"We find the mucus which has remained in the nostrils for some time to be of a dark colour, and if we examine it with a microscope, we find, that this is owing to the presence of small particles of dust or other foreign substances, which the air may have accidentally contained. The mucus first coughed up from the lungs in the morning, is of a dark colour from the same cause, and the facts now maintained prove, that foreign substances suspended in minute particles in the atmosphere, may be inhaled into the lungs. I believe in all the extreme cases which have occurred in colliers and moulders, that there must have existed some previous disease of the lungs which prevented the foreign matter from being thrown off." "According to the views which we have taken of the subject, there are only two ways by which black matters may be deposited in the lungs; first, by a morbid secretion; second, by a foreign substance inhaled with the atmosphere. The former is a rare disease, while the latter is very common. I am inclined to think that the true melanosis generally occurs in the form of rounded tumours, which, when cut in two, present a uniform black colour without any trace of air-cells, while in the spurious melanosis the deposition is general, and black matter flows freely out when the cut surfaces are pressed. At first the lung is crepitous, and swims in water; but as the black matter increases, it becomes solid, and, as in the case of colliers who die of this disease, resembles a piece of wet peat in point of consistence. It is only in the cases of colliers, moulders, or others who inhale great quantities of black matter, that the lungs are rendered perfectly solid." There is an exceedingly interesting and valuable paper, written by Dr Brockmann of Clausthal, upon the pulmonary diseases of a certain class of German miners,--supposed to be in the Hartz mountains,--in _Neumeister's Repertorium_ for December 1844, an abridged translation of which is to be found in the September number of the _Monthly Journal of Medical Science_.