This book is in very good condition , with just a little bumping at the ends of the spine. Internally, the book is in very good condition, with a little foxing near the end. The pages are clean and unmarked. The book contains the original hand-written receipt (for 12s 6d).
The preparation of this book on "Prisms, their use and equivalents", has been prompted by the request of many students and correspondents, though it is written primarily for those who may desire a more extended knowledge on this branch of refraction than is contained in works on Ophthalmology. In fact, this volume is in part a compilation of the writer's lectures on prisms delivere during the winter course at the Philadelphia Polyclinic. The author's double prism, a new and delicate test, for the detection of errors of muscular imbalance whether of small or great amount, is incorporated in the text. To make the subject-matter more entertaining, the writer has not limited himself to the consideration of prisms in ophthalmic practice alone, and by omitting mathematic formulas and inserting many illustrations, the text is made easy of comprehension.