The Edinburgh New Philosophical Journal. 251 



could of itself effect a breach ; but when this power is con- 

 joined with the effect of earthquakes, we can at once under- 

 stand, from innumerable instances of the power of such 

 combined agency, how fissures in the sides of mountain- 

 chains may be effected for the transmission of great rivers. 

 Here also we perceive a use in earthquakes which we were 

 not aware of before, for without their agency in effecting 

 lateral fissures in mountain chains for the transmission of 

 fertilizing rivers, three-fourths of the earth would be un- 

 inhabitable. Thus whatever mystery the cause of earth- 

 quakes may be involved in, and whatever local and temporary 

 desolation and dismay they occasion, we have the most 

 conclusive natural evidence of their good effects as the 

 agents of salutary changes and diversity on the surface of 

 the earth. Mr. D. Liston's paper on the deposits of the Gogra 

 and other rivers, which will be found in our present number, 

 shows how the character of the most flat, and apparently uni- 

 form, plains may be diversified in their influence over plants 

 and animals by the various rivers which pass over them, de- 

 positing earths of various kinds, some suitable for one form 

 of vegetation and some for another ; and some again exerci- 

 sing a peculiar influence over the health and constitutions 

 of animals, thus affording scope for the exercise of human 

 reason, enterprise, and industry, which would be altogether 

 wanting, but for the lateral fissures in mountain chains — 

 the salutary results of earthquakes, phenomena which, from 

 the neglect of physical science, have been hitherto regarded 

 only as calamities. 



We are glad to see the Structure of Fishes' Scales become 

 the subject of research in Europe. The notice of Dr. 

 Mandl's labours which we have seen, is contained in the 

 January number of the Edinburgh Philosophical Journal, 

 from the Ann. des Sciences Naturelles, and although the most 

 important part of the work is omitted, or that which relates 

 to a description of the scales examined, still we may gather 

 something of interest from Dr. Mandl's views and opinions. 



2l 



