370 HUMAN ANATOMY 



When we compare the old anatomical apparatus of Leyser (or 

 Lyser), which is described in his CuUer Anaiomicus with a com- 

 plete anatomic armament of the present time, we see at a glance 

 the great progress which has been made in this elementary part of 

 technique. The great influence of the above-mentioned sciences is 

 also shown in the material which we use to-day, improved steel, 

 nickel-plated instruments, etc. 



This influence is even more marked in the realm of optics. If 

 we require any proof of the fact that one science can be helped 

 by another, we have only to mention the relations of optics to 

 human anatomy, and, of course, its relation to the other natural 

 sciences. 



No other agent has done more to illumine the obscure subject 

 of the human body than has light, from the simplest arrangements 

 for good illumination, by the correct disposition of windows in the 

 dissecting-room, to the ultra-microscope and radioscopy or "Rontgo- 

 graphy." Artificial illumination has made such extraordinary ad- 

 vances in our time that, especially with electric lighting, we can 

 concentrate the light upon any given point and limit it as we will. 

 Then we have the various mirrors, the vaginal speculum, which was 

 known to the physicians of ancient Greece and Rome, the laryngeal 

 mirror, whose fifty-year jubilee we celebrate to-day, the rhino-, 

 pharyngo-, and cesophagoscopes, the otoscope, the cystoscope, 

 and above all Helmholtz's brilliant discovery, the ophthalmoscope, 

 whose latest stereoscopic modification by Dr. Thorner may be seen 

 here in the German "Department of Education." All these dis- 

 coveries have, in addition to their practical importance, been of 

 the greatest service in the study of human anatomy, especially that 

 of the living, and will still continue to be. 



The electric light permits, by its endless adaptability, a large 

 number of additional applications, especially for the illumination 

 of body cavities and hollow organs. I will recall only the transillu- 

 mination of the accessory sinuses of the nose. 



From lenses and eyeglasses, among which are the dissection eye- 

 glasses of Briicke, we pass to the simple and later to the compound 

 microscope, one of the most important inventions which has ever 

 been made or will ever be. How great the progress is which results 

 every year in this special realm, is also shown here by the exhibi- 

 tion of the noted firm of Zeiss in Jena. Every step forward which 

 is made here is of great benefit to human anatomy. 



For anatomic study and the demonstration of new facts, we may 

 mention the drawing apparatus, the projection apparatus, the 

 episcope, and epidiascope, and above all, photography, whose 

 future development we cannot yet foretell. With this discovery, 

 France, which opened the way and has always led in the investiga- 



