PARASITES 443 



others intimately associated with the patient. The spoons, 

 forks, and dishes used by a tubercular person are likely to be 

 infected with the organism and should always be sterilized by 

 boiling water before they are used by others. Strict observ- 

 ance of these and other similar precautions may enable one to 

 live in the same family with a tubercular person and yet avoid 

 infection. 



515. Where Danger Lurks. It seems that the average 

 healthy person has a rather high natural resistance against 

 tuberculosis, provided that he is properly conditioned but many 

 occupations and customs of modern life are highly conducive 

 to the contraction of the disease. People who work indoors, 

 particularly where there is much dust, poor ventilation, and 

 bad sanitary conditions are much more likely to contract 

 the disease than are those who work in a better environment. 

 This is shown by the following table which shows the number 

 of persons per 100,000 of population in the specified occupa- 

 tions, who died from tuberculosis of the lungs in the year 1900. 



Occupation Number of deaths per 100,000 



Marble and stone cutters 540 . 5 



Cigar makers and tobacco workers 476 . 9 



Compositors, printers, and pressmen 435 . 9 



Servants 430 . 3 



Bookkeepers, clerks, and copyists 398 . 



Laborers (not agricultural) 370 . 7 



Farmers 111.7 



Other sickness such as measles, whooping cough, scarlet 

 fever, and influenza which leave the body in a weakened con- 

 dition are often a predisposing cause of tubercular infection. 

 During attacks of these and similar diseases and during con- 

 valescence, one should be extremely careful to avoid all chance 

 of tubercular infection. 



We often hear the statement made that tuberculosis is 

 hereditary and that it tends to run in families. While the 

 former statement is entirely untrue, it is doubtless true that 

 susceptibility to the disease does run in families, or in other 



