[Transcriber’s Note: In this, the text file, italics delimited by underscores, and bold text delimited by equal signs.] [Illustration: RADIOLARIA.] THE MICROSCOPE _ITS HISTORY, CONSTRUCTION, AND APPLICATION_ BEING A FAMILIAR INTRODUCTION TO THE USE OF THE INSTRUMENT, AND THE STUDY OF MICROSCOPICAL SCIENCE BY JABEZ HOGG, M.R.C.S., F.R.M.S., FORMERLY AND FOR TWENTY-FIVE YEARS SURGEON TO THE ROYAL WESTMINSTER OPHTHALMIC HOSPITAL; PAST PRESIDENT OF THE MEDICAL MICROSCOPICAL SOCIETY; HONORARY FELLOW OF THE ACADEMY OF SCIENCES, PHILADELPHIA; OF THE MEDICO-LEGAL SOCIETY, NEW YORK; OF THE BELGIAN MICROSCOPICAL SOCIETY, ETC.; AUTHOR OF “ELEMENTS OF NATURAL PHILOSOPHY,” “A MANUAL OF OPHTHALMOSCOPIC SURGERY,” ETC. _WITH UPWARDS OF NINE HUNDRED ENGRAVED AND COLOURED ILLUSTRATIONS BY TUFFEN WEST AND OTHER ARTISTS_ [Illustration: An 18th Century Microscope.] _FIFTEENTH EDITION RE-CONSTRUCTED, RE-WRITTEN, REVISED, AND ENLARGED THROUGHOUT_ LONDON AND NEW YORK GEORGE ROUTLEDGE & SONS, LIMITED 1898 BRADBURY, AGNEW, & CO. I.D., PRINTERS, LONDON AND TONBRIDGE. PREFACE TO THE FIFTEENTH EDITION. The First Edition of this work appeared in 1854, a time in the history of the Microscope when the instrument, as an aid to original scientific research, may be said to have been in its infancy. Then certainly it was seldom employed in the laboratory or the medical schools. Now, however, as I anticipated, it has asserted its proper position, and has at length become one of the most important auxiliaries to science, and a direct incentive to original work, while it has doubtless exercised considerable influence over the student’s power of observation, and materially assisted in his studies, let his ultimate object and pursuits be what they may. The greater use made of the Microscope has likewise conferred benefits of untold value upon the arts and industries of the country, thereby adding to the national prosperity in ways as manifold as unique. The Microscope has also proved of immense value in the promotion of the health of the community, and the art and science of healing, since the theory of medicine has become a science, resting on the minute microscopical examination of animal tissues.