84. PROCEEDINGS OF SOCIETIES. 
adapted the coils of the Zygnema to its case, and to perceive how 
healthily the alga continued to live, not seemingly suffering from 
the use to which it had been put. When feeding or moving 
about, the insect carried its case much as a caddis-worm would— 
swaying it backwards and forwards. These specimens continued 
to live and move actively for about a week in confinement. 
Mr. Archer brought forward Characium ornithocephalum 
(A. Br.), and what he regarded as Ankistrodesmus convolutus 
(Corda), kindly forwarded by Professor Gagliardi from York- 
shire. 
Mr. Archer took occasion to mention that he had found 
Sorastrum spinulosum (Nag.), Kiitz., in a gathering made near 
Drogheda; they were somewhat larger, but not so brightly 
green, as those he had shown (for the first time in Britain) taken 
rem the Rocky Valley, in September, 1865. (See Club minutes 
of that date.) 
Mr. Tichborne brought before the meeting a slide which repre- 
sented and, he might say, explained a phenomenon observed in 
crystallization. Some chemical salts and many minerals presented 
the peculiarity that unfractured surfaces show—an amorphous 
texture perfectly devoid of crystalline structure, yet, when broken 
through, were found to consist of exquisite geometrical forms, 
which were produced by needles or prisms radiating, from some 
axis or point, towards the amorpkous circumference. The beau- 
tiful and well-known mineral Wavellite may be cited as a speci- 
men of this characteristic crystallization, and many specimens 
which come under the denomination of botryoidal, mamillated, 
and reniform. 
Many of the quinine salts presented the same peculiarity, par- 
ticularly the chlorate—a salt which Mr. Tichborne has had ocea- 
sion to experiment with to some extent lately. When a boiling 
solution of pure chlorate of quinine is allowed to cool, the solu- 
tion becomes quite milky, not (as might be at first sight supposed) 
from a deposition of minute crystals, but (as the microscope 
shows) by the deposition of the salt in the form of oily globules, 
which on cooling become vitreous balls; these in a short time 
change to fine filiform masses of crystals. As the process con- 
tinues, the salt is again deposited upon the periphery of the mass 
in an amorphous condition, at the same time becoming crystalline 
in the interior. The result is, in the case of this salt, most 
curious mushroom-shaped masses, perfectly amorphous on the 
exterior, but beautifully crystalline inside. The slide exhibited 
was procured by allowing the solution of chlorate of quinine to 
cool slowly upon the glass, and, when the globules were suffi- 
ciently collected, to dry rapidly in an air-pump. By this means 
the chlorate was retained in its vitreous condition ; otherwise it 
becomes crystalline. It would be observed, that even here the 
globules seemed to arrange themselves in a symmetrical form—so 
