64 DR. FRANZ ON THE CURE OF CONGENITAL BLINDNESS, 



they appeared to cover each other more than before. He was now for the first time 

 capable, as he said, to look through the spheres, and to perceive a difference, but 

 merely a difference, in the surrounding objects. When he directed his eye steadily 

 towards an object, the visual impression produced by the object was painful and very 

 imperfect, and no clear visual perception of it took place, because the eye, on account 

 of the intolerance of light, could not be kept open long enough for the formation of 

 the idea as derived from visual sensation. The appearance of spheres diminished 

 daily; they became smaller, clearer, and more pellucid, allowed objects to be seen 

 more distinctly, and disappeared entirely after two weeks. The muscoe volitantes, 

 which had the form of black, immoveable, and horizontal stripes, appeared, every 

 time the eye was opened, in a direction upwards and inwards. When the eye was 

 closed, he observed, especially in the evening, in an outward and upward direction, 

 an appearance of dark blue, violet, and red colours ; these colours became gradually 

 less intense, were shaded into bright orange, yellow, and green, which latter colours 

 alone eventually remained, and in the course of five weeks disappeared entirely. 



As soon as the intolerance of light had so far abated that the patient could regard an 

 object without pain and for a sufficient time to gain an idea of it, the following experi- 

 ments were made in the presence of Dr. Swaine. The first experiments were of that 

 class in which the idea of a visible object is derived merely from pure visual sensation ; 

 the succeeding, of that kind in which the idea, in ordinary cases, depends upon the 

 sense of sight combined with the sense of touch, and is gained by reflecting on the im- 

 pressions made on the organs of both senses. It was necessary to perform these expe- 

 riments on different days, as otherwise they would have distressed the eye too much. 



1st Experiment. Silk ribands of different colours, fastened on a black ground, 

 were employed to show, first the primitive, and then the complementary colours. 

 The patient recognized the different colours, with the exception of yellow and green, 

 which he frequently confounded, but could distinguish when both were exhibited at 

 the same time. He could point out each colour correctly when a variety was shown 

 him at the same time. Grey pleased him best, because this colour he said produced 

 an agreeable and grateful sensation ; the effect of red, orange, and yellow was painful, 

 but not disagreeable ; that of violet and brown not painful, but very disagreeable ; 

 the latter he called ugly. Black produced subjective colours, and white occasioned 

 the recurrence of muscae volitantes in a most vehement degree. 



2nd Experiment. The patient sat with his back to the light, and kept his eye 

 closed. A sheet of paper, on which two strong black lines had been drawn, the one 

 horizontal, the other vertical, was placed before him, at the distance of about 

 three feet. He was now allowed to open the eye, and, after attentive examination, 

 he called the lines by their right denominations. When I asked him to point out 

 with his finger the horizontal line, he moved his hand slowly, as if feeling, and pointed 

 to the vertical, but after a short time, observing his error, he corrected himself. 

 The outline in black of a square, six inches in diameter, within which a circle had been 

 drawn, and within the latter a triangle, was, after careful examination, recognized and 



