Proceedings of the Microscopical Society. 65 
mand. He exhibited a “prehistoric” microscope, of date 
1834, and also a number of single lenses, with a magnifying 
power of about 200, by the aid of which all his early work 
had been accomplished. He laughingly remarked “ that if 
in the dawn of microscopy the instruments were poor, the 
observers had to make up for it by looking harder.” Cer- 
tainly nothing can mark more clearly the advance made in 
optical instruments, in response to the demands of science, 
than a comparison between the instrument of 1834 and that 
of to-day. Sie William demonstrated that our Montreal 
limestone is composed almost entirely of organic remains. 
He also exhibited a specimen of clay from McGill College 
grounds, and shewed that it contained a large number of 
foraminifera. Fossil sponges were treated of, and a large 
number of specimens, prepared by the lecturer, were ex- 
amined with much interest by the members. 
A vote of thanks was tendered Sir William for his court- 
esy In preparing so interesting a lecture and demonstration 
for the society. 
Letters of regret at being absent were read from His 
Excellency the Governor-General and others. 
The next meeting of the society will be held on January 
11th, when Prof. Cox of McGill College will lecture on 
“Polarised Light, its usefulness in indicating structure,” 
with lantern illustrations. 
NoTIcES OF BooKs AND PAPERS. 
MANGANESE, ITs Usns, ORES AND Duposits, by R. A. F. Penrose, 
642 pp., Littie Rock, Ark., 1891, being Volume I. of the 
Annual Report of the Arkansas State Geological Survey, 
1890, J. C. Branner, State Geologist. 
In 1889 Dr. R. A. F. Penrose, jr., assistant geologist for the Geo- 
logical Survey of Arkansas, U.S., began the thorough reexamination 
and study of the manganese ceposits of that State,.and his official 
report, now published, proves how very complete and exhaustive 
have been his labors and researches, for not only has he examined 
personally the deposits in Arkansas, but he has visited every 
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