RECREATIVE SCIENCE. 



53 



Eoeoiul form of the sumo affection. If thoy were not regarded 

 ir-'.ry of cerebral (Unease, or as im-ipii-iit Hymptoina of 

 vy, such freaks of Nature might bo thought luniiMtng ; but 

 : .. eye witnesses snoh alarming 1 and abnormal optical 

 effects, it is certainly a warning that should not be disregarded. 

 I : i'..rbr* Wiuslow, in his important work entitled " Obscure 

 Diseases of the Brain and Mind," mentions, amongst the aber- 

 rations of the sense of sight, those of " .sv< in i <J>j<-<-la cut in half, 

 double vision, inversion of objects." Dr. Wollaston relates that 

 it twice occurred to him not to bo able to see but one side of 

 the axis of vision. The first time the left side of each eye was 

 affected he saw but half of a man's face or of any object he 

 looked at; and in attempting to read the name JOHNSON over 

 i door, he saw only .... SON, the commencement of the name 

 being entirely obliterated from his view. The complaint was of 

 short duration. About nineteen years afterwards, the visual 

 phenomenon recurred this time the right side of the eye, about 

 three degrees from the centre of the retina, was affected, and 



orders of media (1) gradual outward growth of the whole, (2) 

 slow rolling of parts, (3) rapid tremor of the margin are 

 especially characteristic of this affection. 



The region of blindnoa* takes a horaoMhoo shape ; the upper 

 arm point* to the centre of eight, while the lower spreads 

 downwards and outwards awaj from the centre. The zigzag 

 pattern is minute near tho centre, and grows larger the farther 

 it recedes. The gleams of colour most conspicuous at the 

 margin are red and blue, yellow, green, orange, in order of 

 ir.-jin-imy. As the blindnoiw spread* outwards, clear vision 

 returns gradually in the concavity of the horseshoe. The sight of 

 both eyes is atfnctod at once exactly in the same manner and in 

 the same degree, though naturally that eye teem* most affected 

 which corresponds to the obliterated side of the field of view, 

 because the nasal half of the field of view of either eye is 

 more limited, and vision there is less distinct than on the tem- 

 poral side. The climax is reached in about twenty-five minutes 

 from the first beginning. The whole duration of the attack U 



Fig. 1. 



its duration was ten minutes. Two analogous casea are also 

 mentioned by Dr. Wollaston. 



Desmoulins states that M. Arago has experienced this affec- 

 tion of vision three times : on the first two occasions objects 

 Jtuated to the right of the axis of vision were invisible ; the 

 third time he saw objects on the right only of this axis. 



The same author notices, also, the following remarkable case : 

 In consequence of a cerebral fever, the external side of the left 



retina of M. de M became insensible ; with his eye he saw 



objects only situate to the left of the centre of vision, and as 

 at the same time there was an outward deviation of the axis of 

 this eye through a paralysis of the nerve of the third pair, when 

 he employed both eyes he saw objects double ; but, what was 

 still more singular, the right eye being closed, he saw with the 

 left eye the objects removed from twenty to twenty-five degrees 

 to the right of their real position. It may be mentioned that 

 Dr. Wollaston, like many other hard workers, died of gradual 

 softening of the brain. 



Dr. Hubert Airy's experience of these attacks of "half- 

 vision " dates from 1854. He says the blindness usually comes 

 on while the eyes are engaged iu toilsome reading some word 

 or letter on he page near the sight-point (generally below to 

 the left) is found to be obliterated. This germ of blindness 

 slowly spreads, with zigzag margin, defined by alternate bright 

 and dark lines, with gleams of colour, the margin rapidly 

 trembling and slowly rolling at the same time. These three 



just half an hour. This half -blindness is followed by oppressive 

 headache, lasting many hours. 



Among the circumstances that have seemed to favour an 

 attack may be mentioned sudden change of air and living, over- 

 exercise, and insufficient sleep. 



Of this class of the affection, when a cloud creeps over a part 

 or whole of the visual area, may be instanced that of a lady 

 who had complained of being out of health, of slight headache, 

 and partial deafness, and then found in the early part of the 

 evening that her sight was disordered. In attempting to read 

 a book, she remarked that the printed letters and sentences were 

 running one into the other. Subsequently the page appeared as 

 if a piece of finely-glazed paper had been placed over it, through 

 which cloud she was just able to discern the letters. This case, 

 like the next related by Winslow, ended fatally with an attack 

 of apoplexy. A sportsman, out shooting, disputed with his 

 gamekeeper as to the number of dogs they had in the field, and 

 asked how he came to bring so many as eight dogs with him. 

 The servant assured him there were but /our, and then the 

 gentleman became aware of his situation, mounted his horse, 

 and rode home. He had not been long in the house when he 

 was attacked with apoplexy, and died. 



A knowledge that such spectral fantasies may disturb the 

 vision ought to be widely spread, as it might induce those who 

 may at any time be suffering from visual aberration to seek 

 medical relief, instead of allowing the disagreeable phenomenon 



