:

fight. Befides, I think, if we could fuppofe the eye to be fo dazzled by the light of the night as to be injured, the injury ought to fall upon the nerve, and not upon the eyelids and external parts. The nitrous particles with which Alpinus imagines the atmosphere of Egypt to the impregnated, will not, I fuppofe, be confidered as a caufe more probable than any of the preceding but the following paffage may ferve to give an idea of the nature of the complaint in queftion, and its frequency, at Cairo. "Plurimafque (oculorum lippitudines) Cayri eafdemque per omnia anni tempora homines in vadere ob nitrofum pulverem, qui continuè oculos habitantium mordicat, & calefacit, obfervatur, longè maximéque in æftatis prima parte, quo tempore calor ambientis fummè calidi oculos inflammat, taliumque morborum numerum auget. Sparfim vero per urbem toto anno hæ oculorum inflammationes vagantur; atque epidemicæ plurimæ in primâ æftatis parte calidiffimâ inæqualiflimâque ob vehementifimum meridionalium ventorum calorem, atque inflammatarum arenarum copiam, quæ ab iifdem ventis afportantur. Eo enim anni tempore è centum hominibus quinquaginta faltem lippientes obfervantur." (De Medicin. Ægypt. P. 24.) The flying fand muft be troublesome, and probably, in many cafes, fupports and increases the inflammation, and in fome may give rife to it; but the following fact, which feems to me to render the induction complete, fhows that the true and general caufe is the great inequality between the tem

perature of the night and day; to which caufe fignal effect is given by the practice of fleeping fub dio. Mr. Clarkfon (in his effay on the impolicy of the African flavetrade) informs us (p. 71) that, "when the flaves are brought on board, the feamen, to make room for them, are turned out of their apartments between decks, and fleep, for the most part, either on deck or in the tops of the veilel during the whole of the middle paffage; or from the time of their leaving the coaft of Africa (where the days are exceffively hot, and the dews are exceffively cold and heavy, ibid. p. 68), to that of their arrival at the Weft-India islands." "From this bad lodging," he proceeds, " and this continual expofure to colds and damps, and fuddenly afterwards to a burning fun, fevers originate which carry many of them off. Nor is this the only effect which this continual viciffitude from heat to extreme dampnefs and cold has upon the furviving crew: inflammatory fevers neceffarily attack them. This fever attacks the whole frame; the eye feels the inflammation most. This inflammation terminates either in difperfion or fuppuration in the first inftance the eyes are faved; in the latter they are loft.

The inflammation of the eye is not the only difeafe produced in Egypt by the fucceffion of hot days to cool nights any more than on board our flave-fhips; in both tuations caufes and effects run parallel, as the reader will find upon recurring to Alpinus and the later travellers. The well-known danger of expofure to dews in hot climates,

climates, and indeed in all climates, in certain cafes, feems to depend upon the fame principle. It is also probable that the heat of the preceding day enables the dews of the night to prepare the fyftem for the ftimulating effects of the heat of the fucceeding day; fo that, of two perfons who fhould expofe themselves without precaution to the cold of night and the heat of the following day, he who fhould have been moft exhaufted the day before by the heat, would, if other circumftances could be rendered alike equal, be most injured by the next alternation.

Several circumftances, fuch as the redness and fwelling of the parts expofed to cold together with the frequent occurrence of inflammatory diforders not long after expofure to cold, were calculated to mislead obfervers into a belief that thefe diforders were the direct effect of cold. Yet the great difference in the ftate of a part during inflammation, and under the influence of cold, might have induced them to fufpect that fo flight an analogy might be illufive: and, after taking into the account other well-afcertained facts they ought to have concluded that the theory was falfe. Linnæus, in a paper in the Amoenitates Academicæ, expreffes his aftonishment at the impunity with which the heated Laplander rubs himself with fnow, or even rolls in the fnow, and drinks the cold fnow-water. We every day fee horses in a state of the most profufe perfpiration freely washed with cold water, and always without injury. I have feveral times within these two years caufed horfes accustomed to be ftabled, to be turned out for a fingle night VOL. XXXVIII,

in winter: and no cough, catarrh, or other diforder, has ever been the

confequence. It appears, therefore, to me, that, within certain limits, and thofe not very narrow, the tranfition from a higher to a lower temperature is attended with no danger to animals in a state of tolerable health; and a perfon, I conceive, might fuddenly pafs from a higher to a lower temperature without inconvenience, even where the difference is fo great as to be capable of producing confiderable inflammation, if the change should be made with equal celerity in a contrary direction. On this, though an interefting fubje&t for obfervations on man, and experiments on animals, we want precife facts; and I ftate the principle in order to induce obfervers to compare it with the facts that fall in their way.

