a cutaneous disease, appearing in small watery pustules on the skin; commonly of a mild nature, though sometimes attended with obstinate and dangerous symptoms. See Medicine Index.

ITCH-Insect. See Acarus, Entomology Index.

In speaking of the manner of finding these insects in the itch, Fabricius observes, that the failure of many who have sought for them has been owing to their having expected to meet with them in the larger vesicles that contain a yellowish fluid like pus; in these, however, he tells us, he has never found them, but in Itch-insect those pustules only which are recent, and contain only a watery fluid. We must therefore, he observes, not expect to find them in the same proportionate number in patients who for many months have been afflicted with the disease, as in those in whom its appearance is recent, and where it is confined to the fingers or wrists. The cause of this difference with respect to the pustules, he conjectures, may be owing to the death of the insect after it has deposited its eggs.

A small transparent vehicle being found, a very minute white point, distinct from the surrounding fluid, may be discovered, and very often even without the assistance of a glass; this is the insect, which may be easily taken out on the point of a needle or penknife, and when placed on a green cloth may be seen much more distinctly, and observed to move. All this, we must remark, probably depends on optical deception.