ACCIDENTS BY KAIL AND SEA. 165 



readily understood why the female sex has furnished so small a proportion 

 to statistics. Again, in cases where experiments are made to discover 

 color-blindness, it is evidently much easier to find opportunities to ex- 

 amine men than women. For the most part, those examined are soldiers, 

 students, agents of police, etc., it being difficult to find equal oppor- 

 tunities for examining women en masse. It is necessary to operate on 

 a large number to obtain very satisfactory statistics. The data we i)os- 

 sess are furnished mainly by experiments among men. This is why wo 

 venture to dispute what is usually admitted as a certain fact, that color- 

 blindness is more common among men than women, the necessary infor- 

 mation being so far wanting to establish such a fact. We must not 

 overlook the testimony of Prof. H. Dor on this subject, who examined 

 the very considerable number of 611 women at Berlin, amongst whom he 

 found only five color-blind, or little less, therefore, than 1 per cent., or 

 exactly 0.82 per cent. We do not desire in the least to deny the possi- 

 bility that color-blindness amongst women is less common ; on the con- 

 trary, we think it even probable that this may bo the case. 



In using the statistics of the experiments thus far made on women, it is 

 important to observe carefully whether the method of scrutiny has been 

 such that previous exercise has not had some effect upon the result. For 

 if the method is founded upon the principle that those examined must be 

 interrogated as to the names of the colored objects presented to them, 

 and their chromatic sense judged according to the answer, it is clear 

 that the proportion of failures will be relatively less amongst women than 

 men, as they have much more practice. We are not certain that this 

 may not be the explanation of the result thus far obtained. 



For a number of years, Dr. Favre devoted himself to the study of color- 

 blindness amongst railway employes, and succeeded in introducing 

 reformatory measures on several railways in France. This circumstance, 

 and the manner, also, in which he has treated this subject from several 

 points of view, are more worthy of attention, since he has boldly pro- 

 nounced in favor of the curability of color-blindness by exercise, and 

 urged measures founded upon this principle. We will give his result 

 in the author's own words: 



" Out of one hundred and forty-six scholars, from seven to sixteen 

 years of age, belonging to two schools, one hundred and eleven named 

 the natural colors without error or hesitation ; thirty-five made mistakes 

 in different degrees; twelve made serious mistakes with regard to sev- 

 eral colors; the errors of the others were with regard to orange, blue, 

 or violet ; some were mistaken about all these three colors, others about 

 two, and some only about violet. These thirty-five children were sub- 

 jected by their instructors to repeated methodical exercises according 

 to the directions I had given them. One of the teachers cured all his 

 defective pupils ; the duration of the treatment varying from two weeks 

 to six months. The other teacher had on the 2d of April of this year 

 only two patients out of eleven uncured." 



