202 BOARD OF AGRICULTURE. [Jan., 



There is another point having a strong bearing upon the health 

 of animals breathing a contaminated atmosphere: it is the disturbed 

 electrical conditions, a subject not yet fully developed, but suf- 

 ficiently so to show that air fit for respiration is positively electric, 

 and impure air, unfitted for breathing, is negatively electric. In 

 this condition there can be no ozone or active oxygen, a higher 

 form of oxygen, as the diamond is a higher form of carbon than 

 we find in common coal. 



Ventilation consists of two processes, the removal of foul air 

 and the introduction of fresh. This art, if I might so term it, is 

 still in a rude and imperfect state, notwithstanding all the recent 

 improvements that have been made. We hear it frequently spoken 

 of now in the sanitary considerations of our houses; it is fashion- 

 able now to talk sanitary science and to be healthy, a step in the 

 right direction — and in ventilating them we are greatly aided by 

 our arrangements for artificial heating, but for our farm building 

 we have no auxiliaries, but must consider it alone. 



As v/e have stated, air, when expelled from the lungs is largely 

 composed of heavy carbonic acid gas ; it might be thought that its 

 heavy specific gravity would cause it to descend, but it must be 

 remembered that it is brought to the same temperature as the body 

 and acquires an upward tendency of very considerable force, as 

 may be illustrated by breathing in the open air in frosty weather; 

 the mixture of vitiated air is much lighter than common air, even 

 at the same temperature, a very beneficent law for our comfort 

 and health, for it quickly rises above the zone of our respiration, 

 so that it cannot be breathed again. If, then, we take advantage. 

 of this simple law, and fashion suitable means of egress in the 

 upper portion of our apartments, where it naturally arises, we free 

 ourselves from its pernicious influence. Its place must be supphed 

 with fresh, through suitable apertures, made in proper positions; 

 it will not come in through the opening in the roof or ceiling, for 

 that is already occupied by a strong current of outgoing aar. The 

 pure air is heavy and seeks for entrance below the space occupied 

 by the impure. "Nature abhors a vacuum;" as the warm and 

 contaminated air arises, a partial one is formed, the external pres- 

 sure of fifteen lbs. to the square inch drives the fresh air in to fill it. 

 If, then, we make suitable apertures near the floor, and in the 

 ceiling, our aim is accomplished. This is the whole art of ventila- 



