24 The Origin of the 



available to land and sea, and therefore necessarily 

 meteoric : for there is no other alternative. Let us 

 now consider the evidence of the facts in relation to 

 this source. 



It is clear from the flint having occasionally 

 flowed among stones, and moulded itself to their 

 interstices, that it was in a fluid condition, not 

 improbably molten. It may be objected that flint 

 is one of the substances most difficult to fuse, 

 requiring the heat of the oxy-hydrogen blowpipe 

 for that purpose; but there is power more than 

 sufficient in the laboratory of nature for that inten- 

 sity of heat, whether by the element of the lightning 

 or otherwise. Geologists assume that all the sub- 

 stances upon the earth were once in a state of 

 incandescent fusion. They who think this, are not 

 in a position to object. And it does not necessarily 

 appear that the flint when previously in combination 

 with some other substance, from which it was 

 separated and precipitated, required so intense a 

 heat for fusion, as now when it has hardened in 

 its separate state. I find it stated, moreover, 6 

 that by Mr. Parker's large burning-glass, flint of 

 the weight of ten grains was fused in half a minute, 

 and carneliau in a minute and a quarter. Xow, Sir 

 Humphry Davy calculated that the heat which an 

 aerolite extricated from the atmosphere by its rapid 

 motion, exceeded 30,000° of Fahrenheit, a heat 

 more intense than that of the fiercest artificial 

 furnace. And I understand that the researches 

 of Professor Sir William Thomson and Mr. Joule 

 furnish data which would, in the case of a velo- 

 city of 39 miles a second, give the temperature 

 ten times higher than this calculation of Sir Hum- 



6 Encycl. Brit. 



