1880. | Geology and Paleontology. 457 
at length to have attended the labors of Mr. Hannay, of Glasgow. 
The method adopted, is by taking advantage of the affinity dis- 
played by hydrogen for certain metals, especially magnesium, ‘at 
a very high temperature, forming extremely stable compounds 
with them. When carbon is by this means set free from a hydro- 
carbon in presence of a stable compound, containing nitrogen, the 
whole being near a red heat and under a very high pressure, the 
carbon is so acted on by the nitrogen compound, that it is obtained 
in the clear transparent form of the diamond. The carbon thus 
obtained is as hard as natural diamond, with a specific gravity, 
ranging as high as 3. 5, scratching all other crystals, and it does 
not effect polarized light. Mr. Hannay obtained crystals with 
curved faces belonging to the octohedral form, the diamond 
being the only substance that crystallizes in this manner. The 
crystals burn easily on thin platinum foil, over a good blowpipe 
and leave no residue, and after two days immersion in hydro- 
fluoric acid, they show no signs of dissolving, even when boiled. 
On heating a splinter in the electric arc, they burn black, a very 
covery was read, Mr. N. S. Maskelyne, F.R.S., the keeper of 
the mineralogical collection at the British Museum, confirmed the 
statements that the crystals sent to him by Mr. Hannay, possessed 
all the properties of the diamond. Mr. Hannay has written to 
the London papers, to allay the fears of diamond merchants as to 
a possible heavy fall in the value of diamonds, stating that the 
Cost of the process is so great that it will probably never amount 
to more than a laboratory experiment. The great difficulty lies 
in the construction of an inclosing vessel, strong enough to with- 
stand the enormous pressure and high temperature, tubes con- 
Structed on the gun-barrel principle, with a wrought iron coil, of 
only half an inch bore, and four inches external diameter, being 
torn open in nine cases out of ten—A. W. Bennett. 
RRECTIONS OF THE GEOLOGICAL Maps oF Orecon.—In the 
To this formation, Dr. Condon gives the name of Astoria shales. 
Above this is an extensive tertiary deposit, rich in Mollusca, which 
1S usually interrupted by the central elevations of the mountain 
axis. Prof. Condon refers this to an Upper Miocene age, under 
the name of the Solen beds. On the flanks of the mountains, 
VOL. XIV —No. VI 
