360 On the Physical Geography of the Alps. 
glaciers, and ice does not arise from the reflection of the firma- 
ment above, but is the peculiar color of water in a fixed condition; 
in the mean it is identical with a mixture 74-9 per cent. of Krem- 
ser-white [white-lead], 24:3 per cent. cobalt, and 0-8 per cent. of 
burnt ochre; being, therefore, always lighter than the blue of 
meer] is in general greater than that of the glacier belonging to 
it:—2. the altitude of the lowest places where “ firn” is met with 
more difficult to thaw, the older it is:—4. the region of the 
dust-snow avalanches [stau blawinen] commences above the limits 
of the forests, and continues downwards only in some cases to 
the “montane region :”—5, the marking of the “ firn-meer” by 
snow-disks [Schnee-ridchen] is only superficial, but it shows that 
even slightly inclined firn-seas are composed of much smaller 
basins :—6: the “ firn” or névé is generally laminated ; an annual 
layer is from 0-75 to 1 metre in depth :—7. with few exceptions, 
there are no glaciers on limestone; the most essential conditions 
for the formation of glaciers are wide basins and an underlying 
rock impenetrable to water. 
From the consideration of the general characters of ice and the 
different forms of the important snow and “ firn” beds that con- 
stitute the earliest conditions for the formation of glaciers, we are 
next led to the subject of the 
= 
* 
Topography of Glaciers proper. 
