s the soil has a
red colour from the disintegration of a reddish-brown slate-clay.
[Sidenote: 187] The summits of the hills that were visited were thinly
coated with loose gravel, composed of smooth pebbles of lydian-stone,
intermixed with some pieces of green felspar, white quartz, limestone,
and chert. In some places almost all the pebbles were as large as a
goose-egg, in others none of them exceeded the size of a hazel nut. The
Rein-deer Mountains terminate in lat. 69 degrees, having previously
diminished in altitude to two hundred feet, and the eastern branch of
the river turns round their northern extremity. White spruce trees grow
at the base of these hills as far as lat. 68-1/2 degrees; north of which
they become very stunted and straggling, and very soon disappear, none
reaching to lat. 69 degrees.

Sir Alexander Mackenzie, who, on his return from the sea, walked over
these hills, says, "Though the country is so elevated, it is one
continued morass, except on the summits of some barren hills. As I
carried my hanger in my hand, I frequently examined if any part of the
ground was in a state of thaw, but could never force the blade into it
beyond the depth of six or eight inches. The face of the high land
towards the river is, in some places, rocky, and in others a mixture of
sand and stone, veined with a kind of red earth, with which the natives
bedaub themselves." It was on the 14th of July that he made these
observations. On the 5th of the same month, in a milder year, we found
that the thaw had penetrated nearly a foot into the beds of clay at the
base of the hills.

ALLUVIAL ISLANDS AT THE MOUTH OF THE MACKENZIE.

The space between the Rocky Mountains and Rein-deer Hills, ninety miles
in length from lat. 67 degrees 40 minutes to 69 degrees 10 minutes, and
from fifteen to forty miles in width, is occupied by flat alluvial
islands, which separate the various branches of the river. Most of these
islands are partially or entirely flooded in the spring, and have their
centres depressed and marshy, or occupied by a lake; whilst their
borders are higher and well clothed by white spruce trees. The spring
floods find their way, through openings in these higher banks, into the
hollow centres of the islands, carrying with them a vast quantity of
drift timber, which, being left there, becomes water-soaked, and,
finally, firmly impacted in the mud. The young willows, which spring up
rapidly, contribute much towards ra