THE MANUFACTURE OE ANTISERUMS 58 1 



DoRSET-NiLES (Antihog Choleea) Serum (Hyperimmune 

 Serum)*. — ^This product has been described in the preceding chapter 

 under "hog cholera vaccine" (Double Treatment). When the hyp^- 

 immune serum is used -unaccompanied by the virus, either among 

 healthy or diseased swine, the process is known as the " Serum- Alone 

 Method." Reichelf has succeeded in producing an antihog cholera 

 serum which is sterile and free from inert solid matter by precipitat- 

 ing the globulins. Dorset and Henley J have announced the produc- 

 tion of a clear and sterile serum by employing an extract of common 

 garden beans together with salt to agglutinate the blood corpuscles. 



Antirabic Serum. — Animals which have been immunized to rabies 

 are bled and the immune serum may be used as a preventive and 

 therapeutic agent. While this "product is not often employed in prac- 

 tice, yet it has been shown by various investigators that considerable 

 protection is obtained from its use. 



Antidysenteric Serum. — Experimental monovalent and poly- 

 valent antiserums for epidemic dysentery have been developed by 

 Shiga and Flexner, by the injection of horses with the filtrates from 

 bouiUon cultures of the dysentery bapillus. 



The Preservation oe Antiserums. — The question of a proper 

 preservative for antiserums has received much attention. The 

 problem of preservation involves several conditions, as the ideal pre- 

 servative, when incorporated in the proper volume of serum in efficient 

 dilutions, must possess marked inhibit! ve and germicidal power, it 

 must prove inert when injected into the patient, and it must produce 

 no objectionable precipitation of serum proteins. At present, trikresol 

 or purified cresols (0.4 of i per cent) is generally employed. 



Biological Products Other than Vaccines and Antiserums 



Tuberculins. — Koch's Tuberculin (Old).— JLoch's tuberculin is the 

 concentrated, glycerinated, beef bouillon in which B^act. tuberculosis has 

 been grown. The active substance of the tuberculin is apparently an 

 albuminous body insoluble in alcohol. The product is harmless for the 

 non-infected, but exerts a toxic action upon tuberculous individuals, the 

 reaction being characterized by a rise in temperature which begins two 



• See U. S. Bureau of Animal Industry, Bull. No. 102. 

 ,tReichel, Proc. i8th Ann. Mtg. U.S.L.S.S. Asso., igis, p. 127. 

 t Dorset and Henley, Jour. Agr. Research, Vol. 6, May 29, 1916. 



