Within this one-mile radius of the A.S.C. headquarters at the Base are some twenty military hospitals improvised out of hotels, gaming-houses, and railway waiting-rooms. For the Base is the great Clearing House for the sick and wounded, and its register of patients is a kind of barometer of the state of affairs at the Front. When that register sinks very low, it means that the atmospheric conditions at the Front are getting stormy, and that an order has come down to evacuate and prepare four thousand beds. Then you watch the newspapers, for you know something is going to happen up there. And in those same hospitals men are working night and day; the bacteriologists studying "smears" under microscopes, while the surgeons are classifying, operating, "dressing," marking temperature-charts, and annotating case-sheets. And in every hospital there is a faint mysterious incense, compounded not disagreeably of chloride of sodium and iodised catgut, which intensifies the dim religious atmosphere of the shaded wards. If G.H.Q. is the greatest of military academies, the Base hospitals are indubitably the wisest of medical schools. Never have the sciences of bacteriology and surgery been studied with such devotion as under these urgent clinical impulses. Here are men of European reputation who have left their laboratories and consulting-rooms at home to wage a never-ending scientific contest with death and corruption. They have slain "frostbite" with lanoline, turpentine, and a change of socks; they have fought septic wounds with chloride of sodium and the ministries of unlimited oxygen; they have defied "shock" after amputation by "blocking" the nerves of the limb by spinal injection, as a signalman blocks traffic. They have called in Nature to the aid of science and have summoned the oxygen of the air and the lymph of the body to the self-help of wounds.