Befides the human species, other animals are fubject to this complaint. It appears in fome of the fineft horfes in Poland. In them it is fituated in the mane, and fometimes in the long hairs around the hoof and fetlock joint. It attacks alfo the different fpecies of the canine genus; dogs, wolves, and foxes. Previous to its occurrence in the first, the symptoms of rabies ufually appear: the tail is dropped between the hind legs, there is a flow of frothy faliva from the mouth, the fight and appetite are impaired or entirely loft; they are fnappith, and difpofed to bite, but their bite does not produce hydrophobia. The wolf is affected in the fame manner; he leaves his wonted concealments in the woods, and runs wildly among the flocks, biting, and deftroying them, but without producing hydrophobia,

The impoffibility of afcertaining the true caufes of this fingular difease, has given rife to feveral vague conjectures on the fubject; as that of Le Fontaine, who attributes it to a corruption of the fat.

It is fomewhat remarkable, that Plica takes place only among the lower class of people; whence fome have conceived, that it is to be confidered merely as a confequence of uncleanlinefs.

But, in objection to this opinion, it may be urged, that it is unknown in the adjoining countries fubject to the Pruffian Govern. ment, where the peasants are habituated to the fame cuftoms and mode of life, or nearly the fame, as in Poland-that its appearance affords evident relief to the fyftem, and its retroceffion is productive of dangerous confequences. The idea that it is a real and idiophatic difeafe,

is confirmed alfo by its occurrence in a variety of animals, and by the circumftance of its being confined to particular parts of the head; for which no reason can be affigned on the former fuppofition.

A peculiarity of climate cannot be adduced as a cause of this disease. Poland differs little in this respect from the adjoining countries. The fummer heat is confiderable, the thermometer rifing frequently to 98°. 100°. 104°. and the cold in winter fo great, that it falls fometimes 10, 15 degrees below o. But though the changes in the atmofphere are so remarkable, at different periods of the year, they take place with the utmost regularity, the temperature paffing, by infenfible degrees, from one extreme to the other.

The Poles themselves are a vigorous, hardy race; inured from infancy to labour, and to expofure to the viciffitudes of the atmofphere; almoft regardless of cold, they frequently fleep in the open air. Their diet confifts chiefly of animal food, and they are much addicted to the ufe of fpirits. They have an equal fondness for other ftrong ftimulating liquids. I have feen them drink, with the greatest pleafure, the falt brine in which herrings have been preserved, and even nitrous acid diluted with

water.

Since no other cause can be affigned for this difeafe, it is probable, that it arifes, according to the general opinion, from contagion; a contagion which, like that of Pfora, can be communicated by contact only: but this I have not been able to afcertain by any obfervations of my own. It is faid, however, by authors

of reputation, that Plica is frequent in Tartary; and that it was brought into Poland in the 13th century by the Tartars, who at that period made frequent irruptions into the eaftern parts of Europe.

A perfect confidence in the liberality and candour of a fociety, the exertions of which have added confiderably to the treafure of ícience, encourages me to fubmit to it these few crude and curfory remarks; trufting that the moft trivial contribution to the general ftock, will not be deemed unworthy its attention. At fome future period I hope to have opportunity and leisure to renew my obfervations on the fubject; and I fhall endeavour to fupply the deficiencies of the prefent iketch, by tranfmitting to the fociety the refult of my future remarks.

On the Power of the fixed Alkaline Salts to Preferve the Flesh of Animals from Putrefactions, by the Rev. High Hamilton. From the Tranfactions of the Royal Irish Academy.

I CAME to the knowledge of the above mentioned power of alkaline falts, I may fay, accidentally; I had a with to procure fome kind of alkaline liquor that might be fafely taken for the purpose of correcting acidities in the ftomach. I knew that a folution of falt of tartar was exceedingly offenfive to the tafte; and that, if it was of ftrength fufficient to neuiralize any quantity of acid in the ftomach, it could not be fwallowed without danger to the paifages; from its caufticity. It occurred to me, that its caufticity might proba

