784 EXPERIMENT STATION RECORD. [Vol. 37 



The virulence of hog-cholera blood at different periods during the disease, 

 R. A. Whiting {Jour. Amer. Vet. Med. Assoc, 51 (1917), No. 4. pp. 4in-493). — 

 The results of a study at the Indiana Experiment Station covering a period of 

 several years show that there is a gradual increase in the virulence of hog- 

 cholera blood as the disease progresses from four to eight days following inocu- 

 lation. Eight-day blood was found to be the most virulent. 



It is noted that in the production of virus for serum production hogs may be 

 killed at six days following inoculation, providing there is a corresponding high 

 temperature and a manifestation of symptoms, especially weakness. Blood ob- 

 tained on slaughter seven or eight days following inoculation was found to be 

 more virulent than any of the blood obtained by tail bleedings. 



See also a previous note by Craig (E. S. R., 34. p. 783). 



Summary of observations on 1,470 hogs hyperimmune to hog cholera, 

 H. C. H. Keenkamp (Jovr. Amer. Yet. Me4. Aisoc, 51 (1917), No. 4, pp. 557- 

 54O). — Observations on 1,470 hogs used in the production of antihog-cholora 

 t-erum at the Minnesota State serum plant, covering a period of approximately 

 87 months, are reported. 



During the first half of the period of observation two methods of hyperim- 

 raunization were used, de.signated as " slow Intravenous " and " intravenous." 

 In the slow intravenous method an interval of from four to eight days between 

 the first and the second injection of the necessary dose of virus to effect a 

 condition of hyperimraunity was allowed. In the intravenous method the injec- 

 tion was done at one operation, the virus l)eing injected into the posterior 

 auricular vein under a pressure of from 3 to 6 lbs. per square inch. A smaller 

 amount of virus is neces.sary in this metluxl. an<l it is considered much more 

 satisfactory than the slow intravenous method. 



Serum therapy for trichinosis, B. Schwartz (Jour. Amer. Med. Assoc., 69 

 (1917), No. 11. pp. 884-886).— The report by Salzer ' that animals fed with in- 

 fested meat later than 24 hours after the administration of serum from a con- 

 valescent animal prove to be immune, that infested meat mixed with immune 

 serum does not produce trichinosis in animals to which it Is fed, and that im- 

 mune serum Injected into animals suffering with the di.«ease produces a curative 

 effect led to the inve.'^tigation here reported, which is summarized by the author 

 as follows: 



" Serum from animals convalescent from trichinosis when injected into other 

 animals did not produce immunity to trichinosis in the latter. Trichinous meat 

 mixed with serum from animals during the active or convalescent stage of the 

 disease proved to be still capable of producing the disease. Animals once in- 

 fected and harboring trichina in their muscle.s were not immune to further 

 infection when fed trichinous meat. Serum from a trichinous animal had no 

 «»bservahlo ill effects on the larvae freed from their cysts by artificial digestion. 

 None of the results of the experiments appear to be in harmony with the a.s- 

 sertions made by Salzor concerning the value of serum from convalescent ani- 

 mals as a prophylactic or cunitive agent in trichinosis." 



Special equine therapy, M. R. Steffen (Chicago: .Amer. Vet. Pub. Co., 1917, 

 pp. 212). — This work gives special attention to diseases and conditions which 

 are unnamed, atypical, or of infrequent occurrence, the discussions being entirely 

 from the viewpoint of the general practitioner. 



Trichomonasis of chicks: A new and highly fatal disease. J. Weinzibl 

 (Jour. Bad.. 2 (1917), No. 4, pp. 44I-445, figs. 2). — Large losses of chicks on 

 ranches in the Puget Sound region of Wa.shington from disease le<l to the Inves- 

 tigation here reported. It is concluded that a protozoan of the genus Trlcho- 



iMed. Rec. [N. T.], 91 (1917), No. 6. p. 2G1. 



