Dr Brockmann, as he advances, puts a question here, which more fully shows that the disease under his consideration was of a mild character compared with that under our notice. "If," says he, "pulmonary melanosis arise entirely from inhalation of carbonaceous dust, why is it not observed in other workmen, who are as much, and even more, exposed to its influence, as for instance, smelters, or moulders, and colliers?" He says, further, "were the carbon inhaled in quantity sufficient to explain the black colour of the lungs, it ought also, from its mechanical irritation, to produce inflammation in the delicate mucous membrane of the organ, but there are no symptoms of this during life, nor any traces of it after death." An answer to these remarks will be most satisfactorily given by a reference to the published cases, where the disease is principally found amongst colliers and moulders, and where the pulmonary organs, particularly in the former, are found to undergo most fearful disorganization from the presence of carbon. It is very remarkable, that the author of these exceedingly interesting observations should never have found excavations of the parenchyma, when it is so general as the result of the same disease in this country, particularly in the locality to which I refer. Not knowing the character of the mine, it is impossible to judge; but I am disposed to conclude that there cannot be the same quantity of carbon floating in the atmosphere breathed by the German miner,--the disease resembles very much that milder form found in the iron moulder. With regard to the carbonaceous state of the blood, I am sorry that I have not yet completed my investigations on that subject. It is still my belief that the carbon being once inhaled, there is an affinity found for that in the circulating fluid, and from its not being consumed, owing to a deficiency of oxygen, there is a progressive increase going on. I am very much gratified to find that Dr Brockmann entertains a somewhat similar opinion in respect to the state of the blood.