364 SECTIONAL TRANSACTIONS .—I. 
years. The bearing of this recently acquired knowledge on public health 
and on the elimination of disease of farm animals is discussed. 
Reference is made to the results of some recent investigations which 
indicate that nutrition as determined by diet is now probably the most 
important factor affecting the health of the community. 
It is suggested that the present generally accepted standards of health 
are too low. If the necessary measures could be taken to ensure that every 
member of the community had a diet which was fully adequate for health, 
the next generation would be of better physique and free from much of the 
disease and indefinite ill-health which afflict the present generation. 
Prof. J. J. R. Macteop, F.R.S. 
The time-honoured belief that health is closely linked with diet, and that 
improvement of the state of bodily nutrition, by dietary control, is an 
important factor in the treatment of disease, has received ample support by 
recent research. Vitamins and minerals, no less than calories and protein 
units, are essential in the diet, and various definite diseases have been 
shown to be the result of deficiencies in the former. Since most of these 
deficiency diseases occur in the lower animals as well as in man, it has been 
possible to determine the exact nature of the deficiencies responsible for 
their occurrence, but the problem awaiting investigation is to determine 
to what extent more general diseases in man may be similarly related. 
There is evidence to show that diabetes, anemia and goitre are nutritional 
diseases, and it is probable that other types of illness are due to faulty 
dietetic habits. But much careful work, in which both laboratory workers 
and doctors collaborate, will have to be done before these problems can be 
solved. That such investigations will be of benefit to mankind is evidenced 
by the discoveries which have been made during recent years in the field of 
animal nutrition. 
Dr. May MELLANBY. 
Dental decay (caries) is almost universal in civilised countries. 
Carefully controlled investigations on man and animals during the past 
fifteen years have resulted in a new outlook in dental science. 
Faulty nutrition, especially in early life, is the cause of defective structure, 
this in turn predisposing towards caries. ‘Teeth are commonly imperfectly 
formed, hence the high incidence of decay; in a microscopical examina- 
tion of 1,500 milk teeth, 93 per cent. of those very defective were decayed as 
compared with 20 per cent. of the perfect. 
For good structure diet of mother during pregnancy and lactation, and 
of child after weaning, must include abundant calcium and phosphorus 
(of which teeth are largely composed), and the specific calcifying-factor, 
vitamin D (egg-yolk, cod-liver oil, milk, etc.). Cereals contain anti- 
calcifying toxamins ; their consumption should be limited. 
Vitamin D helps to prevent and to arrest caries even in imperfect teeth 
(Sheffield and Birmingham investigations). 
Beautiful teeth almost caries-free found in :— 
(1) Eskimos ; vitamin D from blubber. 
(2) Natives of tropics; vitamin D through exposure of whole body, 
especially while young, to ultra-violet rays of the sun. Breast- 
feeding is prolonged. 4 
When these peoples adopt the diet and clothing of civilisation their teeth 
