Mineralogy and Geology. 111 
erystals. The bromid has the formula (H,N=NO—86),PtBr, 
and is the bromid of a true base in which the bromine ma 
Eee by oxygen acids. “The author terms the base plato-nitros- 
The paper contains many interesting and instructive illus- 
Resins of the author’s peculiar views of the qualitative influence 
produced on compounds by the substitution of electr O-positive or 
electronegative elements—views which are set forth with much 
clearness and force in his recently published work “ Die Chemie der 
Jetztzeit. ee der Deutschen Chemischen rape. — 
9, p. 2 
Il. MINERALOGY AND GEOLOGY. 
“Ist.— in a period probably cp oongen with the co 
h of Eu —at least pee oy it in the 
2 events othe porth ern ha the a of No meri 
a climate comparable with that of Greenland ; so cold, that 
wherever there was a copious sey gees of moisture from 
ois Ww 
rection of the glacial furrows proves that one of these ice rivers 
owed from Lake Huron, along a pahaesel now filled with drift, 
and known to be at least 150 feet deep, into Lake Erie, which was 
then not a lake, but an excavated va ey into which the streams of 
orthern Ohio ‘flowed, 100 feet or more the present lake 
level. Following the line of the major axis of Lake Erie to near 
its eastern extremity, here turning northeast, = glacier passed 
through some channel on the Canadian side, n ed np, into 
e Ontario, and thence found its way to ae? hi either 
St. Lawrence o by the Mohawk and son. Another glacier 
occupied the bed of Lake Michigan, having an outlet sout. 
through a channel—now concealed by e 
which occupy ~ surface Pe the south end of the lake—pass- 
, lll. and by some route yet own reac’ 
bie: Mliicatyle which was then much deeper 
this period the continent must have been several 
hundred fi feet higher than now, as is proved by the deeply exca- 
ated channels of the Columbia, Golden Gate, Mississippi, — 
‘in 
Nag cupy them, unless flowing with greater rapidity and im ; 
ower level thant they now do.’ 
urther aplenatains’ he takes up the subject of the Drift 
Deposits. 
