ACCIDENTS BY KAIL AND SEA. 139 



cians. He then proceeded to make an examination of soldiers, sailors, 

 and students. The information we are about to give is principally 

 derived from Dr. Favre's pamphlet, which he kindly sent us. 



We will give a brief statement of his statistics, his method, and his 

 idea of color-blindness, and then his propositions for practical measures. 



In relation to the frequency of color-blindness amongst the personnel 

 of railways, Dr. Favre tell us that out of 1,196 candidates examined by 

 him from June, 186-4, to December, 1872, thirteen were red-blind and 

 one green-blind (1.17 per cent.) ; but out of 728 employes of the same 

 line examined in 1872 and 1873, he found not less than 42 cases (5.76 

 per cent.) of color-blindness more or less pronounced, and that although 

 276 amongst them had previously submitted to an examination for the 

 same defect. During a subsequent examination, from July, 1873, to Oc- 

 tober 1, 1875, he dis(;overed, amongst 1,050 men from eighteen to thirty 

 years of age, nearly all formerly soldiers, not less than 98 color-blind 

 (9.33 per cent.). The increasing proportion of color-blindness at each 

 series of inspection must be attributed to the modifications introduced 

 into the method and diagnosis, owing to which a comparatively much 

 larger number of cases has been classed under the head of color- blind- 

 ness. This large proportion is easily explained by the method and man- 

 ner of making the diagnosis. Dr. Favre's method, which he has devel- 

 oped from year to year, consists in this : he presents to the subjects to be 

 examined wool of different colors corresponding to those of the spectrum, 

 red^ yellow (including orange), green, blue (including indigo), and violet, 

 and demands the name of each of these colors. All who are at fault 

 about them are pronounced color-blind. He regards also as such those 

 who hesitate, and who, when the test is repeated several times, give to a 

 color sometimes its own name and sometimes another. And yet. Dr. 

 Favre thought it his duty to correct the result obtained at the last exam- 

 ination : from the 98 cases, he withdrew 29, who hesitated only in the 

 designation of the colors, and 8, who, after repeated tests, corrected their 

 preceding mistakes ; the proportion falls by that from 9.33 to 5.8 per 

 cent. 



On two points, Dr. Favre has in his works announced new views, and 

 whether they ought to be accepted or merely left to gain supporters, 

 they are of a nature to produce consequences of great importance in the 

 practical world. In fact, it has invited especial attention on one hand 

 to acquired color-blindness, which is quite common, according to his pam- 

 phlet, on the Paris-Ly on-Mediterranean line, and results from various 

 causes. On the other hand, he asserts that congenital color-blindness is 

 not incurable, but can be remedied by means of assiduous and syste- 

 matic exercise in colors. 



The practical measures demanded by Dr. Favre, in accordance with 

 his views and experience and that of his fellow-laborers, with regard 

 to color-blindness, might be embodied in the following terms : an ex- 

 amination of the chromatic sense, obligatory upon all candidates for 



