30 KANSAS ACADEMY OF SCIENCE. 



COLOR-BLINDNESS, AND RAILWAY ACCIDENTS. 



BY JOHN FEE, M. D. 



The visual defect known as Daltonism, or color-blindness, has associated 

 with it two sides — the one theoretical, the other practical. Viewed from a 

 theoretical standpoint, it is connected with the wonderful phenomena of light 

 and its properties, and with the sensitiveness of nerve matter in responding 

 to this imponderable, and, as yet, scarcely understood agent, yet the means 

 of our knowledge of external nature. As a practical topic, it is useful to those 

 unfortunate individuals who, on account of their inability to perceive colors, 

 are unfitted for many avocations, such as painters, artists, or for employment 

 on board of ships, and on railways, in capacities in which they must display 

 and read the language of signals. This practical phase of this subject pre- 

 sents an important question in forensic discussions, when chemists are giving 

 expert testimony, on which depends the life of men charged with crime. No 

 court ought at the present day receive the testimony of any chemist as an 

 expert witness until it has been shown by sworn testimony that he has been 

 tested for culor-blindness. In this day of railways, when every one expects 

 to travel, and does almost weekly or monthly use the railway car, the subject 

 of color-blindness becomes of intense interest, and every person has a right 

 to inquire whether this visual irregularity does endanger his safety and his 

 life. I shall therefore treat this subject from a double view, viz., theoretical 

 and practical. This subject may be said to be new in this country, and, in 

 fact, it is only within the last decade that it has created any agitation in the 

 scientific world. It is true, the existence of this deformity has been known 

 for nearly a century, but prior to 1794 it had not received the investigation 

 of a scientist. At this time, Daltou, the celebrated English chemist, discov- 

 ered that he was color-blind, or rather red-blind, and that he did not see the 

 solar spectrum as others saw it. This discovery of Dalton, and his investi- 

 gations, secured for this irregularity the name of Daltonism, which is the 

 favorite term of the French at the present day for color-blindness. 



From Dalton's investigations, in 1794, until 1837, there is scarcely any- 

 thing written on the subject. It seems to have been almost forgotten. In 

 1837, Dr. Seebeck, of Berlin, revived the subject of color-blindness, and re- 

 investigated it, and invented tests for determining the frequency and extent 

 of this defect. In 1840, Dr. Isaac Hays, editor of the American Journal 

 of Medical Science, published a paper entitled "The Impossibility of Distin- 

 guishing Colors;" and in 1845, Dr. Pliny Earle published in the same jour- 

 nal the report of a singular history of the color-blindness of five generations 

 in his own family. In 1855, George Wilson, Professor of Technology in the 

 University of Edinburgh, published the first practical work on the subject. 

 Wilson's researches were made in view of determining the influence of color- 



