736 
and the greenish shales of Clinton rest on the 
Hudson. In southern Pennsylvania and in 
Virginia, the red and white Medina are both 
present and Hudson forms pass upward into 
the red Medina, occurring abundantly in south- 
west Virginia in a bed only 100 feet below the 
white Medina. At Schoharie, the Niagara is 
differentiated physically from the overlying 
Waterlime, but much of the Niagara fauna 
passes into the Waterlime ; in localities further 
west and south, the Salina shales intervene and 
there is no passage of fauna. The upper 
Waterlime at Schoharie differs greatly in color 
and composition from the Tentaculite or lower 
divisions of the Helderberg, but at least two 
forms, most characteristic of the Tentaculite, 
are foundin the upper Waterlime. These forms 
were not observed by the writer in the Water- 
lime of southern Pennsylvania. The several 
sub-divisions of the Helderberg are very distinct 
physically, the boundaries of each being sharply 
defined ; but the physical changes were such as 
to cause only gradual disappearance of the 
several faunas and forms, which persist through- 
out, showing little variation. The passage 
from Helderberg to Oriskany, at Schoharie, is 
abrupt to the last degree—from a very good 
limestone to a ferruginous and only slightly 
calcareous sandstone. The faunal change is as 
abrupt as the physical. Here again the con- 
trast is very great, for, in southern Pennsyl- 
vania, the passage from Helderberg to Oriskany 
is very gradual through a silicious limestone, 
containing forms belonging to each. In south- 
west Virginia the upper part of the Helderberg 
becomes silicious and in some localities is al- 
most a sandstone. 
In response to a request from the Chairman 
for notes on geological observations during the 
last summer, Professor Kemp reported on the 
progress of his geological survey of the Adiron- 
dack region. One result was the recognition of 
a true quartzite of pre-Cambrian date, affording 
thus a fragmental sediment. The sedimentary 
rocks in the region he found to be widely 
charged with graphite, indicating an abundance 
of organic life in pre-Cambrian time. Further 
types of eruptive rocks had also been identified, 
to fill up gaps in known series. 
Professor Osborn related some results of a 
SCIENCE. 
[N. 8S. Vou. X. No. 255. 
visit, with Dr. Matthews, to the Como Bluffs 
Section, south of the Union Pacific Railroad, 
three hours west of Laramie; the more certain 
establishment of its Jurassic character, with bed 
containing remains of Dinosaurus about 40 feet 
below the top (a fresh water deposit), while, in 
the marine beds below, belemnites and btano- 
don were found, the latter serving as nuclei for 
concretions. Professor Osborn also described 
the mode of occurrence of the mastodon re- 
cently found by a German, while digging in his 
market garden, three miles back of Newburgh, | 
IW 6c 
Professor R. E. Dodge gave a preliminary 
account of his work on the Pueblo ruins at 
Pueblo Bamlo, New Mexico. The deposits on 
which the ruins are situated seem to indicate a 
a very long occupation of the country previous 
to the desertion of the ruins. 
Dr. A. A. Julien discussed the common dis- 
tribution of opal or hyalite; and the exclu- 
sively recent character of all existing occur- 
rences of this mineral. 
Mr. Geo. F. Kunz described his recent visit 
to the ancient locality of jade (nephrite) at Jor- 
daensmuhl, near Breslau, Germany, with the 
special object of study of the minerals associ- 
ated with jade. In an ancient quarry for road 
material, immense masses of zoisite-quartzite 
occurred, forming columns thirty feet in height. 
Dr. Hovey presented some notes of an excur- 
sion with Professor Iddings to the Yellowstone 
Park. ALEXIS A. JULIEN, 
Secretary of Section. 
THE CHEMICAL SOCIETY OF WASHINGTON. 
THE regular meeting was held October 12, 
1899. 
The first paper was read by Mr. J. K. Hay- 
wood and was entitled, ‘The Determination of 
Glycogen,’ by J. K. Haywood and W. D. 
Bigelow. 
The authors proved that methods for the es- 
timation of glycogen, which depend on its 
direct inversion into dextrose, are unreliable 
and have modified the method of Bricke so as 
to make it accurate and fairly rapid. 
The second paper was read by Dr. F. K. 
Cameron and was entitled, ‘A Method for 
Estimating Black Alkali in Soils.’ 
