All these colours, except the blue, are inherent in the horn: that part which appears blue is in reality transparent white, and receives its colour from a thin piece of blue skin inside. This superb bill fades in death, and in three or four days' time has quite lost its original colours.
Till within these few years no idea of the true colours of the bill could be formed from the stuffed toucans brought to Europe. About eight years ago, while eating a boiled toucan, the thought struck me that the colours in the bill of a preserved specimen might be kept as bright as those in life. A series of experiments proved 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.
