236 On the Erratic Phenomena of Scandinavia, 



into one, to penetrate across furrows or very narrow passages, 

 to follow all the sinuosities, and to occupy the whole sec- 

 tion, which varies from one point to another. This appara- 

 tus must, therefore, have possessed the properties of fluid 

 bodies ; moreover, it polished and scratched on all the sur- 

 faces, and on the whole contour, beneath overhanging and 

 even nearly horizontal walls of rock. 



It is evident that a solid body like a mass of ice cannot 

 fulfil these conditions of softness and fluidity ; moreover, 

 glaciers only abrade, polish, and scratch by their lower sur- 

 face, in virtue of the pressure which they exercise on their 

 bed, and of their progressive movement. Here the appara- 

 tus or bearer of the instrument {porte-outil) must have been 

 fluid, but the instrument itself was solid ; it was composed 

 of gravel, sand, and boulders ; in short, of the same matters 

 by the aid of which glaciers polish and striate. Thus we 

 are almost irresistibly led to the supposition of very violent 

 currents carrying along with them detritus of various dimen- 

 sions. 



The examination of the deposits of diluvial debris affords 

 a no less convincing proof of the action by water ; for these 

 deposits do not always assume the form of confused heaps 

 of materials of all sizes. In certain parts of Sweden, and 

 chiefly — which is sufficiently remarkable — in the elevated re- 

 gions, such as Dalecarlia, Helsingland, and Jemtland, we 

 find immense plains, or very continuous plateaus, nearly com- 

 pletely horizontal, and formed of diluvial debris. Sometimes 

 these debris consist of a mixture of sand, gravel, and pebbles, 

 and sometimes of very pure and very fine sand without 

 gravel, and identical with the sand of the shores of the sea ; 

 but they frequently present erratic blocks, either at the sur- 

 face or in the interior. Further, we can ascertain that these 

 two kinds of deposits, the one composed of various sorts of 

 detritus, and the other of pure sand, form alternate zones, 

 which succed each other, and exhibit a kind of coarse and 

 very undulating stratification. If we examine more minutely 

 the nature of the sand, we perceive that it is chiefly formed 

 of grains of quartz, accompanied by a little felspar and 

 by plates of mica. 



