THE MICROSCOPE. 177 
oven or incubator and kept at a temperature of from 120° to 130° 
Fahrenheit for twenty-four hours, when the balsam will be thor- 
oughly hardened and all the air-bubbles driven out. 
Mr. Lickenby does not advocate the use of volatile solvents with 
balsam, he being convinced that a certain amount of gas is always 
retained in the mount in a latent state, requiring only a slicht 
amount of heat to produce bubbles and disfigure the specimen. The 
outer skeleton of insects is composed of a substance called chitine, 
which is quite unique in its chemical composition. It appears to 
be, within certain limits, very resistant to acids and alkalis, and it is 
owing to this fact that caustic potash can be used in such varying 
proportions in treating them for microscopical study. It is said, 
however, that chitine succumbs to the action of chlorine compounds, 
which would render that substance unfit for use in bleaching many 
of the delicate forms. 
The members of the society are strongly in favor of these prac- 
tical demonstrations, and quite a discussion of the matter was 
indulged in, the result of which may be the inauguration of a move- 
ment that will tend greatly to arouse the zeal and add to the 
effectiveness of future microscopic work. 
Before adjourning, the society tendered Mr. Lickenby a hearty 
vote of thanks for his skilful and instructive demonstrations. 
At the regular meeting, held May 8th, 1889, the visitors present 
were A. W. Craig and W. E. Bainbridge. The latter gentleman 
gave a good description and exhibited samples of a remarkable find 
located by him in Ventura county, near the head of the Sespe river. 
It consists of what is called “gem sand,’’ which, when examined 
with a power of about fifty diameters, is seen to consist largely of 
garnets, zirconite and what parties to whom the material was sub- 
mitted in the Eastern States pronounced to be diamonds. 
The gems, to be sure, are small, appearing only the size of a 
rape seed when magnified fifty diameters; but where there is much 
smoke there must be some fire, and the presence of such quantities 
of minute stones surely indicates the existence of larger members of 
the same family. 
Mr. Bainbridge remarked that he had no doubt thrown away 
numbers of the larger stones, thinking them loose quartz crystals, 
as he was only panning out the sand to find gold or large garnets. 
Professor Hanks stated that the small stones said to be diamonds 
had all the characteristics of the California diamond, and his opinion 
is worthy of attention, as he has made a close study of the gem. 
