52 BOARD OF AGRICULTURE. [Jan., 



* 



garded as specially objectionable. I am happy to testify that 

 they are growing less frequent. 



But it is worth while to inquire in what way they may 

 influence unfavorably the health of the family. Four or five 

 hundred years before Christ, Hippocrates, the father of medi- 

 cine, announced the cardinal requisites of a healthy situation 

 to be " Pure Air, Pure Water, and Pure Soil." 



No one since has ventured to dispute his statement. You 

 have read and heard a great deal about ventilation and the 

 necessity of having the air in our houses renewed frequently. 

 But there might be a doubt of the benefit of the change, if 

 the air we admit from the outside is laden with the unfragrant 

 odors of the swill barrel, the cesspool, the privy, and the 

 hog pen. 



It is true that offensive smells are not of themselves capa- 

 ble of causing smallpox or diphtheria, or other infectious 

 diseases, unless they are associated with the germs of those 

 diseases. But a bad air of itself is depressing in its efifect, 

 it lowers the standard of health, diminishes the powers of 

 resistance to disease, causes headaches, sore throats, loss of 

 appetite, and a general feeling of malaise. It is a direct vio- 

 lation of the principle laid down by Hippocrates and con- 

 firmed by the experience of more than two thousand years. 

 To enjoy the best health we must have pure air. 



In order to get a practical idea of the impurities in the 

 house it is only necessary to darken any room in your house 

 after sweeping it and then admit a beam of sunlight through 

 any small crevice in the window and note the myriads of 

 floating particles made visible by that ray of light. This is 

 commonly called dust, but a careful study of its true char- 

 acter determines that a large portion of this dust is in fact 

 composed of living germs — microscopic organisms — bac- 

 teria. Scientists have a way of estimating their number in 

 a given volume of air. By exposing in such a room for a 

 few minutes a plate covered with any material upon which 

 such germs will feed and grow (usually some preparation of 

 gelatine in a moist condition), so that the dust as it falls upon 

 it will adhere to it, then putting the plate aside, properly 

 covered in a warm place, it will be found that these germs so 

 planted wall have grown so as to be visible to the naked eye. 

 Each germ that has found lodgment upon the germ food will 



