LOCAL TEMPERATURES. 571 



funeral ceremonies? a common sentiment of the sacredness of the tomb? 

 Have we not always, and do we not every where set apart a sacerdotal 

 order, who may mediate for us ? In our less advanced civilization, do we 

 not all believe in sorceries, witches, and charms ? It signifies nothing 

 in what particular form our mental conceptions are embodied ; it is the 

 conception that concerns us, and not the aspect it has assumed. Thus 

 equally do the views of the various nations demonstrate their innate be- 

 lief of a future world the undisturbed Hunting-ground of the American 

 Indian, the voluptuous Paradise and society of the houris of the Ara- 

 bian, or the snow hut of the Esquimaux, in which the righteous feed on 

 the blubber of whales. 



Turning our attention to the influence of temperature, it may be ob- 

 served that the development of coloring matter in the skin de- influence of 

 pends on the heat to which we are exposed. Generally, it ^JJIe'com^ 

 might therefore appear that there should be a correspondence piexion. 

 between the complexion and the latitude of the place of our abode, the 

 skin being darker as we approach the equator, and fairer toward the 

 poles, because, since all the heat that we receive comes from the sun, 

 the amount which is furnished to us depends upon the obliquity of his 

 rays, and therefore upon the latitude. But this is true only in a very 

 general way, and many exceptions at once spontaneously suggest them- 

 selves. I may point out some of these variations. 



The temperature of a place depends on three leading circumstances, 

 its latitude, its elevation above the sea, and on meteorolog- causes of local 

 ical conditions. Kespecting the latitude, nothing need be temperatures. 

 added to the remarks already offered ; and as regards the influence of 

 elevation above the sea, it is to be remembered that there is a decline of 

 temperature as we ascend in the atmosphere from any point of the globe, 

 and for this reason, as has been already explained at page 473, even un- 

 der the equator there will be an arrangement answering to climates on 

 every high mountain, its top, if sufficiently elevated, being covered with 

 perpetual snow. Of meteorological conditions, it may be said that they 

 are so numerous as to render it almost impossible to give a full and yet 

 brief statement of them, but as illustrations may be mentioned the prox- 

 imity of the sea, or of great desert tracts, ocean currents, the prevailing 

 winds ; thus, in our hemisphere, a north wind predominating lowers the 

 mean temperature of the place, a south wind tends to raise it ; and thus, 

 also, the great desert of Sahara and the American Gulf Stream increase 

 by many degrees the temperature of Europe. 



For such reasons, therefore, the lines of equal heat do not correspond 

 to the parallels of latitude, but, as an inspection of a chart of them will 

 show, deviate greatly therefrom. 



In treating of the influence of heat on plants, it was shown that, when 



