260 BOARD OF AGRICULTUEE. 



teachings of the microscope and the laboratory, than a theory 

 at all. This is known as the germ theory of disease, and it is 

 that the contagious or infectious diseases — or, in other 

 words, diseases that may be communicated from one person 

 to another — are caused by minute vegetable germs finding 

 lodgment in some of the tissues, or some of the cavities of 

 the body, and there growing or reproducing themselves. 

 For example, one kind of germ or germs fixing themselves 

 in the mouth or throat, and by their growth producing diph- 

 theria ; another kind finding their way to the lower part of 

 the bowels, and by their growth producing typhoid fever ; 

 another, entering the stomach and the upper part of the 

 intestinal canal, and by their growth producing cholera, etc. 



Now, as I have said, it is with these contagious diseases 

 that sanitary science has to deal, and how to prevent these 

 diseases in our homes, and how we can best manage them to 

 protect our families, as well as the families of our neighbors, 

 is the subject that is to engage our attention this evening. 



As every one acts more intelligently Avhen they know the 

 why and wherefore of a thing, — or, in other words, when 

 they know just what they are doing, and why they are doing 

 it, — I have thought best to try and explain to you, in a plain, 

 conversational wa}^ some of the experiments that have led 

 to the adoption of this germ theory of disease, believing 

 that even such a slight knowledge of this theory as can be 

 got in a single evening, and the researches that have led to 

 it, will not only add greatly to the interest of this occasion, 

 but it will enable 3^ou to act much more intelligently in the 

 way of protecting yourselves and families from these terrible 

 maladies. After a half hour spent in this direction, we shall 

 then consider how these contagious diseases may be com- 

 municated from one to another, how best to guard acrainst 

 them in our homes and elsewhere, and finally, how best to 

 protect our families and others when one of these diseases 

 has entered a household. 



Every housewife is familiar with the fact that, in damp 

 places, and particulaj'ly in damp weather, many articles, 

 if left undisturbed for a few days, become covered with 

 a fino bluish mou'd. This is particularly liable to happen 

 to bread, cheese, vegetables, leather, and often to articles of 



