318 THE POPULAR SCIENCE MONTHLY. 



gun. Many do, of course, get a limited benefit in the change of 

 subjects of thought, but they often mistake change of feeling due 

 to excitement for recuperation. "We need to learn how to stop. 

 Instead of rushing across the face of the earth in the delusive 

 hope of finding health on the other side, we need to learn how to 

 sit down and make ourselves comfortable where we are. A man 

 who had lived to a great age in health and contentment was 

 asked to give some simple rule of life out of his experience. In 

 reply, he said, "The only rule I can give is, 'Always keep com- 

 fortable/ " I feel confident that a well-selected residence in the 

 tropics from time to time will prove helpful in acquiring habits 

 of reposefulness. Tropical heat is not oppressive, as many who 

 have not tried it seem to suppose. It is very different from the 

 same -temperature as indicated by the thermometer during a 

 northern summer. One does not fret about the tropical heat as 

 he is apt to do here, but is inclined to keep quiet, lie down and 

 sleep a good deal during the daytime as well as profoundly all 

 night. Wakefulness is a rarity. The relief from nervous tension 

 and irritability is inexpressibly delightful. The increased action 

 of the skin relieves and gives needed rest to overworked kidneys, 

 the air passages are bathed by a moist, bland, nonirritating, warm 

 air, no chilly draughts scourge the nerve centers into activities 

 wasteful of energy, morbid appetites are allayed, digestion is im- 

 proved in sympathy with increased skin activity, and the poor 

 invalid begins to feel that, after all, life may be worth living. It 

 is a delusion, born of constant assertions of the advocates of negro 

 slavery before the war, that white people can not work in the 

 tropics. The island of Porto Rico was originally settled by 

 Catalonian peasants, and the major part of the farm labor has 

 from the beginning till now say for approaching four hundred 

 years been done by white men. True, negro slavery was intro- 

 duced there, but of a milder type than in the other islands ; and 

 the blacks never amounted to much more than one third of the 

 population, and they rapidly mixed with their Spanish colaborers 

 beside whom they worked. The facts are still more startling in 

 regard to the Spanish Main. Along the coasts of Central Amer- 

 ica the mahogany cutters, called " Indians/' are mostly of mixed 

 negro blood ; and along the unhealthy shores of the Magdalen a 

 River, or wherever the sugar cane is cultivated, negro slaves 

 were introduced, and their descendants, largely mixed with the 

 Indian race, still remain. Even in Brazil the negroes and their 

 descendants are confined to a few provinces, and never to exclude 

 white labor ; and in numbers the African blood constitutes but a 

 small proportion of the ten or twelve millions in that country 

 certainly not enough to influence the following statement : From 

 the southern border of the United States through Mexico, the 



