180 PROFESSOR WARTMANN ON DALTONISM, 
a deep green sheep leather, and I exposed it to the intense light 
of the sun. After looking at it for some instants, D * * * 
having raised his eyes to the white ceiling, saw there a black 
circle surrounded with red. The colours had changed places 
instead of becoming complementary. 
I then painted a human head, giving to each part a comple- 
mentary colour. Thus the hair and the eyebrows were white, 
the flesh brownish, the sclerotica black, the lips and cheeks 
green, &c. When I asked him what he thought of the head, 
he replied that it appeared to him natural, that the hair was 
covered with a white cap little marked, and that the carnation 
of the cheeks was that of a person heated by a long walk. 
It may further be interesting to remark, that D * ** sees, 
in the whole extent of the solar spectrum which is luminous to 
him, the black stripes of Fraunhofer exactly as an ordinary eye. 
This I have proved both by projecting these lines on a screen, 
and by showing them to him through a spy-glass, and making 
him place the vertical thread of a micrometer in coincidence 
with them. Daltonians therefore perceive darkness where it 
exists to us also. 
Second observation*.—H. Dickinson of Newcastle-upon-Tyne, 
a draper, has related in the following terms the peculiarities of 
his daltonism. 
As far as I can systematize my experience, the primitive co- 
lours are red, yellow and blue: all the others are only different 
shades of these three types. 
My standard red is the colour of sealing-wax. The leaves of 
the trees, a lively grass green, especially that of the laurel-leaf 
differs from it but extremely little. 
I see yellow and blue in the ordinary manner, and I rarely 
confound objects which are tinted with them, although many 
things appear to me blue which do not appear so to others; a red 
cabbage is by day a magnificent bright blue, whilst I am sur- 
prised at finding it red by candle-light t. 
If I look at a cherry-tree, the cherries on which are ripe, I 
distinguish them from the leaves only when I am near enough 
* T owe the details of it to my friend Dr. Scholfield of Doncaster, who sent 
them to me dated August 17, 1841. 
+ M. M*** of G. being pressed to paint by night the portrait of a person 
whose departure was fixed for the following morning, used yellow for rose-co- 
lour. She nevertheless kept the work of the celebrated painter, assuring him 
that she would only show it after sunset. 
