Goitre and leprosy are the only endemic diseases; but the natives, being underfed, are prone to diarrhoea and dyspepsia.
The climate of Siberia, however, cannot be called unhealthy, except in certain localities where goitre is common, as it is on the Lena, in several valleys of Nerchinsk and in the Altai Mountains.
The following is a list of the principal conditions in which iodides are recognized to be of definite value: metallic poisonings, as by lead and mercury, asthma, aneurism, arteriosclerosis, angina pectoris, gout, goitre, syphilis, haemophilia, Bright's disease (nephritis) and bronchitis.
Professor POffig, also cited by Dr Twining, states that on the east side of the Andes in Chile, in some of the races which live there, he did not see a single case of goitre, and yet in the white inhabitants, who live exactly as the natives, it prevails in a great degree.
To-day their descendants are not more subject to goitre and cretinism than those dwelling around them, and are recognized by tradition and not by features or physical degeneracy.