Review of Recent Geological Literature. 
199 
Michigan, Huron and Ontario were originally the bed of a preglacial river 
which first crossed the Ontario peninsula along the Niagara escarpment, 
and was afterward diverted to a course by way of Long Point on lake Erie 
and the Dundas valley (as already shown by Spencer.) Each of the basins 
—Michigan, Huron, Erie and Ontario—began as two or three smaller lakes. 
Lakes Erie and St. Clair are the most recent, and were, not long since, 
united. While the author minifies the action of glaciers he magnifies that 
of fractures, faults and changes of relative levels. 
Northwest Kansas : Its Topography , Geology , Climate and Resources, by 
Robert Hay, F.G.S.A. This memoir appears to be extracted from the 
4 Sixth Biennial Report of the Kansas State Board of Agriculture,” pp. 91- 
116. It is a well digested and valuable exhibit of the features of the state 
in the particulars and within the limits mentioned. It is noteworthy that 
this, like so mauy similar memoirs in various parts of the country, is the 
outcome of intelligence and enterprise controlled by the agricultural in¬ 
terest. Every survey of natural resources ought to be conducted with due 
regard to that interest; but on the other hand, that interest is recreant to 
itself when it prescribes narrow, unenlightened and miscalled “practical” 
limits to the researches of the geologist. This memoir is illustrated by 
profiles and a geologic section,and by numerous scenic photo-engravings. 
The usual blemishes of public documents printed under contract are seen 
in the absence of the proof-reader’s finishing touches. It may be to the 
same cause that we are to ascribe the disregard of established usage in the 
printing, capitalizing and italicizing of the few technical names employed. 
We are aware that the stock compositors use their own sweet will in dis¬ 
pensing with typographic discriminations and emphasis; but all evidences 
of either ignorance or neglect present a bad appearance in a western pub¬ 
lication. 
Les mineraux dcs todies: By Levy and Lacroix. 334, pp. 8vo; 12,fr 50. 
Paris, Baudry and Co., This new and advanced work on microscopic 
petrography is primarily devoted to the determination of minerals of very 
small demensions by means of mineralogical and chemical tests in con¬ 
nection with the microscope, and secondarily to a summary description of 
the different minerals by the application of the new methods. In their 
researches in optical mineralogy the authors have carried to a gieater 
degree of exact application the laws of polarized light and its modifications 
by minute crystals when placed on the stage between crossed Nicols, than 
has been done in any similar work. The different crystal systems are 
illustrated in great fulness, as they exhibit their characters and extinctions 
in parallel light, and to these actual observations are applied the theories 
of mathematical determinations. A similar exemplification is made of the 
use of convergent light, of refraction, and of polychroism. Another 
chapter presents a r6sum6 of the more recent methods of micro-chemistry 
to the qualitative analysis of minerals. Here are summarized, and some¬ 
times modified and improved, the processes of Boricky, FouquS, Behren s, 
Ilaushofer, Streng, Kliment and Renard; closing with a table of the prin¬ 
cipal micro-chemical reactions. 
