« 이전계속 »
a person of skill on the subject, I rally imagined that such salts w ste to my late worthy and inge- would consume it.
I have some nious friend Dr. M‘Pride, ad ac- flesh prepared with these salts in quainted him with the preparation the year 1772; for finding some I had male, and the inteniion of bits made the year before had con. it. in his answer, he was pleased tinu.d unaltered, I made some to say hi approved of the idea, and more, and laid it by, to see how wou'd make some of the liquor I long it would keep, and what al. descriosd, and let me know what terations it would undergo. I he thought of it. He afterwards made it into a cake, and, when wr te to me, and said he had quite dry, I cut it into round tried the alkaline liquor, and bits, about the size of half-a.crown, thought it might prove an useful and put them into a drawer in my medicine, particularly as it might desk : I shewed some of them to be mixed with milk and given to Mr. Kirwan the summer before last, children, who have often acids in when I had the honour of receiving their stomachs. He also mentioned a visit from him at Armagh; and a physician, then in Dublin, to a few months ago I found some whom he had recommended the li. pieces in another drawer, where quor, and who had found great be. they have lain near two and twenty nefit from it. I first made this .years, and remain unaltered. When liquor in the year 1771; and, in these pieces are broken, they hang the year 1777, being then in Bath, together by fibres, and look like a I met with an account of some ex. piece of plaster taken from a wall; periments made by Mr. Bewly, an the fibrous or stringy parts of the ingenious chemist, which plainly flesh do not seem to have been cor. proved that fixed air is an acid, roded or dissolved by the salt. and saturates alkaline salts; this at After I knew that fixed air was once informed me what it was, in an acid, and saturated alkaline the flesh of an animal, that al. salts, I began to form conjectures kaline salts had such a strong about the means by which these affinity to
At the same time salts had so entirely prevented pu. I got from London one of Dr. trefaction in the Aesh to which they Nooth's glass machines, for im. were united. Animal substances pregnating water with fixed air, afford much volatile alkali, and and to the water I added salt of now they are known to contain tartar; after this, I thought no also a volatile acid gas. While these, more of my alkaline broth, having two volatile principles continue got a way of obtaining what I united with each other, they may wanted in a much more elegant prevent any material change from manner.
taking place in the substance ; The only thing now worth but, if one of them by any means attention in the experiment I have escapes, the other will follow; the related, is, that it discovered a acid seems to be the most volatile, power in even caustic alkaline salts and escapes first, though we may to preserve Aesh, I may say, incore not be sensible of its escape, bé. ruprible; though it has been gene. cause it has no such strong smell as
the aikali has. The letting loose length of time, will be apt to run these volatile principles seems to into a sort of fermentation, with be ihe beginning of putrefac- an intestine motion among the mi. tion. If this be the case, we may nute particles; this will bring on see the reason why flesh, when some change in the texture of the growing patrid, is restored to substance, and every fermentation, sweetness by fixed air; that acid when long continued, ends in pu. replacing what has escaped, and trefaction, which, indeed, is said se aining the volatile alkali. It is to be the last stage of fermentation. probably on this account, that the Whether the conjectures I have aeriai acid is found io be of use in offered on this subject be well or ill stopping the progress of some putrid founded is but of little consequence; disorders; it seems to act as a sort the facts I have mentioned may be of pickle. If vinegar preserve flesh
relied on. by keeping its volatile alkali united with this acid, which is volatile, we may expect a fixed Observations on the Nature of H-ner, alkali will have a like effect in pre. particularly on its sacı harine Parts serving flesh, by expelling the when obtained in a silid Form. By weaker volarile alkali, and uniting Mr. Lowitz, of the Oeconomical itself to the volatile acid, which Society at St. Petersburg, will therefore be atrained. This I found to be really the case ; for, 1. A substance so remarkable while the flesh and aikali were com- and so useful as honey, ought to bining in the mortar, a very strong
have been long since accurately smell arose, like that of sal volatile; analyzed by the chemists. Its and, at one time that I used a brass , saccharine taste has always led or metal mortar, I perceived its them to suppose that it contained a edges to be tinged with blue, which large quantity of sugar; but the shewed that the metal had been great question was, how to sepa. affected by the volatile alkali. rate the saccharine part from the
There seems to be a good reason mucilaginous, and other heteroge. why fixed alkaline salts should pre. neous parts. This separation was serve flesh much longer than any , the principal object of my inquiry, fuid acid, such as vinegar can do ; in the experiments of which I am for when the alkaline salt com- going to give some account. bines with the flesh, it expels what II. The property possessed by is volatile, the mass grows hard, charcoal, of decomposing and ab. and it is easily reduced to a state of sorbing the mucilaginous and phlo. dryness, in which no sort of fer. gistic parts of various substances, mntation, or any intestine motion (a discovery which I formerly made,
