WHAT WE BREATHE 49 



of various descriptions of disease germs. He con- 

 structed an apparatus in which he suspended pieces 

 of linen soaked in broth infected with the particular 

 micro-organism to be tested. Tobacco smoke was 

 then admitted, and the microbes were retained in 

 this stifling atmosphere for half an hour. In these 

 surroundings cholera and typhoid germs were 

 destroyed, and other bacteria, such as the anthrax 

 bacillus and the pneumonia bacillus, were so pre- 

 judicially affected, that when subsequently trans- 

 ferred to their normal surroundings it was only with 

 extreme difficulty that they could be revived. 

 When, however, the tobacco smoke was made to 

 pass through water before reaching the bacteria, its 

 pernicious influence was entirely removed, and the 

 latter suffered no detriment. Hence the practice, 

 so often seen in the East, of passing tobacco smoke 

 through rose or other perfumed water before inhal- 

 ing it, whilst doubtless rendering it less noxious to 

 the smoker, deprives the exhaled tobacco fumes of 

 all their bactericidal or disinfecting properties. 



To return, however, after this somewhat lengthy 

 digression, to the question of dust and its bacterial 

 properties, we have learnt enough to enable us to 

 realise that the movement for the migration of 

 the working-classes from crowded streets to rural 

 districts, in which Mr. George Cadbury has played 

 so practical and important a part in the creation of 



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