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NOTES AND MEMOKANDA. 
lUummation in connection with Polarization.— There is a capital 
paper on this somewhat complex subject iu the ' Journal of the 
Quekett Club' for September, 1876. It is, however, too loug for 
insertion as a whole, and it is very difficult to abstract. We observe 
also that the author has appended a note to the effect that he has 
succeeded in adapting the principle of the side reflector as a suh-stage 
arrangement for transparent objects, which possesses all the merits of 
the Bramhall mode of illumination without any of its defects ; and 
combines also the additional advantage of being applicable to general 
purposes (which the other is not), producing a beautifully soft and 
clear light, with great perfection of definition. It is so arranged that 
the angle of incidence may be regulated at will and set at any degree 
of obliquity capable of producing from a dark-ground illumination to 
almost direct rays ; whilst it admits of the lamp being placed in front 
of the instrument, so as to be entirely out of the way of the hands 
and face. 
A New Mode of Mounting Foraminifera is given by a very 
distinguished authority, Professor H. L. Smith, of Hobart College, 
New York. It is published in the ' Journal of the Quekett Club ' 
(September), and contains besides the description of the above mode 
an account of a somewhat similar method for the Diatomacese. For 
the Foraminifera he punches out of a sheet of wax (dark-green or 
black), a disk a trifle larger than the brass curtain-ring which is 
to constitute the wall of the cell. This disk is pressed by one edge 
to the centre of a glass slide, and slowly warmed till it melts — if well 
done no bubble of air is enclosed under it, and the whole cools with 
a smooth, somewhat dead surface. The ring is then pressed into this, 
and centered by the turn-table, and then again pressed fully home, 
showing the brass, when looked at from the under side ; and the 
whole finished with the usual " Brunswick black " outside, and also 
the ring inside. To attach the Foraminifera, or other objects, a 
minute drop of turpentine is applied to the wax, and in a minute 
or so, before it is quite dry (and we may proceed leisurely), the 
object is placed on the softened wax ; when thoroughly dry, it will 
be found so strongly attached that a violent blow or a fall will not 
dislodge it. Of course, if the object is very large the turpentine may 
have a little of the Brunswick black or some size dissolved in it. 
The improvement over the glistening gum attachment for minute 
objects is very manifest — indeed no signs of the cementing material 
show if the turpentine is judiciously used. While all this is being 
done, the Brunswick black on the brass ring will have set sufficiently 
to fasten the cover, which should be of such a size as to rest, not on 
the top of the ring, but to slip just within, so that its surface will be 
flush with the top of the ring. When the cover is pressed home, the 
whole may at onCe, without any danger of its " running in," be 
finished with the black varnish. Nothing can exceed the soft and 
