A fractured limb may be completely mended; a fluid is poured out around and between the edges of the broken bone; by degrees this hardens, it undergoes changes which convert it into solid bone, and the limb is once more as serviceable as before, though some indications of the fracture may still be perceptible in the texture of the bone itself. Or, a person receives a severe blow on his arm or leg; in course of time the blood which had flowed from the ruptured vessels, and had formed a big bruise, is absorbed, and all is as before the injury was inflicted. If more serious damage has been done, the fibres of some muscles may have been torn, even though the skin remains unbroken. Inflammation is set up, the injured parts die, and are melted down into the matter of an abscess. The abscess discharges itself, its walls contract, the opposite surfaces come into contact, and are welded together again, so that there is no loss of substance, nor anything save a scar on the surface to indicate what has happened. In the case of the deposits of consumption or scrofula these changes cannot take place. In technical language the matter is said to be incapable of organisation; that is to say, it cannot be transformed by nature's alchemy into anything good or useful. It is rubbish to be got rid of; and the patient's recovery depends on the possibility of getting rid of it. If there is much of it, so as to be removed from the vivifying influence which adjacent living structures still maintain about it, the deposit softens at its centre. This softening gradually extends to the circumference; the mass irritates more and more the parts around it, and where the irritation is greatest the structures yield, and are removed to make a way for its escape, and the patient spits up the contents of the abscess. But the abscess of the lungs is not like an abscess which follows an injury. It has not formed in the midst of previously healthy parts which are capable of reproducing the original structure; its walls are themselves involved in the disease, and, in accordance with the rule I have already mentioned, 'much will have more,' and the patient goes on spitting up the perpetually renewed contents of the abscess for months or years; until by its gradually increasing size, and the more and more abundant discharge of matter, and further and further destruction of lung-substance, death takes place.