iake place, and therefore there and of which I then gave an ac. is nothing that can effect a change count), induced me to hope that I ia this compound
substance. could, by its means, obtain the ob. Vinnareas, when an animal or vege. ject I had in view. I did indeed table substance is immersed in succeed in depriving honey, which vinega', 'a very heterogeneous had previously been dissolved in a mixture is formed, which, in sufficient quantity of water, of that
smell which is peculiar to it, and gentle heat, and reduced it into also of its taste and colour ; but, powder ; this powder did not at. when I evaporated the solution, by tract moisture, and had a very a very gentle fire, it soon acquired agreeabie sweet taste. its former brown colour, and did IV. As the granulated consiste not she'w any disposition to pro. ence of white honey seems to arise duce regular crystais. I therefore from the coagulation of its sac. thought it reasonable to conclude, charine parts, I endeavoured to se. that this property of recovering parate that part by means of the its original colour, either was na purest spirit of wine, and which sural to the whole substance of contained the smallest possible hongs or belonged exclusively to quantity of water. Fron twelve one of those constituent parts of it ounces of this sort of honey, I pro. upon which charcoal had no power ; 'cured three ounces of saccharine for when a solution of common matter. This matter still contained sugar is thickened by boiling, even hererogeneous substances, though it is made to boil violently, which appear not to be soluble in it does not contract any colour un. spirit of wine, To dissolve the sac. til all the aqueous parts are evapo. charine part, I again had recourse rated.
to the purest spirit of wine I could III. The honey which had been procure; which I made use of by treated with charcoal, and thick. purring the mixture into a glass ened by evaporation, in the man. matrass, and boiling it therein for ner already described, was observ. some time. By these means the ed, two months after, to have a saccharine part was entirely dis. great number of small white luinps solved; while the insoluble part in it, which had the appearance of remained behind upon the filter, crystals; and, soon after, the whole having the appearance of a greyish. mass seemed to be full of them. dirty slime. I had filtered the To distinguish accurately the na. mixture while it was hot ; after ture of these small lumps, it was which I had poured the clear li. necessary to separate them from the quor into another matrass, rest of the mass, which was which I let it stand quiet for some tirely coagulated, very thick and days. After that time the sugar glutinous. This operation I per- ' of the honey began to fix itself to formed tolerably well, by wash. the bottom of the vessel, in the ing the mass with alkalized spirit of form of little spherical knobs, wine, without heat. I soon per- ranged in lines by the side of each ceived that the spirit dissolved the other ; these, increasing in num. glutinous part completely, merely ber every day, formed at last a solid by shaking the mixture ; but that crust, which was as white as snow, fluid did not seem to have any ef. rather rough at the top, and which fect upon the white granulated after being separated from the li. part; so that I succeeded in obtain. quor above it, was so firm as to ing this last quite pure. After bear cutting with a knife into having separated this saccharine very thin slices. The remaining granulated part from the liquor, by liquor, having been left quiet for means of a filter, I dried it by a some days, let fall, in that inter.
val, a fresh portion of this saccha. honey, while it was upon the fire, sine matter, which was exally simi. produced a very strong effries. lar to thar already spoken ot. cence, and the mixtise immedi.
V. L'avirg thu pre vided mysef ately became of a dark brown with a certain quantity of this colour, almost back. By conuni. kind of sugar, I trid various me. ing to add quick lim ütil the theds 10 make it take a regular effervescence ceased, to Sagor of crystallized form; but in that re- honey was erite. becomind; spect, all sny trials were in vain, the mixture tui vit quiie b.. k; Whether I used the purest “pirit of and emissed a smil which wis wine, or waier, to dissolve this very disagre able, and even subsiance, the result was the same. I remurker, indeed, that the so- 3. Thed rk coloured so'itio.coi. lution of it in water, wbich had tains a large quantity of 'ine, whih been thickened to the con istence cannot be precipitated by mans of of syrup deposited, afrer some time, aerated alkali, nor by an aikali ren. small knobs on the sides of the ves. dered perfectly c:ustic. Sol, which had the form of cauli. 4. If vitriviic acid is made use flowers ; the whole solution afier- of io precipitare this lime, it then wards coagulated, and appeared a pears in the form of gypsum; like a solid, dry, white mass, full but the remainder ot' he liquor still of small cavities, which, when ex. contains a very empyreumatic acid, amined with a microscope, seemed which seems to hive a strong to be composed of very small lng analogy with the malic acid of crystals, extremely thin, and hardly Scheele. visible to the naked eye.
