The lividity of countenance, and the other concomitant symptoms, which presented themselves, gave decided indications of the morbid effects of this extraneous body. It requires little explanation to show how such a diseased state of the pulmonary organs, as has been described, should produce such results, by impeding the necessary chemical change of the blood. Imperfect oxygenation of the blood, consequent on the altered pulmonary structure, must cause a general depression of all the vital organs. The excess of excrementitious matter in the circulation, must produce effusion of serum into the various cavities, and also into the cellular structure; and the appearances exhibited on the surface of the brain and its membranes, afford a full explanation of the sluggish inanimate condition of all the sufferers towards the close of their existence.
From the cases above reported, it must be evident, that black phthisis is the result of foreign matter inhaled and retained within the pulmonary structure.
It is a melancholy fact connected with mining occupations in the locality described, that few or none who engage in it, escape this remarkable disease. I have never known one collier in many hundreds, who, even in his usual health, was not, as he expressed it, more or less "touched in his breathing;" and after much experience in auscultation in such pulmonary affections, I am the more convinced that the dyspnœa from which they suffer, arises from impaction of the minute bronchial ramifications induced during their labour below ground, surrounded by an impure atmosphere. The East Lothian colliers, of all miners throughout the kingdom, are certainly most subject to this disease; and those at Pencaitland are so to a fearful extent. In the late inquiry for the Parliamentary report, such has been manifestly brought out, and I am quite able to corroborate the conclusions at which the commissioners have arrived. It has been supposed by many that this carbonaceous affection was caused by inhalation of coal-dust. Now, when it can be proved, that there is as much coal-dust at one coal-work as at another, the question comes to be, why should colliers, labouring at one coal-work, be subject to the disease; while those engaged at another, escape? For instance, there is as much coal-dust at Penston and Huntlaw, where there has never been black spit, as there is at Pencaitland, Preston-Hall, and Blindwells. I conclude, therefore, that this cannot be the cause, otherwise they should all be liable to the disease. Again, those who labour as coal-bankers at the mouth of the shaft, are obliged to inhale much coal-dust in shovelling and arranging the coal received from the pit, and have the sputum tinged to a certain extent by it—which resumes its natural appearance when the collier leaves the labour producing it. They are not subject to the miners' cough, nor is there carbonaceous infiltration found in the lungs of such labourers after death. The females and boys, when, as formerly, both were allowed to labour, could not fail to inhale much of the coal-dust in which they were generally enveloped in their daily occupation; but no carbonaceous deposit has ever been found in the pulmonary tissue of either the one or the other. There are very interesting facts connected with the history of this disease, showing the length of time which the carbon can be retained, brought out by two cases on record, the one published as formerly mentioned by Dr James Gregory, in the Edinburgh Med. and Surg. Journal for 1831, denominated, "Spurious Melanosis;" the other, a case published by Dr William Thomson, (Medico-Chirurgical Transactions of London for 1837), and which was reported to him by Dr Simpson, now Professor of Midwifery in Edinburgh.
Dr Gregory's case is that of John Hogg, who had been in the army for more than twenty years, had seen much service as a soldier in America and the West Indies, and had served in Spain during the Peninsular war. On his return to his native country, he was engaged for a short time before his death as a collier at Dalkeith. I understand, upon inquiry, from those who were connected with Hogg, that he wrought in early life as a miner at Pencaitland coal-work, and was obliged, though a young man, to relinquish such employment on account of a chest affection, and exchange the pick for the musket. From the history of this case, and from the character of his occupation in early life, I apprehend that the carbonaceous deposit took place when he was first labouring as a miner at Pencaitland; and that he carried the foreign body in his lungs, throughout his campaigns.
The case reported to Dr Thomson by Dr Simpson is that of a George Hogg, who lived at Collinshiel, near Bathgate. In early life, this man laboured at Pencaitland coal-work, where the greater number of the cases now under consideration occurred; and it is stated as a certainty, that he contracted the black phthisis while occupied in that district; for I find from those who knew him at an early period, that his breathing was much affected while at Pencaitland, and he was long supposed by his fellow-miners to have imbibed the disease,—indeed he removed from Pencaitland on account of it. The two Hoggs were relatives, and natives of East Lothian.
