Montreal Microscopical Society. 141 
PROCEEDINGS OF THE MONTREAL MICROSCOPICAL 
SOCIETY. 
The regular monthly meeting of this Society was held on 
January 11th when it was expected that Prof. Cox would 
give a paper on polarized light, but owing to his indisposi- 
tion the lecture had to be postponed. The members, however, 
were requested to bring slides or other objects of interest, 
which several of them did, and a very successful meeting 
resulted. 
Feb. 8th, Jos. Bemrose, F.C.S., read a paper on “ Crystal- 
line forms modified by Impurity.” The formation of crys- 
tals was carefully explained and the effect of impurities on 
the forms of crystal described. Poisons forming crystals, 
it was stated, could be detected, separated from food, exam- 
ined microscopically, and the kind of poison identified by 
its crystals. The lecturer had specially prepared a large 
number of slides to illustrate his subject, which demonstrated 
that there was great beauty of form and colour, as well 
as delightful and valuable results to be obtained by careful 
study of crystals. Polarized light was largely used in 
demonstrating the structure of the crystals exhibited. 
Feb. 26th. A special meeting was held to hear Prof. Cox’s 
paper ‘“ Polarized light, its usefulness in indicating struc- 
ture.” Ordinary light waves were first referred to, and then 
the special character of polarized light was treated of. The 
effect of Iceland spar in dividing the rays of light 
was demonstrated by introducing a crystal of that 
substance into the lantern, when the most wonderful changes 
in colour were observed on the screen. The actual forma- 
tion of crystals was also shown in the same way by placing 
Benzoic Acid between two thin plates of glass, when after 
heating, the crystals could be observed forming. This was 
a most successful experiment and clearly demonstrated the 
value of “ polarized light in indicating structure.” Through- 
out, the lecture was illustrated at every point with mechani- 
cal and electrical apparatus, and at its close a vote of thanks 
was proposed by Hon. Senator Murphy, eee by Dr. J. 
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