CLOTHING AND THE ATMOSPHERE. 797 



add that such clothing, to afford real protection, should be frequently- 

 washed. Cotton is next to wool in value, and is preferable to linen, 

 because it gives a gentle excitation to the skin. Silk also has a warm 

 feeling, and might be substituted for flannel in the winter ; but it 

 could hardly be worn next to the skin in summer, on account of the 

 excessive heat it provokes. Dr. Balestra insists that it is best for in- 

 habitants of unhealthy countries never to go out without being pro- 

 vided with a woolen cloak or blanket, to be used in case the weather 

 should change. The ancient Romans wore ample over-garments over 

 their tunics, and never put them away. It is no less important to be 

 well covered during the night ; and precautions of this kind should 

 be recommended to all who live in a swampy country. We are 

 sometimes astonished when we see the natives of particularly warm 

 countries enveloped in woolen, as the Arab in his burnoose, or the 

 Spanish peasant in his tobacco-colored cloak. Such materials protect 

 both against the rays of the sun and against the coolness of the night, 

 and are excellent regulators of heat. It is dangerously imprudent to 

 travel in southern countries without provision of warm clothing. 



The hat completes the dress, as the roof crowns the house. It 

 preserves the head from insolation and cold, and protects it against 

 accidents. Without going so far as M. Bouchardat, who says that the 

 best head-dress is none, we content ourselves with remarking that the 

 hat should be light and well aired. According to M. Troupeau's ex- 

 periments, conical and rounded head-coverings are cooler than flat 

 ones, and preferable in hot countries. 



The bed is not only a piece of furniture indispensable to secure 

 repose ; it is also, in fact, a dress for the night. Like other articles 

 of clothing, it should be both warm and permeable to the air. The 

 heat which the body gives off to the mattress and the coverings is 

 continually taken away by the air that traverses them. " Beds de- 

 signed to regulate the flow of heat," says Dr. Pettenkofer, " are with 

 us thicker than the garments which clothe us during the day, for two 

 reasons : first, because, the circulation being less active during rest and 

 sleep, less heat is evolved ; and, secondly, because the ascending cur- 

 rents cool us more rapidly in the horizontal than in the vertical posi- 

 tion, where they rise from the feet to the head, passing over the whole 

 body." The heat of the bed thus favors the peripheric circulation 

 and assists the internal organs that have to keep up the calorification. 

 To do without a bed for several days in succession is a great privation, 

 not only because it deprives the limbs of rest, but also because of the 

 troubles to the economy it induces. A too hot and too soft bed is 

 also objectionable because it keeps the body in a condition of moisture 

 that enfeebles the muscular system and reduces all the functions. 

 Feather-beds are generally more noxious than useful. They are warm 

 on account of the air they hold ; but an air-mattress should be a& 

 warm. Birds also clothe themselves in heat when they sleep, by ruf- 



