THE

EDINBURGH NEW

2929 2-16

PHILOSOPHICAL JOURNAL.

THE

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, M.A., M.D.,

F.R.SS.L. & E., F.L.S.,

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

FOR AMERICA,

HENRY DARWIN ROGERS, Hon. F.R.S.E., F.G.S.,

STATE GEOLOGIST, PENNSYLVANIA; LATE PROFESSOR OF GEOLOGY AND MINERALOGY,
UNIVERSITY, PENNSYLVANIA.

JULY ...... OCTOBER 1856.

VOL. IV. NEW SERIES.

EDINBURGH :

ADAM AND CHARLES BLACK.

LONGMAN, BROWN, GREEN, & LONGMANS, LONDON.

MDCCCLVI.