PRINCIPLES

OF

HUMAN PHYSIOLOGY.

BY THE SAME AUTHOR.

PRINCIPLES OF COMPARATIVE PHYSIOLOGY.

With Three Hundred Wood Engravings.

FOURTH EDITION, 8vo. 248.

A MANUAL OF PHYSIOLOGY,

Encluding Physiological Anatomy.

With One Hundred and Ninety Illustrations on Steel and Wood,

SECOND EDITION, FCAP. 8vo. 12s. 6d.

Preparing for Publication,

PRINCIPLES OF GENERAL PHYSIOLOGY,

INCLUDING

Organic Chemistry and Histology.

WITH A GENERAL SKETCH OF THE VEGETABLE AND
ANIMAL KINGDOMS.

With numerous Illustrations. FOURTH EDITION, SVO.

OF

HUMAN PHYSIOLOGY:

WITH THEIR CHIEF APPLICATIONS TO PSYCHOLOGY, PATHOLOGY,
THERAPEUTICS, HYGIÈNE, & FORENSIC MEDICINE.

BY

WILLIAM B. CARPENTER, M.D., F.R.S., F.G.S.,

EXAMINER IN PHYSIOLOGY AND COMPARATIVE ANATOMY IN THE UNIVERSITY OF LONDON;
PROFESSOR OF MEDICAL JURISPRUDENCE IN UNIVERSITY COLLEGE;
PRESIDENT OF THE MICROSCOPICAL SOCIETY OF LONDON,

PREFACE TO THE FIFTH EDITION.

THE issue of the Fourth Edition of the present work was attended with much apprehension on the part of the Author, lest the overgrown bulk which it had attained, in consequence of his desire to render every part of it as complete as possible, might prevent the continuance of that general demand, which it had been the good fortune of previous Editions to excite. It has been, therefore, a source of peculiar satisfaction to him, that the unprecedently-rapid sale of a large impression should have so promptly renewed the assurance of a kind appreciation of his labours, on the part of those to whom he most desires to render them acceptable. And the success which has thus attended them, has been an additional inducement to him to spare no pains to deserve a continuance of it.

In commencing the preparation of a New Edition, however, it was evident to him, that, as the dimensions of the volume altogether precluded any increase in the number of its pages, whilst their previous repletion equally prevented any augmentation of their capacity, no addition of new matter could be made, without a corresponding omission of old,-a proceeding which he could not bring himself to adopt. But having already been led, by the occurrence of the same difficulty in the case of his "Principles of General and Comparative Physiology," to determine upon the division of that work into two separate and independent treatises, on "General" and "Comparative Physiology" respectively, it seemed to him to be the simplest and most desirable plan, to transfer from the "Human" to the "General Phy siology" such parts of the former as could with propriety be incorporated with the latter; thus effecting such a reduction in the size of the "Human," as might enable him to make any additions to it that the progress of Science should require; and at the same time rendering the "General" more comprehensive and complete in itself,