In

Befides the fucceffion of heat and vice verfa, there is a third cafe well worthy of confideration; and this where part of the body is expofed to one of these powers, and the remaining part to the other; as, for inftance, where a ftream of comparatively cold air flows upon part of the body of a person fitting in a warm room, and perhaps alfo drinking ftimulating liquors. making chemical experiments it often happens that a cold (catarrh) is taken, if the hands be much immerfed in cold water, when the laboratory is much heated; by adding warm water, to raise the temperature of that in the trough, this danger is eafily avoided. In thefe cafes the effect feems to be the fame as that of the fucceffion of heat to cold. In perfons whose bowels are extremely liable to be affected, it fometimes happens, as I have myself known it to happen,

D d

that

that the removal of a foot into a cold part of the bed, after the body has beco ne warm in bed, thall bring on acute pain in the bowels; and yet no pain is produced in getting into bed, though the temperature be the fame, and perhaps lower, than that of the part into which the foot is removed; and, probably, total immerfion into cold water would not produce any pain in the bowels. The laws of fuch phanomena, however deferving of investigation, have, as yet, fcarcely been an object of attention with pathologifts. It is probable that the phænomena, in any given cafe, are regulated by two circumftances: firit, by the excels of heat (or the ftrength of the ftimulus, whatever it be,) to which the greater part of the body is expofed, above that to which the fmaller is expofed. The fecond circumftance is the difference between the extent of the heated and cooled furfaces. When the latter is not extremely minute, and yet confined within moderate limits, the inflammatory effects feem to be confiderable. Should the circumftances be reverfed, and a stream of air, fo warm as to convey heat to the body, inftead of carrying it away, play upon a fmall part of its furface, the rest being expofed to a moderate or a low temperature, it is probable the refult would be the fame as when moderate cold fucceeds to warmth, i. e. no. bad effect would follow.

Account of the Manner of treating Bees in Portugal. From Murphy's Travels in that Country.

TO form a colony of bees, a spot of ground is choten for the hives,

exposed towards the fouth or fouth. eat, well fheltered from the northern, blafts, and furrounded with fhrubs and flowers; of the latter, the beft is rofemary. The richer the neighbouring grounds are the better, for bees are faid to range for food to the distance of a league from their homes. The fituation being chofen, lanes must be cut through the fhrubby thickets of five or fix feet wide. The fences between the lanes fhould be about the fame dimenfions, and formed at intervals into fmall receffes, like bowers or niches, to receive the hives.

The figures of the hives ufed here in general are cylindrical; in height about twenty-feven inches by fourteen diameter. They are formed of the rind of the corktree, and covered with a pan of earthen-ware inverted, the edge of which projects over the hive like a cornice. The whole is fattened with pegs made of fome hard and durable wood, and the joints topped with peat. In the front of the cylinder, at the height of about eight inches, there is a small aperture where the bees enter. The infide is divided into three equal divifions, which are feparated by crofs flicks: here the bees form their combs or cells.

When the bees fwarm, which is ufually in the month of May or june, the hives are placed to re ceive them where they light. If they defcend on a tree, they are fhaken off: the perion who per forms this operation must not be afraid of them, as they do not commonly sting unless they are irritated; it will be fafer, however, 10 cover the head with a wire-math, and the hands with gloves.

Some bees are so wild, that they

By away in attempting to collect them, but they may be caught again in this manner: a fheet is placed by night on the ground contiguous to the fwarm, and when they alight, the hive is placed over them, with the entrance ftopped; then the whole is covered with a theet, in which they are carried home. But they thould not be placed near the hive whence they had originally departed.

