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Dr. Lyon Playfair a few years ago, when addressing a meeting 
on Social Science, made a remark which may well be repeated in 
introducing to you this subject. He said, “ Hypocrates was the 
first to write a book on public health, and he took for his text, 
‘Pure air, pure water, and a pure soil’ ;—so that the moderns, 
after an age or more of ignorant neglect of his teachings, have 
arrived at the same essential conditions of health.” 
We can scarcely take up a newspaper at present without 
finding much space devoted to the question of water supply ; and 
in the scientific journals we frequently find interesting matters in 
connection with the same subject; so that we may conclude from 
this alone that it is one of general importance, increasing with the 
increase of population, and one which is receiving attention from 
those who are able to comprehend the importance of it. 
Again, considering the gigantic schemes for the supply of 
water to Manchester, from Thirlmere ; to Liverpool, from one of 
the Welsh rivers; and, indeed, the question of National Water 
Supply, under the consideration of the Society of Arts, we may at 
least apprehend the fact that expense is of secondary consideration 
to the matter of having a constant supply of wholesome water at 
the command of every inhabitant of our large towns. 
While, then, the supply of wholesome water is of public 
importance, it is evidently desirable that the conditions and im- 
purities which render it unwholesome should be more generally 
understood. We cannot safely act without reason. 
It is certain that at the present time we have in almost every 
direction a great deal of theory, but too little practice; and in 
regard to sanitary matters, Punch some weeks ago gave a striking 
illustration where a sea-side visitor, who had evidently studied the 
science of health, fully appreciated the delicious aroma of what 
was supposed to be the healthful iodine from the sea, but which 
on enquiry of a well-seasoned resident, was found to be due to the 
“town drains as flowed out just there” ! 
Certainly the bases of continued health are—pure air and 
pure water; but it is impossible to secure these absolutely—and 
especially the former—by any method of legislation, unless the 
people understand and endeavour, from their own desire, to avoid 
