=Acarus Siro=, the _cheese-mite_ (fig. _c_). The dry and powdery parts of decayed cheese, which by careful watching may very frequently be seen in movement, consist almost wholly of this insect and their eggs in different stages of development. The cheese-mite can hardly be seen without the aid of the microscope. They are very tenacious of life, even when kept without food. Mr Blyth says that under these circumstances “it is no uncommon sight to see them killing and devouring each other; and that cheese is rapidly destroyed by them; they crumble it into minute pieces, and emit a liquid substance which causes the decayed parts to spread speedily.” They may be destroyed by being exposed to a strong heat, or by putting the cheese for a short time in whisky. [Illustration: FIG. _d._] =Acarus Scabiei=, the _itch-insect_ (fig. _d_). The parasitic character of the disease known as the itch was first demonstrated by Dr Bononio, who on turning out the contents of one of the little bladders that show themselves between the fingers of those affected with the complaint, and placing the fluid under the microscope, discovered a minute animal, very nimble in its movements, covered with short hairs, having a short head, a pair of strong mandibles or cutting-jaws, and eight legs, terminating in remarkable appendages, each provided with a sucker and setæ. It has no eyes; but when disturbed it quickly draws in its head and feet, and then somewhat resembles the tortoise in appearance, its march being precisely the same. It usually lays sixteen eggs, which are carefully deposited in furrows under the skin, and ranged in pairs; these are hatched in about ten days. “To find the itch-insect,” says Mr Jabez Hogg, “the operator must carefully examine the parts surrounding each pustule; he will then see a red line or spot communicating with it; this part, and not the pustule, must be probed with a fine-pointed instrument. The operator must not be disappointed by repeated failures.” =ACCIDENT′AL COLOURS.= See COLOURS (Complementary). =ACCIDENTS.= _Black eye._ Bathe the eye frequently with a soft piece of linen rag dipped in a lotion composed of one part of tincture of arnica and seven parts of water. _Burns and Scalds._ Refer to BURNS and SCALDS. _Charcoal_, _combustion of_, _poisoning by._ Refer to CARBONIC ANHYDRIDE. _Choking, or suffocation from substances sticking in the throat._ Refer to CHOKING. _Cut Finger._ Refer to CUTS. _Precautions against Fires._ Refer to FIRES.