ranging 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