INTERACTION OF THE SCIENCES 137 



six points within half a mile powerful veins of red 

 granite piercing the black micaceous schist and giv- 

 ing every indication of having been intruded from 

 beneath, with great violence, into the earlier forma- 

 tion. 



Hutton felt confirmed in his view that in nature 

 there is wisdom, system, and consistency. Even the 

 volcano and earthquake, instead of being accidents, 

 or arbitrary manifestations of divine wrath, are part 

 of the economy of nature, and the best clue we have 

 to the stupendous force necessary to heave up the 

 strata, inject veins of metals and igneous rocks, and 

 insure a succession of habitable worlds. 



In 1795 Dr. Hutton published a more elaborate 

 statement of his theory in two volumes. In 1802 

 Playfair printed Illustrations of the Huttonian 

 Theory, a simplification, having, naturally, little 

 originality. Before his death In 1797 Hutton de- 

 voted his time to reading new volumes by Saussure 

 on the Alps, and to preparing a book on The Ele- 

 ments of Agriculture. 



Sir James Hall of Dunglass was a reluctant con- 

 vert to Hutton's system of geology. Three arguments 

 against the Huttonian hypothesis gave him cause for 

 doubt. Would not matter solidifying after fusion 

 form a glass, a vitreous, rather than a crystalline 

 product ? Why do basalts, whinstones, and other sup- 

 posedly volcanic rocks differ so much in structure 

 from lava? How can marble and other limestones 

 have been fused, seeing that they are readily cal- 

 cined by heat ? Hutton thought that the compression 

 under which the subterranean heat had been applied 

 was a factor in the solution of these problems. He 



