OR COLOUR BLINDNESS. 169 
and red are the most indistinct to him; moreover, he does not 
say freely that a tint is gray or yellow*. Blue and yellow are 
what contrast most forcibly to his eye. He judges very incom- 
pletely of the opposition of colours. He distinguishes three 
fundamental colours, which he calls green, blue and red; the 
last appears to him brown when it is deep. This daltonian sees 
the limits of the spectrum as we do. He confounds blue with 
violet and with a slightly bluish-red, more in the colours pro- 
duced by the prism or by interferences than in those of opake 
substances. 
§ 4. Cases of Daltonism incompletely described. 
Besides the facts which I have just related, there are a small 
number of others which are recorded in various works, but with 
too few details to render it possible to characterize them well. 
The following are the principal among them :— 
Mr. Scott+ informs us, that a full red and full green, pale 
blue and pink, deep red and blue gave him the same sensation, 
whilst he easily distinguished yellow and deep blue. He called 
the claret colour of a garment deep black. The same imper- 
fection existed in his father, his maternal uncle, one of his sis- 
ters, and the two sons of the latter. 
Gall} states that Dr. Unzer of Altona could never distinguish 
green from blue. 
Rozier § speaks of an individual whom a similar vision pre- 
vented from devoting himself to painting ; he used red instead 
of deep blue. Helling|| mentions a person who confounded 
light blue with green and red. 
Dr. Butter] describes the daltonism of a young man, R. Tucker, 
aged nineteen. To this person the red of the spectrum appeared 
brown; the orange, green; the yellow, orange; the blue, pink; 
lastly, the indigo and violet, purple. 
* M. Seebeck remarks, that all the persons whom he examined confounded 
the colours with gray,—an important fact, and one which had not hitherto been 
noticed. 
+ An account of a remarkable imperfection of sight; in a letter from J. Scott 
to the Rev. Mr. Whisson of Trin. Coll. Cambridge ; communicated by the Rev. 
Michael Lort.—Phil. Trans., vol. lxviii. p. 611 (1779). 
{ Gall. Anatomie et Physiologie du Systéme Nerveuz, tome iv. p. 98. Spurz- 
heim, op. cil. p. 276. De Ville, op. cit. p. 108. 
§ Rozier. Observations sur la Physique, tome xiii. p. 86. 
|| Helling. Praktisches Handbuch der Augenkrankheiten, Bd. i. p. 1. 
4] Remarks on the Insensibility of the Eye to certain colours, by John But- 
ter, M.D., Edinb. Philos. Journal, vol. vi. p. 185 (1822). Transactions of the 
Phrenological Society, p. 209, Combe’s System of Phrenology. 
