T. Sterry Hunt on Granitic Rocks. 115 
creek. In the valley of this stream are hundreds of little mud 
or turbid water vents, which keep up a simmering noise, show- 
ing the nature of the earth beneath the crust. Several of our 
party broke through the thin covering, and were severely scalded 
by the hot mud 
Two miles above, on the same side of the Yellowstone, is 
water; suddenly immense columns of steam shoot up with a 
rumbling noise, the water overflows the basin, and then a 
tion, with a noise like distant thunder. The ground as well as 
the trees for a horizontal distance of 200 feet around were 
covered with the mud which had been ejected at some of its 
periodical outbursts. It would require a volume to descri 
these springs in 
[To be continued.] 
Art. XVIIL—Notes on Granitic Rocks.—Part III; by T. 
STERRY T. 
(Continued from vol. i, p. 191.) 
VONTENTS of Sections.—§ 32, Laurentian gneisses; § 33, Pyroxenites and limestones; 
= Lbsence of mica-schists; § 35, Clas Granitic veinstones ; 
Noite ion ri banded (piece Ee 
eleton-crystals; § 42, Rounded crystals; , Qua 
veins; § 44, read of veinstones; feldspathic ; $45, Calear 
§ 46, Order of succession of minerals; § 47, Attitude of —— is 48, Caleare- 
e 
§ 32. It was mentioned at the close of the second part of this 
paper that the third part would be devoted to the consideration 
of the granitic veinstones found in Laurentian rocks. The stra- 
tified rocks of this ancient gneissic series, as I have elsewhere 
pointed out, differ considerably from those of the White Moun- 
