Page:A manual and atlas of medical ophthalmoscopy.djvu/7

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PREFACE.


The first intention in the preparation of the following work was the publication of the series of illustrations of medical ophthalmoscopy contained in the appended plates, and of the cases from which they were made. I have thought, however, that the utility of these would be increased by the addition of a systematic account of the subject which they illustrate.

With one or two exceptions all the cases described and figured were met with in the course of purely medical work, chiefly at University College Hospital, and at the National Hospital for the Paralysed and Epileptic. In the preparation of the illustrations, great care has been taken to secure the utmost possible exactness. The autotype plates are reproductions of sepia drawings; and this method has been chiefly employed because by it a more exact representation of delicate pathological appearances can be obtained than by chromo-lithography. This method has also the advantage of fixing the attention on the changes of form, rather than upon the alterations in colour, which, important as they are, very often mislead the inexperienced. Chromo-lithography has been employed for some subjects in which the changes of tint are of predominant importance. It is intended that the autotype plates should be studied by the aid of the descriptions prefixed to them, and it is believed that, thus examined, those who are accustomed to the use of the ophthalmoscope will not miss the absent colours. With