The quantity of sulphur in coal is another matter of importance that may be determined by chemical analysis. (See Sulphur.) The presence of more than 1% of sulphur renders coal unfit for the economical production of good light-gas, and more than 2% of sulphur renders it objectionable for use as domestic fuel. In like manner, coals containing mineral ingredients in excess are to be avoided, not merely on account of the quantity of ashes left by them, but for their tendency to vitrify upon the bars of the furnace, and to produce what is technically called ‘clinkers.’ The presence of much silica or alumina, and more particularly of any of the salts of lime, in ‘steam coal,’ is, on this account, highly objectionable.
For some further information connected with this subject, see Anthracite, Chimneys, Coke, Fuel, Gas, Lignite, Oils, (Mineral), Organic substances, &c.
PLAGUE. (Pestis). “A specific fever attended with bubo of the inguinal and other glands, and occasionally with carbuncles.”
Such is the definition of plague given in the ‘Nomenclature of Diseases’ (published in 1869), drawn up by a joint committee appointed by the College of Physicians.
More detailed accounts of the disease,
described by other pathologists, state that it attacks the patient with great suddeness, or only after a few premonitory symptoms. These are:—Shivering, extreme prostration, intense headache and giddiness, excessive restlessness, and an overwhelming sense of anxiety. The patient’s gait becomes uncertain, and he staggers like a drunken man. These symptoms are more or less accompanied by nausea, bilious vomiting, and frequently by bilious diarrhœa. As the disease advances, delirium very frequently sets in; the nausea, vomiting, and diarrhœa increase in intensity, the tongue becomes swollen and covered with a dark fur, whilst the lips, teeth, and nostrils are coated with a dry fetid incrustation. Provided the attack does not terminate fatally, in a very rapid manner, these symptoms are accompanied by sharp pains (increasing in intensity during the progress of the malady) in the groin, armpits, and neck. These pains in the above parts precede the appearance of the buboes, and in many cases, of the carbuncles, which, associated with the fever, are so characteristic of plague. These glandular swellings vary, in different cases, as to the time when they make their appearance. Sometimes they do so during the first day of the attack, at others, after two or three days—and in others, again, not until near the close of the disease. With the buboes and carbuncles, small red purplish spots (petechiæ), frequently appear on the body. The carbuncle is by no means an invariable accompaniment of the disease. Dr Russell, out of 2700 cases, found only 490 in which it showed itself. He states that when carbuncle develops itself, it is distributed over the whole surface of the body with the exception of the scalp, the palms of the hands, and the soles of the feet.
“The plague may be said to assume four degrees of severity:—1. Slight fever, without delirium or buboes. 2. Fever, delirium, and buboes. 3. Fever, delirium, or coma, buboes, carbuncles, and petechiæ/e. 4. Congestive fever, fatal on the first, second, or third day, before the appearance of buboes. The fever, though usually continued, may assume the intermittent or remittent type.”[110]
[110] Hooper’s ‘Vade Mecum,’ edited by Messrs Guy and Harley.
There is considerable diversity of opinion as to the origin of plague. By some pathologists it is maintained that it spreads solely by contagion; by others the contagion theory is altogether repudiated, and certain local and epidemic agencies are referred to as its source; whilst others, again, adopt a medium view and, whilst not denying its contagious origin, hold that it may also be developed by endemic and epidemic causes. It bears a great resemblance to typhus.
With the exception of the outbreak of plague at Veltianka, in Astrakan, in the beginning of the current year (1879), the pestilence has not visited Western Europe during