576 EXPERIMENT STATION RECORD. 



5,700,000 per gram; the lowest number was 8,600 and the highest 41,000,000. 

 There was no particular relation between the number of bacteria and any other 

 constituent determined, such as salt reaction, moisture, etc. The number of 

 bacteria diminished markedly with age, in one sample 85.8 per cent in 2 weeks, 

 in another 93.7 per cent in 4 weeks, and in another 95.6 per cent in 6 weeks. 

 The number of bacteria may therefore be used as an index to the age of the 

 butter. 



Bacillus coli was found in only 6 of the 25 samples and then only in small 

 numbers. It seems that B. coli soon dies out in butter. Streptococci were 

 found in 14 samples, but no special relation between their presence and viru- 

 lence as tested upon guinea pigs could be made out. Bacterium wclchii was 

 not found in any of the samples. Tubercle bacilli were demonstrated in 2 of 

 the 21 samples tested for these organisms and from butter of apparently first 

 quality. Pasteurization of cream intended for butter is recommended. 



Butter (Maine Sta. Off. Insp. 58 (19 U), pp. 21-32).— Thia reports official 

 inspections made of the weight and chemical analyses of samples of package 

 butter in different parts of the State. 



Inquiry into the factors which control the texture of Cheddar cheese, I, 

 A. Geake (Jour. Agr. Sci. [England], 6 {19U), No. 2, pp. 169-178, figs. 3).— 

 This investigation was undertaken with the view of ascertaining the influence 

 of acidity on curd, caseinogen, and casein. In the course of the investigation 

 the following acids were used: Fatty acids; formic, acetic, propionic, butyric, 

 isobutyric, valerianic, and isovalerianic acids; oxyacids; and glycollic, lactic, 

 a-oxybutyric, j3-oxybutyric, and oxyisobutyric acids. 



It was shown that in the presence of weak organic acids, caseinogen and 

 casein swell and finally dissolve to a greater or lesser extent. The presence of 

 lactic or acetic acids hindered the solution of rennet curd. This is explained 

 as being due to the acids hindering the action of the enzyms, since these solu- 

 tions did not become putrid so readily as those in pure water. The acid curd, 

 in which the presence of large amounts of enzyms was excluded, was much 

 more readily dissolved by the acids than by water and by the stronger than 

 by the weaker lactic acid solutions. It was found that the addition of sodium 

 chlorid to lactic acid solutions of caseinogen lessens the solubility of the 

 caseinogen and if sufficient salt is added the protein is more or less completely 

 salted out. It was noted that there is a " very rapid change in the percentage 

 of caseinogen precipitated by concentrations of sodium chlorid between about 

 0.1 N and 0.17 N. At the former concentration the amount of caseinogen pre- 

 cipitated is less than 10 per cent, and at the latter is more than 90 per cent. 

 This illustrates the value of the method of separating proteins by fractional 

 salting out from solution." 



VETERINAEY ]V[EDICINE. 



Atlas and text-book of the more important animal parasites and their 

 means of transmission, R. O. Neumann and M. Mayeb (Atlas und Lehrbuch 

 wichtiger ticrisclier Parasiten und Hirer Uhertrager mit heso-nderer Berilck- 

 sichtigung der Tropenpathologie. Munich, 19H, vol. 11, pp. VI+580-{-93, pis. 

 49, figs. 260; rev. in Science, n. scr., J/O (1914), No. 1023, pp. 210-212) .—This 

 work, which deals with the more important animal parasites, includes 45 

 colored plates. 



Vaccination for infectious diseases, R. M. Staley (Proc. Penn. State Vet. 

 Med. Assoc, 30 (1913), I, pp. 64-69; Amer. Yet. Rev., 43 (1913), No. 6, pp. 

 611-6111).— This deals especially with the methods as carried out by the Com- 



