180 The American Naturalist. [March, 



From the 13th to the 16th century, astronomy, travels, and 

 commercial interests occupied the attention of the different 

 nations, but geology did not appear as a separate science until 

 in Italy in the 16th century. It began by being a record of 

 observed facts. This was not enough, however, for it did not 

 satisfy the demand as to how the phenomena were produced. 

 High above sea level, and far inland, imbedded in solid rock, 

 were found fossils. At the outset it was unfortunately linked 

 to the belief that they were relics of the Noachean deluge. 

 Some held that they were the result of the formation of a fatty 

 matter, or of terrestrial exhalations or of the influence of the 

 heavenly bodies, or that they were merely concreations, or 

 sports of nature. The abundance of fossils in the strata of the 

 Apennine range could not fail to arrest attention and excite 

 inquiries. Leonardo da Vinci (1519) and Fracostaro, whose 

 attention was engaged by the multitude of curious petrifac- 

 tions which were brought to light in 1517 on the mountains 

 of Verona in quarrying rock for repairing the city, had sound 

 views, and showed the inadequacy of the terrestrial deluge to 

 collect marine fossils. 



Collections were made for museums, that of Canceolarius, 

 at Verona being the most famous. Descriptive catalogues of 

 these collections were published. 



Only a few held that they were the remains of animals. 

 Palissy in 1580, was the first who dared to assert in Paris that 

 fossil remains once belonged to marine animals. The ques- 

 tion was naturally asked " How came they there? " The re- 

 sult of investigation showed that the rocks must have accu- 

 mulated around them, and hence could not always have been 

 as they were found and that the arrangement must have 

 changed since they were formed. This brought about the 

 study of the construction of the earth. 



Their chief objects were the examination of the materials 

 out of which the solid framework of the earth was built, and 

 the determination of their chemical composition, physical 

 properties, manner of occurrence, and their characteristics. 

 Thus they started out with the idea that rocks were made 

 through secondary causes. 



