34 HISTORY OF GEOLOGY AND PALAEONTOLOGY. 



in them, represented marine deposits that had been pushed 

 upward by the expansive force working centrifugally through 

 the earth. Needham explained the Mosaic "Days" as primi- 

 tive periods of protracted length. 



Justi, in his Geschichte des Erdkorpers (Berlin, 1771), 

 regarded all planets and comets as torn fragments of the sun. 

 The Earth was originally a mixture of soft earth and water, 

 mixed with oily and mercurial substances. The spherical 

 form was developed as a result of rotation round an axis. The 

 water taken from the sun distributed itself over the globe, 

 and the latter became enveloped by a vaporous atmosphere. 

 Life began to inhabit the water, and minerals and the various 

 kinds of rock were formed by new combinations of the original 

 ingredients. The whole work is a compilation of fancies hung 

 on a few slender pegs of fact. 



Other German writers, Gleichen-Rosswurm, Professor 

 Johann Gottlob Kriiger, and Johann Silberschlag, allowed their 

 imagination to carry them into still more glaring absurdities. 

 But it is worth mentioning that Rosswurm, in sketching the 

 development of life on the globe, begins with the existence of 

 infusoria in the sea. The skeletons of these are said to have 

 formed an " elementary earth " on the sea-basin, from which 

 sprang larger and rougher forms of animals, until at last, after 

 immeasurably long epochs, all aquatic forms of animal life had 

 come into existence. 



Beginnings of Geological Observation. The true spirit of 

 research was still kept alive by men who confined themselves 

 to special subjects of investigation, or described the strati- 

 graphy of particular localities. 



Friedrich Mylius published in 1704 and 1718 a valuable 

 work on the rocks of the Thuringian district. John Strachey, 

 in England, gave an admirable description of the various kinds 

 of strata present in the coal districts of Somerset and North- 

 umberland (Philos. Trans., 17 14 and 1725). Holloway studied 

 the chalk deposits in Bedfordshire (Philos. Trans., 1723). 



In Italy, Spada and the Sicilian observer, Schiavo, drew 

 attention to the fossiliferous deposits of the younger Tertiary 

 periods; the Venetian teacher, Donati, compared the present 

 deposits and fauna of the Adriatic Sea with the deposits and 

 fossils at the base of the Apennines. Baldassari contributed 

 a similar work on the deposits near Siena. The traveller 



