Ejection of Stones from the Ice. Idl 



We are, therefore, relieved from the difficulty of account- 

 ing for the cold which would be necessary to freeze the infil- 

 trated water which was at one time believed necessary to ex- 

 plain the conversion of the rieioe into proper ice. This would 

 be liable to most of the objections urged against the Dilata- 

 tion Theory. 



(3.) ON THE FIRST APPEARANCB OF STONES (ERRATICi) ON THE 

 SURFACE OF GLACIERS. 



I shall conclude this letter with a few very partial ob- 

 servations upon what I must consider as one of the pheno- 

 mena of glaciers, still obscure as to its explanation, although 

 most familiar as a fact, — I mean their supposed tendency to 

 reject impurities, and the undoubted fact that stones are al- 

 ways found near or upon the surface of the ice. It is strange 

 that it should not have occurred to every one who sought to 

 explain the appearance of stones on the surface by the abla" 

 tion of the ice, that in order to arrive there at all, the blocks 

 must previously have been imbedded in the virgin ice, where 

 popular belief, and, generally speaking, more accurate obser- 

 vations also, give them no place. Yet, in the thousands of 

 crevasses which an active observer passes and examines in 

 a week, how few cases of imbedded stones in these vast ver- 

 tical sections are ever visible % I might almost ask whether 

 they are ever seen, except in the neighbourhood of the sides 

 of a glacier, i, e., under the lateral moraines ; and even there 

 how rare ! 



The object of the present memorandum is, on the one 

 hand, to direct attention anew to the apparently perpetual 

 paradox which the glaciers present in this respect, and 

 which, I am persuaded, offers something yet for careful ob- 

 servation, and, on the other, to give what seems to me in- 

 controvertible evidence, that what I have so seldom seen 

 myself must yet exist, and that stones are actually extrud- 

 ed, although in a peculiar manner, from pure ice, or at least 

 exposed by the ablation of the surface. 



In my Travels, p. 241, referring to the excessively gradual 

 development of the moraine of La Noire on the Mer de 

 Glace of Chamoni, I stated my belief, that this moraine was 



