PROCEEDINGS OF SOCIETIES. 149 
Tare Council of the Microscopical Society of London, being 
desirous of extending as far as possible the study of Microscopical 
Science, have determined to give their public approval, and grant 
a Quekett Medal, to that which shall be adjudged, after careful 
comparison, to be the best Microscope of each of the three fol- 
lowing classes. 
1. An Epucatronan Microscoprrs to be sold for Toren Gurnzas. 
2. A Stuprent’s Microscope » Erve GUINEAS. 
38. A StupEnt’s Binocutar Microscope ,, Ten GurNeas. 
The Council consider that the talent and ingenuity of the In- 
strument makers should be restricted as little as possible in the 
specifications put forth ; and in fixing on the following conditions 
for each Instrument, they confine themselves to what they will 
consider absolutely necessary to allow Instruments to compete on 
their merits. 
1. The Three Guinea Educational must have good achromatic 
low powers, which may be made to act in combination or sepa- 
rately, to give a magnifying power ranging from 40 to 120 
diameters. Fine adjustment may be made by the draw tube: 
good optical performance will be preferred to complexity of 
mechanism, but some means of inclining the Microscope will be 
desirable. 
2. The Five Guinea Student’s Microscope to have good achro- 
matic powers, which may be made to act in combination or 
separately, ranging from 25 to 200 diameters. Two Eye-pieces, 
Bull’s Eye Condensor, and Live Box; Camera Lucida, or some 
other apparatus for drawing. The stand to be capable of incli- 
nation. : 
8. The Ten Guinea Student’s Binocular to be capable of being 
used as a Uniocular Instrument, to have powers which may be 
made to act in combination or separately, ranging from 25 to 
200 diameters. One pair of Eye-pieces, Bull’s Eye Condensor, 
Live Box, and Lieberkiihn with dark stops, for the lower powers. 
The stand to be capable of inclination. 
They are also prepared to offer a Certificate of Excellence for a 
Hand Achromatic Microscope for field or clinical purposes. The 
Instrument, with a Live Box, to be supplied for One Guinea. — 
Each Instrument to be fitted with the Society’s screw, and with 
its apparatus to be packed in a case. 
The Council, in stating the foregoing conditions to be neces- 
sary, without which Instruments will not be allowed to compete, 
do not wish to place any limit to the mechanism or to the appa- 
ratus supplied with each; at the same time, in comparing the 
merits of the Instruments sent in, they will consider good optical 
performance as the most essential point in determining which 
Instrument shall be selected for the Medal. 
The Instrument of each class which obtains the Medal to re- 
main the property of the Society, to be available as a standard of 
comparison, by which purchasers of corresponding. instruments 
