value. 



ThQ ocular micrometer consists of a glass plate on which certain lines are 

 scratched or etched. In the center is a small square which is of such a size 

 that when the lens is focused upon the object, it will cover 1/400 sq. mm., and 

 also a square which represents 5/400 sq. mm. of the object surface. Both of 

 the squares are surrounded by 2 circles, the inner one of which represents a 

 surface of 10/400 sq. mm., and the outer 12.5/400. Finally the entire field is 

 intersected by 2 lines which divide the field into 4 parts. The bacteria, etc., 

 present in from 10 to 20 fields are counted in the operation. A table for simpli- 

 fying the calculation is given. 



When bacteria alone are to be counted, the milk can be pretreated with sodium 

 hydroxid (30 per cent) ; this makes the bacteria very distinct. The errors 

 encountered in making bacterial counts on gelatin plates are discussed. 



About Cornalba's figures in milk examinations, F. Leperre (A6«. in Chem. 

 Ztg., 36 (1912), No. 25, p. 222). — New investigations have shown that Cornalba's 

 figures are only constant when milks from the same cow are examined. Great 

 differences were observed with various cows from different localities. 



Variations in the total solid and ash content of milk from cows affected 

 with streptococcic mastitis, Chretien (Hyg. Viande et Lait, 6 (1912), No. 7, 

 pp. 382, 3S3; abs. in Berlin. Tierarztl. Wchnschr., 28 (1912), No. 49, p. 924).— 

 The total solids and ash content of milk coming from cows affected with 

 mastitis increase at the beginning of the disease but diminish as it goes on 

 until the mammary gland becomes sclerotic. The total solids varied between 

 10.29 and 22.89 per cent, and the ash between 0.34 and 1.025 per cent. See also 

 a previous note by Fetzer (E. S. R., 27, p. 878). 



About international methods for judging milk, C. Barthel and O. Jensen 

 (Milchw. Zentm., 41 (1912), No. 14, PP- 4^7-^29; K. Landtbr. Akad Eandl. och 

 Tidskr., 51 (1912), No. 7-8, pp. 596-610).— It is stated that the reductase test will 

 probably become recognized as an international test for determining the quahty of 

 milk. It is, however, necessary to use uniform methylene blue preparation free 



