INTRODUCTION 1 1/ 



1749 he examined the Cretaceous rocks in Schonen, and in 

 the last edition (1768) of his Systema Naturcc he gave a 

 complete list of the fossils known to him, and arranged them 

 according to their occurrence in his system of the rock 

 succession. He arrived also at remarkably clear conceptions 

 about the accumulation of different kinds of sedimentary 

 deposit upon the floor of the ocean. 



While Linnaeus was a true empirical observer, and may be 

 regarded as the founder of constructive geology in Sweden, a 

 contemporary of his, Tobern Bergman (1735-84), inculcated 

 theories regarding mineral structure and the constitution of 

 the earth's crust which were largely adopted by Werner, and 

 were thus destined to wield a European influence. His 

 Physical Description of the Globe (1769) was translated into 

 German, and was the foundation of the Wernerian doctrine 

 that the earth's crust was composed of successive strata of 

 different thicknesses and constitution, but uniformly envelop- 

 ing the spherical earth ; further, that these have arisen as 

 chemical precipitates, and not simultaneously, but gradually 

 during protracted epochs of time. In addition there were 

 deposits accumulated by mechanical means and volcanic 

 rocks. He classified the rock-succession in four sub-divisions : 



(1) Primitive rocks, comprising the chemical precipitates; 



(2) the Flotz series, comprising sediments of mechanical 

 origin ; (3) transported rocks ; (4) volcanic rocks. 



Daniel Tilas (1712-72) made a special study of the erratic 

 blocks and superficial pebble -beds of Sweden. He wrote 

 strongly on the importance of petrography, and to his warm 

 advocacy Sweden doubtless owes the preparation of its earliest 

 geological maps: the map of West Gothland by Hisinger in 

 1797, and the maps of Nerike, Schonen, West and East 

 Gothland by Gustaf Hermelin, published between 1797 

 and 1807. Both these authors contributed an explanatory 

 text to their maps, and thus laid the basis of stratigraphy in 

 Sweden, Hisinger (1766-1825) wrote a general description of 

 the mineralogical relations of Sweden; and the second edition, 

 soon after its appearance in 1808, was twice translated into 

 German. This work contains a historical review of all the 

 facts known about Swedish rocks up to that date, and applies 

 Werner's systematic arrangement. 



The oldest information about the geography, minerals, and 

 rocks of Norway is to be found in Erich Pontoppidan's Natural 



