80 LAIRY CHEMISTRY 



and harnesses stored in poorly ventilated stables. As 

 is well known, it causes rotting of the leather, and 

 as could be reasonably assumed has a similar destruc- 

 tive action upon the mucous membranes. Animals 

 can stand a low temperature in pure air with less 

 discomfort than a higher temperature with impure 

 air. However, good ventilation does not necessarily 

 mean cold stables. Stables can be so constructed 

 that the income and outgo of air can be regulated, 

 rather than leaving the ventilation to faulty con- 

 struction. Ventilators made of drain tiles are more 

 sanitary than those made of wood. An old ventilat- 

 ing flue is often a source of pollution, due to the 

 moist air causing decay of the wood, which then 

 furnishes lodgment for disease germs. In order to 

 secure the best sanitary conditions in a stable, the 

 walls should be whitewashed at least once a year, 

 oftener if any contagious disease has occurred. 



Care of Milk and Dairy Utensils. — Milk is often 

 rendered unsanitary by unnecessary exposure to foul 

 air, and by handling in unclean pails, pans, and other 

 dairy utensils. In order to improve the keeping 

 qualities of milk, it should be cooled by exposure to 

 clean, pure air. When not cooled at once, fermenta- 

 tion changes often begin immediately, causing an in- 

 crease in the bacterial content of the milk. Too 

 frequently milk is strained in the stable, in which 

 case it becomes additionally fouled from the stable 

 air, filled with dust particles carrying innumerable 

 ferment bodies. The straining should be done out- 



