_Prophylaxis._—Ward off attacks of fleas. A substance called pesterine is good for this purpose, and consists of kerosene 20 parts, soft soap 1 part, and water 5 parts. Powdered naphthalene and tricresol powder are useful. Attendants on plague patients should be protected from infection. They should wear puttees or gum-boots, gloves, and overalls, and those looking after pneumonic cases must wear masks, goggles, and overalls. There is a protective vaccine for plague, and those travelling in districts where plague is epidemic should avail themselves of its protective power. _Treatment._—The only treatment which is of any value, and this only in bubonic plague and when given early, is the administration of plague anti-toxin, which should only be given by a medical man. The symptoms should be treated in order to relieve the patient’s distress. Belladonna and glycerine may be applied to the buboes, and they should be opened and carefully dressed once suppuration is established. Morphia is often required for the restlessness and insomnia, and cardiac stimulants are indicated in nearly every case. _Pleurisy, or Inflammation of the Membrane Covering the Lung._ This is more a disease of cold climates, and is usually the result of chill following severe exertion. _Symptoms._—Pleurisy is accompanied by less fever and general sickness than pneumonia; its characteristic symptom is the “stitch in the side”, which always accompanies it. There is also a short, dry cough, without expectoration, which the patient tries to restrain, as it “catches” in the side, and causes acute pain. For the same reason the breathing is shallow, as any attempt to draw a deep breath causes extreme suffering. _Treatment._—The patient suffers greatly, therefore in the early stages treatment must be directed to the pain. If leeches are procurable, the application of half-a-dozen to the painful region of the chest is advisable. Mustard leaves or poultices should be applied over the part, or it may be painted with tincture of iodine; opium may be given to relieve the acute pain, in the form of Dover’s powder, fifteen grains three times a day. Five grains of quinine may be given twice a day. _Pneumonia, or Inflammation of the Lungs._ It has been definitely proved that the black races are specially susceptible to the organism which is the cause of pneumonia, and it is a frequent source of invaliding amongst the native attendants of travellers in Africa and elsewhere. _Causes._—As predisposing factors may be noted change of climate, chill, insanitary conditions of life, fatigue, and overwork. Malaria, syphilis, alcoholism, and excessive tobacco-smoking also play a part. The disease is believed to be spread by personal contact, but this has not been definitely established.