276 APPENDIX 



well-known mountain resorts are very favourable climatic 

 helps. In this connection, however, one cannot tell how 

 far purity of air, hygienic surroundings, and a suitable 

 dietary may counteract upon an unfavourable earth 

 condition. We can only be sure that a lowered vitality 

 not only predisposes to disease but operates against its 

 cure. 



In the polar regions larger temperature ranges can be 

 endured in the winter, when the air is dry. In severe cold 

 the vitality of the body is lowered and the ability to bear 

 hardships decreased. But here, again, the body is acted 

 upon directly by cold. The resistance of the natural (semi- 

 liquid) conductors is increased, the blood circulates more 

 slowly, the surface blood-vessels contract, and only an 

 added skin-resistance, by helping to conserve energy, 

 prevents the heart and lungs from becoming dangerously 

 affected. Eskimos are protected against the cold by their 

 thick, fatty tissues, which give them high absolute- 

 insulation. 



It is a complex subject. " Diseases usually charac- 

 teristic of one zone are known to spread widely over other 

 zones. Diseases which usually prefer the warmer months 

 sometimes occur in the coldest. Rules, previously deter- 

 mined as the result of careful investigation, often break 

 down in the most perplexing way. Some of the difficulty 

 in this lack of agreement results from untrustworthy 

 statistics, often collected under varying conditions and 

 really not comparable. Curves are smoothed to such an 

 extent that they can be made to show anything. Con- 

 clusions are drawn in individual cases which are neither of 

 general application, nor do they even apply locally on any 

 other occasion than the special one in question. Most of 

 this disagreement comes from the fact that not only may 

 the different weather elements themselves, temperature, 

 moisture, wind, sunshine, and so on, each have some 



