XV 



maturing*, as well as of the construction in that year, by Helmholiz, 

 at Konigsberg, of a dioptric apparatus for rendering visible the 

 fundns of the eye, Bonders, a stranger there too, could, on his side, 

 explain many discoveries of his own in the physiological field, and, 

 among other things, declare the true nature of the act of accommoda- 

 tion, quite recently disclosed with certainty by his countryman 

 Cramer, under, it may be added, his own inspiration and in his own 

 laboratory. It was somewhat later, though independently, that 

 Helmholtz arrived at the same conclusion. 



It is not wonderful that Bonders, on his return to Utrecht, should 

 have already decided on adding to the abounding work of his four- 

 fold lectureship, including the theoretical side of Ophthalmology, 

 the onerous responsibility of its daily practice. He had, in fact, 

 been gradually led to recognise more and more that this department 

 of the healing art, from the very nature of its subject-matter, affords 

 an ampler scope and a firmer ground than any other for the applica- 

 tion and exemplification of those scientific principles which must 

 eventually bear sway in all its departments, if vagueness and uncer- 

 tainty are to disappear under the slow but certain advances of exact 

 knowledge.* But in addition he was then swayed by a special 

 impulse hard to be resisted. It had long been known that in animals 

 having a tapetum luctdum the rays of light entering the eye through 

 the pupil are in part reflected outwards by that shining surface along 

 the lines of entrance ; and in 1846 our countryman Gumming, too early 

 lost to us, had shown that in man also such a reflex was in a certain way 

 demonstrable. But, in 1851, Helmholtz discerned that it must surely 

 be possible, by an optical contrivance, to render visible the reflecting 

 fundus itself by bringing these emergent rays to a focus upon the 

 retina of an observer; and, as just mentioned, such means he had 

 devised. The Ophthalmoscope was thus given to mankind, a dis- 

 covery rather than an invention, as Helmholtz has himself remarked 

 a revelation transforming ophthalmology, and of itself entitling 

 that great man to our ever grateful remembrance. In the words of 

 Bonders, " the whole world spoke of it ; every one wanted to see the 

 ophthalmoscope, which revived long-lost hope." But Bonders felt 

 that a sphere for its employment in Holland was still needed ; and his 

 fellow citizens, appealed to for this, and fired with some of his own 

 enthusiasm, provided him with a temporary hospital ; a few years 

 later subscribing funds for a permanent one.f " That result," he 

 remarks, " was obtained through the influence of the discovery of the 

 ophthalmoscope and the appearance of von Graefe at Berlin." " In 



* Vide Francisci Cornell! Ponders, oratio de justa necessifcudine scientiam inter 

 et, artem medicam, et de utriusque juribus et mutuis officiia, quam habuit die xxvi 

 m. Martii a. MDCCCLIII, quum magistratum academicum deponeret. 



f Opened February, 1859, with forty beds. 



