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."

He pointed to the palette lying on his work-table. Different shades of
black pigments were brushed on it. One, in particular, I could hardly
see. It gave my eyes a blurring sensation, and I rubbed them and looked
again.

"That," he said impressively, "is the blackest black you or any mortal
man ever looked upon. But just you wait, and I'll have a black so black
that no mortal man will be able to look upon it--and see it!"

On the other hand, I used to find Paul Tichlorne plunged as deeply into
the study of light polarization, diffraction, and interference, single
and double refraction, and all manner of strange organic compounds.

"Transparency: a state or quality of body which permits all rays of
light to pass through," he defined for me. "That is what I am seeking.
Lloyd blunders up against the shadow with his perfect opaqueness. But I
escape it. A transparent body casts no shadow; neither does it reflect
light-waves--that is, the perfectly transparent does not. So, avoiding
high lights, not only will such a body cast no shadow, but, since it
reflects no light, it will also be invisible."

We were standing by the window at another time. Paul was engaged
in polishing a number of lenses, which were ranged along the sill.
Suddenly, after a pause in the conversation, he said, "Oh! I've dropped
a lens.