The Farmer's Veterinary Adviser. 



banks, ships, quays, yards, manure-pits, drains, cess-pools, 

 harness, clothing, utensils, etc., all decaying organic mat- 

 ter should be removed, by scraping, washing, emptying, 

 etc., as such decomposing organic matter is the food which 

 sustains and preserves the disease germs out of the body. 

 Even the water and air must be carefully seen to, since in 

 close places they are usually charged with invisible par- 

 ticles of organic matter in a state of decay, the most 

 suitable field for the growth of contagious principles. 

 These, too, tend to purify themselves in. a free circulation 

 of air, and ventilation may be largely rehed upon for this 

 purpose, imless the deleterious supplies are too abimdant 

 from some adjacent putrid accumulation, as dung-heaps, 

 cess-pools, leaky draias, or soil saturated with filth. Pu- 

 rity of the surroundings kOls many contagious elements on 

 the priaciple of starvation. 



Of agents reputed to be disinfectants, some act merely 

 by changiag the physical condition of organic mat- 

 ter, without any abstraction from, or addition to its con- 

 stituents. Thus, heating to the boiling point (212° F.), co- 

 agulates albuminous matters and destroys infectious prop- 

 erties generally. But it must be prolonged for a variable 

 time according to the size of the object to allow of the 

 heat penetrating to all parts alike. Clothing may be 

 heated in an oven to 300° F., or safer, boiled, and even 

 the prolonged application of hot transparent steam di- 

 rected from a hose, upon wood-work, etc., previously well 

 cleaned, is found very effectual. , Some poisons, like that 

 of Texas-fever, are destroyed by freezing, while others are 

 unaffected. 



Other disinfectants act by changing the chemical re- 

 lations of organic matter, and hence of contagious princi- 

 ples, by uniting with them to form new compounds, by ab- 

 stracting some of their constituent elements or by adding 

 a new one. Thus the alotropic state of oxygen, called 

 ozone, produced abundantly during thunder-storms, is sup- 

 posed to be one of nature's most potent disinfectants, act- 



