ON FEVERS AMONGST HORSES, CATTLE, ETC. 251 



and decomposition to pollute the air and produce antlirax if it 

 only needs the effluvia of such to enter the lungs. It is there- 

 fore clear something more is needed. If due care is exercised in 

 allowing pure water and food in moderate quantity, all goes well; 

 but once allow the products of decomposition to mix with the 

 nourishment of which the animal partakes, then the most 

 malignant form of anthrax fever will rapidly appear, and a 

 likewise fatal modification, viz., splenic apoplexy, will succeed a 

 continuance of heavy feeding on meals and oil-cake with few 

 roots and no water, providing the animals take no exercise, even 

 where the ventilation is as perfect as human minds can ensure it. 



We have the additional fact before us, viz., that even during 

 the existence of malignant anthrax in a herd confined to a 

 particular pasture, other cattle in adjoining fields entirely escape, 

 although conditions are to all appearances identical. 



The part that deficient drainage plays consists in the produc- 

 tion of a cold and wet surface, bearing but scanty food in winter 

 and spring, and during warm weather vegetation is forced rapidly 

 into growth, while the heat and moisture highly favours decom- 

 position. The first acts upon the system powerfully. After the 

 vicissitudes of winter the functions are suddenly called into 

 severe work, and nutritious elements are plentifully supplied. 

 The animal grazes long and breathes a polluted air which lies 

 close to the ground, and the herbage is contaminated if not 

 saturated with putrescent elements. As long as the land is 

 perfectly dry or covered with water no harm usually arises. 

 The poison — paludal or malarious poison— of marshy land is 

 developed by decomposition under the influence of temperature 

 higher than 60° F. and moisture within the soil. The action of 

 the poison appears to be that of a depressant or sedative to the 

 nervous system, and so interfering with the proper performance 

 of the assimilative functions while the blood is corrupted or 

 poisoned, and it becomes surcharged with all the elements of 

 decomposition, constituting the so-called septic or putrid state. 



Are the Septic or Anthrax Fevers Contagions ? — If we rest 

 merely upon the outward revelations which characterise these 

 affections, we might, with apparent reason, answer this question 

 in the affirmative. It must, however, be borne in mind that the 

 suddenness of attack, rapid and malignant course, together with 

 fatal terminations, are not necessarily the prominent features of 

 ^ contagious malady. It is a well-known fact that few epizootic 

 affections possess even these qualifications, and, conversely, there 

 are few enzootic or indigenous and non-contagious diseases 

 common to our domestic animals that do not possess most of 

 them. Contagious diseases are propagated by the transmission 

 of a morbid virus, which, in the case of those of foreign origin 

 particularly, requires a certain length of time to develop within 



