214 PROGRESS OF MICROSCOPICAL SCIENCE. [*joum^ifocri!^^^^^^^^ 
puscles found in defibrinated blood are, he says, the best for observa- 
tion. — Vide 'New York Medical Record,' August 16th. 
Dr. Carpenter 8 Deep-sea Expedition. — At the meeting of the 
British Association a letter was read by the Rev. A. M. Norman from 
Professor Wyville Thomson on the " Successful Dredging of H.M.S. 
' Porcupine ' in 2435 fathoms." This is nearly the height of Mont 
Blanc. It must be understood that dredging is a very different thing 
from sounding. The first dredge brought up IJ cwt. of ooze, the 
second 2 cwt., from this great depth. The bottom temperature was 
30°. The sun's heat extended downwards 20 fathoms ; that of the 
Gulf-stream 500 fathoms ; after that the temperature sank generally 
at the rate of two-tenths of a degree for every 200 fathoms. Not 
only was animal life abundant at the great depth of nearly 2500 
fathoms, but many new forms were added to science, and several 
related to the British fauna. The chemical condition of the water at 
great depths showed that it was strongly impregnated with organic 
matter, which accounted for the food provided for the animals at the 
bottom of the sea. The dredging demonstrated that there were living 
creatures now at the bottom of the sea precisely similar to the fossils 
of the chalk. 
Microscopic Examination of Obsidian. — Mr. W. C. Roberts, F.C.S., 
F.G.S., gave an account at the Exeter meeting of his application of 
the microscope to the examination of specimens of obsidian from 
Java. The paper was a statement of the results of the examination of 
a substance that, from the indefinite character of its composition, par- 
takes of the nature of a rock rather than that of a mineral. The spe- 
cimen of obsidian was from Java, originally in the cabinet of Bernard 
Woodward, Esq., but the label does not give the exact locality. It 
appeared to differ much from that, also from Java, now in the British 
Museum. The specific gravity of the specimen was 2*35; in thin 
sections it is perfectly transparent. Mr. Roberts gave an analysis of 
its composition, and said that it may be easily cut into thin sections, 
and by the aid of a low power, say 200 diameters, at least three dis- 
tinct minerals (beautifully crystallized) may be distinguished, dia- 
grams of which were produced with the specimen. 
Photographs of Noherfs Lines. — The recently-published ' Transac- 
tions of the Philadelphia Academy of Natural Science' gives the 
following account of the presentation of Drs. Curtis and Woodward's 
photographs of Nobert's lines, and as the photographs are also in the 
library of the Royal Microscopical Society, the observations may be 
of interest to our readers : — " The bands were very beautifully photo- 
graphed, showing up to the sixteenth perfect lines that can be counted 
through the whole width. Their instruments failing to resolve, or 
rather, to photograph the four finer bands, sixteen, seventeen, eighteen, 
and nineteen. Dr. Woodward infers that the last four bands have not 
been resolved. Mr. Stodder remarked that in his opinion the claim 
to have resolved the finer bands, advanced by Mr. Greenleaf and him- 
self, was not disproved by this failure to photograph them. The 
condition of the microscope for photographing (without an eye-piece) 
