610 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1911. 
arduous industries and the like is real, if it can not be accurately 
determined or estimated. Certain activities of a health department 
may be worth continuing for their educational value, although their 
direct utility may be questioned. Many topics need investigation 
in order to discover their real bearing upon the public health. 
Among these are such matters as the effect of a smoky atmosphere, 
the alleged nervous strain due to city noise, and numerous important 
questions in the domain of food adulteration and contamination. 
Premature and drastic action by health authorities in matters con- 
cerning which there is profound disagreement among experts may 
cast discredit on other lines of activity m which there is and can be 
no difference of opinion. 
For the present it seems worth while to emphasize more sharply 
than heretofore the distinction between public health measures of 
proved value and those that owe their existence to tradition or to 
misdirected and uninformed enthusiasm. Further study of the 
results obtained by certain of the usual and conventional health 
department activities is also much needed, and as a preliminary to 
such study the proper collection and handling of vital statistics is 
essential. It is poor management and unscientific procedure to 
continue to work blindly in matters pertaining to the public health, 
to employ measures of whose real efficiency we are ignorant, and 
even to refrain from collecting facts that might throw light upon their 
efficiency. 
