It is particularly gratifying to me to be called on to speak before a gathering of physicians, as it gives an excellent opportunity to air certain grievances which, as a sanitary engineer, I have against the physician.
One of the chief of these grievances is that there is often so little apparent relation between the quality of a water supply and the health of those habitually using the water. Engineering is supposed to be an exact science, and when the cause is present the engineer looks at once for the effect. It grieves him, therefore, when a water supply is obviously polluted, when it is known to contain excreta from typhoid fever patients, that the epidemic of typhoid fever does not follow. On the other hand, he is even more annoyed when, after he has introduced an unpolluted water supply, the high typhoid fever death rate which obtained when the