SIXTH ANNUAL YEAR BOOK — PART VIII. 



VENTILATION OF COW BARNS. 



619 



EXCHANGE. 



If the farmers in the northern states wish to avoid the introduction of 

 tubercuicsis into their herds, or to prevent its further spread when once 

 introduced, it is absolutely imperative that they provide better ventilation 

 in their barns, and especially in their cow barns. It is no secret to intelli- 

 gent men that while tuberculosis is decreasing in the human family it is 

 increasing among live stock in all those sections of the countrj- all the 

 v,'orld over where said live stock spend a considerable portion of the year 

 in barns. One reason why it is decreasing in the human family is because 

 physicians now thoroughly understand that it is not hereditary but a germ 

 disease. The two lines of policy adopted for the treatment of the dis- 

 ease are, first, the destruction of the sputum containing the germs, and, 

 second, keeping their patients as far as possible in the open air and well 

 nourished. Since these methods have been adopted, together with better 

 ventilation of dwellings and an ample supply of nutritious food, the 

 disease is rapidly decreasing. There are, however, enough of the germs 

 in the human family and in the live stock of the country to insure its 

 spread wherever either human beings are kept in improperly ventilated 

 houses or live stock in improperly ventilated stables. 



The reasons for this are obvious to any man who will do a little solid 

 thinking. Pure air is quite as necessary to health as either fcod or water, 

 and therefore whenever a large number of animals are massed together 

 in close stables ample provision must be made both for getting pure air in 

 and the impure air out. The vital element of air is the oxygen. Four- 

 fifths of the air is nitrogen, used apparently to dilute the oxygen; other- 

 wise the striking of a match would set the world on fire. Air once 

 breathed is deprived of this oxygen and unfit for breathing again, and will 

 not sustain life. When air is expelled from the lungs this oxygen has 

 been replaced by carbon dioxide or carbolic acid gas. moistui'e, ammonia, 

 and organic matter; still further when ventilation is imperfect, bacteria 

 and other disease-producing organisms multiply in the stable. 



The animal in the stable throws off through the lungs and pores a very 

 large proportion of its food and drink in the form of invisible vapor. Con- 

 sequently the air becomes damp and this interferes with the proper action 

 of the lungs and skin. Whenever moisture accumulates on the walls and 

 ceilings or floors, it is an unmistakable evidence that the stables are insuf- 

 ficiently ventilated. Whenever the farmer on opening his stable door on 

 a cold winted morning is met by a cloud of steam, he may know that Ms 

 barn ventilation is imperfect and that if he has a case of tuberculosis it 

 will speedily spread through his entire herd. 



Thus far we are looking at it purely from the farmer's standpoint. 

 Here is another view: The consumption of milk is increasing every year. 

 even more rapidly than population, for whole milk is now one of the 



