56 PUBLIC HEALTH 



had been long used empirically, and although it was a public health 

 measure now of the utmost interest and capable at the time of 

 great practical service, it had until recently no scientific basis, but 

 belonged in nearly the same class as the amulets and charms, the 

 prayers and incantations, of the superstitious. 



It was not until the middle of the eighteenth century, namely, 

 in 1767, that Sir George Baker, by the use of the methods of pure 

 inductive reasoning, made the first scientific discovery in public 

 health science in the subdivision of epidemiology, namely, that 

 the epidemic cholic of Devonshire, England, was due to an obscure 

 poisoning by lead conveyed through the common cider used for 

 drinking in that district. In 1774, the foundations of state hygiene 

 and sanitation were laid in consequence of the patient investiga- 

 tions and startling revelations of John Howard, by an act of Par- 

 liament providing for the sanitation of jails and prisons. The 

 beginnings of marine hygiene and sanitation appear in 1776, when 

 Captain Cook, the navigator, was awarded the Copley Medal of the 

 Royal Society for his remarkable success in protecting the lives of 

 his sailors on his second voyage. In 1796, Edward Jenner, working 

 also in a strictly scientific manner, and employing the methods 

 of rigid inductive research, laid securely for all time the founda- 

 tions of personal hygiene and immunization, by showing how we 

 can produce at will such modifications of the physiological resist- 

 ance or susceptibility of the human body as to make it immune to 

 small-pox. 



The importance of these fundamental and splendid discoveries, 

 not only to the public health of the time, but far more to the develop- 

 ment of public health science in all the centuries to come, is incal- 

 culable. Reduced to their lowest terms, we have in these eighteenth 

 century discoveries the germs of some of the most important 

 divisions of public health science as it is to-day, namely, (1) epidemi- 

 ology, (2) sanitation of the environment, and (3) immunization 

 of the human mechanism, this last the most marvelous phenomenon 

 hitherto discovered in personal hygiene. 



Time fails me to do more than name some of the principal steps 

 in the advancement of public health science in the nineteenth 

 century. We have, for example, in 1802, the beginnings of factory 

 hygiene and sanitation; in 1829, the first municipal water-filter, one 

 acre in area, constructed for the Chelsea Company of London; in 

 1834, recognition of the important relation of poverty to public 

 health, in the famous report of the Poor Law Commissioners of 

 that year; in 1839, the beginnings of registration and accurate 

 vital statistics; in 1842, an important report on the sanitary con- 

 dition of the laboring population of England; and in 1843, a similar 

 report on the health of towns; in 1854, for the first time clearly 



