ADDISON, 0\ ULOOD-CORPUSCLES. 1(57 



It has been declared upon authority that, ''Epidemic, 

 endemic, and contagious diseases are those in which the 

 blood is, probably, in the greater number of them the primary 

 seat of disease ; and they are considered the resvilt of specific 

 poisons of organic origin, either derived from without or 

 generated within the body." — Hippo crates, Sydenham, 

 Sprengel, Villerme, Williams, Liebig, Ozanam. ' Regis- 

 tration of the Causes of Death,' General Register Office, 

 1843. 



The smallpox disease is a contagious fever. It may arise 

 in a healthy person from inoculation of the smallpox virus; 

 also from inhaling an infectious atmosphere. In whichever 

 of these ways the disease is communicated, numerous pustules 

 appear on the body, each containing a secretion of contagious 

 quality, viz., the smallpox virus. This secretion must have 

 its origin in some cell -agency ; the question is, to what class 

 of cells it is to be ascribed. 



Liebig's hypothesis respecting the actions which siicceed 

 the introduction of the smallpox virus into the blood is well 

 known ; he speaks of particles of blood undergoing trans- 

 formation, but he does not specify them. 



First, — As respects inoculation. A quantity of matter 

 so small that it may be borne on a pin's point is sufficient to 

 establish the disease But this small quantity cannot well 

 be supposed sufficient to infect the whole of the fluid part of 

 the blood — the liquor sanguinis. Granting it is sufficient ; 

 still the main phenomenon — the reproduction of the virus — 

 would have to be accounted for. It is not the diffusion of 

 the virus used, it is the regeneration of it a myriad-fold 

 which is in discussion. 



It may be said the new virus is formed in the pustules ; 

 but the person suffers illness, general distress, and fever, 

 before the pustules appear — before they contain any virus. 

 Moreover, it is admitted that the primary seat of the disease 

 is in the blood. 



Colourless corpuscles, or white cells, exist in the blood in a 

 comparatively very small number — too few, it would seem, to 

 account for the very large reproduction of the smallpox virus ; 

 and in states of disease where the number of these white 

 corpuscles has been enormously increased, the symptoms 

 are not those of fever. 



Dismissing then the liquor sanguinis, because the question 

 entertained is the reproduction of the smallpox virus — a se- 

 cretion which requires cellular action; dismissing also the 

 cells of the pustules, because the inquiry has reference to some 

 determinate action in the blood ; and lastly, deeming the 



