100 ELEMENTS OF GENERAL SCIENCE 



It is best always to use a handkerchief when coughing or 

 sneezing. Spitting on sidewalks, streets, and in other public 

 places is even worse than spitting in private houses, since 

 less attention is paid in public places to detailed cleaning, 

 and the quick drying of the sputum in the open air rapidly 

 makes it a part of the dust. Hands rapidly accumulate this 

 dust from stair rails, door knobs, pencils, books, and other 

 objects of common use. Protect your mouth against the 

 entrance of everything except clean food and water. Many 

 states have laws regarding the use of public towels and 

 drinking cups and the display of uncovered food. Is this 

 true in your state ? 



115. Transmission of typhoid bacteria. Within the body of 

 a person who has typhoid fever the number of bacteria may 

 become enormous and may produce such injury as to cause 

 death. But no matter how many typhoid bacteria there may 

 be that affect this person, no other person would catch typhoid 

 from him unless some of the bacteria were transmitted to 

 the second person. Obviously it is of great importance that 

 disease-producing bacteria shall not be transmitted from one 

 person to another. The way to prevent transmission is to 

 make sure that all bacteria from a person who has typhoid 

 fever are promptly killed. This is most difficult, for it is not 

 easy to sterilize everything that might carry bacteria. Further- 

 more, some people who have recovered from typhoid fever 

 continue to have living typhoid bacteria in their bodies for 

 several years, thus making possible continuous distribution 

 of disease germs. 



116. Importance of pure milk and water. Milk and water 

 have often been the means of carrying typhoid bacteria. 

 Many cases show conclusively that when a dairyman or 

 some member of his family has typhoid, many of the 

 people whose milk supply comes partly or wholly from this 

 dairy may take the disease. Lack of care has made possi- 

 ble the introduction of typhoid germs into the milk, and 



