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of the real fermenting matter, as five mon life, that, if we did not know the
of the distiller : yet In justice, therefore, to this
corresponds with that given by our
ever, is disengaged, in very great medicine which it affords; but it serves abundance, in the process of fermenta- for a number of other beneficial purțion, and it is, no doubt, from having poses in the countries where it grows. observed this circumstance, that the In the East Indies, aloes are employabove assertion is made regarding the ed as a varnish to preserve wood from formation of yeast. But, granting worms and other insects; and skins that yeast were chiefy composed of and even living animals are anointed carbonic acid, what proof is there that with it for the same reason. The hait must be deprived of that chief in voc committed by the white ants in gredient, by the moderate degree of India first suggested the trial of aloe heat to which it may be exposed in juice, to protect wood from them; for the operations of evaporation and con which purpose the juice is either used centration? For example, the carbonate as extracted, or in solution by some of lime is a substance almost entirely solvent. Aloes have also been found composed of the carbonic acid, yet it effectual in preserving ships from the requires a temperature equal to red ravages of the worm, and the adhesion heat, to disengage the aerial Aud; of barnacles. The ship's bottom, for and, in common pit coal, hydrogen this purpose, is smeared with a comgas is a principal constituent, and is position of hepatic aloes, turpentine, much more volatile than carbonic acid; tallow, and white lead. In proof of yet the coat must be burnt, or other- the efficacy of this method, two planks wise exposed to a very high tempera- of equal thickness, and cut from the ture, in order to expel the hydrogen same tree, were placed under water, gas.
one in its natural state and the other These anticipations, therefore, re smeared with the composition; when, garding the inferiority of yeast pow on taking them up after being immerder, are obviously entirely groundless. sed eight months, the latter was found Let the distillers, then, in the first in- to be as perfect as at first, while the stance, only bestow some little atten- former was entirely penetrated by intion, in order to acquaint themselves sects, and in a state of absolute rottenwith the most proper manner of ap ness. An aquatic solution of hepatic plying this succedaneum, and they will aloes preserves young plants from der find a sufficient recompence in having struction by insects, and also dead atheir liquors regularly fermented, and nimals and vegetables from putrefacproperly attenuated, effects so much tion ; which genders it of great use in wished to be obtained by every intelli- the cabinets of naturalists. The spigent distiller. When once they have situous extract is best for the purpose, resolved to be at this little trouble, though in this respect it is inferior to their purpose is half effected, and that of cantharides, prepared by infuthereafter they will neither feel the sing two grains in one ounce of spirits, want, nor suffer the loss, which at pre- which has been found to be so effecsent are so often occasioned by a scar tual in the extirpation of bugs. Pærcity of liquid yeast.
ner asserts, that a simple decoction of aloes communicates a fine brown colour to wool. Fabroni, of Florence,
has extracted a beautiful violet colour, Memoirs of the Progress of MANU- which resists the acids and alkalis, from
FACTURES, CHEMISTRY, SCIENCE, the juice of the fresh leaves of the a. and the FINE ARTS.
loe exposed to the air by degrees.
The liquid first becomes red, and at FEW persons in this country know the end of a certain period turns to a
any other use of the aloe than the beautiful purple violet, which adheres April 1809.
to silk by simple immersion, without in order to divide the particles, may the aid of acids.
be purified of its oily particles, and deRichard Walker, Esq. of Oxford, prived of its empyreumatic smell, has proposed an alteration in the scale when sublimed with a small quantiof the thermometer, which suggested ty of potash. The process by which itself to him during a long course of this effect is produced, is described experiments, and which has been a as follows: Two drachms of camdopted by himself and his friends from phor, with considerable empyreumathe persuasion of its being founded on tic smell, and dirty, were mixed with the truest principles.-" The two fixed one of olive oil, and eight of sand; afpoints, the freezing and boiling points ter which twenty grains of pure potof water as they have hitherto been, ash were added and heat applied ; but will (he observes) probably never fail though it was grcater than is necessato be continued, as being perfectly ry for its sublimation, the product was sufficient for the accurate adjustment perfectly free from empyruematic of thermometers. The commence- smell, and a little whiter than it genement of the scale, and the number of rally is. The substitution of linseed oil divisions, only appear to claim atten- produced no alteration in the product, tion. With respect to the first, since The subcarbonate does not answer the neither the extremes of heat or cold purpose, because in that state the afare likely to be ascertained, the hope finity of potash for oils is less than of fixing 0 at either of these may be when entirely deprived of carbonic ą. entirely relinquished, and it renains cid. to fix it at the fittest intermediate point. Here I propose the following mode of graduation : Having ascer. tained that the temperature of 62° of Original Letter from SWIFT to Dr Fahrenheit is the temperature at which
JENNY, at his house in ARMAGH*. the human body in health is conscious From Barrett's Essay on the earlier part of of no inconvenience from heat or cold,
the Life of Swift. and that a deviation from that point
Dublin, June 8. 1732, of only one or two degrees, above or
SIR, below, actually produces that effect under ordinary circumstances, I fixed
IT is true, that some weeks ago a
manuscript paper of verses my zero or Othere. I adopted the handed about this town, and afterdivisions of Fahrenheit, 'considering wards printed. The subject was my those of Reaumur, the centigrades, &c.
