174 COLOR-BLINDNESS IN ITS RELATION TO 



and still less a color-blind individual, could be regarded as born espe- 

 cially for a railway employ6. Numerous otber vocations are open to the 

 color-blind, although they might, on account of this defect, run the risk 

 of finding themselves excluded from many occupations where color- 

 blindness is much less injurious than to railways. Hence, we conclude 

 that the decision to be adopted in this matter must be comparatively 

 very stringent, that is to say, that a relatively slight defect of the chromatic 

 sense must suffice to prohibit admission to the service of railways. 



The question is quite a different one with respect to those already 

 employed on railways, and other points must be weighed. It may be 

 necessary, perhaps, to remove them from a position which suits them, 

 and where they have earned a livelihood, and performed their duties in 

 the most irreproachable and decorous manner. It is just, therefore, that 

 the least severe principles he applied, and their personal interests as much as 

 possible considered without violating the requirements for the safety of the line. 



In this case, no one should be dismissed without plausible reasons, 

 and when any such exist, the employes to be discharged should be trea- 

 ted with as much consideration as possible, and receive a legitimate 

 compensation for their loss by the offer of another place or a pension. 



In order to secure an intelligent supervision and control, each employ^ 

 should submit to a rigorous examination of the chromatic sense, that 

 there might not be the slightest doubt as to the nature of its capacity. 

 To be able to attain this end in a perfectly certain and at the same time 

 practical manner, while creating as few difficulties as possible, is with- 

 out doubt the most difiicult part of the reform to execute. It is admit- 

 ted as a fact that color-blindness may manifest itself ir. persons formerly 

 endowed with a perfectly normal chromatic sense. TIjis is what is 

 called acquired or pathological color-blindness, only lately known, and 

 far from being as much studied as the congenital defect. It would be 

 perhaps more suitable for our practical purpose to divide pathological 

 color-blindness into two classes, one of which might be called general or 

 regular, and the other local or irregular. We will understand, by the 

 first term, that kind of pathological blindness due to general causes, and 

 usually concentrically disposed about the yellow spot; and, by the second, 

 that which is produced by local causes, and appears eccentrically placed 

 in the visual field, or having its center in the blind spot. This last class 

 should not belong to the subdivision now occupying us, principally because 

 it rarely appears in such a degree as to be able to occasion any danger to 

 railways. There is no doubt but that this acquired blindness really exists. 

 Dr.Favre and several other writers have especially devoted themselves to 

 this form of color-blindness amongst railway employes; they have pointed 

 out several causes to which it is due, and proposed measures for discov- 

 ering it. It is of the highest importance here, it seems to us, that per- 

 fectly certain methods of investigation should be employed. Dr. Stilling 

 justly remarks that the great frequency of congenital color-blindness 

 constitutes one of the principal difficulties encountered in obtaining an 



