'JHE CAVENDISH LECTURE 7 



and teeth, occur in every organ examined — even to that most 

 delicate organ, the human brain. We are now proposing national 

 legislation with regard to the feeble-minded — a class familiar to 

 most school medical officers — and yet do we really know defi- 

 nitely at present how far the feeble-minded produce the feeble- 

 minded ? I have been looking into that question recently and 

 have been struck by the hopelessly unscientific character of most 

 of the evidence on the subject, and yet 0*5 to i per cent, of 

 our school population are recognised as feeble-minded, and one 

 feels quite certain that with the aid of a couple of keen medical 

 men and half a dozen trained district visitors that problem could 

 be satisfactorily answered in eighteen months. Take another 

 aspect of it : the 60 to 70 per cent, of mentally defective among 

 the female inebriates, and the 30 to 40 per cent, mentally defective 

 among our habitual criminals — where did they spring from ? Are 

 they merely the grown-ups of the feeble-minded among our school- 

 children ? It is nobody's business to investigate and find out, 

 and yet by the expenditure of a relatively small sum of money a 

 definite answer on this crucial point could be secured. The 

 illustrations I have given may suffice to show you how effective 

 inquiry on the part of medical men in the public health service, 

 whether of municipality, school, prison or reformatory, is directly 

 checked by the short-sightedness of government departments and 

 of local authorities. 



But there is another feature of the matter which deserves our 

 attention. The public health service, in the wide sense in which 

 I am dealing with it here, is relatively new ; it brings its officers 

 into contact with a whole set of new problems, often social and 

 ■economic in character, frequently actuarial and statistical rather 

 than medical. No provision has so far been made for training 

 the public health service to deal with problems of this character. 

 It is almost piteous to see how the reports of medical officers of 

 health and of school medical officers grope towards solutions of 

 nationally important medico-social problems. The most complex 

 and difficult problems in vital statistics — problems to which trained 

 actuaries with the highest mathematical knowledge have devoted 

 years of work — are solved to the apparent satisfaction of the pro- 

 posers in a few lines of simple arithmetic. I could give you 

 numerous instances of such cases where the writer tumbles into 

 pitfalls which every actuary, every trained statistician has learnt by 

 training and by experience to avoid. 



