314 
THE ETIOLOGY OF BLACKLEG. 
table nature in spontaneous charbon, of animal nature in 
contagion, cannot in the present day be contested; neither 
simple plethora, nor fatiguing journeys, nor over-crowded 
stables, can occasion charbon.” 
I will refer to but one more authority, that of Dr. F. M. 
Roll, Director of the Veterinary Institute of Vienna. In 
considering the etiology of cbarbon, that gentleman says 
(‘ Manual of the Pathology and Therapeutics of the Domestic 
Animals,’ 3rd edition, 1867), in describing the charbonic 
districts —“ It is the organic substances decomposing under 
the influence of the humidity of the atmosphere which fur¬ 
nish the miasma, the cause of cbarbon. It results from 
evidence that an elevated temperature, favouring the evapo¬ 
ration of the water of these earths, rich in humours, with an 
impermeable subsoil, marshy or boggy, and in laying have a 
great quantity of organic substances enclosed in the soil, is 
favorable to the decomposition of these matters, and to the 
accumulation of the products resulting from it, in the soil, 
air, and beverages.” And in the course of his argument a 
little further on, he says— 
“ The real producing agent of anthrax, miasmatic in its 
origin, appears, after Virchow, to act on the blood as a septic 
ferment. After a certain time the alteration of the blood will 
cause, according to him, local derangements, which in their 
turn will keep up the disease of the blood.” 
The preceding quotations plainly show that Continental 
veterinarians hold a decided opinion on the etiology of black¬ 
leg, and that opinion is in direct opposition to that held by 
British veterinarians. Further experiment directly contra¬ 
dicts the theory that this disease is caused by any use or 
abuse of ordinary food. Observers agree, however, in their 
description of the localities in which it is found: they are 
low-lying, liable to be flooded, in the vicinity of bodies of 
water, undrained; soils with an impermeable subsoil, rich 
alluvial soil, soils containing much vegetable matter. In 
these localities one aid alone is necessary to cause the disease, 
and that is a great elevation of temperature; this is a fact 
admitted on all sides, the result of ages of observation, 
chronicled in indisputable bistory. It is probable, for there 
are facts which rather seem in its favour, that the idea of 
Virchow may be correct, that, altered by the septic ferment 
or miasma, the blood produces local derangements of a gan¬ 
grenous nature; these may be tbe focuses of a virus which 
keeps up the disorder of the blood. 
It is much to be regretted that experiments are hardly in 
the power of veterinarians to test still farther the fallacy of 
