PRESIDENTIAL ADDRESS. vii 



greatly strengthened by experiments made in England and else- 

 where to determine whether sewer air is actually dangerous or not. 

 Medical officers of health are more conservative in their views, and 

 are for the most part strongly ' in favor of the retention of the 

 trap. 



It is probably true that there is no local sanitary authority in 

 this province, where sewers, drains and plumbing exist, which has 

 not had to deal, at some period or other, with complaints as to the 

 nuisance caused by the escape of sewer gas, and it may therefore be 

 assumed that the subject is of importance to every section of the 

 community. 



It is not advisable or necessary in these remarks to introduce 

 the technical pros and cons that are so often used. Such arguments 

 may be reserved for a technical paper or for the benefit of 

 municipal sanitary authorities. The question which is of special 

 interest to us, and which, too, must be considered to a certain 

 extent unsettled, since it is yet under investigation, is, does sewer 

 air injuriously affect health? 



About a year ago the borough council of Hampstead, England, 

 employe I two experts, F. W. Andrews, M. D., F. E. C. P., D. P. H., 

 and W. H. Hurtley, I). Sc., to make analyses of sewer air and 

 report on the bacteria suspended therein. 



The .particular points which the experts set themselves to 

 investigate were: (1) Can it be determined whether the emana- 

 tions from the sewers are likely to cause disease? (2) What is the 

 substance which gives rise to the disagreeable odors? (3) What is 

 the chemical composition of the sewer air at different levels? 



As regards the first point, which is the most important, it is the 

 general, but not altogether unanimous opinion, that sewage bacteria 

 do not exist in sewer air. This opinion has been based upon the 

 results of only a few investigations; and on the other hand it has 

 been abundantly proved that sewer air, escaping direct into houses, 

 has injuriously affected the health of the inmates. This fact has 

 led to the assumption that there must be some subtle chemical 

 action in such cases which has not yet been discovered, and which 

 might possibly also exert its influence in the open air. 



