Montlilv Microscopical"! 
Journal, Nov. 1, 1869. J 
NOTES AND MEMORANDA. 
279 
ment will prove by no means to be limited to the single object viewed, 
but also to embrace somewhere within the limits of a half rotation of the 
lower p'ism (the selenites themselves now remaining stationary) the 
finest optical development of many other slides containing tissues of 
the same or closely allied character. For example, I found a mag- 
nificent setting for exhibiting the cuticle of the Equisetum ; and I 
have no vegetable cuticle in my possession that does not come out 
superhly under the same selenite adjustment, but with a different posi- 
tion of the polarizer. So in relation to deep-coloured entomological 
objects difficult to polarize, and many others, they class themselves 
under certain optical heads as to the settings, only needing a changed 
position of the polarizer; and thus a great amount of time and 
labour is saved, for the pism can be set to its recorded reading in- 
stantly, whilst the instrument remains in situ — in fact, without any dis- 
turbance of the general arrangements at all. Lastly, by means of this 
polariscope the elementary colours can be mingled in any order or 
proportion that may be desired ; so that any coloured field whatever, of 
absolute uniformity throughout, from the dirtiest brown to the deepest 
and purest azure blue (even by lamp-light), may be produced instantly 
by making a known setting. In conclusion, I wish to point out that 
this is essentially an instrument of precision, and therefore demands 
skill and patience on the part of the operator to make it do its work ; 
but when employed with the ability and tact characterizing all skilled 
microscopists, it is competent to yield results of surpassing delicacy 
and beauty. 
This demand upon the operator's skill and patience, however, is 
only that made by every instrument of precision (witness wide-angled 
objectives) ; for the greater the range and powers of any instrument, 
the more care and thought must necessarily be employed in its use. 
NOTES AND MEMOEANDA. 
The Montreal Microscopic Club. — This club, which was estab- 
lished last year, has already proved itself a success. In plan it is 
something like that excellent working body the Dublin Microscopical 
Club. The club appoints a secretary, who arranges for the meetings, 
and suggests a special subject for illustration at each. The host for 
the evening is the President of the club ; minutes are recorded and 
read, visitors introduced, miscellaneous business discussed, and micro- 
scopic investigation proceeded with. At 10.30 p.m. the President 
announces the adjournment, the microscopes are returned to their 
cases, and a parting cup of coffee closes the seance. During the 
intervals of meeting the Monthly and Quarterly Microscopic Journals 
circulate amongst the members, and afford material for discussion and 
illustration. 
A Translation of Strieker's Histology.— It is said that the New 
Sydenham Society has selected for translation Herr Strieker's ' Hand- 
buch der Lehre von den Geweben.' 
