TEMPERATURE REQUIRED FOR SHEEP. 



81 



vapour of the valleys in a winter morning, we feel as if 

 the transition had been from a temperate to an icy re- 

 gion. Hence one of the reasons why sheep thrive best 

 in a rather elevated situation. Moist air, however, is 

 exceedingly oppressive in hot weather, because eva- 

 poration, from the surface of the body, is to a great 

 extent diminished ; and it is only by the perspiration 

 being allowed to escape rapidly, and to convey away 

 the heated particles, that we can manage to be in any 

 degree comfortable during the heat of summer. This 

 free evaporation we endeavour in every way to obtain, 

 and often in a manner that ignorant people would con- 

 sider as the reverse of sensible. It is well known that 

 draughts of cold liquids are very far from answering 

 the purpose of lowering our temperature when above a 

 pleasant standard ; but we find that a basin of hot 

 soup, or tea, will speedily bring about the desired end, 

 by producing a copious determination of fluid to the 

 skin. Yet, if the air contained no moisture, we should 

 experience sensations just as unpleasant as those al- 

 ready mentioned; for evaporation from our bodies 

 would proceed at such a rate, that we would soon be 

 parched. It is to counteract this tendency of dry air 

 that the Americans are in the habit of placing a small 

 vessel of water on their stoves, by which contrivance a 

 quantity of vapour is diffused through the apartment, 

 sufficient to balance the loss from the arid warmth of 

 the fire. 



That an equable temperature is only to be obtained 

 by draining and clearing a marshy and wooded coun- 

 try, is sufficiently authenticated. In the thickly wooded 

 and swampy territories of Guiana, rain falls continually 



