Rett hil 
736 SCIENCE. 
fusion of rock-masses by lightning. The greater por- 
tion of Mr. Diller’s time in April was devoted to the 
study of this rock, which was deemed worthy of spe- 
cial examination, not only on account of its rarity, but 
also from the fact that it presents the opportunity to 
study the products of an uncommon method of fus- 
ion. While the formation of fulgurite in sand is of 
frequent occurrence, it is only exceptionally produced 
in solid rock. ‘The most important locality where it 
has been heretofore discovered in solid rock is Little 
Ararat in Armenia reported by Abich. Upon the 
specimen collected by him, Wichmann has made a 
brief microscopical research. An endeavor is being 
made to obtain some of the fulgurite of Little Ararat 
for comparison with the Oregon specimens. 
Saussure mentions glazed hornblende schist as 
occurring on the summit of Mont Blanc; Humboldt 
reports fulgurite from one of the peaks in Mexico; 
Ramond saw it at several points in the Pyrenees and 
the Auvergne: but these occurrences have never been 
investigated. 
Mr. Diller prepared a number of delicate, thin sec- 
tions of the fulgurite from Mount Thielson; and its 
relation to the various constituents of the rock has 
been very clearly made out. A chemical analysis has 
been made by Prof. F. W. Clarke. 
The material fused by the lightning was cooled so 
quickly that it all remained amorphous, and formed a 
dark, porous glass. In order to test the conclusions 
reached in the microscopical analysis, an attempt was 
made to crystallize the fulgurite. A completely amor- 
[Vor. IIL, No. he 
phous fragment was heated without fusion in a Bun- 
sen lamp for six hours, and then found, in polarized 
light, to be made up of strongly doubly refracting 
fibres, with a marked tendency to spherulitic arrange- 
ment. A finely pulverized portion was fused, and as 
highly heated as possible in a blast-lamp for four hours 
and three-quarters, and then allowed to cool gradually. 
Under the microscope, it was found that much of the 
felspar, some pyroxene, and many undeterminable mi- 
crolites, crystallized out of the glass during the heat- 
ing. The various stages in the development of fel- 
spar crystals from more or less regular groups of 
microlites, through lathe-shaped bundles of fibres toa 
completely clear, transparent crystal, are easily traced. 
The microscopical as well as the chemical evidence, 
and that derived from the re-crystallization of the 
fulgurite, all indicate that the fusion was confined 
chiefly to the siliceous groundmass of the rock with 
which the fulgurite is associated. ‘The rhombic py- 
roxene was also fused to some extent, while the pla- 
gioclase felspar and olivine were not affected. The 
examination also indicates that the composition of 
the glass derived from the fusion of parts of a heter- 
ogeneous rock is a function of the fusibility and elec- 
tric resistance of its various constituents. 
The basaltic rock on which the fulgurite has been 
found is unique in the character of its pyroxene. 
The various mineral constituents of the rock are now 
being separated, for the purpose of a chemical analy- 
sis, by means of Thoulet’s solution. 
RECENT PROCEEDINGS OF SCIENTIFIC SOCIETIES. 
Brooklyn entomological society. 
May 31.— Mr. Roberts gave an account of the 
habits of the Elmidae, a large number of which were 
collected by him at the Clifton excursion. —— Mr. 
Schwensen called attention to the food-habits of some 
species of the Chrysomelidae, belonging or allied to 
Cryptocephalus. Many species are, in his experience, 
omnivorous; others, found only on certain groups of 
plants. 
Academy of natural sciences, Philadelphia, 
May 20. — Mr. Joseph Willcox stated, that, on the 
west coast of Florida, shell-mounds are very numer- 
ous, indicating the former favorite camping-grounds 
of Indians. The largest accumulation of shells is at 
Cedar Keys. A portion of the town is built on the 
mounds; and great quantities of the material, consist- 
ing almost entirely of oyster-shells, have been used 
in grading the streets. Human bones, stone imple- 
ments, and fragments of pottery, are frequently found 
among the shells. Although Professor Wyman, in his 
memoir on Florida shell-heaps, asserts that stone chips 
are not common, being only found separately or a few. 
together, and in no case indicating a place for the 
manufacture of arrow-heads or other implements, 
such a place of manufacture may be seen on John’s 
Island, at the mouth of the Cheeshowiska River. 
Several bushels of chips are here scattered about, all 
made of the chert rock, the only material in Florida 
suitable for the purpose. —— Professor Heilprin, re- 
ferring to the Foraminifera found in the rock-masses 
from Florida, stated, that, after a careful search, he 
had been able to add but one genus, Spheroidina, to 
those before enumerated. It was, he believed, the 
first time that any of the genera named at the meeting 
of April 22, except Orbitoides, had been discovered 
in America. He had also found another species of 
Nummulites, making, with N. Willcoxii, the second 
American form. The new species is twice the size 
of that named; and the septa are more numerous, and 
bent at a more acute angle. ‘Two additional forms of 
Orbitoides had been determined, the presence of one 
of which, O. ephippium, places beyond doubt the 
oligocene age of the deposits containing it. —— Mr. 
Thomas Meehan exhibited flowers of the remark- 
able Halesia, the striking variation in the leaves and 
seeds of which had formed the subject of a former 
communication. The flowers of the sport are cup- 
shaped instead of tubular; and the wide divergence ~ 
reached without any intervening modifications was — 
another illustration of the fact that the maxim of 
