82 EXPEEIMENT STATION RECORD. 



and animal material is introduced, since an equal value, independent of the 

 actual lethal time and weight of individual animal, can now be attached to all 

 the experimental data. 



" The results obtained will also possess a greater validity and a wider appli- 

 cation than it has hitherto been possible to attain by the use of an arbitrary 

 death time and a fixed standard weight of experimental animal." 



See also previous work (E. S. R., 31, p. 80). 



Studies in anaphylaxis, R. Weil {Jour. Med. Research, 30 {19U), No. 3, pp. 

 299-364, figs. 33). — This series of studies includes the relation between antibody 

 content and lethal dose in anaphylaxis, the function of circulating antibody 

 and the avidity of cellular antibody, the relation between partial desensitiza- 

 tion and the minimal lethal dose in anaphylaxis, and the persistence of intra- 

 cellular antigen as a factor in immunity. Each of the problems is said to have 

 an important bearing on the understanding of certain aspects of immunity. 



A theoretical discussion of the share of intracellular antigen in immunity and 

 in desensitization is appended. 



The relation of vaccine therapy to veterinary practice, R. E. Spline (Amer. 

 Vet. Rev., J,5 {191-',}, Nos. 1, pp. 19-29; 2. pp. 161-177).— A detailed exposition. 



Observations upon the standardization of bacterial vaccines by the 

 Wright, the liemocytometer, and the plate-culture methods, E. Glynn, Mil- 

 dred Powell, A. A. Rees, and G. L. Cox {Jour. Path, and Bad., 18 {1914), ^o. 3, 

 pp. 379-400, tils. 3; ahs. in Lancet [London], 1914, I, No. 15, pr>. 1028-1032, figs. 

 4; Jour. Amer. Med. Assoc, 62 {1914), No. 19, p. 1509). — "Four methods of 

 standardizing vaccines have been compared — Wright's and Allen's modification 

 of it, the hemocytometer, and the plate culture. The gravimetric will be con- 

 sidered on a future occasion. 



" The most scientific method of enumerating the bacteria is in some form 

 of hemocytometer chamber. An optically plane cover slip must be used with 

 such apparatus, for it is recognized as essential when counting blood, and is 

 still more essential when counting bacteria, where accuracy is of greater 

 importance. Owing to the small free working distance of oil-immersion lenses, 

 most optically plane cover slips are too thick. 



"Two types of hemocytometer chamber may be employed: (a) The ordinary 

 chamber 0.1 mm. deep with an optically plane cover slip 0.13 mm. thick. This 

 is suitable for all oil-immersion lenses with a free working distance of 0.17 

 and some of 0.15 mm.; (b) a chamber of 0.02 mm. deep with a special safety 

 trench 2.5 mm. wide, and optically plane cover slip 0.18 mm. thick. This is 

 suitable for all achromatic oil-immersion lenses, even if the free working dis- 

 tance is as low as 0.09. The 0.02 mm. chamber is preferable, for the following 

 reasons: (a) Almost all the bacteria settle at the bottom in 15 minutes, when 

 :i ecu rate counts can be made, whereas in the 0.1 chamber a considerable num- 

 l)er are still moving after half an hour; (b) bacteria adhering to the under 

 surface of the cover slip or still floating in the chamber are much more easily 

 enumerated; (c) the optical definition of the bacteria is better owing to the 

 smaller quantity of fluid; (d) the free working distance is greater, the cover 

 .slip more durable. A weak solution of carbol thionin is the best diluting and 

 staining fluid; unlike Giemsa it is quite free from precipitate and stains more 

 intensely. 



" In order to ascertain whether the Wright film or the 0.02 hemocytometer 

 chamber was more accurate, two observers standardized the same emulsion by 

 each method, and took as the practical test of accuracy the percentage devia- 

 tion from the arithmetic mean of their two counts. The error for each method, 

 as estimated iu a larger series of prepared emulsions of staphylococcus, strep- 