great as too few, and decimal divisions unnecessary. Hence it will follow that O being placed at 62° of Fahrenheit,
* Where Dr Jenny, it is believed, 150° will be the boiling, and minus was Rector. He resided in the neigh, 30°, the freezing point of water, and bourhood of Sir Arthur Acheson, and is
introduced into Swift's poem on Hamil. all other points on Fahrenheit's scale tun's Bawn. See Swift's Works, 1808, may be reduced to this, by subtract- vol. xvii. p. go. This perfectly characing 62 for any degree above 0 of Fah- teristic Letter, which has been among renheit, and adding 62 for any de- the desiderata of ail former editions, is gree below 0. For ordinary meteoro
now first printed by the favour of Lord logical purposes, a scale of this kind Viscount Cremorne, in whose family it extending to 65° above, and as many been, many years ago, noticed by Dr
has been preserved. The letter bad below 0, will be sufficient."
Thomas Campbell, an Irish clergyman, It has been found that camphor in his Philosophical Survey of the South mixed with different fixed oils and sand, of Ireland." N.
great ingratitude and breach of hos- persons and proceedings. As to Iren
but they were that among at least two thousand pa
such who knew
little of you or pers, full of groundless reflections me; for others, who were better acagainst me, hundreds of which I have quainted with us both, have always seen, and heard of more, I ever saw cleared you, because they did not any one production that the meanest look upon that paper any way equal writer could have cause to be proud to your known good sense and canof; for which I can assign a very na- dour, or talent of writing. And as tural reason; that during the whole to myself, I had further conviction, busy time of my life, the men of wit because I knew how well you were (in England) were all my particular acquainted with the whole history and friends, although many of them dif- occasion of writing those verses on the fered from me in opinions of public Barrack; how well pleased the mas
ter and lady of the family were with it;
that you had read it more than once; + These verses were written in 1729. that it was no secret to any neighbour, See them in vol. xvii. p. 85. See also, nor any reserve but that against giving in vol. xvi. p. 444, the Dean's Poem in 1928,“ On cutting down the old Thorn dents that reserve was broken by grant
a copy. You know well by what inci. at Market. hill." N.
# At Gaulstown, in the county of ing a copy to a great person, and from Westmeath, in the year 1727. See vol. thence how it fell into other hands, xvi, pp. 251-2, 182. N.
and so çame (as it is the constant case
his own way
to be published, and is now forgot. I that the whole dozen should be pubconfess my own conjectures about this lished if I would not let him alone. late libel against me lay towards ano This was a little hard upon me, who ther gentleman, who, I am informed, had never one single moment in my hath since cleared himself, I mean Dr life the least inclination to enter the Tisdall* ; but that suspicion was first lists with him, at those or any other taught me by others; and yet I weapons whatsoever, any more than I know very well, that for at least fif. would venture to sit four hours. disputeen years past, he hath been often en- ting with him any point of controversy. gaged in a kind of firting war of sa- I confess, this keenness of the Doctor tiric burlesque verse with certain wags in determining, whenever he was atboth in town and country, who, it tacked, to fix on me for his adversary, seems, were provoked with his faculty inclined me to conceive that he might of jibing, and used to answer him in have probably writ this last paper, and
Yet I have been as other people had the same thought; sured, that in these coinbats he was but I hear he hath utterly denied it; generally mistaken in his adversaries, and I believe him ; for I am confident falling foul upon many persons who he is an honest man, but unhappily never dipt a pen either for or against misled through the whole course of him; and I think you, among others, his life, by mistaking his talent, which had some marks of his favour. But, he hath, against nature, applied to wit, as to me, who, I solemnly profess, was and raillery, and rhyming : besides always entirely innocent, during the which, his incurable absence of mind, whole time that his pen and tongue on all occasions, and in all companies, took this unhappy turn, as well as be- hath led him into ten thousand errors, fore and since, I could never be one especially of that kind, which are mormonth at peace for his wit ; what- tal to all agreeable or improving conever was writ to ridicule him was laid versation, and which hath put him at my door, and only by himself; upon such a foot with every friend, with a further declaration, much to that I heartily lament the situation he my honour, that he knew my stile, is in. would trouble himself to inquire no I intreat your pardon for the length farther; and, using my surname, said, and insignificancy of this letter, but I was his man. Some of his perform- my solitary way of life is apt to make ances I have seen, and have heard of me talkative upon paper. I desire more, besides the great number he you would believe, first, that I have kept in petto; so that five or six gentle- so frequently been libelled, that my men have often and very lately assured curiosity to know the authors is quite me, that in one evening sitting he has extinct, though that of some friends is produced a dozen of his libels wholly not; secondly, that I am not hasty in against me ; desiring I might be told judging men's stile, or matter, or maof it, and assuring those gentlemen lice. I can venture to say, that a
thing is not written by such a person,
because it is much below his good * To this gentleman Dr Swift addres. sense; and to look among the herd of sed a letter, April 20. 1704, on the sub- dunces is endless. As to yourself, I ject of his addresses to Mrs Johnson ; hope you will be my witness, that I assuring him very candidly, that he had have always treated you with particuhimself never seen any other, lady lar distinction ; and if we differ in opiwhose conversation he entirely
valued ; nions relating to public proceedings, it and freely giving consent to her mar. rying" Dr Tisdall. See vol. x. pp. 33,
is for very good reasons : you are an 41. N.
expectant from the world and from