PREFACE.

It is now, for upwards of nine years, that a great portion of my time has been specially devoted to the subject comprised by the present volume. Working as I had done, whilst in Paris, under the originator of the glycogenic theory, it was not unnatural that I should have been impressed with a desire, on my return to England, to prosecute a continuance of his researches, in a direction where it was admitted a deficiency existed.

Taking it for granted, that the views I had learnt, and which had obtained such universal acceptance, were substantial and true; I endeavoured, at the onset of my researches, to make out the nature of the process by which sugar underwent its supposed destruction in the lungsthe only point upon which, it seemed, there really remained anything connected with the subject to be disclosed.

From the early results I obtained, I formed an opinion regarding sugar-destruction which, however, subsequent research proved to me was untenable. I had not, at first, a shadow of reason to induce me to imagine that the doctrine I was proceeding on, was otherwise than unimpeachably correct. Time, however, led me to discover, that in my starting-point I was resting upon a fallacious foundation. Time revealed to me, that the mode of experimenting which

had been hitherto adopted, had conducted to the formation of erroneous conclusions, regarding the main points relied upon, in support of glycogenesis. The discovery of truth, being the only admissible goal of scientific research, I could not hesitate, however much I might expose myself to the criticism of others, to abandon the support I had previously given to the glycogenic theory.

The facts I discovered, formed the subject of a communication, published in the Philosophical Transactions' for 1860; they are fully brought forward in the physiological part of this work. No one, I think, will deny that these facts materially alter the position that was formerly maintained. To my mind, they refute the validity of the doctrine of glycogenesis, and I feel myself justified in saying, that time has only served to strengthen all that I originally stated. Whatever fresh evidence I have obtained has given me support; and, nothing that I have seen, which has been adduced in opposition, would appear to me to call for the slightest alteration.

The points that are here referred to, present, I believe, a bearing of importance in reference to the pathology of Diabetes. Latterly, ideas have been fixed upon an excessive production of sugar in the liver, on the one hand; or, a defective destruction in the lungs, on the other; to account for the elimination that takes place in the complaint. But, the results that have been now obtained, looked at in the light I read them, carry us back to the position maintained by our countryman Dr. Prout previous to the promulgation of the glycogenic theory.

Although I am obliged, then, to dissent from Bernard's

glycogenic views, yet, I most willingly admit, how much this subject is indebted to him for the present advanced position it may be considered to hold. To this distinguished physiologist, likewise belongs the merit of an unquestionably important discovery; for, it was he, who first made known the amyloid substance of the liver.

Acting upon the principle of avoiding the ingestion of starch and sugar in the treatment of Diabetes, I have instituted a substitute for bread out of almonds and eggs. This will be found referred to, in the latter portion of the volume, and I eagerly hope it may prove a desirable accession to the limited list of articles from the vegetable kingdom, that, under such a restriction, the Diabetic is allowed to con

sume.

33, BEDFORD PLACE, RUSSELL SQUARE;

May 10th, 1862.