368 Bibliography. 
themselves to our consideration. I have offered no opinion here 
on the atomic mechanism which is invelved in these changes 
from an active to a passive state, though it is impossible to deal 
with these things without the reflection arising in our minds, 
that here we are on the brink of an extensive system of evidence 
connected with the polarity of atoms,—an idea which, under a 
variety of forms, is now occurring in every department of natural 
philosophy. 
University of New York, July 29, 1845. 
Art. X.— Bibliographical Notices. 
1. Travels in North Americain the Years 1841-42, with Geological 
Observations on the United States, Canada, and Nova Scotia; by 
Cuartes Lye.t, Esq., F. R. 8., Author of the Principles of Geology, 
&c. In two Vols. 18mo, pp. 251 and 231, with plates. New York, 
Wiley & Putnam, 1845.—These volumes have been looked for with 
much interest by all classes of readers in this country ; for while their 
author owes his reputation mainly to his scientific writings, he was also 
extensively known while here as an intelligent and highly educated 
English gentleman, who had opportunity and a disposition to observe 
the nature of American institutions and the state of society, as well as 
the relations of our rocks and their fossil contents. He has given the 
diary form to his travels, covering the period from July 20th, 1841, to 
Aug. 18th, 1842, during which time he was almost constantly on the 
wing, and actively engaged in geological observations. Sojourning in 
Boston, New York, and Philadelphia long enough to give a course of 
lectures on geology to audiences in each of those cities, to the first of 
which he was specially invited from England by the trustee of the 
‘* Lowell Institute,’ a well known institution for popular instruction. 
No one interested in American geology can fail to give an attentive 
perusal to Mr. Lyell’s “ Geological Observations’—they are found scat- 
tered through these volumes with a liberal hand, in the order of his 
line of route, and are drawn up in the direct and felicitous style, with 
which all readers of the ‘‘ Principles” and ‘‘ Elements” of the same 
author are already familiar. ‘The volumes are illustrated by Mr. 
Bakewell’s bird’s-eye view of the Falls of Niagara, colored geologically 
—and exposing the relative position of the several beds composing the 
cliffs at Queenston and in the rocky gorge of the Niagara river. He 
gives also a fac simile of Father Hennepin’s view of the Falls as he 
saw them two hundred years ago, with the remarkable third schute or 
Pref 4s 
