TWELFTH ANNUAL YEAR BOOK— PART X 497 



man and farmer does not realize the Importance of thoroughly disin- 

 fecting his premises following an outbreak of contag'ous disease. There 

 is apparently a widespread lack of information regarding the germi- 

 cidal power of various substances, commonly termed disinfectants. There 

 is also a lack of knowledge concerning practical and economical methods 

 ance of a contagious disease on premises from which it was believed 

 to have been eradicated may frequently be traced to careless or imper- 

 fect work in connection with the cleaning and disinfection of the place. 

 This bulletin has been prepared with a view to emphasizing the im- 

 portance of the thorough disinfection of contaminated buildings and 

 to point out some of the most reliable disinfecting agents, together with 

 methods of their application. 



THE NECESSITY FOE DISINFECTION. 



It is but natural to acknowledge the presence of only such objects 

 as can be seen with the unaided eye. Since, however, by means of the 

 high-pcwered microscope, has clearly proved the ex'stence of numerous 

 minute animal and vegetable organism — microorganism — and it is a mat- 

 ter of common knowledge that many of these organisms frequently find 

 their way into the animal body and produce disease. It is also well 

 known that these microorganisms, or germs, vary in form and other 

 characteristics and that for each disease of an infectious nature there 

 is a specific germ. 



If these germs could be confined to the animal tody and die with it there 

 would be no such thing as an infectious disease. Unfortunately, how- 

 ever, they are thrown off by the animal through the excretions and lie in 

 the earth, in the litter of stables, upon the floor and walls, and in 

 cracks and crevices. Here they may remain and maintain their viru- 

 lence for an indefinite period, ready at any time to be gathered up by 

 an animal in its feed or to be blown about in dust and drawn into the 

 lungs. 



For example, we have tuderculosis in cattle and glanders in the horse. 

 In the former disease the causative agent is a rod-shaped germ (Bacillus 

 tuberculosis) , which is about one thousandth of an inch in length. Cattle 

 affected with tuberculosis pass myriads of these germs with the manure, 

 and it is not difficult to understand how in the average stable they 

 would have little difficulty in finding many lodging places. In glanders 

 the causative agent is another rod-shaped germ (Bacillus mallei), about 

 the same length as the tuberculosis germ, but somewhat thicker. A 

 characteristic of this disease is the formation of ulcers in the ncs'rils 

 and other portions of the body, from which there is more or less dis- 

 charge laden with the glanders germ. And here, again, it is not difficult 

 to understand how one diseased animal may contaminate extensive 

 premises. 



As has been stated, some of these minute forms are vegetable organ- 

 Isms. In fact, these vegetable parasites are the cause of some of the 

 most destructive diseases, and some of them are very difficult to destroy. 



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