9 
than that for the Decembers of ten years before, which had 
been 33°88°, and lower than that of any December during 
that period, save those of 1867, when the mean was 28°, and 
1868, when it was 28:11°. Snows, generally light, fell on 
eleven days; but on the 26th it fell to the depth of two feet. 
The quantity of water, from rain and melted snow, was 4'53 
inches for the month. 
The barometer ranged from 80°436 inches on the 25th, to 
29-495 inches on the 26th, a difference of ‘941 inch in 
thirty-eight hours. 
The prevailing winds were westerly. Lunar coronas were 
noted on the nights of the 9th, 11th and 13th, and lunar 
halos on those of the 11th and 17th. 
The total number of deaths in the city during the month 
was 2245, or an average of 72°35 daily, of these, 906, a daily 
average of 29-2, were children under five years of age. The 
chief causes of death were diseases of the lungs. 
January 20th. 
The President, Dr. Newberry, in the chair. Sixteen persons 
. present. 
Pror. NEWBERRY exhibited a series of quartz pebbles and 
bowlders, obtained by him from bituminous clays associated 
with the lignite beds of the Cretaceous formation at Keyport, 
New Jersey. All of these, which had been angular frag- 
ments of quartz rock, gave evidence of having been exposed 
to the action of some chemical solvent, as all their angles 
were rounded, the surfaces smooth as though artificially 
polished, or pitted in a peculiar way. This singular appear- 
ance ‘was attributed by Dr. Newberry to the solvent power of 
humus on silica. These pebbles and bowlders occur along 
certain lines in the clays, and were evidently floated and 
dropped on what was then a stratum of bituminous mud that 
formed the bottom of an estuary or lagoon. ‘The clays con- 
tain so much carbonaceous matter, as to be almost black, 
