34 PHARMACEUTICAL BACTERIOLOGY. 



perc.c. Filthy milk: may contain millions of microbes per c.c. From 100,000 

 to 3,000,000 microbes per c.c. is not uncommon in some milk which careless 

 dairymen declare to be "good." Soups, broths, etc., boiled squash, potatoes, 

 meats, and cooked organic substances generally, if allowed to stand for a day 

 or two, contain many living microbes. In the course of two or three days, 

 if the weather is warm, these substances teem with microbes and are rendered 

 wholly unfit for food because of the predominating rotting microbes which 

 develop the highly poisonous ptomaines. 



Microbes do not live and multiply in aseptic and antiseptic substances, 

 such as strong solutions of acids, of alkalies, of salts, etc. Used and dirty 

 cups, drinking vessels, milk bottles, dishes, cooking utensils, knives, spoons 

 and forks, hold numerous microbes. The public drinking cup has been the 

 source of numerous disease infections. Disease is carried by the tools of the 

 careless dentist and by the clothing, the apparatus and the clinical thermom- 

 eter of the indifferent and careless physician. The hand-shaking and kiss- 

 ing habits spread disease. These facts are generally known and indicate the 

 wide dissemination of the different kinds of microbes. 



From the foregoing it becomes clear that microbes are present almost 

 everywhere, and that it is impossible to escape them. It is the aim of the 

 science of bacteriology to distinguish between good and bad microbes, 

 between those which are desirable and those which are undesirable, between 

 useful and harmful microbes. It is not the aim of the science of bacteriology 

 to destroy them all, or to devise ways and means to escape from all of them. 

 In fact, we owe our very existence to these very minute organisms, as has 

 already been explained. 



Under certain conditions bacteria multiply very rapidly. Such sub- 

 stances as meat, milk, and organic foods of all kinds, if exposed to moisture, 

 warmth and removed from sunlight, soon swarm with microbes. Certain 

 non-pathogenic microbes, as the root nodule bacteria (of the Leguminosae) , 

 multiply very rapidly within the tissue cells. Others multiply upon the 

 exterior of roots and of root hairs, where they no doubt serve a useful pur- 

 pose to the plant. In bacterial diseases of plants and animals the microbes 

 multiply very rapidly and form large aggregates, as a rule. To pathological 

 conditions accompanied by extensive and general bacterial or microbic inva- 

 sion, we apply the term bacteremia. In some diseases the microbic invasion 

 remains localized and yet there are proiiounced general or systemic effects, 

 due to the absorption, into the system, of the toxins liberated by the microbes. 

 To such conditions we applythe term toxemia. Toxemia may, however, also 

 occur in bacteremia. 



Microbes do not multiply in the air itself, rather upon the organic dust 

 particles present, provided warmth and moisture are adequate. 



Since microbes multiply rapidly, perhaps one septation in from twenty to 



