PALEONTOLOGICAL DISCOVERY. 229 



that shells and corals were being imbedded in the deposits there, just 

 as they were found in the rocks. 



John Gesner's dissertation, " De Petrificatis," published at Leyden 

 in 1758, was a valuable contribution to the science. He enumerated 

 the various kinds of fossils, and the different conditions in which they 

 are found petrified, and stated that some of them, like those at Oenin- 

 gen, resembled the shells, fishes, and plants of the neighboring region, 

 while others, such as Ammonites and Belemnites, were either unknown 

 species, or those found only in distant seas. He discusses the struc- 

 ture of the earth at length, and speculates as to the causes of changes 

 in sea and land. He estimates that, at the observed rate of recession 

 of the ocean, to allow the Apennines, whose summits are filled with 

 marine shells, to reach their present height, would have taken about 

 eighty thousand years, a period more than " ten times greater than the 

 age of the universe." He accordingly refers the change to the direct 

 command of the Deity, as related by Moses, that " the waters should 

 be gathered together in one place, and the dry land appear." 



Voltaire (1694-1778) discussed geological questions and the nature 

 of fossils in several of his works, but his published opinions are far 

 from consistent. He ridiculed effectively and justly the cosmogonists 

 of his day, and showed also that he knew the true nature of organic 

 remains. Finding, however, that theologians used these objects to 

 confirm the Scriptural account of the deluge, he changed his views, 

 and accounted for fossil shells found in the Alps by suggesting that 

 they were Eastern species, dropped by the pilgrims on their return 

 from the Holy Land ! 



Buffon, in 1749, published his important work on natural history, 

 and included in it his " Theory of the Earth," in which he discussed, 

 with much ability, many points in geology. Soon after the book was 

 published, he received an official letter from the Faculty of Theology 

 in Paris, stating that fourteen propositions in his works were repre- 

 hensible, and contrary to the creed of the Church. The first objection- 

 able proposition was as follows : " The waters of the sea have pro- 

 duced the mountains and valleys of the land ; the waters of the 

 heavens, reducing all to a level, will at last deliver the whole land over 

 to the sea ; and the sea, successively prevailing over the land, will leave 

 dry new continents like those we inhabit." 



Buffon was politely requested by the college to recant, and, having 

 no particular desire to be a martyr to science, submitted the following 

 declaration, which he was required to publish in his next work : " I 

 declare that I had no intention to contradict the text of Scripture ; 

 that I believe most firmly all therein related about the creation, both 

 as to order of time and matter of fact ; and I abandon everything in 

 my book respecting the formation of the earth, and, generally, all 

 which may be contrary to the narration of Moses." 



This single instance will suffice to indicate one great obstacle to 



