23S 



THE GEOLOGIST. 



melted state, an alteration in the stratified rock in immediate contact with 

 it takes place." JNTow rocks do not meet as friends do in walking about 

 the earth, the superior and subjacent rock must, we apprehend, be in im- 

 mediate contact, at any rate since the first deposit of the latter ; and there- 

 fore if granite be an igneous rock or fire-heated rock, must not the 

 sedimentary rock have been deposited originally upon it, if it be right to say 

 one rock of one kind of formation is changed by coming into contact with 

 another rock of another kind of formation ? We know, of course, the 

 popular notions, but we expect from a geologist in Professor Eamsay's posi- 

 tion something more than a parrot-like repetition of popular notions. Such 

 a book as the present, however admirable it may be as an elementary intro- 

 duction to a deep and attractive science, — and this merit we freely and 

 willingly accord it, — would be unworthy of the author, and his rank as a 

 geologist, and his standing in society, unless it were the vehicle of higher 

 instruction than could be given by a college youth fresh from his class. Ele- 

 mentary treatises we do not expect — unless of more voluminous character, 

 like Ly ell's, Delabeche's, Phillips's, or Mantell's — from a savant of eminence ; 

 and such small essays as the present are rather the class to expect from 

 young men coming into notoriety than those older men who have acquired 

 fame, and from whom we expect, especially when they are in the national 

 service, higher and far more responsible works. Why time should not 

 permit the Professor from showing how heat " sometimes eats '(sic) its way 

 towards the surface in a manner not immediately connected with volcanic 

 action ;" why, for his own part, he should believe, and yet leave unex- 

 plained his belief, that in one sense granite is an igneous, and in another 

 sense a metamorphic rock ; why fusion by heat is_ necessary for the soften- 

 ing of the rock and the movements of the constituent particles in the act 

 of crystallization ; why he should forbear at present from entering on the 

 theory of the essential presence of highly heated water in the formation of 

 granite, as being foreign to the object of his lecture, — are mattersScf regret, 

 for their subjects are points of very great interest, and properly dealt with 

 would have given high charms to this rudimentary production. But he has 

 preferred to hide his light under a bushel, and to leave the world in darkness. 

 Altogether, metamorphism is, to our minds, so treated with such a want of 

 logic, and such a muddle of facts, and forgetfulness or neglect of recent re- 

 searches, that it would have been far better for geological science, if not for 

 the author's reputation, that this portion had been eliminated. The third 

 lecture is on the Physical Structure of England, and deals concisely with the 

 various stratified formations, taking up, amongst other topics, the relation- 

 ship between disturbance and form of country, the effects of disturbance, 

 and denudation. The fourth treats of the distribution of the Miocene and 

 Pliocene Tertiary Strata, Glacial Phenomena, and Origin of certain Lakes, 

 — the glacial epoch, illustrated by glacier and other existing ice pheno- 

 mena, being treated in a remarkably simple and explanatory manner, and 

 thoroughly worthy of any writer; indeed this portion possesses a charming 

 clearness and enthusiasm rarely equalled. The fifth lecture deals still with 

 the newer or Pliocene strata, treating of the denudation of the coasts of 

 Britain, the present British climates and their causes, areas of drainage, river- 

 valleys and their origin, old river-gravels and prehistoric human remains, 

 historical elevation of the country. Upon this latter subject we have also 

 a word of comment to make. It is very easy for geologists to say " heave 

 up the land," but it is as yet rather doubtful whether nature is quite so 

 ready or able to do U as geologists are to suppose it done to get difficulties 

 out of their way. It is quite possible that many of the so-called "heaves 

 up " of the land may have other explanations than any heaving at all; and 



