Variola : Pox. 381 



The contagion varies greatly in force in the different forms of 

 variola, the milder horsepox or cowpox, requiring actual contact 

 (inoculation) while in smallpox and sheeppox, infection may take 

 place at some distance from the patient (in sheep over 200 yards). 



A particulate infecting material was demonstrated by Chau- 

 veau, who filtered the virus and inoculated the -filtered liquid 

 without effect, while the solids retained on the filter invariably 

 produced the disease. 



The identity of the microbe of variola has been much discussed, 

 Guttmann and Grigorjew found in the lymph a coccus (Staphy- 

 lococcus albus variolse), Ruete a very motile diplococcus, and 

 others streptococcus, but in cutaneous lesions it is very difficult 

 to exclude such elements. Pfeiffer, Guarnieri, Van der I^oeff, 

 Wasielewski and others have drawn attention to small proto- 

 plasmic bodies (manifestly protozoa) found in the vaccine lymph, 

 and which appear to be the infecting agents. Wasielewski culti- 

 vated these on a rabbit's cornea to the 48th generation, and from 

 the last successfully inoculated a calf and several children. 



Funck finds this sporidium vaccinale constantly in the vaccine 

 lymph and surrounding tissue, as a refractile, amoeboid, spherfcal 

 organism (spore) i to 3/* in diameter, and, less abundantly, a 

 round or ovoid spore cyst 25/*. These cysts are either smooth, 

 or uneven like a raspberry, and have a single or double contoured 

 membrane. They are easily stained with Sudan III. Examined 

 in hanging drops they are seen just under the cover glass, not on 

 the surface of the drops. Larger flattened bodies found in the 

 lymph, with many included spores are manifestly epithelial cells. 

 Copiman cultivated the organism in glycerinated collodion cap- 

 sules in th^ peritonea] cavity of rabbits and dogs, producing 

 zoogloea masses staining peripherically with methylene blue, 

 andwhich caused typical vacciniain calves. He found the same 

 elements in variola of man. The research of Councilman sus- 

 tains the theory of a protozoon. 



HORSE POX. VARIOLA EQUINA. 



This was recognized toward the end of the i8th century, in the 

 valley of -the Severn, England, by Jenner, who beheved it to be 

 the origin of cowpox, but failed apparently to distinguish it from 

 ordinary ''grease.'' Today, when we must trace each case to a 



