134 SCIENTIFIC ILLUSTRATIONS [Gol 



see the sun with absolute clearness. When there are less 

 favourable conditions it is enveloped in dimness. But the 

 change is not in the sun : it is contingent upon the exhalations 

 of sublunary things. For it is evident that at each hour of 

 the day the solar rays come from the parts above the atmosphere 

 with the same power whether the sky be clouded or clear. If 

 no cloud intervenes, all the rays come to the surface of the 

 earth and heat it, but if one-half or one-fourth of them should 

 be intercepted by cloud, only the other half or three-fourths of 

 the rays can affect the surface ; and when the whole sky is 

 covered with dense clouds, the greater part of the solar rays 

 will be intercepted by it. ON. 



The Accuracy of Job's Reference to Gold and Silver. 



The fear that gold may be greatly depreciated in value 

 relative to silver (a fear which at one time seized upon the 

 minds of some people) seems unwarranted by the data regis- 

 tered in the crust of the earth ; for looking to all the recent 

 discoveries, we may be assured that gold is much the 'most 

 restricted (in its native distribution) of the precious metals. 

 Argentiferous lead, on the contrary, expands so largely down- 

 wards into the bowels of the rocks as to lead us to believe that 

 it must yield enormous quantities of silver for ages to come, and 

 the more so in proportion as better machinery and new inventions 

 shall lessen the difficulty of subterranean mining. It may 

 indeed well be doubted if the quantities both of gold and silver 

 procured from regions unknown to our progenitors will prove 

 more than sufficient to meet the exigencies of an enormously 

 increased population and our augmenting commerce and luxury. 

 And the author of "Siluria" as a geologist says that Pro- 

 vidence seems to have adjusted the relative value of these 

 two precious metals for the use of man, and that their relations, 

 having remained the same for ages, will long survive all theories. 

 Modern science in short, instead of contradicting, only confirms 

 the truth of the aphorism of the Patriarch Job, which thus 

 shadowed forth the downward persistence of the one and the 

 superficial distribution of the other: "Surely there is a vein 

 for the silver. . . . The earth hath dust of gold." si. 



