Fossil Fishes. 33 



granted, and, in fact, can never be proved. First, they suppose, 

 that nature is constant in her operations ; namely, that the same 

 causes always produce the same effects, and vice versa. Secondly, 

 they suppose in us, that any other man's mind has the same sus- 

 ceptibility v^^ith our own. And, thirdly, they suppose we take for 

 granted, that every event, or every change in mind or body, is pre- 

 ceded by some other event which we consider as its cause, and I 

 may add, is succeeded by another still, which we consider as its ef- 

 fect. These are principles vi'hich all mankind admit, but which 

 none can prove, which lie at the foundation of all philosophical en- 

 quiry, and without the admission of which, we cannot proceed one 

 step in the unravelling of nature's operations. 



The force of the terms employed to denote the more simple men- 

 tal operations, being thus settled or agreed upon, in the manner that 

 has been mentioned, which never could be done by verbal descripr 

 tion ; the names of the more complex feelings, may possibly have 

 their meaning explained by words, the simple feelings of which they 

 consist having been determined in the former method. Many of 

 the terms introduced and employed in this manner, imply a com- 

 bination of inward feelings with many external actions. Thus, the 

 words, justice, government, liberty, aristocracy, proneness, baseness, 

 mtirder, imply a complicated assemblage of mental feelings joined 

 to many habitual acts. Verbal descriptions, and detailed explana- 

 tions of the numerous ideas implied in each of these terms, may be 

 of great use in leading us to form more correct conceptions of their 

 meaning ; but unless the simpler feeling originally implied in each 

 of them be previously understood, no verbal elucidation whatever 

 can ever lead us to the ideas intended. 



Art. V. — Fossil Fishes. 



This interesting class of fossils is now in a way to be developed 

 far more thoroughly than before. 



The labors of Prof. Agassiz, which we have had frequent occa- 

 sion to mention, are presenting us with many new facts and new 

 views of the greatest interest. 



Prof. Jameson, of Edinburgh, in his Journal for October, has given 

 an able analysis of the work of Prof. Agassiz as far as it is published, 

 and we gladly avail ourselves of the opportunity to present it to our 



Vol. XXX.— No. 1. 5 



