THE

EDINBURGH NEW

PHILOSOPHICAL JOURNAL.

EDINBURGH NEW

PHILOSOPHICAL JOURNAL,

EXHIBITING A VIEW OF THE

PROGRESSIVE DISCOVERIES AND IMPROVEMENTS

IN THE

SCIENCES AND THE ARTS.

EDITORS.

THOMAS ANDERSON, M.D., F.R.S.E.,

REGIUS PROFESSOR OF CHEMISTRY, UNIVERSITY OF GLASGOW;

SIR WILLIAM JARDINE, BART., F.R.S.E. ;
JOHN HUTTON BALFOUR, A.M., M.D.,
F.R.SS. L. & E., F.L.S.,

REGIOS KEEPER OF THE ROYAL BOTANIC GARDEN, AND PROFESSOR OF MEDICINE AND BOTANY,
UNIVERSITY OF EDINBURGH.

FOR AMERICA,

HENRY D. ROGERS, LL.D., Hon. F.R.S.E., F.G.S.,

STATE GEOLOGIST, PENNSYLVANIA; PROFESSOR OF NATURAL HISTORY IN THE
UNIVERSITY OF GLASGOW.

JANUARY ...... APRIL 1861.

VOL. XIII. NEW SERIES.

EDINBURGH:

ADAM AND CHARLES BLACK.

LONGMAN, BROWN, GREEN, & LONGMANS, LONDON.