With regard to the prevention of this disease, ventilation, as has been stated, is very much neglected in the pits now under consideration, where the various cases have occurred; and to that neglect I ascribe the prevalence of the malady. In those pits referred to, the workable apartments are so confined, and become after a time so destitute of oxygen, as, along with the smoke from lamps and gunpowder, to render the air unfit for healthy respiration. The only effectual remedy is a free admission of pure air, so applied as to remove the confined smoke. This remark both applies to coal and stone-mining. The introduction of some other mode of lighting such pits than by oil is required. I know several coal-pits where there is no carbonaceous disease, 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 Penston coal-work, which joins Pencaitland, has ever been free from this disease; but many of the Penston colliers, on coming to work at Pencaitland, have been seized with, and died shortly after, of the black spit: for instance, G. case No. 5, and D. case No. 8, are such. How this is to be accomplished, is for the scientific man to say. With all due deference, I may be allowed to suggest various modes which might be adopted to free the underground atmosphere of the noxious ingredients. Could fresh air not be forced down by the power of the steam-engine, which is at every coal-pit? Could extensive fanners not be erected and propelled by the same machinery?[26] I am much surprised that no attempt has been made to light these pits with portable gas in some way or other. As far as I can understand, such an application of it would not be difficult. A small gasometer could be erected, and the necessary apparatus procured at little expense, and by such means, I would suppose, it could be carried to any part of the mines, which are not extensive. Many proprietors may grudge the expense involved in such improvements, and thus prove a barrier to these necessary alterations; but I would ask any candid and generous mind, what is expense when the object in view is the removal of a disease to which many human beings fall a sacrifice?[27] It must appear to every one that these collier diseases are crying evils, the preventive of which is based, as will be seen, on thorough ventilation; and in order to protect the miner, there should be a vigilant attention paid to the economy of underground works. No one need be surprised at the result of such a noxious atmosphere; and it becomes a duty with the government to protect these poor people by laws, and to adopt those measures which are best calculated to preserve their health; and should there arise difficulties of an insurmountable character in the ventilation of these pits, why continue the mining operation in such situations at such a sacrifice of human life?[28] * * * * *