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.
This fatal issue, however, is not invariable. In favourable circumstances, and especially in childhood, the radical constitutional defect may be amended, and with a healthier condition of the blood the unhealthy deposit may cease to take place. The lung-substance, however, with all its curious structure of air-cells and their network of minute vessels where, as in nature's laboratory, the blood receives its due supply of oxygen, is not reproduced. The lung shrinks, the sides of the abscess come together, and by slow degrees a dense material cuts it off from the adjacent healthy structure, but the most complete recovery leaves the patient with his breathing power lessened, and with his vigour consequently more or less impaired.
When the deposit is less considerable, a different change takes place. The material dries by degrees, and is at last converted by a purely chemical change into a hard chalky substance, which in the course of time becomes of more than stony hardness.