bly arife from its having a ftrong affinity to fomething or other, to get at which it burned or destroyed the texture of the fleth. If this fhould be the cafe, it was natural to fuppofe, that this falt, if intimately mixed with fleth, would faturate itfelf with whatever it was that it had fuch a ftrong appetite for; and, being fo faturated, it would act no farther on our flesh, and might, without danger, be taken inwardly. To try this, I first inclofed fome bits of lean raw mutton in a vial, with a ftrong folution of falt of tartar: but, after ftanding feveral days, no fuch alteration as I expected appeared in the liquor. I was willing to account for this, by fuppofing the falt had a greater affinity to the water than to any thing in the flesh; I therefore cut fome flesh from the breast of a turkey, roafted the day before, and made it as dry as I could; this I pounded in a mortar, adding, by degrees, fome dry and finely powdered fait of tartar, until I thought there was enough, for I had no rule to judge by. The mixture grew moift; and, when it was fufficiently pounded, I fpread it into a thin cake on an earthen dish, and fet it before the fire, where it foon became dry, I found it had then a faponaceous mild tafte, for, the tate of the falt was fcarcely perceptible. Having macerated this flefh in warm water, and poured off the clear liquor, I found it etwhich fervefeed with vinegar, fhewed that the falt was not so far neutralized but that it would unite itfelf with an acid, fo that I confidered it as a mild alkaline liquor, fuch as I fought for. However, that I might have an opinion from

a perfo

a perfon of skill on the fubject, I wrote to my late worthy and ingenious friend Dr. M'Bride, and acquainted him with the preparation I had made, and the intention of it. In his anfwer, he was pleafed to fay he approved of the idea, and would make fome of the liquor I defcribed, and let me know what he thought of it. He afterwards wrote to me, and faid he had tried the alkaline liquor, and thought it might prove an ufeful medicine, particularly as it might be mixed with milk and given to children, who have often acids in their ftomachs. He alfo mentioned a phyfician, then in Dublin, to whom he had recommended the liquor, and who had found great benefit from it. I firit made this liquor in the year 1771; and, in the year 1777, being then at Bath, I met with an account of fome experiments made by Mr. Bewly, an ingenious chemift, which plainly proved that fixed air is an acid, and faturates alkaline falts; this at once informed me what it was, in the flesh of an animal, that alkaline falts had fuch a ftrong affinity to. At the fame time I got from London one of Dr. Nooth's glafs machines, for impregnating water with fixed air, and to the water I added falt of tartar; after this, I thought no more of my alkaline broth, having got a way of obtaining what I wanted in a much more elegant

manner.

The only thing now worth attention in the experiment I have related is, that it difcovered a power in even cauftic alkaline falts to preferve ficth, I may fay, incorruptible; though it has been gene

rally imagined that fuch falts would confume it. I have fome fleth prepared with these faits in the year 1772; for finding fome bits made the year before had continued unaltered, I made fome more, and laid it by, to fee how long it would keep, and what alterations it would undergo. I made it into a cake, and, when quite dry, I cut it into round bits, about the fize of half a crown, and put them into a drawer in my deik: I fhewed fome of them to Mr. Kirwan the fummer before laft, when I had the honour of receiving. a vifit from him at Armagh; and a few months ago I found fome pieces in another drawer, where they have lain near two and twenty years, and remain unaltered. When thefe pieces are broken they hang together by fibres, and look like a piece of plafter taken from a wall; the fibrous or ftringy parts of the fleth do not feem to have been corroded or diffolved by the falt.

After I knew that fixed air was an acid, and faturated alkaline falis, I began to form conjectures about the means by which thefe falts had fo entirely prevented putrefaction in the fleth to which they were united.

Animal fubftances afford much volatile alkali, and now they are known to contain alio a volatile acid gas. While these two volatile principles continue united with each other, they may prevent any material change from taking place in the fubitance; but, if one of them by any means efcapes, the other will follow; the ao d feems to be the moft volatile, and efcapes firft, though we may not be fenfible of its efcape, becaufe it has no fuch strong imell as Dda

the

the alkali has. The letting loofe thefe volatile principles feems to be the beginning of putrefaction. If this be the cafe we may fee the reason why fleth, when growing putrid, is restored to fweetness by fixed air; that acid replacing what has efcaped, and retaining the volatile alkali. It is It is probably on this account, that the aerial acid is found to be of use in ftopping the progrefs of fome putrid diforders; it seems to act as a fort of pickle. If vinegar preferve flesh by keeping its volatile alkali united with this acid, which is not volatile, we may expect a fixed alkali will have a like effect in preferving flesh, by expelling the weaker volatile alkali, and uniting itself to the volatile acid, which will therefore be attained. This I found to be really the cafe; for, while the flesh and alkali were combining in the mortar, a very strong fmell arofe, like that of fal volatile; and, at one time that I used a brafs or metal mortar, I perceived its edges to be tinged with blue, which fhewed that the metal had been affected by the volatile alkali.