5. If the acid of sugar of honey is VI. Though this manner of crys- treated with nitrous acid, it is con. talysing sufficiently distinguishes verted into acid of sugar. the saccharine part of honey from 6. A much more pure acid may common sugar, I suspected, at first, be obtained by making use of a that this difference proceeded only double affinity. For this purpose, from the presence of some herero. it is only necessary to boil together geneous parts, from which ihe cqual parts of honey and quick honey was not sufficiently cleared ; lime, in a great quantity of water, but the following experinnents evi. adding to this solution, which is dently shewed, that these two sub. of a brownish colour, as much stances differ from each other by charcoal powder as may be reoui. properties which are very strongly site to take away the colour en marked.
tirely. The solution must then be 1. If a certain quantity of lime. filtered, and to the clear liquor water is added to a watery solution must be added, a very saturated so of the sugar of honey, it instantly lution of lead in distilled vinegar, acquires a brown colour, though' until all precipitation has ceased. it was before quite limpid and The precipitate obtained by these colourless.
means must be washed in such a 2. Quick lime, which I added quantity of water as will edulcorate to the watery solution of sugar of it thoroughly, after which, as
ach diluted vitriolic acid must be may be distinguished from the su. ded as may be sficient to sepa- gar of honey, by the following prote the acid of the honey from ihe perty, viz. that it cannot be re. ad: this acid may then be con- duced into a dry or solid form. It intrated by evaporation.
is owing to this particular part that 7. If the solution of honey and the solution of honey so readily conuick lime is thickoned by evapo.
tracts a brown colour ; for a solu. ition, after its brown colour is tion of sugar of honey, deprived of aken away by charcoal, a trans- this glutinous part, may be thick. arent mass of a light yellow co. ened upon the fire without suff-r. pur,
is produced, which resem. ing any alteration of colour. In les gum' arabic; it has a bitter other respects, the yellow gluti. aste, and does not grow most by nous part of honey, here spoken of, being exposed to the air.
shews nearly the same properties as 8. The clear mass which is the sugar of honey ; and when produced from a mixture of the treated with caustic alkalies, or acid of honey and line is perfectly with quick lime, its taste is also insoluble in spirit of wine ; and it
the same. may be precipitated from its solu. VIII. The properties which I I tion in water by this spirit.
have above described, are those by 9. Caustic fixed alkalies produce which the sugar of honey differs upon honey, and upon the sugar essentially from
essentially from common sugar. which is procured from it, the If this last is treated like honey, same effect as lime. Honey, as it exhibits the following results. well as its sugar, is entirely decom- 1. Neither quick lime nor fixed posed by them; and always with a alkalies produce any decomposition very violent effervescence. The in sugars ; no effervescence is obdark coloured extractive mass which served, nor does the solution shew is obtained by these means is com.
any change of colour. pletely insoluble in spirit of wine ;
2. Whatever quantity of sugar and, when the quantities of the is added to fixed alkalies, they al. two substances are exactly propor- ways preserve their causticity; and, tioned, very little taste can be per
even if they are boiled with sugar ceived in the mass; that liitle is
for a considerable time, they never means alkaline, and can appear to be united with its acid. hardly be called saline. This proves As quick lime, when combined that alkalies, as well as quick lime, with sugar, is attended with some may be perfectly saturated by the phænomena which appear not to acid contained in honey.
have been taken notice of by any. 10. Volatile alkali also decom. person, I shall here mention them. poses honey in the same manner, By boiling together equal parts of and with the same circumstances, sugar and quick lime, in a suffici. as other alkalies ; but this decoma ent quantity of water, a solution is position takes place much more obtained, which, by the surpris. slowly, and only when heat is at ing quantity of lime it contains, the same time made use of.
may be considered as highly satu. VII. That constituent part of rated lime-water, in which the honey which is got from it by treat. taste of the sugar is not to be pering it with the spirit of wine (10.) ceived.