In this, as in the former edition, I have received great assistance from my friend Mr. Lennox Browne, the eminent throat surgeon, who, by ever patiently discussing with me debatable points, and by giving me access to cases, interesting from a physiological point of view, both at the Central Throat and Ear Hospital, Gray's Inn Road, and in his extensive private practice, has afforded me opportunities of increasing my knowledge and experience which would not have arisen otherwise. I feel it a pleasure as well as a duty publicly to acknowledge my indebtedness to him, which I have, many times before, expressed in private. My best thanks are also due to Mr. J. Spencer Curwen, for the help he has rendered me in many ways. And finally, it would indeed be ungrateful on my part, if I did not place on record the obligation under which I consider myself to my reviewers for the uniformly favourable notice they have so kindly taken of my first effort, and for several useful hints of which I have duly taken advantage. One objection has been made which strikes at the very root of the plan upon which I have proceeded in my little volume, and to which, therefore, I beg leave to say a few words in reply. A learned writer in the _Athenaeum_ finds fault with me for making use of popular instead of scientific terms, which, he says, may be the cause to the reader of great confusion if he refers to other works, and he adds that "Back Ring-Pyramid Muscle" is almost as hard a mouthful as "Crico-Arytenoideus posticus." I have asked several non-scientific friends of good general education to read this sentence to me, and they succeeded very well with "Back Ring-Pyramid Muscle," while they utterly collapsed when coming to "Crico-Arytenoideus posticus." This is, however, in my humble opinion, of minor importance. The great point is, that my terms--which by the way are not inventions, but simply translations--convey a meaning to the general reader, and the originals do not. This is a fact which I dared not ignore, because my essay is intended for the people and not for men of science. As I have taken care also, for the sake of those who might wish to consult other and more learned books than mine, to give the terms generally used by physiologists by the side of my translations, I do not think there is anything that could ever confuse my readers. I conscientiously believe that these are good and weighty reasons for the plan I adopted in the first edition, and trust my reviewers, as well as my readers, will accept them as a sufficient justification of the same practice in the present volume. E. B. _February, 1881._ PREFACE TO THE FIRST EDITION.