RECEEATIVE SCIENCE. 



257 



the Mediterranean, and in its course from 

 Japan to the Caspian, through the heart of 

 Southern Asia, there are fewer signs of acti- 

 vity than in any other part of its course. The 

 towering Himalayas serve to connect Pon- 

 dicherry, which raged violently in 1757, and 

 the " Terribles," where there are two craters 

 together in the Bay of Bengal, with the hills of 

 Thian-Shan, ^A'here the last great earthquake 

 occurred in 1832, and the line then passes direct 

 to the southern shore of the Caspian, where 



The European Group, from the Caspian to the Azores. 



Demavend rejoices in a local fiery renown. 

 Thus the two great opposing forces. Fire and 

 Water, have intimate neighbourship in the 

 superficial projection of the globe, and, as we 

 shall see hereafter, they work together in 

 modelling its hills and valleys, determining the 

 contour of its coast-lines, the dotting of its 

 seas with islands, and the building up of ram- 

 parts for the defence of continental lines. If 

 the sea silently, but surely sunders the old 

 landmarks, the fire compensates in an hour 

 for the spoliation of centuries, and thus, ac- 

 cording to God's great purposes, the propor- 

 tions of land and water are maintained in the 



face of forces which, separately considered, 

 appear sufficient for supreme domination. 



Supposing that the combinations of cer- 

 tain chemical ingredients originated these 

 extensive exhibitions of volcanic force, we 

 might reasonably expect to find in the pro- 

 ducts of combustion a clue to the processes 

 by which they are produced. If the chemist 

 mingles pounded sugar, chlorate of potash, 

 and alchohol, and applies a single drop of 

 sulphuric acid, the compound will imme- 

 diately take fire. Every tyro can 

 perform similar experiments. But 

 the accomplished chemist can do 

 something more than the tyro in 

 this case ; he can take the products 

 of the combustion, and, by an ex- 

 amination of these, determine out 

 of what materials the ashes were 

 produced. The conclusion then is 

 forced upon us, that if volcanic ope- 

 rations were brought about by the 

 meeting together of materials cal- 

 culated to give rise to combustion, 

 the theory of such explosions would 

 long since have been built upon a 

 firm chemical basis. Such has not 

 been done, for the simple reason that 

 the scoriae and lava ejected from 

 active volcanoes afford the chemist 

 no evidence of such a special cause. 

 A notable fact is the force exerted 

 in volcanic action. Cotopaxi, in 1738, threw 

 its fiery rockets 3000 feet above its crater, 

 while in 1744 the blazing mass, struggling for 

 an outlet, roared like a furnace, so that its 

 awful voice was heard at a distance of more 

 than six hundred miles. In 1797 the crater 

 of Tunguragua, one of the great peaks of the 

 Andes, flung out torrents of miid, which 

 dammed up rivers, opened new lakes, and in 

 valleys of a thousand feet wide made deposits 

 six hundred feet deep. The stream from 

 Vesuvius, which, in 1737, passed through 

 Torre del Greco, contained 33,600,000 cubiq 



feet of solid matter; and, in 1794, when Torre 



