dissolved in a very large portion of water, the emetic power which it possessed will be destroyed. The same loss of power will ensue if a dose of opium be administered either previously or in conjunction with it, by which the stomach will become insensible to its action. And lastly, if an alkaline salt be added to it, the decomposition thus produced will render it inert. A knowledge of these several correctives of contagion is interesting to the magistrate as well as to the physician. But the most important of them, and what is now chiefly to be considered, is dilution, which. may, I trust, be accomplished, so as to obviate the communication of infection, by smaller supplies of fresh air, than you seem to apprehend.

Contagion, like all other poisons, must subsist in some definite quantity, or degree of concentration, to be capable of producing its deleterious effects. And though the minimum, or least point of activity, under which, when reducedby diffusion, it becomes innoxious, hath not, and perhaps cannot, be precisely ascertained; yet we have sufficient evidence to satisfy us that this subsists at no great distance from its source. Dr. Mackenzie, who practised physic thirty years in the cities of Smyrna, and Constantinople, assures us, that he was never afraid to go into a large house wherein a person lay under the plague, provided the patient was confined to one room. And the Rev. Thomas Dawes, chaplain to the British factory at Aleppo, in his account of a dreadful pestilence which raged with such violence in that place in the years 1761 and 1762, that from two to three hundred persons were buried daily, relates that the plague twice broke out in two houses adjoining to that in which the British Consul lived: but although, according to the custom of the East, they constantly slept during the months of July and August, in the open air on the house-top, and a Franciscan friar, whose bed was only six yards distant from that of Mr. Dawes, (both being placed near a wall eight feet high, by which the terraces of the two houses were separated,) died of the disease after two days' illness, yet he and all the family escaped infection. I shall recite a more remarkable fact from the authority of my late honoured friend, Sir John Pringle, which still further illustrates what has been advanced. In the year 1750, on the 7th of May, the sessions commenced at the Old Bailey, and continued several days, during which time more criminals were tried, and a greater multitude was present, than usual. This court is only thirty feet square; and the corruption of the air was aggravated by the foul steams of the bail- dock, and

of two rooms opening into it, in which the prisoners were the whole day crowded together, till they were brought forth to take their trial. The bench consisted of six persons, four of whom died of the gaol distemper, together with two or three of the counsel, one of the under-sheriffs, several of the Middlesex jury, and above forty other persons. It is to be noted, that the Chief Justice, who sat at the Lord Mayor's right-hand, escaped; whilst his lordship, with the rest of the bench on his left, was seized with the infection; that the Middlesex jury, on the same side of the court, lost many, whilst the London jury, opposite to them, received no injury; and that of the multitude present, but one or two, or at most a small number, of those that were on the side of the court to the Lord Mayor's right-hand, were taken ill. Sir John Pringle ascribes this partial action of contagion to the opening of a window at the end of the court, most distant from the bench, by which he deems it probable that the poisonous miasms were directed to, and accumulated in, that part of the hall where the fatality so remarkably occurred. And I think we are equally warranted to conclude, from his narrative that the air of the whole court must have been contaminated, and that a moderate degree of dilution sufficed to render the contagious particles innoxious.

Thus far I had written more than a month ago, as you will perceive by the date of my letter. Successive and very urgent engagements have dissipated my thoughts on this interesting subject, and still continue to engross my time. I hope you will not infer from the observations, which I have with much freedom suggested to you, that I regard the ventilation of gaols as an object of little importance; for it appears to me to claim the most serious attention, so far as it can be rendered compatible with essential purposes of confinement. And I rejoice to find that Mr. Blackburne, an ingenious architect now employed in this county, and in various other parts of England, in the erection of new prisons, purposes to surround them with a wall of no great height, but covered at the top with chevaux de frise, which will afford perfect security, at the same time that it is pervious to the wind.

I meant to have offered to you some hints concerning the accommodation, clothing, diet, indulgences, and medical treatment of the prisoners, as they relate to the prevention or cure of the gaol distemper. But I have at present no leisure to digest my thoughts; and it is probable they would donvey little information to one who has so fully considered

these subjects. When you see Dr. Jebb, be pleased to present my best respects to him: he has a claim to the warm esteem of every lover of his country.

This letter will be conveyed to you by Mr. Blackburne. I am called to a meeting of our magistrates, which is to be held to-day for the purpose of conferring with him on the erection of a new prison here.

I have the honour to be, with very cordial respect, Sir, your most faithful, humble servant,

1787, Sept.

THO. PERCIVAL.

