232 EXPERIMENTS ON METAMORPHISM AND 



sudden process*. In short, according to the system of Werner, all 

 the strata were produced at their origin as they now exist. The in- 

 ternal activit}'^ of the globe is completely disregarded as well in re- 

 spect to the formation of crystalline rocks and metalliferous deposits, 

 as to its being the cause of the dislocations undergone by the strati- 

 lied deposits of all ages. 



CHAPTER II. 

 HUTTONIAN SYSTEM. 



While the teachings of Werner began to captivate general atten- 

 tion and excite the enthusiasm of his pupils, thanks to the graces of 

 speech of the master and to the power of the method with which the 

 facts then known were brought together, another and a very different 

 doctrine arose in Scotland. Gifted with a genius for observation not less 

 eminent than the professor of Freyberg, James Hutton came to opposite 

 conclusions on certain fundamental phenomena, and these two antago- 

 nistic schools were simultaneously established. As far back as 1785 

 Hutton published his Theory of the Earth, f Ten years later, after 

 having made several journeys in Scotland to collect new observations, 

 he developed his ideas in a more voluminous work under the same 

 title. But what contributed more than anything else to make Hut- 

 ton's doctrine known was the work of John Playfair, :j: his disciple 

 and friend, who was at the same time a mathematician, a geologist, 

 and a distinguished writer. His talent of exposition and elegance of 

 style vigorously sustained the new ideas, as well against the violent 

 attacks of a small number who accorded to them a serious considera- 

 tion, as against the disdainful indifference of the majority, Avho re- 

 garded them as unfounded. The importance of the works of Hutton 

 and of Playfair, in which, for the hrst time, we find certain fundamen- 

 tal ideas of modern geology established and developed, and in par- 

 ticular the principle of metamorphism, obliges me to give here their 

 leading propositions, as I have done for those of Werner. This is, in 



- When the solution covered the whole of the globe, and was of great depth, it was 

 tranquil and pure. For this reason the first rocks were exclusively crystalline. After- 

 wards, when the level of the sea was lowered and the earth appeared above it, currents 

 exercised a greater influence and destroyed a part of the pre-existing masses. On the 

 other hand, atmospheric agencies attacked the emerged rocks. It is thus tliat mechanical 

 deposits were formed, and even became abundant 



f Theory of the Earth, or on Inrestig tion of the Laws Observable in the Composition, Dissolution, 

 and Be^toration of Lund upon the Globe; by James Hutton, M D., F R.S. Read the 7th of 

 March and the 4th of April, 1785, before the Royal Society of Edinburg ; 96 pages, in 

 4to. A second paper on the same subject appeared in 1786. The second edition of the 

 work is entitled, Tluory of the Earth, with Proofs and Illustrations. In four parts. Edinburg, 

 2 vols., in 8vo., 1795. 



On the other hand, Werner published his Treatise mi the Characters of Minerals, in 1774. at 

 the age of twenty-four years. Soon after, about 1780, he began to develope in his lectures 

 the principles of Geognosy. His Classification and Description of Strata dates 1787, and his Nem 

 Theory of the Formation of Veins in 1791. 



X Playfair's Illustrations of the HuUonian Theory of the Earth. Edinburg, 1802. 



