THE

AMERICAN JOURNAL

OF

SCIENCE AND ARTS.

CONDUCTED BY

PROFESSORS B. SILLIMAN AND JAMES D. DANA,

IN CONNECTION WITH

PROFESSORS ASA GRAY, AND WOLCOTT GIBBS,
OF CAMBRIDGE,

AND

PROFESSORS H. A. NEWTON, S. W. JOHNSON,
GEO. J. BRUSH, AND A. E. VERRILL,
OF NEW HAVEN.

SECOND SERIES.

VOL. L.-[WHOLE NUMBER, C.]

Nos. 148, 149, 150.

JULY, SEPTEMBER, NOVEMBER.

NEW HAVEN: EDITORS.
AW1870.

PRINTED BY TUTTLE, MOREHOUSE & TAYLOR, 221 State ST.

CONTENTS OF VOL. L.

NUMBER CXLVIII.

ART. I.-Photometric Experiments. PART SECOND.---On the

amount of light transmitted by plates of polished crown

glass at a perpendicular incidence; by OGDEN N. ROOD,

II. The Ethers of Arsenic Acid and of Arsenious Acid; by

J. M. CRAFTS,

III.-On the probable seat of Volcanic Action; by T. STERRY

HUNT,..

IV.-Notes on some features of the Flora of Eastern Kan-

sas; by ELIHU HALL,..

V.-Notice of some Minerals from New Jersey; by Prof.

W. T. ROPPER,

VI.-On the size of Atoms; by Prof. Sir W. THOMSON,----

VII-Miscellaneous Optical Notices; by WOLCOTT GIBBS, -

VIII. On the Occurrence of a Peat bed beneath deposits

of Drift in Southwestern Ohio,

IX.-On the Theoretical Temperature of the Sun, under the

hypothesis of a Gaseous Mass maintaining its Volume

by its Internal Heat, and depending on the Laws of

Gases as known to Terrestrial Experiment; by J. HOMER

LANE,..

X.-On the mode of observing the coming Transits of Ve-

nus; by SIMON NEWCOMB,

XI.-On the Geology of Eastern New England; by Dr. T.

STERRY HUNT, - -

83

XII.-Mineralogical Contributions; by CHARLES UPHAM

SHEPARD, Sr.,

90

XIII.-Notice of a new Species of Gavial from the Eocene

of New Jersey; by Prof. O. C. MARSH,

97

XIV.-On Hydrogenium-amalgam; by O. LOEW,

99

XV.-The Brachiopoda, a Division of Annelida; by EDWARD

S. MORSE,

100

A New Comet,

104