ABSTRACT
In the metabolism which forms part of physiological life, and on the normal character of which health depends, many factors are concerned. Among these the significance of minute deficiency in the intake of some chemical substances has been demonstrated by recent discoveries as to goitre and cretinism. Schafer has described the thyroid secretion as the most powerful stimulant of body metabolism known, and when it is deficient, physical growth and mental development are both impeded. Mental dulness or even imbecility may result from its deficiency, and cretinism in the progeny is produced when there is severe shortage of it during pregnancy. McGarrison on the basis of Indian evidence has advanced the view that goitre is due to the presence in the water supply of living microorganisms. The distribution of iodine in nature bears on the prevention of goitre. A wellbalanced and varied diet evidently is important in its prevention, as well as a diet which is free from organic contaminations.
