he wing-cases which will presently
replace white by red.

In two or three days the colourless becomes the coloured, a process
whose rapidity implies a fresh molecular structure rather than a
change of composition. The building-stone remains the same, but is
arranged in a different order; and the structure alters in appearance.

The Scarabaeus is now all red. The first brown stains show themselves
on the denticulations of the forehead and fore-legs, the sign of an
earlier maturity in the implements of labour, which are to acquire an
exceptional hardness. The smoky tinge spreads more or less all over
the insect, replaces the red, turns darker and finally becomes the
regulation black. In less than a week the colourless insect turns a
rusty red, next a sooty brown and then an ebony black. The process is
completed; the insect possesses its normal colouring.

Even so do the Copres, the Gymnopleuri,[8] the Onites, the Onthophagi
and many others behave; even so must the jewel of the pampas, the
Splendid Phanaeus set to work. With as much certainty as though I had
him before my eyes at the moment when he divests himself of his
nymphal swaddling-bands, I see him a dull red, rusty or crimson,
excepting on the wing-covers and the abdomen, which are at first
colourless and presently turn the same colour as the rest. In the
Sacred Beetle this initial red is followed by black; the Phanaeus
replaces it by the brilliance of copper and the reflections of the
emerald. Ebony, metal, the gem: have they the same origin here then?
Evidently.

[Footnote 8: Cf. _The Sacred Beetle and Others_: chap.
viii.--_Translator's Note_.]

The metallic lustre does not call for a change of nature; a mere
nothing is enough to produce it. Silver, when very finely subdivided
by the methods whereof chemistry knows the secret, becomes a dust as
poor to look at as soot. When pressed between two hard bodies, this
dirty powder, which might be dried mud, at once acquires the metallic
sheen and again becomes the silver which we know. A mere molecular
contact has wrought the miracle.

Dissolved in water, the murexide derived from uric acid is a
magnificent crimson. Solidified by crystallization, it rivals in
splendour the gold-green of the Cantharides. The widely-used fuschine
affords a well-known example of like properties.

Everything, then, appears to show that the same substance, derived
from urinary excretions, yields, according to the mode in which its