“It is a matter of science,” he said. “It is not very easy for a doctor to explain it all to a layman. This friend of yours, now, I think you said she was the daughter of my old friend Ashley. Now there you have an exceptionally sound stock still surviving. Probably with no trace of the affliction at all.”
While these remarks, which were totally unintelligible to him, were being uttered with the same donnish and disdainful benevolence, the attention of the visitor was fixed on something else. He was studying with much more attention the girl in the background.
The face itself was much more interesting than he had supposed from the glimpse in the gloom of the doorway. She had tossed back the black elf-locks that had hung over her eyes like plumes on a hearse. Her profile was what is called aquiline and its thinness made it a little too literally like an eagle. But she did not cease to seem young even when she might almost be said to seem dead or dying. There was a taut and alert quality about her and her eyes were very watchful; especially at that moment. For it seemed clear that she did not like the direction that the talk was taking.
“There are two plain principles of physiology,” her father went on in his easy explanatory style, “which I never could get my colleagues to understand. One is that a malady may affect a majority. It may affect a whole generation, as a pestilence affects a whole countryside. The second is that maladies affecting the chief senses are akin to maladies of the mind. Why should colour-blindness be any exception?”
“Oh,” said Murrel, sitting up suddenly with a jump, and a half-light breaking on his bewilderment. “Oh. Yes. Colour-blindness. You mean that all this has arisen because nearly everybody is colour-blind.”
“Nearly everybody subjected to the peculiar conditions of this period of the earth’s history,” corrected the doctor in a kindly manner. “As to the duration of the epidemic, or its possible periodicity, that is another matter. If you would care to see a number of notes I have compiled–”
“You mean to say,” said Murrel, “that that big shop all the way down the street was built in a sort of passion of colour-blindness; and poor old Wister had his portrait put on ten thousand leaflets to celebrate the occasion of his becoming colour-blind.”
“It is obvious that the matter has some traceable scientific origin,” said Dr. Hendry, “and it seems to me that my hypothesis holds the field.”
“It seems to me that the big shop holds the field,” said Murrel, “and I wonder whether that shop girl who offered me chalks and red ink knows about her scientific origin.”
“I remember my old friend Potter used to say,” observed the other, gazing at the ceiling, “that when you had found the scientific origin, it was always quite a simple origin. In this case, for instance, anybody looking at the surface of the situation would naturally say that the whole of humanity had gone mad. Anybody who says the paints they advertise in that leaflet are better than my paints obviously must be mad. And so, in a sense, most of these people really are mad. What the scientific men of the age have failed altogether to investigate adequately is why they are mad. Now by my theory the unmistakable symptom of colour-blindness is connected with–”