ved this beyond a doubt. If you take
your penknife and cut away the roof of the upper mandible, you will find
that the space betwixt it and the outer shell contains a large collection
of veins, and small osseous fibres running in all directions through the
whole extent of the bill. Clear away all these with your knife, and you
will come to a substance more firm than skin, but of not so strong a
texture as the horn itself; cut this away also, and behind it is
discovered a thin and tender membrane: yellow where it has touched the
yellow part of the horn, blue where it has touched the red part, and
black towards the edge and point. When dried, this thin and tender
membrane becomes nearly black; as soon as it is cut away, nothing remains
but the outer horn, red and yellow, and now become transparent. The
under mandible must undergo the same operation. Great care must be
taken, and the knife used very cautiously when you are cutting through
the different parts close to where the bill joins on to the head: if you
cut away too much, the bill drops off; if you press too hard, the knife
comes through the horn; if you leave too great a portion of the membrane,
it appears through the horn, and by becoming black when dried, makes the
horn appear black also, and has a bad effect. Judgment, caution, skill,
and practice will ensure success.

You have now cleared the bill of all those bodies which are the cause of
its apparent fading; for, as has been said before, these bodies dry in
death, and become quite discoloured, and appear so through the horn; and
reviewing the bill in this state, you conclude that its former bright
colours are lost.

Something still remains to be done. You have rendered the bill
transparent by the operation, and that transparency must be done away to
make it appear perfectly natural. Pound some clean chalk, and give it
enough water till it be of the consistency of tar; add a proportion of
gum-arabic to make it adhesive; then take a camel-hair brush, and give
the inside of both mandibles a coat; apply a second when the first is
dry, then another, and a fourth to finish all. The gum-arabic will
prevent the chalk from cracking and falling off. If you remember, there
is a little space of transparent white on the lower mandible which
originally appeared blue, but which became transparent white as soon as
the thin piece of blue skin was cut away; this must be painted blue
inside. When all this is complet