314 SeiiiHific Notices^^Miscellaneous, [Oct. 



it appeared to contain only sulphate and carbonate of soda, and 

 in the following proportions : 



Sulphate of soda 99-78 



Carhonate of soda 0*22 



100-00 

 (Journal de Pharmacie.) 



Miscellaneous. 



4. Remarks on Bowlders, By Peter Dobson. 



I have had occasion to dig up a great number of bowlders, of 

 red sandstone, and of the conglomerate kind, in erecting a cot- 

 ton manufactory; and it was not uncommon to find them worn 

 smooth on the under side, as if done by their having been 

 dragged over rocks and gravelly earth, in one steady position. 

 On examination, they exhibit scratches and furrows on the 

 abraded part ; and if among the minerals composing the rock, 

 there happened to be pebbles of felspar, or quartz, (which was 

 not uncommon,) they usually appeared not to be worn so much 

 as the rest of the stone, preserving their more tender parts in a 

 ridge, extending some inches. When several of these pebbles 

 happen to be in one block, the preserved ridges were on the 

 same side of the pebbles, so that it is easy to determine which 

 part of the stone moved forward, in the act of wearing. 



I have caused blocks, with the above appearances, and 

 weighing 15 tons, to be split up ; and there are now a number 

 of good specimens about the place, that will weigh from 10 to 

 50 cwt., dug out of the earth 200 feet above the stream of water 

 in the vicinity. 



These bowlders are found, not only on the surface, but I have 

 discovered them a number of feet deep, in the earth, in the hard 

 compound of clay, sand, and gravel. 



One block of more than 30 cwt., marked and worn as above 

 described, was dug out of a well, at the depth of 24 feet ; a 

 part of which is still to be seen. 



Bowlders, with these marks upon them, I have observed, not 

 only in this town, but in Manchester, Ellington, and Wilbraham. 



I think we cannot account for these appearances, unless we 

 call in the aid of ice along with water, and that they have been 

 worn by being suspended and carried in ice, over rocks and 

 earth, under water. 



It is stated in the Edinburgh Encyclopedia, vol. xiii. p. 426, 

 that " fields of ice sometimes rise from the bottom, and bring 

 with them masses of rock, of several hundred tons weight. 

 These masses of stone are imbedded in the ice, they are carried 

 along with the ice, and deposited on shores at a great distance 

 from their original situatioii." 



