1%6 THE MICROSCOPE. 
PROCEEDINGS OF, SOC@IE Rae 
SAN FRANCISCO MICROSCOPICAL SOCIETY. 
HE regular meeting of this society was held at its rooms, 120 
Sutter street, April 24, 1889, President Payzan presiding. 
A fine series of photographs was exhibited, containing some graphic 
enlargements on the new Eastman bromide paper. This process of 
enlarging on bromide paper, though quite recent, is very popular 
and produces excellent results, the effect, when exposure and nega- 
tives are properly manipulated, being almost equal to steel engraving. 
Examples were shown of Pleurosigma Angulatum, the nega- 
tives of which were taken at a magnification of sixteen-hundred 
diameters. 
The bromide process commends itself to those interested in 
photomicography by its simplicity compared with the tedious work 
of printing from silver paper. The donations to the library included 
a very satisfactory résumé of the progress of microscopical investiga- 
tion both at home and abroad. 
Mr. Lickenby occupied most of the evening in concluding his 
practical demonstration of preparing and mounting insects in balsam. 
A general summary of his methods was given in the report of April 
10th, but some special points were brought out at this meeting which 
are of interest to those engaged in this branch of the study. It is 
quite difficult in preparing many of the smaller forms of insects to 
remove the debris from the surface of the specimen without injuring 
the delicate portions. This the gentleman accomplishes by the aid 
of albumen, flowing the white of an egg over the object and immers- 
ing the slide in hot water till the albumen is coagulated, when it will 
generally crack open and may be removed in two portions, carrying 
with it all the foreign matter and leaving the surface of the specimen 
perfectly clean. Another thing strongly advocated is thorough 
washing of the objects in running water and a final rinsing in either 
filtered or distilled water before placing in alcohol. 
In mounting, the insect is placed under the cover glass arranged 
in proper shape, the clearing solution applied, and, when sufficiently 
transparent, the oil of cloves is drained away and Canada balsam 
introduced at one edge of the cover-glass, the slide being held over 
the flame of a lamp to gently warm the balsam and allow it to flow 
in and displace the remaining oil of cloves. No annoyance need be 
felt at the presence of bubbles of air, as they will all gradually dis- 
appear. The mount, when filled with balsam, is placed in a warm 
