244 THE BIOLOGY OF DISEASE 



Many hotels, public institutions, and well-run house- 

 holds insist that a prospective servant shall be examined 

 by a competent physician before being engaged for work. 

 In this way carriers may be detected, and persons with 

 germ diseases, like tuberculosis, for instance, are pre- 

 vented from spreading disease either in the food or in 

 the air. 



( hildren in the schools frequently have diphtheria germs 

 living in their nasal passages or throats, but are not ill. 

 After a time a number of children come down with the dis- 

 ease. A doctor then takes a sample of the contents of the 

 throat and nose of each child. The bacteria in the mucus 

 from the nasal passages is allowed to grow for twenty-four 

 hours in a special preparation called a culture (page 346). 

 At the end of that period the cultures are stained and ex- 

 amined with a high power of the microscope, and if diph- 

 theria germs are present, they are easily seen. If one of 

 the well children has these germs, he is treated until they 

 disappear. 



185. Quacks and Patent Medicines. — The term quack is 

 applied to a person who advertises that he can cure vari- 

 ous diseases by some new invention or newly discovered 

 remedy. A patent medicine is one which has been regis- 

 tered at the patent office, and this registration gives the 

 patentee exclusive right to the use and name of the so- 

 called remedy. Many millions of dollars are spent an- 

 nually in advertising special " cures " and new mechanical 

 contrivances guaranteed to cure diseases for which they 

 can do nothing, or even to cure such diseases as cancer, 

 for which there is no known remedy. 



Many people who do not understand the causes of dis- 

 ease are reluctant to consult a well-trained physician, but 

 read and believe the carefully worded advertisement of 

 some quack doctor or of some patent medicine. The 



