FILTERABLE VIRUSES 437 



made by Maggiora and Valenti 6 who, in thirty experiments, 

 found that dilute mixtures of blood and water (1 in 40 or 60) 

 were still infective when passed through Berkefeld or Cham- 

 ber land F. niters, which were proved to be efficient for the 

 arrest of such small visible organisms as the pyogenic staphylo- 

 cocci. On the other hand, the filtrate furnished by a Chamber- 

 land K. filter under a pressure of not more than one and a half 

 atmospheres, was non- infective. 



Other diseases of fowls and birds. Schiffmann 7 found 

 in the brains of pigeons and young geese in which the disease 

 is not acute well defined corpuscles which present a certain 

 resemblance to the Negri bodies of rabies. All attempts to 

 induce the virus of fowl plague to multiply outside the body 

 have failed. Maggiora and Valenti found that the blood kept 

 in hermetically sealed tubes in a cool place and in the dark 

 retained its virulence for at least 45 days. Dried blood kept 

 under similar conditions retained its virulence for 22 days. 

 When exposed to the air in diffuse sunlight it remained viru- 

 lent for 15 days. According to Lode 8 pieces of the organs 

 such as the liver placed in glycerine retained their virulence 

 for from four to five months. 



Marx and Stickner 9 found that the virus of the affection 

 of birds known as epithelioma contagiosum would pass through 

 a filter. Juliusberg 10 confirmed the results of Marx and 

 Stickner and showed that the virus of this disease in pigeons 

 was also filterable. Burnet X1 obtained varying results in his 

 experiments with the pigeon virus. 



Maggiora and Valenti found that the Chamberland filter 

 K. under a pressure of one and one-half atmospheres held 

 back the virus of exudative typhus of chickens or chicken pest. 



Rinderpest (cattle plague). Nicolle and Adil-Bey 12 



Maggiora and Valenti. Zeit. f. Hyg., Bd. XLII (1903) p. 185. 

 7 Schiffmann. Zeit. f. Hyg., Bd. LII (1903) p. 185. 

 Lode. Centralbl. f. Bakt, Bd. XLIII (1906) p. 355. 



9 Marx and Stickner. Deut. med. Woch., 1902, p. 893. 



10 Juliusberg. Deut. med. Woch., Oct. 1904. 



11 Burnet. Ann. de 1'Inst. Pasteur, Vol. XX (1906) p. 742. 

 "Nicolle and Adil-Bey. Ann. de 1'Inst. Pasteur, Vol. XVI (1902) 



p. 56. 



