"Dr. Makellar, Pencaitland, East Lothian: 'The most serious and fatal disease which I have been called to treat, connected with colliers, is a carbonaceous infiltration into the substance of the lungs. It is a disease which has long been overlooked, on account of the unwillingness which formerly existed among that class of people to allow examination of the body after death; but of late such a prejudice has in a great measure been removed. From the nature of Pencaitland coal-works, the seams of coal being thin when compared with other coal-pits, mining operations are carried on with difficulty, and, in such a situation, there is a deficiency in the supply of atmospheric gas, thereby causing difficulty in breathing, and, consequently, the inhalation of the carbon which the lungs in exhalation throw off, and also any carbonaceous substance floating in this impure atmosphere. I consider the pulmonary diseases of coal-miners to be excited chiefly by two causes, viz. first, by running stone-mines with the use of gunpowder; and, secondly, coal-mining in an atmosphere charged with lamp-smoke and the carbon exhaled from the lungs. All who are engaged at coal-pits here, are either employed as coal or stone miners; and the peculiar disease to which both parties are liable varies considerably according to the employment.'—Ibid. Appendix A, No. 3, p. 422. See also witnesses Nos. 7, 44, 112, 144, 146. For a full account of this disease, see reports of Drs. Alison, Makellar, and Reid, in the Appendix to the sub-commissioner's report for the East of Scotland." Dr. Makellar gives the following remarkable evidence as to the efficacy of ventilation in obviating the production of this disease:— "The only effectual remedy for this disease is a free admission of pure air, and to be so applied as to remove the confined smoke, both as to stone-mining and coal-mining, and also the introduction of some other mode of lighting such pits than by oil. I know many coal-pits where there is no _black-spit_, nor was it ever known, and, on examination, I find that there is and ever has been in them a free circulation of air. For example, the Penstone coal-works, which join Pencaitland, has ever been free of this disease; but many of the Penstone colliers, on coming to work at Pencaitland pit, have been seized with, and died of, this disease. Penstone has always good air, while it is quite the contrary at Pencaitland.'—Ibid. Appendix A, No. 3; App. pt. i. p. 422." Other diseases, produced by employment in coal-mines, less fatal, but scarcely less painful, are rheumatism and inflammation of the joints.