“Do you see that red-whiskered man?” he asked, pointing across the ring to the fifth tier of seats on the opposite side.  “And do you see the next man to him, the one in the white hat?  Well, there is quite a gap between them, is there not?”

“Certainly,” I answered.  “They are a seat apart.  The gap is the unoccupied seat.”

He leaned over to me and spoke seriously.  “Between the red-whiskered man and the white-hatted man sits Ben Wasson.  You have heard me speak of him.  He is the cleverest pugilist of his weight in the country.  He is also a Caribbean negro, full-blooded, and the blackest in the United States.  He has on a black overcoat buttoned up.  I saw him when he came in and took that seat.  As soon as he sat down he disappeared.  Watch closely; he may smile.”

I was for crossing over to verify Lloyd’s statement, but he restrained me.  “Wait,” he said.

I waited and watched, till the red-whiskered man turned his head as though addressing the unoccupied seat; and then, in that empty space, I saw the rolling whites of a pair of eyes and the white double-crescent of two rows of teeth, and for the instant I could make out a negro’s face.  But with the passing of the smile his visibility passed, and the chair seemed vacant as before.

“Were he perfectly black, you could sit alongside him and not see him,” Lloyd said; and I confess the illustration was apt enough to make me well-nigh convinced.

I visited Lloyd’s laboratory a number of times after that, and found him always deep in his search after the absolute black.  His experiments covered all sorts of pigments, such as lamp-blacks, tars, carbonized vegetable matters, soots of oils and fats, and the various carbonized animal substances.

“White light is composed of the seven primary colors,” he argued to me.  “But it is itself, of itself, invisible.  Only by being reflected from objects do it and the objects become visible.  But only that portion of it that is reflected becomes visible.  For instance, here is a blue tobacco-box.  The white light strikes against it, and, with one exception, all its component colors—­violet, indigo, green, yellow, orange, and red—­are absorbed.  The one exception is blue.  It is not absorbed, but reflected.  Wherefore the tobacco-box gives us a sensation of blueness.  We do not see the other colors because they are absorbed.  We see only the blue.  For the same reason grass is green.  The green waves of white light are thrown upon our eyes.”

“When we paint our houses, we do not apply color to them,” he said at another time.  “What we do is to apply certain substances that have the property of absorbing from white light all the colors except those that we would have our houses appear.  When a substance reflects all the colors to the eye, it seems to us white.  When it absorbs all the colors, it is black.  But, as I said before, we have as yet no perfect black.  All the colors are not absorbed.  The perfect black, guarding against high lights, will be utterly and absolutely invisible.  Look at that, for example.”