DR HUGHES BENNETT said, that the antagonism of this carbonaceous disease to tubercle, was a fact of great interest and importance, especially in connection with two other recent observations; viz. 1st, That the depositions of carbon in the lungs of old people, (which French pathologists describe,) are not found associated with tubercle; and, 2d, That under the supposed cicatrices of pulmonary tubercular cavities, a layer of carbonaceous matter is commonly found. Dr Makellar's paper called forth some interesting observations from the President, Professor Simpson, and others. BLACK PHTHISIS, OR ULCERATION INDUCED BY CARBONACEOUS ACCUMULATION IN THE LUNGS OF COAL-MINERS Among the many diseases incident to the coal-miner, none come oftener under medical treatment, than affections of the respiratory and circulating organs. While the collier is subject--during his short but laborious life--to the other diseases which afflict the labouring classes in this country, such as inflammations, fevers, acute rheumatism, and the various eruptive diseases, he, at last, unavoidably, falls a victim to lesions within the cavity of the chest, arising from the nature of his employment. In the present communication, it is proposed to lay before the profession a series of remarks, which I have been enabled to put together, with a view to elucidate the cause and progress of that very peculiar pulmonary disease, incident to coal-miners, which I shall denominate BLACK PHTHISIS, or Ulceration induced by Carbonaceous Accumulation in the Lungs. The rise and progress of the malady may be thus sketched: A robust young man, engaged as a miner, after being for a short time so occupied, becomes affected with cough, inky expectoration, rapidly decreasing pulse, and general exhaustion. In the course of a few years, he sinks under the disease; and, on examination of the chest after death, the lungs are found excavated, and several of the cavities filled with a solid or fluid carbonaceous matter. During the last ten years, my attention has been much directed, in the course of my professional labours in the neighbourhood of the coal-mining district of Haddingtonshire, to the above phenomena in the pathology of the lungs, which have not hitherto been brought so fully before the profession, as their importance demands. The subject presents a very interesting field of investigation to the physiologist and pathologist. When we consider the difficulties which the medical man has to encounter, in prosecuting his researches in morbid anatomy in a mining district, it is sufficiently explained why the peculiarly diseased structures in the body of the coal-miner should have been left so long uninvestigated.