]78 president's address — section I. 



the performance of other such work not involving construction, and 

 for the supervision of all house and other building done by private 

 persons, so as to secure good wholesome dwellings, workrooms, 

 and meeting places of all kinds. The tendency of modern legis- 

 lation is, as I have already mentioned, to leave in sanitary matters 

 less and less to private initiative. The result is that in some large 

 cities the town surveyor's staff is a very important one, and directs 

 a considerable body of workmen of all sorts. 



Enactments relative to public health may be broadly classed 

 into measures for securing the purity of the air we breathe ; 

 measures for securing the wholesomeness of the food and water 

 we eat and drink : measures for securing the healthiness of the 

 houses we dwell in, or work in, or meet together in ; measures 

 taken with respect to infectious diseases ; and measures other than 

 these, but which have a general reference to the public health. In 

 connection with ail these measures it is interesting to note how they 

 are being more and more based on scientific principles, and how 

 more and more attention is being paid to the investigation of those 

 principles. Much of this investigation is beyond the means of 

 small communities, and has to be undertaken either by the central 

 government of a coimtry or by the local authorities of large and 

 wealthy cities. To some of these authorities much praise is due 

 for the perseverance with which some branches of inquiry have 

 been carried on, not only in directions that have at once proved 

 useful, but also in some that are thus far apparently barren, of 

 practical result. Still more is praise due to scientific men in 

 private life, especially to medical men, for their unwearying inves- 

 tigations in matters of such vital importance to their fellow men, 

 for facts and coincidences are being observed and recorded that 

 may yet serve to point out law and order where now all is obscure 

 and seemingly disconnected. 



II. 



The work to be done by a local board of health, acting as a 

 municipal authority, may be thus summarised in the classes above 

 mentioned : — 



(«) MEASURES FOR SECURING THE PURITY OF THE AIR. 



1. The determination of the condition of the air, by observation. 



2. The removal of superfluous moisture, by drainage. 



3. The collection, removal, and proper disposal of sewage. 



4. The construction of streets in a manner to be easily kept clean. 



5. The proper cleansing of streets and disposal of street refuse. 



6. The proper control of offensive trades. 



7. Smoke prevention. 



8. The proper construction and cleansing of yards and courts. 



9. The prevention of over-density of population on a given area. 



