The history of the remote and proximate causes of pneumony will furnish us with a still more remarkable analogy of the connection between a _local_ affection, and a _general_ disease of the system. The pneumony is produced by remote exciting causes which act on the whole system. The whole arterial system is frequently agitated by a fever in this disease before a pain is perceived in the breast or sides, and this fever generally constitutes its strength and danger. The expectoration which terminates the disease in health, is always the effect of effusions produced by a general disease, and even the vomicas, which sometimes succeed a deficiency of bleeding, always depend upon the same general cause. From this view of the analogy between pneumony and pulmonary consumption, it would seem that the two diseases differed from each other only by the shorter or longer operation of the causes which induce them, and by the greater or less violence and duration of their symptoms. The pneumony appears to be an _acute_ consumption, and the consumption a _chronic_ pneumony. From the analogy of the pulmonary consumption with the diminutive term of certain fevers, I have taken the liberty of calling it a PNEUMONICULA. 5. I infer that the pulmonary consumption is a disease of the whole system, from its existence without ulcers in the lungs. Of this there are many cases recorded in books of medicine. Dr. Leigh informs us, in his Natural History of Lancashire, that the consumption was a very common disease on the sea coast of that country; but that it was not accompanied either by previous inflammation or ulcers in the lungs. It was generally attended, he says, by an unusual peevishness of temper. 6. I infer that the pulmonary consumption is a disease of the whole system, from its being relieved, or cured, only by remedies which act upon the whole system. This will appear, I hope, hereafter, when we come to treat of the cure of this disease. Let us now enquire how far the principles I have laid down will apply to the supposed causes of consumption. These causes have been said to be, an abscess in the lungs, hæmoptysis, tubercles, without and with ulcers, catarrh, hereditary diathesis, contagion, and the matter of cutaneous eruptions, or sores repelled, and thrown upon the lungs. I shall make a few observations upon each of them.