PREFACE THE SCHEME of the following little work, first thought of some years ago, was fixed on during convalescence from a recent illness, when its arrangement played a pleasant part in beguiling long hours of tedium. And the writer has been induced to place himself in the printer's hands with the idea, it might not be disadvantageous to give publicity to a plan, whereby visitors to the Opera, technically uninstructed, should be helped to analyse profitably their impressions. He further hoped the appearance of his tentative essay might lead some one of musical attainments to undertake a more ambitious treatise of the kind; and it likewise seemed worth showing how naturally one of the most fascinating of the fine arts falls within the scope of medical study. The short physiological and acoustic details, introduced mainly for the purpose of proving the |