Lung Plague and Qholera. 159 



tion, reducing the size of the lung-cells by the irritating 

 excess of carbonic acid and poisonous animal matters, thus 

 having their breathing capacity diminished, until the stage 

 of suffocation is reached. 



In either of the above cases, the certain primary cause 

 of a deficient supply and reduced proportion of oxygen in 

 the circulation, arises from the close and long-continued 

 confinement of cows, in most instances in which lung- 

 plague occurs.* 



When lung-plague becomes contagious, it is because 

 Bacteria or other scavenger or fungoid growths, mature in 

 the poisoned blood, the result being that spores are ex- 

 naled by affected cows, and inhaled by others that breathe 

 exhaled air containing spores ; whether the cattle that in- 

 hale the spores be predisposed by poisoned blood or not. 



There is but little danger of lung-plague when a fair' 

 extent of out-door exercise and breathing keep the blood 

 pure. But when the circulation is surcharged with excre- 

 tory poisons, as usually happens to inactive cows that 

 breathe but little oxygen, while taking but little exercise, 

 the danger arising from inactivity and retained poison in 

 the blood is much augmented. In fact, the danger of in- 

 fection and contagion is increased in proportion to the| 

 excess of excretory poisons that are wranecessarily retained 

 in the blood; the poisoning of the blood in such cases 

 arising from the exercise and breathing having been re- 

 duced to a much less extent than is necessary to maintain 

 the sound quality of blood and the sound health that re-, 

 suit from regular daily exercise, which causes active breath- 

 ing and a healthy supply of oxygen in the circulation. 



When hogs are fed almost exclusively with corn or corn- 

 meal, their blood becomes over-loaded with carbonaceous 



* We believe that tlie blood of cattle that arc affected severely with lung 

 fevers, either acute or long-continned, is over-charged with excretory poi- 

 sons; and that a large majority of cows or other cattle that arc affected with 

 Ehinderpest are by far too much restricted in their exercise and breathing. 



