114 



HOUSEHOLD BACTERIOLOGY 



Dust as 



Source 



of Danger 



Summary 



of Special 



Terms 



possessions or the few that may bring disease to her 

 family. 



In general the harmful bacteria and other forms are 

 brought into her house as dust, which through some- 

 body's ignorance or criminal carelessness, is allowed 

 to scatter itself; dust allowed to collect in dark warm 

 places, to be blown about by wind ; dust rising from 

 dried expectorated matter on sidewalks, floors or fab- 

 rics, from drainage infected soil, possibly carried to 

 the water or food supplies. 



It used to be said that dirt was matter in the wrong 

 place. We see now that dangerous dirt is simply a 

 certain kind of matter in the wrong place. It is in- 

 deed, filth, because this dirt is alive it must not be 

 allowed to grow under any conditions which may bring 

 harm to man. 



A summary of a few special terms explained in the 

 text may serve as a review. 



Fermentation from a physiological standpoint is the 

 result of growth in organic matter of a living organ- 

 ized ferment. 



Alcoholic fermentation is usually brought about by 

 yeasts. A few bacteria and molds are found to be 

 capable of making weak alcoholic solutions. 



Fermentation is applied to the process when the 

 products are desirable or agreeable and non-poisonous. 



Putrefaction is fermentation carried so far or under 

 such conditions that the products are undesirable, dis- 

 agreeable, foul smelling and poisonous. 



