Mercers' company lectures on recent advances in the physiology of digestion, delivered in the Michaelmas term, 1905, in the Physiological Department of University College, London

Preface

In recognition of a generous gift by the Mercers' Company in aid of the work of the Physiological Department at University College, the Council of the College resolved that a course of Lectures should be given each year dealing with the original investigations made in the Department.

In presenting this first course of Mercers' Company Lectures I have attempted, in the light of researches which have been carried out in this laboratory, to give an appreciation of the present state of our knowledge on certain aspects of the subject of digestion, in preference to describing at length the researches themselves, which can be read in the original papers enumerated at the end of this book.

The great development in this branch of Physiology, which has taken place in recent years, owes its inception to the masterly series of researches carried out by Pawlow in the Institute of Experimental Medicine at St. Petersburg, researches to which I shall have repeated occasion to refer in the course of the following Lectures. Two other important lines of investigation have presented themselves as necessary to the proper understanding of the biological facts elucidated by Pawlow. The first of these is the study of the chemical and physical conditions which determine the digestive changes in the food-stufis. As will be seen in the first two Lectures, we approach here a subject which must play a great part in all our future conceptions of intracellular mechanism, i.e., the study

VI PREFACE.

of chemical and physical changes in capillary and colloidal systems, where the modification of physical condition occurring at sm-faces determines changes of quite another order to those which have so far formed the chief pre-occupation of physics and chemistry.

The second line had its starting point in the discovery that the pancreas is normally excited to secrete, in response to stimuli originating in the gut, not, as Pawlow thought, by means of the nervous system, but by the dispatch of a chemical messenger or hormone from the seat of stimulation to the reacting gland through the blood-stream. Subsequent investigations have shown the existence of other chemical correlations of the same nature and suggest that, by the detection and isolation of such hormones, we may later be in a position to influence and control a number of the chief functions of the body.

I trust that the publication of these Lectures may serve to interest a larger audience of students and medical men in the " growing border " of these important subjects and to give them some idea of the aims and objects of this branch of physiological research.

EENEST H. STAELING.

Physiological Laboratory,

University College,