REPORT 
OF AN 
EXAMINATION OF RAILROAD MEN 
FOR 
COLOR BLINDNESS, 
(Read before the (Pennsylvania State Medical Society, 
May 22nd, i8jg, 
BY 
P. D. KEYSER, A. M„ M. D. 
Fellow of the American Academy of Medicine ; Member of the Philada. County Medical Society; 
Pennsylvania State Medical Society; American Medical Association, &c., &c. 
EXTRACTED FROM THE TRANSACTIONS OF THE PENNSYLVANIA 
STATE MEDICAL SOCIETY. 
1879. Compliments of 
the Author. FRACTURE OF THE LOWER END OF THE RADIUS. 
641 
With the object of retaining the apposition of the fractured sur- 
faces, by overcoming displacing forces, I have practised for many 
years on the principles involved in the splint here illustrated, the 
'application of which will not require much description. 
In the treatment of fracture of, the lower end of the radius it is 
essential that proper allowance be made for the curvature of the 
anterior or palmar surface of this payt of the bone. This is insured 
in the splint which I -have devised, follows correctly the radial 
curvature; and the fixing of the thenar and hypothenar eminences 
of the hand in their moulded beds, maintains the splint immovably 
in its correct position with reference to the radial curve. 
The splint is made of copper, so as to be readily conformable by 
bending to suit the peculiarities of size and form of forearms. The 
series of little pointed elevations along the edge is for the purpose 
of keeping the bandage from slipping. It is tinned to prevent oxi- 
dation. 
The splint will usually fit the forearm- so accurately that but little 
padding will be required, and a piece of woven lint or of cotton or 
woollen flannel is all that is necessary for its lining. No dorsal splint 
is needed, but as before referred to, a small pad will, in most cases 
be required over the dorsal surface of the lower fragment. For re- 
tention of the splint an ordinary bandage, two inches and a halt, to 
three inches wide, is all that is necessary. 
This splint has the merits of being applicable to all cases of frac- 
ture of the lower end of the radius, and also to many other injuries 
involving the forearm and wrist; it is almost indestructible, and, as 
now supplied, is very inexpensive. It may be obtained by address- 
ing any of the leading surgical instrument makers. REPORT OF AN EXAMINATION OF RAILROAD 
MEN FOR COLOR BLINDNESS. 
By P. D. KEYSER, M.D., 
SURGEON WILLS EYE HOSPITAL, PHILADELPHIA. 
The ancients seem not to have been aware of the defect of color 
blindness, as nothing has been found written at that time upon the 
subject, or even that would give a clue to their having the least 
knowledge or idea of any such a defect in vision. 
Pliny wrote that the art of painting in his time was inferior to 
that of previous times, meaning that the handling of colors by the 
painters, in their pictures, was not as skilful, elaborate, and fine as 
in those of earlier date, but says nothing about any defect in the 
perception of colors. 
Really no note seems to have been made of this anomaly until 
1830, when Dalton, who had discovered his inability to distinguish 
red from green, published an account thereof. 
There is no doubt that this defect has always existed among the 
inhabitants of the earth, in some greater or less extent, but as the 
compositions and effects of colors were not studied at that time, no 
notice was taken of it by the learned men of those early days. 
Even after Dalton’s publication of his observations on the anoma- 
lies of the perception of colors, and the description of his own defect, 
no great note thereof was taken except to classify it as one of the 
very rare forms of anomalies in vision. No attempt was made to 
examine the mass of the people to see to what extent it could be 
found. Only within the past few years has attention been drawn to 
it and interest taken therein by the simple discovery on investigating 
the causes of some railroad accidents, that the engineers did not or 
could not distinguish the signals of danger that were displayed. 
This, as might be said, “opened the eyes” of the physiologists, 
ophthalmologists, and other scientific men, and general examinations 
of all train hands as ivell as school children have been and are being 
made throughout the different countries in Europe at the present 
day. COLOR BLINDNESS IN RAILROAD MEN. 
