720 DISTRIBUTION AND HABITAT OF THE BACTERIA. 



however, where it is waxed and polished, this reservoir 

 of bacteria with its danger of infection need not be taken 

 into consideration. 



Further, the furniture, curtains, and corners of the 

 rooms, which are usually insufficiently cleaned, form 

 places on which bacteria may be deposited and preserved 

 for a considerable time. 



Bacteria in The refuse of houses and of cattle stalls forms also a 

 favourable place for the accumulation of bacteria. The 

 intestinal excreta contain at times infective agents mixed 

 with the large numbers of saprophytes; for example, 

 typhoid bacilli, cholera bacilli, tubercle bacilli, anthrax 

 bacilli, the bacilli of swine fever, of chicken cholera, &c.; 

 further, probably the infective agents of dysentery and of 

 the epidemic diarrhoea of children. Fresh urine seldom 

 contains micro-organisms, but it is a suitable nutritive 

 substratum for the most various kinds of bacteria; we must 

 further bear in mind the kitchen refuse, kitchen water and 

 washing water, which are for the most part laden from 

 the first with numerous bacteria, and can also serve as a 

 settling place for others when it stands for a long time. 

 Not a good All these waste materials have up to the present been 

 nutritive sub- looked on as the chief nutritive materials for pathogenic 



stratum for . . , / 



pathogenic bacteria, and in this respect have as a rule been much 

 over-estimated ; on the contrary, they usually offer such 

 excellent nutrient conditions for the saprophytes that 

 they are totally unsuitable for the growth of infective 

 agents. We see in all waste waters, in putrid fluids, 

 &c., that the facultative parasites, even when they are 

 sown in them in enormous quantities, die in a few hours, 

 or at most days ; and it is only in the spore form that 

 they can be preserved (without multiplication) for a 

 longer time. 



Dangerous on Hence these waste materials are only of importance 

 -account of the f or the spread of the infective diseases in so far as they 

 dejecta which may at times contain obligatory or facultative parasites 

 ^ which come from the bodies of diseased individuals ; and 

 hence the most important hygienic point with regard to 

 the removal of the waste materials is that the whole 

 mass, with the infective agents which may be present in 



