42 HISTORY Or THE SCIENCE. 



Mr. Hopkins lias recently applied, in a. highly successful 

 manner, the principles of mathematical investigation to the 

 explanation of geological phenomena, particularly with refer- 

 ence to the dynamics of the science, the elevation of entire 

 tracts of country, the prevalence of anticlinal lines, and the 

 nature of transverse fissures, and fractures occurring at right 

 angles to the central rise. He has thus brought a powerful 

 auxiliary into the field of geological research, and has supplied 

 a new link between mathematical and natural science. 



The discovery of erect trees in the coal-formation, particu- 

 larly of six splendid specimens found by Mr. Hawkshaw, on 

 the line of the Bolton and Manchester Eailway, together 

 with the researches of Mr. Bowman, Mr. Logan, and others, 

 has tended to modify, to a considerable extent, the opinions 

 previously entertained as to the mode in which coal was 

 deposited; and whereas it was formerly believed to have 

 been generally distributed by drift, and but occasionally to 

 have vegetated on the spot where it is now discovered, the 

 reverse of this sentiment seems now to prevail, and the 

 greater part of the coal is believed to have grown on or near 

 the spot where it is now found, while the instances of drift, 

 at all events, to any remote distance, are conceived to form 

 the exception to this rule. Certain coal-plants, the $igillari&, 

 which have hitherto been regarded as monocotyledonous, 

 are now, with more probability, considered to be dicotyle- 

 donous: and as the genus is numerous, such an alteration 

 would change, to a considerable extent, the relative proportion 

 of the two orders of plants of this formation. 



It may be added among the most recent advances in 

 geological inquiry, that Sir B>. Murchison having some time 

 since stated* it to be his opinion that the Silurian deposits 

 are the oldest fossiliferous rocks, recent researches have 

 tended strongly to confirm this view, and to show that both 

 the Cambrian and Cumbrian systems, which lie beneath, 

 present so close an analogy, in many important points, with 

 the Silurian, as to render it highly probable that the whole 

 will hereafter be regarded as one common series, that of the 

 protozoic or earliest rocks which contain organic remains. 



ERRATIC BLOCKS. With reference to these phenomena, 

 the large boulders and masses of primary rocks, which are 

 found scattered over the superficial soil, in every country of 