643 
Ever since the establishment of railroads there have been unac- 
countable accidents. The switches have been found in their proper 
places, the signals correctly displayed, but still trains have run one 
in the other, telescoped as it is called in railroad parlance; run into 
all sorts of dangerous places, etc., when signals were out. At last 
the eyes of some of the officials became opened while making thorough 
investigations of some unaccountable accident in Sweden; it was 
discovered that the engineer did not recognize the danger signals 
that were displayed and passed on as if all were right and the way 
clear; thus causing the accident that had occurred. From this 
knowledge it was determined to have the hands on the road examined 
with the signals, and to their surprise it was found that quite a 
number could not distinguish the colors, mistaking red for green 
and vice versa. 
Examinations have now been made throughout Europe, of all the 
railroad employes, with the astonishing discovery of from 2 to 10 
per cent, color blind among them. 
The government of Sweden and Norway was the first to take an 
active interest in this matter, and placed it in the hands of Prof. 
Holmgren, of Epsala, to investigate. He has made careful exami- 
nations of the school children in the higher and lower schools, rail- 
road employes, sailors, soldiers, factory hands, and prisoners, with 
the following results: Public schools 4.54 per cent. Elementary 
schools 3.45 per cent. Students 3.08 per cent. Young people of 
different positions and conditions 4.50 per cent. Railroad hands 
2.15 per cent. Sailors 2.22 per cent. Soldiers 3.54 per cent. Fac- 
tory hands 4.77 per cent. Prisoners 5.60 per cent. 
Prof. Donders, of Utrecht, examined the railroad hands in Hol- 
land and found 6.60 per cent, color blind. In France it is reported 
that 10 per cent, of this defect was found among the persons em- 
ployed on the railroads. In Germany it is about 4 per cent. The 
examination for color blindness is now being carried on in all the 
employes of the railroads in Europe, so that the dangers from this 
one defect can be removed. 
With this point in view I addressed a letter on the 2d of July last 
to the presidents of all the railroads centering in this city, upon the 
subject, desiring to examine their train hands. 
I received prompt replies from all of those to whom I wrote ex- 
cepting one (the Pennsylvania Railroad, who took no notice of my 
letter), placing their men at my disposition for examination. They 
had been noticing the different reports upon the subject from Euro- 
pean files or cuttings that appeared from time to time in our news- 
papers, which caused them to be much interested in the matter. 644 
COLOR BLINDNESS IN RAILROAD MEN. 
I have up to this time examined the train hands of the Philadel- 
phia, Wilmington and Baltimore, the Delaware, the North Pennsyl- 
vania, and the Bound Brook railroads, and have found 3.5 per cent, 
color blind, that is, those who mistake colors one for the other, etc., 
and 8.5 per cent, more, who although able to distinguish the colors 
are unable to tell the shades of colors—who shade badly—thus 
making 12 per cent, of those examined who are not quick and sharp 
in the noticing and distinguishment of all colors and shades thereof. 
But of this 12 per cent, only the 3.5 per cent, were of such a character 
of defect as to make them really incapable and unsafe to fill the 
positions they occupied. 
In the examination of these men, several methods were used, so 
that there should he no mistake, and perhaps cause the removal of 
a reliable person from a responsible position, or the retention of one 
in whom there might be danger for the man}r unsuspecting travellers 
on the train. 
The method of Prof. Holmgren, of Sweden, in testing with skeins 
of colored worsteds, was first placed before them; then that of Dr. 
Stilling, in which colored letters on a black card are displayed; after 
which plates of colored glass were held in front of a gas flame in a 
darkened room, and finally the different signal lamps used on the 
roads were brought before them in various ways. 
The examinations were at first made in the evening by gaslight, 
and those found defective in the least were re-examined vei'y care- 
fully in daylight. 
The refraction of the eyes was carefully examined with the oph- 
thalmoscope, and vision taken, and of the number under examination 
79.4 per cent, were emmetropic; 14 per cent, hypermetropic; 3.9 per 
cent, myopic; and 2.68 per cent, astigmatic. 
