254 Prof. Huxley on the Structure of Glacier Ice. 
the more numerous the fissures. The same thing would happen 
to the glacier if its thickness were less, and if the external heat 
had access to it on all sides. Nevertheless its surface decom- 
poses more or less, the fissures dilate in consequence of the 
circulation, and the fragments are so dislocated as to be 
moveable on one another without however becoming detached.” 
—P. 163. 
(12) “ The angular fragments and the capillary fissures 
seem to disappear the moment the ice is covered. Thus on 
sweeping clean a part of a moraine, or the side of a gravel 
cone, the ice beneath is found to be perfectly smooth, and appa- 
rently without a trace of a fracture. But it is sufficient to 
leave these same surfaces uncovered for some instants, and the 
capillary fissures immediately show themselves, and, in conse- 
quence, the angular fragments. They appear with such regu- 
larity, that one might be tempted to believe that they are formed 
spontaneously at the very moment of their appearance. But on 
examining them with a little attention, one becomes convinced 
that they are of older date. ; 
« ] by no means pretend to deny that heat, acting suddenly 
at the moment the moraine is uncovered, may not develope 
some cracks. I have myself seen such cracks form suddenly 
(par éclat), but I conceive they are but few. If it were other- 
wise, and if the fissures were formed as they appear, it would 
be necessary to suppose that there are none in the ice of the 
moraine before it is uncovered, which would be contrary to all 
we know of the transformations of the ice.”—P. 165. 
(13) “Let us now make the opposite experiment, and cover 
with sand and gravel a portion of the surface of the glacier. 
However fissured and disaggregated it may be, the fissures and 
angular fragments will disappear at the end of some time so 
completely, that on removing the gravel the surface will be 
found as compact and transparent as that of a portion of mo- 
raine which has never been uncovered. And yet it is not pro- 
bable that the fissures have reunited during the interval. It is, 
on the contrary, the gravel, which, intercepting the air and 
keeping the fissures full of water, renders them invisible, and 
gives to the whole mass a false appearance of compactness, 
which ceases the moment the air again has access to the 
fissures.” —P. 166. 
If the extract (8) were to be taken merely as a description of 
the superficial layer of a glacier, I should only have to object, 
that, so far as I have been able to observe, the colour of the dis- 
integrated blue veins is not much affected. by the water they 
contain, and that no amount of watery infiltration will confer 
on the white ice the beautiful transparency and colour of the 