When the time arrives for taking out the honey combs, which is generally in the month of June, when the flowers begin to decay, it should be done in the heat of the day, as the greater part of the bees are then abroad, but not during a high wind, or at the commencement of a new or full moon. The hiver must have his face and hands defended as above-mentioned, and accompanied by a perfon holding a chaffing dish, with a coal fire, covered with moist peat, to make the greater smoke: this fmoke being infufed among the bees from the top of the cylinder, they fly away or remain intoxicated at the bottom, then the hive is taken to pieces by drawing out the pins. The combs are cut out without deftroying the bees, except two cells, which are left around the hive; and, left the bees fhould feed on what remains, the incifion is covered with pulverized clay after this, the hive is put together as

before.

The combs fhould not be taken out but when they are full of honey; it is rarely good the firft year the bees affemble. In the months of March and Auguft the wax is

taken out, which is lodged in the firft divifion of the hive, after which the bees form other combs, and generate a young colony.

The hiver fhould often vifit the

ground, and repair any accidents that have happened. If fnakes frequent the place, they fhould not be killed, fince they do not moleft the bees, but deftroy the toads and lizards, which are obnoxious to them.

When the hives are decayed, they are taken afunder and fumigated; then the bees forfake their habitations and take fhelter in an adjoining hive, previously prepared for that purpofe. This thould be performed in the fpring, when the flowers begin to open and afford them fuccour. fame method may be used in taking out the honey; but if repeatedly practifed, it will extinguith the colony.

The

As the bees, in returning from their excurfions, are loaded and fatigued, there should be nothing near the hives to obftruct their defcent, which is not in a perpendicular courfe, but in an oblique one.

On Plica Polonica by Mr. Frederick Hoffman. From the Memoirs of the Manchester Society.

SYNONYMS. Lues Pocufienfis:* 7 rice:

Trichoma. POL. Keltun or Gozdz. GERMAN. Juden-zopff: wichtel 20pff: wixel-zorff: weichel-zorff. DISEASES, the tendency of which is fatal, and the occurrence Dd2 frequent,

frequent, peculiarly claim the attention of the practical physician; while morbid affections which appear more rarely, and prefent unfual phænomena, more efpecially attract the enquiries of those whole object is the extenfion of general fcience. The disease termed Plica Polonica is of the latter class. It is endemic in Poland; and feldom, if ever, observed in any other part of Europe. During a long ftay at Breslau in Silefia, I had frequent opportunies of obferving this difeafe and, as it is at prefent little known in Britain, I truft a brief narration of the principal circumftances connected with it will not prove uninterefting.

Both fexes are equally liable to the attacks of Plica. It usually appears during infancy; and but feldom after the age of twenty. When once produced, it continues during the remainder of life. The acceffion of the complaint is in general preceded by irregular fpafmodic affections, pains in different parts of the body, a flow fever, and various diseases of the eyes; all which ceafe immediately on the appearance of the Plica.

The diforder confifts in a præternaturally rapid growth of the hair, with a copious fecretion of a vifcid matter from its bulbs. For the moft part, the hairs of the head are alone affected; and that only in peculiar parts. In thefe, the hairs grow confiderably longer than in the reft; and are knotted and entangled with each other; being alfo covered with the vifcid matter which iffues from their roots, and which affitts in gluing them to gether.

In proportion as the quantity of

this gluten, and the implication of the hair increases, it is ftill more and more difficult to clean and comb it; hence a degree of Phthiriafis is produced, and the head contracts an extremely fœtid fmell, to which however the Polish peafants are fo much accustomed that they endure it without complaint, or any manifeft inconvenience.

It is also an opinion univerfally prevalent with them, that the difcafe is a falutary effort of nature to expel a morbid matter from the body; and that to interrupt the course of it would be productive of eminent danger; hence they make no attempt to cure, or even palliate the complaint. And if we may repofe confidence in authors of eftablished reputation, morbid af fections of a fimilar nature to those which precede its occurrence, paralyfis, and even death itfelf, have fucceeded imprudent attempts to check the progrefs of the difeafe. In this respect, Plica bears fome analogy to the exanthemata, and various chronic cutaneous eruptions.

I am as yet unable to decide whether this complaint is hereditary or not. From fome obfervations indeed it appears, that a predifpofition to it may be tranfmitted from parents to their offspring; but my information on this head is too limited to afcertain the point. In one cafe which fell under my own obfervation, two brothers had Plica, both on the left fide of the head, and in about one third of their hairs: I learned from them, that their father and grandfather bad alfo been affected with the difeate in a form exactly fimilar. Befides