386 



SCIENCE OF HOME AND COMMUNITY 



acts of coughing and sneezing. These may find entrance 

 into another body in three ways: (i) by being breathed in 

 through the mouth or nostrils, (2) by being taken in food or 

 drink, and (3) by entering wounds. The first two are the 

 most common. 



Bacteria in foods. It is known that cattle are subject to 

 tuberculosis and it seems now to have been definitely proven 

 that through the meat and milk of diseased cows the bac- 

 teria of tuberculosis may be taken into the human system. 

 On the other hand, cattle may take the disease from human 

 beings by eating grass upon which the sputum of a sick 

 person has been deposited. 



FIG. 152. How the germs of consumption are carried from the sick to the well. 

 By sputum. By two people taking a bite from the same apple. 



It has been found that young children are specially sus- 

 ceptible to the germs in milk from tuberculous cows. These 

 bacteria may be found not only in the milk itself but in the 

 products obtained from it, as cream, butter, and cheese ; and 

 in oleomargarine, sometimes used as a substitute for butter. 

 Investigations made in the city of Washington showed that 

 5^ per cent of the samples of milk tested contained bacteria 

 of tuberculosis. It was found also that 17 per cent of the 

 cows examined in the neighborhood of this city were affected 

 with tuberculosis. Investigations made in Europe indicate 

 that the per cent of butter containing the tubercle bacilli is 

 slightly larger than the per cent of milk. 