It is evident, from several of the cases, that it is no uncommon feature of this affection for the carbon to remain concealed in the pulmonary tissue for very many years; and as both the Hoggs were miners at Pencaitland, I have not the smallest doubt that it was then and there that the disease had its origin; for I have never known a collier who was a stone-miner who did not ultimately die of the carbonaceous infiltration.
Apart from colliers and coal-mines, as a proof that carbonaceous particles floating in the atmosphere are inhaled and lodged in the bronchial ramifications, I may state the following circumstance, which came under my own observation several years ago. After a gale of wind, which had continued for more than a week, off the coast of America, in the July of 1832, I was applied to for advice by several of the seamen, on account of a tickling cough, followed by a peculiarly dark blue expectoration, which I was told was almost general amongst the crew. I was certainly at a loss, and put to my shifts, to render a reason; but, upon investigating the matter further, I found that, during the gale, the chimney of the cook's apartment in the 'tween-decks was rendered inefficient, whereby the sleeping-berths were constantly filled with smoke. I found almost all the seamen, to the number of nearly a hundred, suffering considerably from cough, and expectorating an inky-coloured phlegm, which continued more or less for about a fortnight. I ordered soothing expectorants, and the dark sputa were profusely voided, and ultimately disappeared; but whether any of the carbon had made a permanent lodgment in the pulmonary tissue, is what I have never been able to ascertain. I am now convinced, in recalling this occurrence, that whatever be the situation, should carbon be floating in the air, it can be conveyed into the air-cells; and had these seamen been longer subjected to this foul atmosphere, a permanent lodgment of the carbon would undoubtedly have been the consequence, and the disease now under our consideration to a certainty produced. I further remember seeing, several years ago, a case of partially carbonized lungs in a person who had lived for a length of time in a smoky and confined room in Glasgow. The patient died of dropsy, consequent, no doubt, on the pulmonary affection; and on examining the chest, the upper lobe of both lungs, and the bronchial glands contained black matter, similar in appearance to that found in the colliers.
While engaged in committing these remarks to paper, I have been led in my investigations to compare the various kinds of labour carried on in coal-pits with the underground operations of many of the railways now in progress throughout the kingdom; and being convinced of the very injurious effects produced upon miners while prosecuting these operations in confined situations where gunpowder is used, I shall be much surprised if the same results do not follow the hazardous undertakings connected with railway tunnelling, where gunpowder is had recourse to, and in the course of years find in our public hospitals cases of carbonaceous lung arising from this cause.[19]
It is no uncommon occurrence, in examining the pulmonary structure of those who have resided in large and smoky towns, to find both the substance of the lungs and bronchial glands containing black matter; and this is the case especially with persons who, in such situations, have passed the prime of life. But few, though not living in crowded towns, have not, at some period of their life, come in contact with smoke, and been obliged to breathe it, minutely combined with the air. It is not, therefore, to be supposed improbable, that a portion of the infinitely small particles, thus suspended in the atmosphere, should effect a settlement in the more minute air-cells, and in course of time, be conveyed to the interlobular cellular tissue by the process of absorption, and thence to the bronchial glands. There are several cases on record, from amongst iron-moulders,[20] where the pulmonary structure has been found heavily charged with carbonaceous matter, from the inhalation of the charcoal used in their processes, and where, during life, there was a free black expectoration.[21]
There is, then, little doubt that the bronchial glands, from their appearance in miners, moulders, and others, are the recipients of a portion of impurities which have been carried into the pulmonary structure by inhalation, and also those left after the process of oxygenation of the blood; and when it is fully ascertained, from the character of the atmosphere in the coal mine, that deleterious matter in this form must be conveyed to the air-cells during respiration, there is little difficulty in coming to the conclusion, that the black fluid found to such an extent in these glands in the collier and moulder, is similar to, and a part of, that discovered infiltrated into the substance of the lungs. If we trace the black matter in the lymphatic vessels, (which has been done), from the pulmonary organs to the bronchial, mediastinal, and thoracic glands, and from thence to the thoracic duct, we cannot but admit, that it does find its way into the venous system, and thereby contaminates the vital current.[22]