(_b_) _Of irritation._ The patient should be kept in a darkened room and should not be worried more than is absolutely necessary for diagnostic purposes. An attendant is usually required, whose methods should be persuasive rather than forcible. Great tact is required. Morphia is of the greatest value in the treatment of this condition. It relieves the headache, acts as a damper on the hyperæmic brain, and keeps the patient from threshing about in bed and injuring himself. Sleep is essential for an early recovery and cure. In the _more severe cases_ venesection should be carried out, and operative measures will be required if the rising temperature and slowed high-tension pulse herald the advent or indicate the presence of compression of the brain. (_c_) _Of compression._ The various operations carried out for the relief of compression of the brain are discussed elsewhere. They include such operations as are conducted for localized hæmorrhages, whether subdural or extra-dural (see Chap. V), and such also as are described as ‘decompression’ operations (see p. 121). With regard to the general indications for adopting active surgical measures, the surgeon is, of course, guided in his estimation of the case by the general condition of the patient--depth of unconsciousness, &c.--but more especially by the temperature changes and alterations in blood-pressure. In my own practice I am guided very largely by the temperature changes--as described on p. 114. On the other hand, some surgeons pin their faith more especially on the blood-pressure changes. Thus Archibald writes: ‘If the blood-pressure be 130 mm. Hg. on admission, an hour later 150, still later 200 or 250, we are immediately in possession of the fact that the available intracranial space is being steadily, dangerously reduced, and that the vaso-motor centre is straining every nerve to stave off defeat.’ I am, of course, ready to concede the great value of blood-pressure tracings, but, in my experience, the temperature changes have been even more consistent, so much so that I base my treatment of a case very largely on such changes. One word of warning--the temperature must be taken every half-hour, and active surgical measures adopted _so soon as_ the rising temperature, slowing high-tension pulse, and deepening unconsciousness point to advancing compression. There is undoubtedly a growing tendency amongst those who have carefully studied the effects of trauma on the skull and brain to carry out exploratory and decompression operations at an early period, even in cases which present no symptoms of special localizing significance. The pathological conditions so commonly found and the excellent results that have been obtained prove that the adoption of early surgical treatment is founded on a very sound basis.