The victims of my observation I have frequently wrapped in cloth of various colours, and have left them for a considerable time, but when I visited them I did not find that they partook of any of the colours, but uniformly were of a tarnished yellow, or greyish black, the colours they always assume when in a state of suffering and distress, and I never could succeed in making them take any other when in a situation of constraint.  The skin of the cameleon is of a very soft and delicate texture, and appears to the observer similar to a shagreen skin, elastic and pliable; and it may be owing to this extraordinary construction that it changes its colours and size with that facility which astonishes us; but what may be considered as a more wonderful faculty is, its expanding and contracting itself at pleasure, and, as it were, retaining the fluid in an uniform manner, when in health, but exhaling it when in a state of suffering, so as to reduce its dimensions to a more contracted size.  Its peculiar organization is such, that the atmospheric air which it inhales so generally throughout every part of its body, distends and projects even its eyes and extremities.  I have frequently seen it after many days fasting become suddenly plump, and continue so for a fortnight, when immediately it became nothing but a skeleton of skin and bone.

The tenuity of its body is at these seasons astonishing, the spine of its back becomes pointed, the flesh of its sides adhere to each other, and apparently form one united subsance, when it will, in a few hours, at pleasure, resume its rotund state; and this appears to me to be a most extraordinary circumstance in the construction of this animal, which invites the minutest research of the naturalist.

To convince myself how far the assertion might be admitted, that the cameleon can exist upon air, I have placed them in a cage, so constructed, as to exclude any thing else, even the minutest insect; when I have visited my captives, they have opened their mouths and expelled the air towards me so as to be felt and heard.  In the first stage of their privation and imprisonment, which has continued for more than a month, I have found them in continual motion around their prison, but afterwards their excursions became more circumscribed, and they have sunk to the bottom, when their powers of distension and contraction became languid and decreased, and were never again capable of performing their accustomed transformation.  The one which I brought to England preserved in spirits, after undergoing upwards of two months of famine, when I carried it among the grass, or placed it in the thick foliage of a tree, in little more than a week regained its green colour, and power of expansion; but not contented with my experiment, and determined to ascertain it to the utmost, I redoubled my precautions to exclude every thing but air, and my devoted victim was doomed to another series of trial, and continued to exist upwards of a month, when it fell a sacrifice to my curiosity.