CONTROL AND USE OF BACTERIA 395 



All of these matters are related to health because they have to 

 do with special kinds of disease microbes. 



For the purpose of enabling the public to measure from 

 time to time the progress (or the reverse) in matters of 

 health, population, etc. many states and cities require the 

 registration of all births as well as of all deaths, and the 

 notification of the health authorities in every case of conta- 

 gious or infectious disease. By means of records thus obtained 

 the public is helped in protecting itself. Many diseases are 

 subjected to quarantine and placarding. There are provisions 

 for supplying vaccines, serums, etc. through public laboratories, 

 and for supervising the manufacture and sale of such prepara- 

 tions for profit. There are laboratories for making accurate 

 examinations of blood and other specimens obtained from 

 patients for the purpose of diagnosis. Provision is made for 

 disinfection of discharges from the bodies of sick people ; vac- 

 cination where needed ; inspection of schools and factories to 

 determine sanitary conditions ; exclusion of sick persons from 

 schools etc. In some places there are visiting nurses, ambu- 

 lance service, and hospital service, all helping to keep down 

 the amount and the intensity of sickness. 



The activities of various classes of workers are regulated in 

 the interests of public health. Licenses are required of physi- 

 cians, dentists, druggists, nurses, and midwives. Rules are pro- 

 vided to guard against the transmission of bacteria in barber 

 shops and through manicurists and masseurs. 



The keeping of animals within city limits — dogs and cats, 

 as well as horses, cows, and poultry — is regulated for the 

 purpose of preventing the multiplication and spread of bacteria. 

 In many cities dogs have to be muzzled ; this device must 

 eventually eliminate all rabies from towns, since this disease is 

 transmitted by the bites of dogs. The burial or other disposal 

 of dead animals is also regulated. 



Lodging houses, tenements, and workshops must provide sui-"-- 

 able conditions of light, ventilation, and plumbing. Plumbing 



