76 HISTORY OF GEOLOGY AND PAL/EONTOLOGY. 



great desire was to bring the facts of science into complete 

 and unquestionable harmony with the words of Holy Writ. 



A special interest is attached to De Luc's Letters on some 

 parts of Switzerland, which were originally addressed to 

 Queen Charlotte, and were afterwards published in 1778. In 

 the preface to these letters he proposes the term Geology as 

 the most suitable for a scientific study purporting to deal with 

 the history of the earth. The preface is written in bombastic 

 style, announcing that a new outline of cosmology and geology 

 would be enunciated by the writer. The Letters themselves 

 contain little that could be supposed to bear out the high 

 promises of the preface, but a year later De Luc's theory 

 appeared in a work of five volumes, entitled Physical and 

 Moral Letters on the History of the Earth and of Man, The 

 moral discourses are comprised in the first part of the work. 

 Then the scientific letters begin with a resume of the theories 

 of the earth's origin constructed by Burnet, Whiston, Wood- 

 ward, Leibnitz, Scheuchzer, and others, all of which are found 

 erroneous and set aside by De Luc. He then describes his 

 travels in different parts of Europe, and records any geological 

 observations he had made. 



He states his reasons for disbelieving in the enormous 

 erosive activity which contemporaneous writers ascribed to 

 water. And he strongly expresses himself in favour of the 

 eruptive origin of basalt, as against the ideas held by Werner's 

 school. The fifth volume is that in which De Luc unfolds his 

 own theory. He distinguishes primordial mountains com- 

 posed of rocks of unknown origin, such as granite, schist, 

 serpentine, quartzite from secondary mountains, composed of 

 stratified deposits containing fossils, and clearly of aqueous 

 origin. As there are terrestrial plants and animals among the 

 fossils of the "secondary mountains," De Luc supposes that, 

 although the ocean must have originally covered the earth's 

 surface, there must have been land areas at the time when the 

 strata of the "secondary mountains" were deposited. The 

 floor of this restricted ocean was, he said, formed by the 

 "primordial mountains," but in the heart of these mountains 

 there were cavities of irregular shape disposed tier upon tier 

 above one another, so that the firm rock merely formed a 

 scaffolding. Owing to subterranean fire or any other disturbing 

 cause, it sometimes happened that the rock pillars in these 

 hollow areas gave way, and crust-inthrows ensued. The 