LXXVII. Provincial dislike to Game, how to be accounted for.

MR. URBAN,

IF you ask a countryman in the south-west part of the kingdom to dine, he objects to any kind of game which comes to your table, and says, in his provincial dialect, I never eats hollow fowl; under which term he includes hares and rabbits, as well as wild fowl, and every kind of poultry. It is in vain to inquire whence this dislike proceeds, for he can tell you no more than that he derives it from his father. Cæsar, it is very remarkable, describes the inhabitants of this country as having exactly the same prejudice. They esteemed it (says he) a crime to eat hares, poultry, or geese; they kept them nevertheless for amusement. "Leporem, et gallinam, et anserem gustare fas non putant: hæc tamen alunt, animi voluptatisque causa." De Bell. Gall. lib. 5. c. 12. Had the generality of our people been descendants of the Britons whom Cæsar encountered, there would have been then little difficulty in accounting for this superstition, as it might reasonably be supposed to be the remains of a druidical inhibition continued to this time. But history allows of no such solution; for the Saxons found the southern end of our island, deserted by the Romans and ravaged by the Picts, in such a state of desolation, that, so far from adopting the customs of the few surviving natives, they gave new names to the rivers and mountains, and even to the villages and cities. Now we have the authority of Cæsar for asserting, that the Germans, from whom our Saxon ancestors are descended, had no connection with the Druids, but that they had religious rites and ceremonies of

their own. Whether this injunction might have been part of the religion of the Germans, as Tacitus is silent on the subject, cannot now, I think, be ascertained. But what could induce the legislators of two distinct nations to forbid a food so obvious, delicate, and wholesome? And yet it is not easy to imagine that the Saxons would, after their arrival here, impose such an unmeaning restraint on themselves.

There is, however, an abstinence from some of these ani, mals as to food still more inexplicable. It is well known to sportsmen, that spaniels refuse to eat the bones of pheasants, partridges, and wild fowl, though they hunt them naturally: they reject also the bones of the woodcock, which bird they must be trained to flush. Is this antipathy dietated by instinct, or does it arise from being domesticated? Yours, &c.

1787, Oct.

T. H. W.

LXXVIII. Instance of a singular Dream and Corresponding Event.

MR. URBAN,

THE curiosity of mankind has been often excited on the subject of dreams; the lower people in all counties are inclined to regard them with reverence and awe; but the opinions of the more enlightened classes of men have been at great variance with respect to this phenomenon. Some have been led to consider dreams as one species of proof, that there is existing within us a principle independent of the material frame. The vivid appearance of objects, the new and surprising combinations formed, the exertions of the passions, the regular trains of reasoning, the play of the imagination, seem occasionally to be as much realized in the state of slumber, as when awake and in motion. It may be assumed as a certain fact, that almost every man has, at some one period or other of his life, experienced in sleep a consciousness of every action he could have performed

"Germani multum ab hac consuetudine (Gallorum) differunt. Nam neque Druides habent, qui rebus divinis præsint; neque sacrificiis student.” De Bell. Gall. 1. VI. c. 20.

when awake. He travels over extended regions; he runs, walks, rides, with freedom and agility, and not unfrequently seems endued with new and superior powers; he soars aloft, and is wafted through the air, or, gently descending, he glides through the waters, and with such perfect command and security, that, when he awakens, he is hardly persuaded it was but a dream. In opposition to these observations it is urged, that exactly similar effects are produced from disease; such is its influence in numberless cases, that the subject seems just as forcibly prepossessed as from any ideas that could be received from actual impression. Persons insane will persevere in exercises beyond their usual strength, seeming all the while never to entertain a doubt but that they are moving in carriages, on horseback, performing military exercise and evolutions, or buried in philosophical experiments. Multitudes of such instances will readily occur: and it is argued, that as the mind, in those examples, is evidently not disengaged from the control of the body, so neither, in the other, is there any reason to suppose it different, the circumstance of sleep and insensibility being something not unlike disease, a state of suspension of many of the active powers.

Some philosophers imagine that the mind never remains inert, that successions of ideas incessantly present themselves, and thought is always employed. With respect, however, to this notion, it may be alleged, that it is highly improbable that dreams, which, according to the supposition, must perpetually occur, should be so seldom and so faintly recollected. To this it may be answered, that the same thing happens when we are awake. Let any person try to recal the whole train of ideas that has passed through his mind during twelve hours that he has been stirring about in the ordinary business of the day, he will be able to remember particular essential transactions; but, if he attempts to recover the mass of ideas that filled his mind for that portion of time, or even only a considerable part of the time, he will find it impracticable labour; he will in vain endeavour to trace the connection of his ideas; the same broken confused assemblage will be perceived, even by him who possesses the most retentive memory, as when he first awakens with that imperfect consciousness that is usually termed a dream. Were we to commit to writing, in the minutest manner, every idea our remembrance then suggested, it would be difficult, perhaps impossible, to collect such number as would employ one hour to read over. The popular belief, that dreams are a kind of preterna