Of the color blind 47.0 per cent, were emmetropic, 35.0 per cent, 
hypermetropic, 12.0 myopic, and 5.9 per cent, astigmatic. Of those 
who only shaded badly, 77.5 per cent, were emmetropic, 17 5 per 
cent, hjrpermetropic, 2.5 per cent, myopic, and 2.5 per cent, astig- 
matic. 
It will this be seen that color blindness is not governed by any 
defect of refraction. In cases of myopia when the vision was only 
all shades of color could be promptly and correctly distinguished 
c 
at a distance of thrice the range of vision with the worsteds, and at 
a much greater distance with the signal lights. 
Age has nothing to do with this anomaly, for those found defec- 
tive in the least range from 20 to 53 years of age. COLOR BLINDNESS IN RAILROAD MEN. 
645 
Of those defective 49.9 per cent, were green blind, 44.4 per cent, 
red, and 5 5 per cent. blue. 
Of the 8.5 per cent, defective in shading, 95 per cent, were so in 
greens, and 5 per cent, in red. I have no doubt in the least that the 
cause of these being so defective in shading colors is the want of 
education. None had ever been placed in such a position or condi- 
tion to handle and examine colors. 
My attention was attracted to two peculiarities among those found 
color blind. One was the fact of two men who could not distinguish 
red from green on test, had educated themselves to know that red 
was an intense color, and thus distinguished bright red signals by 
their luminosity, but at the same time, bright greens and other bright 
colors were red to them, and for such said they would stop the trains; 
thus being on the safe side and never having an accident to occur to 
them Green the}7 called a deep or dull color, and dark reds, dark 
greens, and browns were all green to them, and they would pass 
them by as all right on the road, thus causing them to be unreliable 
in their positions. 
The other was the power of distinguishing bright red when held 
within three feet of the eyes, while at 10, 20, and 30 feet it was 
invariably called green. In sorting the wools bright reds and light 
greens he picked out together for red. The acuity of vision was 
20 
normal In this case it appears that the retina was only affected 
by the luminousness of the color when close to the eyes and not 
when held at a distance. This being a new feature in the perception 
of color, and fearing some error or deception, I carefully examined 
him several times and in different ways with the same result. 
During the past winter I have examined, with the assistance of 
Drs. Tlios. II. Fenton and Frank Fisher, the boys of the Keystone 
Grammar School to the number of 17'6, of whom 18 were defective, 
none, however, being really color blind, but all defective in shading. 
One called all dark shades of yellow, browns; with eight, purples 
were blue; two said that dark green was brownish; one took light 
browns for red; the rest shaded badly in greens. 
It is just as necessary for sea-faring men to be free from this de- 
fect of color blindness as railroad men, to prevent the accidents of 
collision at night. 
The Cunard Steamship Compan}7 has for many years examined 
their men by the display of colored lights at the longest possible 
distance, and a single error disqualifies the man for their service. 
All officers and soldiers should be tested before placing 
them into the signal corps of the army, particularly in time of war. 646 
COLOR BLINDNESS IN RAILROAD MEN. 
Since these examinations have been made throughout Europe, 
several forms of the defect have been found, and Holmgren has 
divided them into three grades of intensity. 
1. Total color blindness (Totale Farbenblindheit) (Achromatop- 
sia). A condition in which there is entire absence of the perception 
of colors. Everything looks in black and white like a photograph. 
This grade is mostly acquired from some disease of the brain or 
optic nerve. It is very rarely congenital. Only 2 or 3 so found 
are recorded. 
2. Complete color blindness (Vollstandige Farbenblindheit) (Par- 
tial Achromatopsia). In which there fails the perception of one of 
the fundamental colors, red, green, or violet (blue). In this grade 
we can generally place the congenital cases. 
There are many cases that may come under this grade which 
might have been improved by education ; but one born color blind 
will always remain so, no matter how assiduously he attempts to 
educate his eye to distinguish the intensity of the color. lie will 
not be able to see it in the same way nor with the promptness of a 
normal eye. He does not realty see the color, but the intensity of 
it. In this way the distinguishment of the colors is acquired by 
practice, but is not constant and very uncertain. Just as we have 
seen in the two cases mentioned previously, in which they failed to 
recognize red on test, but by practice and observation had learned 
to know a bright red by its of color. 
