THE BACTERIA 217 
(refuse from stables, exposed and decaying garbage, etc.) 
and to keep flies out of public and private dwelling places ; 
to insure a pure and well-kept supply of milk and water ;! to 
keep vegetables and other foods that are sold in public places 
free from dust and flies and promiscuous handling ; to disinfect 
all known or suspected disease-bearing materials of all kinds ;? 
to have abundance of fresh air; to have all the sunshine possi- 
ble, since sunshine is destructive to many disease germs. 
202. Importance of high standards. The maintenance of a 
high standard of vigor is evidently important as a means of 
preventing bacterial disease. Many people have had disease- 
producing bacteria introduced into their bodies without any 
serious consequences — indeed, without even being conscious 
of danger. They were in such vigorous condition that the 
initial growth of bacteria was prevented. An instructive 
experiment relative to this pomt was performed by Pasteur. 
Ordinary domesticated fowls are not readily susceptible to 
anthrax ; Pasteur found, however, that if he kept the fowls 
at lower temperatures than was normal for them, they were 
very susceptible to anthrax, and that under such circum- 
stances it proved deadly to them. This is a common principle 
of hygiene. When, through excessive fatigue, loss of proper 
sleep or nourishment, or any other cause, bodily vigor is greatly 
reduced, susceptibility to disease is increased. 
Modern bacteriology has offered the human race the means 
of escape from many diseases. Ignorance, lack of care, and 
financial greed are often the only excuses that can be offered 
when certain diseases occur. If only those who are responsible 
1In Germany it is unlawful for filtered water to contain more than 100 
bacteria per cubic centimeter, and it should always contain less. Boston 
has a legal standard which requires that market milk shall not contain more 
than 500,000 bacteria per cubic centimeter, and Rochester, New York, and 
Milwaukee, Wisconsin, have legal standards of 250,000 per cubic centimeter. 
Certified milk should not contain over 10,000 bacteria per cubic centimeter. 
There is milk in which the number runs from one million to several millions. 
2In ‘Bacteria, Yeasts, and Molds in the Home,”’ by H. W. Conn (Ginn 
and Company), there is an excellent popular discussion of the nature of 
bacteria and the effects of their growth. 
