Acute infections of the upper respiratory tract, whether manifested as coryza, acute rhinitis, pharyngitis, or tracheobronchitis, are of the commonest incidence. A "cold," the grip, influenza nostras, catarrhal fever, acute bronchitis, are common terms used to designate such attacks. The infectious nature of the disease is almost universally accepted, although the identity of the infecting agent is not established. Walter's investigations1 are of practical interest. He shows that the Bacillus segmentosus of Cautley and the Micrococcus catarrhalis are probably sometimes causative of acute rhinitis and infections of the middle ear and accessory nasal sinuses.
A cold may cause as much suffering and incapacity as many diseases considered more serious. Often the illness is prolonged from the usual few days to ten days or two weeks. These infections are only too frequently the starting-point of complications that are a life-long menace to well-being. Among such complications and sequelæ are a