Holst’s Studies in Glacial Geology. 597 
very turbulent, and the kryokonite, therefore, mingles with the 
clays and sands, which are whirled down by them into the sea. 
But if such inland ice were advancing over a plain, and the kryo- 
konite were washed out from it by quietly-running water, it would, 
no doubt, get an independent geological significance. 
This theory presupposes the existence of kryokonite, not only on 
the surface of the inland ice, but also in its deeper parts. That this 
is the actual case is plainly visible near the borders of the ice. 
Microscopical analyses of the kryokonite were made in 1881 by 
A. von Lasaule, F. Zirkel, and E. Swedmark. All agree in the 
main: The kryokonite contains nothing but the ordinary components 
of primitive rock. 
Professor Zirkel found Dr. Holst’s samples to contain mainly the, 
following minerals, viz., quartz, orthoclase, plagioclase, greenish and 
brownish mica,—which he supposes to be a magnesia mica,—and 
colorless potassium mica (this last mineral occurring but rarely) 
He also found some hornblende, garnet, magnetite, and (doubtfully) 
traces of titanite and epidote. In all cases the principal constituents 
were quartz, magnesia mica, and feldspar. The thinnest scales of 
_ Mica pierce through the feldspar fragments, just as they do in the 
gneisses, Metallic iron was never identified in the samples. Pro- 
fessor Zirkel calls particular attention to the total absence of any 
augite, olivin, or glass. Both chemical and microscopical analyses 
agreeing, it may be regarded as a settled fact that the kryokonite 
has the same origin as the moraines, It is far more difficult to solve 
the question regarding the geological significance of the kryokonite. 
During his visit to Greenland, Dr. Holst was inclined to suppose 
that it nowhere forms independent deposits, but always occurs 
commingled with the clays and fine sands of the till, the kryokonite, 
as to its grain, being intermediate between the two. It is sand, but 
considerably less palpable than any ordinary kind of sand. How- 
ever, since he had opportunity of studying the /oess in Saxony, he 
came to the conclusion that the loess is nothing but kryokonite. 
_ Considering the loess (kryokonite) as a product of repeated wash- 
ing processes, in the manner above stated, it is easy to conceive why 
ìt has reached such remarkable extent and purity. 
The State Geologist, E. Swedmark, having examined microscopi- 
cally samples of loess collected at Ebendorff, near Magdeburg, and 
