A human body is diseased in every part. A flag of distress is hung out in the form of some malady at the surface. Some physician whose thinking is on the surface of things applies an ointment, which compels the malady to go back within the body again. Then he cries, "I have cured him; see, it is all gone!" It may be said, that, when the disease attacks the lungs, it must be driven from that vital organ at any sacrifice. I reply, if the drug vapors which are inhaled could disperse the tuberculous deposit,--which is impossible,--the tubercle could not be transferred to any other internal organ where it would do less harm. No other internal organ can bear tuberculous deposit or ulceration with less danger to life. In 1847, two brothers, bank-officers, afflicted with chronic inflammation of the eyes, came under my care. I repeatedly prescribed for them, but their eyes got no better. Indeed, they had little hope of relief; for, during their years of suffering, many physicians had treated them without avail. At length I told them there was no hope but in absence from their business, and such recreation as would elevate the general tone. A few months of hunting, fishing, and enjoyment in the country sufficed to remove the redness and weakness from their eyes. As I have argued, the disease was not one of the eyes, but of the entire system, which had assumed a local expression. This dependence of particular upon general disease is a common idea with the people. A young man begins business with a large capital. He falls into dissipation. In ten years it exhausts his fortune. When at last we see him begging for bread, we do not say this exhibition of his poverty is his financial disease. His financial _constitution_ has been ruined. The begging is only an unpleasant exhibition of that ruin. During this course of dissipation, the young man, in addition to the exhaustion of his fortune, ruins his health. His lungs fall into consumption. Some doctor may tell you it is disease of the lungs. But it is no more disease of the lungs than was begging the man's financial malady. In either case, the apparent disease is only an exhibition of the constitutional malady. In brief, a local disease is an impossibility. Every disease must be systemic before it can assume any local expression. Or, in other words, every local pathological manifestation is an expression of systemic pathological conditions. Now what is the practical value of this argument? I reply: So long as people believe bronchitis to be a disease of the throat, or consumption a disease of the lungs, so long will they labor under the hallucination that a cure is to be found in applications to these parts. But when they are convinced that these diseases are local expressions of morbid conditions pervading the whole organism, then whatever will invigorate their general health, as Nature's hygienic agents, will receive their constant and earnest attention. CAUSES OF CONSUMPTION.