680 EXPEmMETrr ffCATTOir BECOBD. tV«l.88 



production of hemolysins, agglutinins, and opsonins was observed In the In- 

 jected animals, as compared with normal controls injected with the same 

 antigen. The depression was most marked in the case of hemolysins and 

 least so in the case of opsonins. 



On the concentration of antitoxic sera, Annie Homeb (Biochem. Jour., 10 

 {1916), No. 2, pp. 280-S07, figs. 5).— The work reported shows that the advan- 

 tages claimed by Banzhaf '^ for the one-fraction process in the concentration of 

 sera are often vitiated by the fact that a final product is obtained which on 

 account of the presence of an opalescent suspension, presumably euglobulin, 

 can not be filtered except after long standing. The successful preparation of 

 an easily filterable end product has been found to depend on the initial heating 

 of the serum mixtures. The heating process does not cause a conversion of 

 pseudoglobulin into euglobulin, but merely serves to complete the aggregation 

 of the euglobulin into particles sufficiently large to admit of separation by 

 filtration. 



The uncertainty with regard to the successful heating of the serum mixtures 

 is obviated by the addition of 1.5 per cent sodium chlorid. It is deemed pos- 

 sible that the addition of sodium chlorid exerts a favorable influence on the 

 filtration process by an adjustment of the hydrogen-ion concentration of the 

 serum mixtures. 



Observations with regard to the effect of the addition of sodium chlorid to 

 the serum mixtures have also been made and are reported in detail. 



A multiple pipette for the complement-fixation test, J. M. Buck {Jour. 

 Infect. Diseases, 19 {1916), No. 2, pp. 267-271, figs. 3).— A. pipette by means of 

 which twelve portions of either normal salt solution, complement, sensitized 

 serum, or any of the other elements used in serological diagnosis can be dis- 

 tributed at one time is described, as well as a special container for the sub- 

 stance to be distributed and a modified test-tube rack. The multiple pipette 

 not only permits of indefinitely greater progress with greater accuracy but also 

 eliminates the severe eye strain resulting from the constant reading of the 

 type of pipette generally used. 



Hemolytic streptococci found in milk: Their significance and their rela- 

 tion to virulent streptococci of human origin, D. J. Davis {Jour. Infect. Dis- 

 eases, 19 {1916), No. 2, pp. 2S6-252, figs. 2).— The results of the study reported 

 are summarized as follows : 



" Hemolytic streptococci, having a wide clear zone, occur commonly in both 

 pasteurized and unpasteurized (certified) milk. These strains vary among 

 themselves. They are more resistant to heat than human strains of hemolytic 

 streptococci, and possess little or no virulence for rabbits, therefore in all proba- 

 bility none for man. They rapidly acidify and coagulate milk, and grow well at 

 20° C. They form short or long chains, but as seen in milk often appear in 

 pairs or a chain of few elements. While they are definitely hemolytic . . ., the 

 characteristics of the hemolytic zone on plates may vary in certain respects. 



" The milk strains are different from certain strains of hemolytic streptococci 

 found at times in diseased udders in cows. These latter resemble the strains 

 of hemolytic streptococci from human sources, and are virulent for rabbits. 



" There is no reason to consider that these organisms have any sanitary signifi- 

 cance. The importance, however, of certain types of hemolytic streptococci in 

 relation to epidemics of sore throat makes It necessary to study carefully all 

 such organisms in milk. By itself the hemolytic property has no more value 

 for identification purposes than many other characteristics, but is greatly im- 

 portant on account of the practical value of the blood-agar-plate method as a 



•CoUected Studies Bur. Lab. Dept Health N. Y. City, 7 (1912-13), pp. 114-116. 