There feems to be a good reafon why fixed alkaline falts fhould preferve fleth much longer than any fluid acid, fuch as vinegar can do; for when the alkaline falt combines with the Beth it expels what is volatile, the mafs grows haid, and it is eafily reduced to a state of drynefs, in which no fort of fermentation, or any intettine motion can take place, and therefore there is nothing that can effect a change in

this compound fubftance. Whereas, when an animal or ve getable fubftance is immerfed in vinegar, a very heterogeneous mixture is formed, which, in

length of time, will be apt to rub into a fort of fermentation, with an inteftine motion among the minute particles; this will bring on fome change in the texture of the fubftance, and every fermentation, when long continued, ends in putrefaction, which, indeed, is faid to be the laft ftage of fermentation.

Whether the conjectures I have offered on this subject be well or ill founded is but of little confequence; the facts I have mentioned may be relied on.

Obfervations on the Nature of Honey, particularly on its faccharine Parts when obtained in a folid Form. By Mr. Lowitz, of the Oeconomical Society at St. Petersburg.

I. A fubftance fo remarkable and fo ufeful as honey, ought to have been long fince accurately analyzed by the chemifts. Its faccharine tafte has always led them to fuppofe that it contained a large quantity of fugar; but the great question was, how to fepa rate the faccharine part from the mucilaginous, and other heterogeneous parts. This feparation was the principal object of my enquiry, in the experiments which I am going to give fome account.

II. The property poffeffed by charcoal, of decompofing and abforbing the mucilaginous and phlogiftic parts of various fubftances, (a difcovery which I formerly made, and of which I then gave an account,) induced me to hope that I could, by its means, obtain the object I had in view. I did indeed fucceed in depriving honey, which had previously been diffolved in a fufficient quantity of water, of that

fmell which is peculiar to it, and alfo of its tafte and colour; but, when I evaporated the solution, by a very gentle fire, it foon acquired its former brown colour, and did not fhew any difpofition to produce regular cryftals. I therefore thought it reasonable to conclude, that this property, of recovering its original colour, either was natural to the whole fubftance of honey, or belonged exclufively to one of those conftituent parts of it upon which charcoal had no power; for when a folution of common fugar is thickened by boiling, even though it is made to boil violently, it does not contract any colour until all the aqueous parts are evaporated.

III. The honey which had been treated with charcoal, and thickened by evaporation, in the manner already defcribed, was obferved, two months after, to have a great number of finall white lumps in it, which had the appearance of crystals; and, foon after, the whole mafs feemed to be full of them. To diftinguish accurately the nature of these small lumps, it was neceffary to separate them from the reft of the mafs, which was entirely coagulated, very thick and glutinous. This operation I performed tolerably well, by wash ing the mafs with alkalized spirit of wine, without heat. I foon per ceived that the fpirit diffolved the glutinous part completely, merely by fhaking the mixture; but that fluid did not feem to have any effect upon the white granulated part; fo that I fucceeded in obtaining this laft quite pure. After having feparated this faccharine granulated part from the liquor, by means of a filter, I dried it by a

gentle heat, and reduced it into powder: this powder did not attract moisture, and had a very agreeable sweet taste.

IV. As the granulated confiftence of white honey feems to arife from the coagulation of its faccharine parts, I endeavoured to feparate that part by means of the pureft fpirit of wine, and which contained the fmalleft poffible quantity of water. From twelve ounces of this fort of honey, I procured three ounces of faccharine matter. This matter ftill contained fome heterogeneous fubftances, which appear not to be foluble in fpirit of wine. To diffolve the faccharine part, I again had recourse to the pureft fpirit of wine I could procure; which I made ufe of by putting the mixture into a glafs matrafs, and boiling it therein for fome time. By thefe means the faccharine part was entirely diffolved; while the infoluble part remained behind upon the filter, having the appearance of a greyish dirty flime. I had filtered the mixture while it was hot; after which I had poured the clear liquor into another matrafs, in which I let it ftand quiet for fome days. After that time the fugar of the honey began to fix itfelt to the bottom of the veffel, in the form of little fpherical knobs, ranged in lines by the fide of each other; thefe, increafing in number every day, formed at laft a folid cruft, which was as white as (now, rather rough at the top, and which after being feparated from the liquor above it, was fo firm as to bear cutting with a knife into very thin flices. The remaining liquor, having been left quiet for fome days, let fall, in that inter