3. Incomplete color blindness (Unvollstandige Farbenblindheit) 
(Pyschromatopsia). This form is more frequent, and consists in a 
reduced sensitiveness in recognizing one of the fundamental colors, 
particularly the shades of a color when the fundamental color may 
be perceived. The impression or perception is not so strong and 
clear in certain shades as in others. This grade of the defect can 
be very greatly remedied by education; and care should be taken to 
teach children all the colors and shades thereof. 
I am pleased to know that the regular teaching of the distinguish- 
ment of colors has been introduced in our public schools, beginning 
in the lowest sections of the primary schools with the primary colors, 
red, yellow, blue, and advancing slowly and regularly with the colors 
and shades in the higher sections as the pupils are promoted. 
Magnus, of Breslau, has added a fourth grade of this defect which 
he calls “Dulness or sluggishness of color distinction (,Farbentrag- 
heit). This is characterized by an individual in first sorting the 
colored wools, who lays many together of different shades as if color 
blind, but on looking at them again to see if he is correct notices COLOR BLINDNESS IN RAILROAD MEN. 
647 
his mistake and then re-sorts them correctly. In such cases the color 
perception is normal but slow in comprehension. 
While writing this report I had the good fortune to be able to 
test the suggestion of Javal for the cure of this defect in some cases 
by the use of a solution of fuchsine between thin plates of glass, 
and although skeptical upon the idea, I found that great improve- 
ment took place in its use in this following case:— 
Chas. Stottmeister, set. 45, came to me May the 14th, saying that 
although a dyer by trade and in business since boyhood, his father 
having a dye house in Germany, he was color blind and had been so 
from youth. He made the dyes according to the receipt furnished 
him, and until they looked like the sample to him; but at the same 
time he could not distinguish purple from blue. Reds on green or 
blue he could not see, that is red tinges in any color in which green 
or blue were combined. A gray-brown looked green to him. A lead 
is pink. A deep blue is purple. A clear brown and an olive-green 
are one color. He cannot see a red tinge in a mixture with yellow. 
Browns all have a green shade. 
On several different occasions I have tested him by day and by 
night with a solution of fuchsine (1 gr. to the ounce of water), 
between two thin glass plates before the eyes, and invariably it 
corrects the defects. The colors become clearer, “ all blues are 
bluer,” browns are correct. He sees the red tinges in the shades 
which he could not see before, but knew they were there from the 
mixture in making the dyes. Purples and blues are distinct; the 
red in the purple being clearly defined. The difference between the 
brown and olive-green is distinctly seen. When red is on j’ellow, 
the red is brought out. Greens are more positive. Without the 
fuchsine all browns have a greenish cast, with the fuchsine the red 
comes out and the green fades away, showing clear brown. When 
there is no red in the color, the fuchsine does not cause such a shade 
over all the colors as it does in a normal eye. 
This is a very clear and interesting case, as the man is a bright 
intelligent person; prompt in observation, and naturally interested 
in his situation, as it has prevented him holding most excellent places 
in dye houses. 
The cause of this action in fuchsine has as yet not been explained ; 
it arises perhaps from the power of polarization—in separating and 
absorbing certain chemical rays. 
This correction by fuchsine, however, cannot be made by persons 
employed in railroad service ; and I do not think it will be of benefit 
in many cases. While it brings out the red in colors it also destroys 
VOL. XII. 648 
COLOR BLINDNESS IN RAILROAD MEN. 
the green, so that dark greens become almost black. Thus, as it 
might be said, correcting red blind and making green blind. 
While preparing a pair of glasses with the fuchsine my friend Mr. 
W. Mitchell McAllister made a careful examination into the powers 
and properties of this liquid. He found that it entirely destroys or 
neutralizes most of the green shades in colors. The very dark 
shades it makes almost black, the medium brown, and affects very 
little the lighter shades. It adds red to all the other colors. Deepens 
the yellows. It has, however, no power of polarization. Its power 
is in the separating and absorbing of chemical rays. It is a hydro- 
chlorate of aniline. 
Philadelphia, 1630 Arcli Street.