Scientific Research and Public Health 19 



this is the ideal thing to do, but it takes little consideration of the subject 

 to make us realize also that it is a very difficult thing to do. To detect 

 and interpret a minor deviation from the normal by the aid of subjective 

 or objective symptoms is in itself a most intricate problem, when we 

 remember the long period of time which may intervene between the 

 initial symptoms and the appearance of the outspoken physical signs 

 that reveal their significance, and when we remember also that the 

 correlations thus indicated must be established by a large collection 

 of cases. But were this much accomplished and were it possible to 

 give a precise interpretation to early symptoms we should still be at a 

 loss as to the proper hygienic measures to be adopted for the restoration 

 of normal conditions. For the sake of an example let me use one of 

 Mackenzie's illustrations. Hardening of the arteries, arterial sclerosis, 

 is a frequent defect in middle and late life. Even when it does not shorten 

 life prematurely it interferes seriously with the ability of the body to 

 meet the ordinary demands of living. When the condition has advanced 

 so far as to be recognizable by obvious physical signs it is too late to deal 

 with it satisfactorily. Its progress may be blocked by rigorous changes 

 in the mode of living but it may be doubted whether any treatment can 

 be devised that will restore completely the status quo ante. Suppose 

 that by careful observations on blood-pressure or by other means we 

 could detect the earliest stages of this trouble, long before it gave the 

 patient any serious inconvenience. What remedial measures could be 

 suggested? I do not think that at present we have sufficient knowledge 

 to be sure of the answer to this question. The physician by long con- 

 tinued observations and the use of the laborious method of trial and error 

 might finally hit upon the right solution. But a shorter and surer 

 method of reaching this same end would be to turn the problem over to 

 laboratory investigators Let them determine which of the many 

 abnormal conditions to which the arteries are subjected is responsible for 

 the beginning of the trouble. Once this is determined and probably 

 only after it is determined will it be possible for us to protect ourselves 

 with any certainty from the development of this particular defect. What 

 is true of this tissue is applicable to most of the other tissues and organs 

 of the body. We are as a matter of fact very ignorant in regard to what 

 might be called the rules of right living, that is to say the kind of living 

 that would maintain the functions of our body at the highest standard of 

 efficiency. The working out and formulating of these rules constitutes 

 the main objective of so-called personal hygiene. This term I fear has 

 no very high place in the public estimation. The subject in fact has 

 been somewhat discredited by the kind of literature that has been given 

 to the public in its name. Part of it has been written by very ignorant 



