Cataract, however, may appear in young people, and is sometimes even congenital or present at birth. In the early stages of senile cataract, medicinal " drops " will often temporarily improve the sight, but must be ordered by an oculist. In a later stage, when the vision is sometimes reduced to mere perception of light, extraction of the lens is the proper treatment.

Catarrh is an inflammation of the mucous membrane, which forms a fine transparent lining to the entire length of the digestive tract from the mouth downwards, and to the respiratory tract, including the nose, throat, trachea, and bronchial tubes. Shreds of this membrane can sometimes be pulled off the inner side of the lips. it is, in a sense, an internal skin. It, like other tissues, is liable to be attacked by microbes, especially when the vitality is low. When the catarrh is limited to the nose, it is called nasal catarrh, cold in the head, or coryza.

This catarrh may spread to the throat, the trachea, the bronchial tubes, producing laryngitis, tracheitis, or bronchitis, as the case may be. In the digestive tract we may have a catarrh of the stomach mucous membrane caused by the irritation of unsuitable foods, or we may have catarrh of the bowels, or enteritis, causing diarrhoea. The eyelids and eyeball are also covered with mucous membrane, which is subject to catarrh, the signs of which, are running at the eyes, redness, and general discomfort. Thus it can be seen that catarrh is due to an irritation which may be mechanical, chemical, or microbic. The proper treatment for these catarrhs will be considered under their several headings, when it will be shown that removal of the cause of irritation and soothing applications are the best methods of dealing with the condition.

Chicken-pox is a mild disorder of childhood characterised by an eruption of groups of vesicles associated with slight fever. The symptoms are chilliness or fever, and the early appearance of a rash of pink papules or pimples, which, after twelve hours, become what is called vesicular, because they contain fluid. These vesicles or blisters increase in size, become depressed in the centre, dry up, and fall off in about five days. The rash appears on the chest and neck, and spreads over the back. The face and hands generally escape. A useful diagnostic feature of the eruption is that it appears in successive crops. The condition is contagious so long as the rash is present, so that it is as well to keep an infected child apart from the others, because, although chicken-pox is a trivial disorder, it is never wise to expose a child to any ailment unnecessarily. The attack is usually over in a week or ten days, but it is apt to leave some weakness afterwards.

The treatment consists in guarding against chill, in giving the child light diet, and gentle aperients. The rash is accompanied by itching, which is often troublesome, and soothing applications are generally necessary, especially in the case of a sensitive child. A teaspoonful of creolin mixed with a little cold water, and then added to the child's bath, relieves the irritation. Calamine lotion may be applied to any irritating spots.

Chilblains are painful inflammatory conditions of the skin, due to the action of cold on people whose circulation is poor and whose constitution is feeble. They generally appear on the ringers and toes, and they are attended with itching and tenderness. The condition sometimes goes on to ulceration. Children and old people suffer most from chilblains, which may appear every winter when the cold weather comes. Local treatment consists in applying stimulating lotions, such as iodine, but if the chilblains are broken they should be treated like an ordinary ulcer by bathing with boracic solution and applying a dressing of boracic lint.

It is most important to treat the general health and to do all that is possible to improve the circulation. Long-sleeved Shetland-wool vests should be worn, and warm woollen stockings. The feet and hands should be bathed with cold water twice daily, then rubbed with a rough towel to improve the circulation. Outdoor exercise is necessary, and wanning the feet or handover the fire should be prohibited. Warmth must be obtained by exercise and friction, and not by artificial heat.

Chorea (St. Vitus Dance) is a fairly common nervous disorder, chiefly occurring in childhood, associated with awkward spasmodic movements of the limbs and other nervous symptoms. The movements generally affect the muscles of the face and hands, but any group of muscles may be affected. True chorea, or St. Vitus dance, must be distinguished from mere habit spasms. Chorea is much more serious than habit spasm, because of the tendency to be associated with disease of the valves of the heart. It very often follows rheumatism or scarlet fever, but fright or sudden emotion may bring on an attack. It generally lasts a few months, and the important point is to watch for any evidences of heart disease or rheumatism. The child should be removed from school and treated by a medical man. A quiet life must form part of the treatment, and hygienic conditions in the shape of fresh air, moderate exercise out of doors, and plenty of sleep must be observed.

Certain authorities consider that chorea, or St. Vitus dance, is infectious, and there is no doubt that other children are apt to develop the spasmodic symptoms by so-called "imitation." The disease, however, is now coming to be considered microbic in origin, and good management will help considerably to avoid recurrence of an attack. As in the case of rheumatism, the child must be guarded from damp. The strain of a too severe curriculum at school is certainly a factor in producing the disease. The bright, intelligent child, who is encouraged to apply himself too closely to lessons, is only too apt to break down with an attack of chorea. Early symptoms of the condition, such as restlessness, emotional disturbances, night terrors, headache, should receive every attention. When they occur in children of a neurotic family, mental and bodily quiet must be ordered, and the child should be confined to bed in a recumbent position. These measures are often sufficient without drugs.