378 EXPERIMENT STATION RECORD. [Vol.38 



Certified milk is also satisfactory in this respect. A sane milk supply, however, 

 must also be free from excessive dirt. To eliminate dirt the milk should 

 be rated on the basis of laboratory tests, such as (1) total count, (2) Bacilhis 

 coli determination, (3) visible dirt test, and (4) B. sporogenes determination. 

 It should be graded according to the laboratory tests into A, B, and C grades, 

 and these stated upon the bottles and containers in which the milk is sold. 



A sane milk supply must also be cheap enough to be within reach of the 

 common people. For this purpose certified milk is a failure. If dairy demon- 

 stration supersedes dairy inspection and laboratory tests the score card in 

 grading milk, and care is made superior to equipment in barns and machinery, 

 then it is maintained that a clean milk may be had at a reasonable price as well. 



Milk and its distribution in Philadelphia, T. B. Harbison {Pliiladeiphia: 

 Chamber Com., Ed. Committee, 1911, pp. 12, figs. 12). — This number of the 

 series of educational pamphlets issued by the Phila^lelphia Chamber of Com- 

 merce explains the methods of handling and safeguarding the milk supply of 

 Philadelphia. 



Dairying in Colorado, R. McCann {Denver, Colo.: Colo. Bd. Imrnigr. [1917], 

 pp. 10, figs. 2). — The development and future prospects of the dairy industry in 

 Colorado are outlined. 



VETERINARY MEDICINE. 



Immune sera, C F. Boldtjan and J. Koopman {New York: John Wiley & 

 Sons, Inc., 1917, 5. ed., rev., pp. Till +206, figs. 9).— This is the fifth edition of 

 the work previously noted (E. S. K., 26, p. 579). Neither the plan nor scope 

 of the previous edition has been changed, but the entire material has been 

 revised. 



Dichloramin T and chlorinated eucalyptol 1.2, 2, R. B. Keauss and E. 

 Cbede {Jour. Amer. Chem. Soc., 39 {1917), No. 12, pp. 2720-2722) .—The authors 

 describe a method for the preparation of stable toluene-p-sulphon-dichloraraid 

 (dichloramin T), a method for the preparation of chlorinated eucalyptol 

 (specific gravity 1.2), and other chlorinatlon products of eucalyptol on a 

 large scale. 



Preparation of a preservative from cresol, Mary Nevin and B. Mann {Jour. 

 Amer. Chem. Soc., S9 {1917), No. 12, pp. 2752-2756).— Experimental data pre- 

 sented show that purified and redistilled cresol can be used as a preservative 

 for biological products. The fraction boiling between 199 and 204° C. (specific 

 gravity 1.03 at 25°) was best for this purpose. Its toxicity was found to be 

 the same as phenol, slightly lower than that of " Trikresol," but having a 

 germicidal coefficient of 2.55, which Is higher than that of Trikresol. 



It is Indicated that Investigations are being carried out to determine the 

 practical value of preservatives In Immune sera and purified antitoxin. 



The toxin of Bacillus welchii {Jour. Infect. Diseases, 21 {1917), No. 6, pp. 

 580-599). — The two following papers are presented: 



I. Toxin production by various strains, P. H. DeKruif, T. W. Adams, and 

 P. M. Ireland. — The authors have studied the toxlcogenlc power of ten strains 

 of B. welchii, and have found that all produce toxin in a greater or less degree. 

 An antitoxin produced by the injection of toxin from a single strain neutralized 

 all of the other toxins, a fact which Indicates the common nature of the toxic 

 products of the various strains. In studying various methods of toxin produc- 

 tion. It was found that the usual layer of sterile paraffin oil was not neces- 

 sary for securing growth or toxin production, and that methods of removing 

 oxygen, smch as exhaustion or absorption, were superfluous. Boiling the 

 medium before use was found to be sufficient. A considerable concentration 



