HOUSEMAID'S KNEE. Name given to a condition characterised by a chronic swelling in front of the knee-joint. It is due to an inflammation of the membrane lining the synovial cavity of that joint (see p. t3o), and a consequent accumulation of Iluid. The affection has derived its name from the circumstance that it chiefly arises from working in a kneeling posture. Rest and cold applications may reduce the swelling, which is often accom panied with much pain ; but in stubborn cases operative treatment may be necessary. Similar swellings occurring generally on the wrist are called ganglia. See GANGLION.
HUMULUS (HOPS).—The carefully dried strobiles of liniments Lupines, or hop-vine, a very widely distributed, climbing herb. Its most important constituent is a yellowish, glandular powder termed lupulinc, which contains volatile oils, terpenes, and a number of unknown constituents. The action of hops is diuretic and slightly sedative, and it is used internally as an anti spasmodic. It has very little of its reputed value to cause sleep.
HUNCHBACK.—The development of a deformity in the back (Fig. 231) affords indisputable evidence of the existence of an inflammation in the vertebral column, a destructive process in one or more vertebrae. In the majority of cases the condi tion is due to a tuberculous disease of the backbone, a chronic process which it may take years to cure. In the course of the disease other serious symptoms may appear, including paralysis of the legs, of the bladder, and of the intestine.
Suppuration may also set in, resulting in the formation of cold abscesses which may burrow their way into the pelvis or into the thigh. The treatment of this disease requires great care. Efforts 4 to prevent further deformity de- f, mind rest on a hard, flat mattress ; suspension in a special form of sling ; the application of various apparatus or plaister corsets, etc. • The cold abscesses usually disappear by a process of gradual absorption ; but if this does not take place they may be evacuated by incision or by aid of an aspirator, followed by the injection of various medicinal substances.
HYDRASTIS.—The dried rhizome of Hydras/is Canadensis, a low herb growing in open woodlands. It is known also as golden-seal. orange-root, and turmeric-root. Its active principle is the alkaloid hydraslinc, and the root also contains a small percentage of oil, berberine, and other inert substances. II vdrastine acts chiefly on the unstriped muscle-tissue in the body, and is therefore utilised to constrict the blood-vessels and to raise blood pressure. Furthermore, it is of value in the treatment of relaxed conditions of the hollow organs, particularly in some forms of diarrhea and in bladder disturbances. It is chiefly used in the form of the fluid extract, in doses of from 5 to 15 drops.