376 On the Physical Geography of the Alps. 
carbonate of lime. A quantitative examination of the waters of 
two Alpine streams, made by M. Adolph Schlagintweit, is here 
given. 
1. The Moll at Heiligenblut. 2. The Oetz at Vent. 
378000 grammes of the grammes of the 
é water evaporated. water evaporated. 
Carbonate of lime, ..........%. 03182 018044 
Carbonate of magnesia, ........ 01334 000144 
BiG oe coe 0:2719 0°25170 
hlorid of potassium, ........ 
Santo t — oe 
3 Oxyd of iron, WOUCS TE oes ccs paxapeees 037728 
paaremnesa Ss a oe ne cee 01221 traces. 
Uris vo vedas Gis a traces traces. 
*# Sulphates, .. . traces. saagie 
_ Sand in suspension, ............ WUTSES fas ck 6s as ca ee oes 0°24888 
09882 102230 
Although both of these rivers rise in the crystalline slate range, 
and resemble each other in the mass of the substances held in 
solution, yet the above analyses show important differences in the 
individual constituents. This is particularly the case with the 
~carbenate of lime and carbonate of magnesia; the larger propor- 
tion of these in analysis No. 1, is due to the general distribution 
of carbonate of lime in all the rocks of the Upper Méll district, 
the composition and stratigraphical conditions of which are refer- 
red to in chapter x; whilst in the Oetz Valley only a few, quite 
isolated limestone masses occur. On the other hand, the greater 
proportion of oxyd of iron is present in analysis No. 2; and this 
is alWays an important product of weathering. The greater pro- 
portion of calcareous matter in the M@ll district is of much interest 
with respect to the series of observations on Alpine vegetation, 
given by the author in a subsequent chapter of this work. : 
The history of the hydrographical phenomena of the Alps is 
succeeded by observations on Erosion, having reference to the 
present effects of rivers as eroding agents, and their relation to the 
formation of valleys in general; the sudden emptying of large 
reservoirs of water; notices of the course of the great flood (from 
the bursting of the Vernagt Lake) in the year 1848, with a table, 
showing the remarkable differences between the time required 
for the passage through the valley of the great bulk of the flood- 
ieal properties of the earth and its composition, of the nature and 
properties of humus, aud of the influence of vegetation on the 
