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thofe difeafes of the Tuba Euftachiana in which this method can be of moft fervice: fome other objections, too, may be made, both to his quotations and cafes.
Art. 36. Tentamen Chemicum de calcis vive actione in falem volatilem alcalinum. Auctore Johanne Alberto Schloffer, Ultrajectino, M. D.
Dr. Schloffer obferves, that there is no difference in volatile alcaline falts; but by the admixture of quick-lime, great part of their qualities are deftroyed; and therefore it is neceflary to diftinguith a falt thus prepared, by a different name, Boerhaave calls it an igneous fpirit, from a kind of igneous property he imagined was communicated to it from the quick-lime; and this name our Author has adopted.
Hoffman, Boerhaave, Pott, Duhamel, Macquer, Malouin, Alfton, and Whytt, have made a great variety of experiments on quick-lime, from a careful comparison of which, particularly thofe of Boerhaave and Pott, the Doctor is perfuaded, That quick-lime is a true fimple alcaline earth, brought to its utmofk purity by the force of fire; that the falts extracted from quick-lime do not properly belong to its original compofition, but are derived from various acids, attracted from the atmosphere, and united with quick-lime, as a real alcaline earth; and therefore, that the pureft and ftrongeft quicklime water, is a fimple and well faturated folution of this alcaline earth.. Adding, that if fome of the above authors had read Pott, their experiments would have probably been conducted in a different manner.
In order to discover the nature and properties of the igneous fpirit, our Author took a drachm of very pure volatile, alcaline falt, extracted from fal amoniac, by a fixed alcali, which he diffolved in a little diftilled rain-water. Into this folution he poured twelve ounces of ftrong quick-lime water filtrated; the mixture immediately became opaque and milky, and white flocculi precipitated to the bottom and fides of the veffel. As thefe flocculi precipitated, the milkinefs difappeared, and the liquor recovered its tranfparency. The fame quantity of lime-water was again added, and the fame phænomena followed. In this manner the addition was repeated, till fifty-four ounces of lime-water was poured into the volatile alcaline folution; the fame phenomena fucceeding each affufion of the lime water, but in a lefs degree, fo that the Taft affufion produced hardly any alteration."
On examining the liquor, the flocculi were found adhering fo fast to the bottom and fides of the vefiel, as not to be se
parated by agitating the liquor, fo that our Author was obliged to make ufe of a small ftick. The liquor was then filtrated through paper, by which means it was again rendered tranfparent, and the flocculi remained in the paper cone.
The filtrated liquor retained a small tafte of the lime, but was not the leaft faline. It had a strong smell of an igneous fpirit. Syrup of violets being mixed with it, fcarce indicated any change to green. A very ftrong vitriolic acid mixed with it caufed no effervefcence; nor was there any effect produced by adding a fixed alcaline falt.
The flocculi in the paper cone being thoroughly and carefully dried, were found to have increafed one drachm, fix grains, in weight; but had neither smell nor taste. A drachm of the powder of these flocculi was put into a clean crucible, and the fire gradually increafed till it attained a perfect ignition. It was then fuffered to cool, and on examination it was found to have loft almoft fixteen grains of its weight, and to have acquired an igneous tafte, refembling quick-lime. Some pure diftilled rain water being poured upon a few grains of this calcined falt, was immediately turned into a real quick-lime water, as fufficiently appeared from its tafte and precipitating effect on the addition of fome volatile alcaline falt.
Dr. Schloffer made feveral other experiments, both on the liquor and flocculi, from whence he concludes, that the igneous spirit is produced from the real volatile alcaline falt of the quick-lime.',
Art. 37. Fifty-feven inches of inteftine, which had been forced out at the anus of a boy of 13 years of age, by the fall of a cart upon him, after various attempts to replace and keep them in their natural fituation, were cut off by John Nedham, Surgeon, of North Waltham, in Norfolk. traordinary fact, with the boy's entire recovery, is witneffed by another furgeon.
Art. 38. In this article Dr. Brocklesby confirms fome of Haller's experiments, with regard to the fenfibility and irritability of the feveral parts of animals. He alfo recommends the long continued rubbing in of fallad oil, as a remedy in rheumatisms. Art. 41. A fhort account of fome new Aftronomical and Phyfical Obfervations, made in Afia; and communicated to Matthew Maty, M. D. F. R. S. by his Excellency Mr. Porter, his Majefty's Ambaffador at Conftantinople, and F. R. S.
This Gentleman has determined the latitudes of Aleppo, Mount Caffius, Seleucia in Syria, Antioch, Diarbekir, and
Bagdad; and obferved an occultation of a ftar in Virgo, marked in Bayer's catalogue, by the moon, on June 10, 1755. He is perfuaded, that the vast number of ftars imagined to be feen in Europe, in a clear winter's night, are not, as gene-rally fuppofed, mere fcintillations, but real ftars. He fays, that nitre is produced by a combination of the univerfal acid with the natrum of the antients; that affa fœtida is drawn from a ferulaceous plant of the thapfia kind, very common in Media, &c. that he has had the good fortune to find the Nardus Indica, a gramineous plant, of which fome bear fpicaceous flowers, both male and female, and others only female ones: and that the country is fo dry, that electrical experiments often fucceed, without any stand of bitumen, pitch, filk, glafs, &c.
Art. 42. Some obfervations proving, that the foetus is in part nourished by the liquor amnii. By Malcolm Fleming, M. D.
From hairs being conftantly found in the meconium of ripe calves, Dr. Fleming concludes, that the liquor amnii, which detaches them from the fkin of the calf, contri'butes in part to the alimentary fupport of the foetus. Befides the liquor is concretable by heat, like the white of an egg; a farther proof of its alimentary nature.-As chance led the Doctor to a difcovery of thefe hairs, he has fince found, that Swammerdam, in his Biblia Nature, and Slade, an Amfterdam phyfician, under the feigned name of Aldes, in his Epiftola contra Harveium, had observed the fame phænomenon, but without making any phyfiological applications.
Art. 45. This article is no improper fupplement to one by the fame author (Dr. Brackenridge) in the laft volume of the Tranfactions.From the number of houfes, and quantity of wheat ufed in England, the Doctor concludes, that this kingdom contains rather lefs than fix million of inhabitants; of whom, according to Dr. Halley's rule, fifteen hundred thoufand are capable of bearing arms; but that if properly cultivated, the country could cloath and feed, with the help of fifhing, nine millions, independent of trade, and our American colonies.
Ireland contains only a million, but were it fully cultivated, it might maintain three times that number.
Scotland has a million and an half of inhabitants; but if all its arable acres were cultivated, it might fupport half a million
See Review, Vol. XIII. p. 428.
The whole globe, if fully improved, might maintain twenty-fix times its prefent inhabitants.
The annual increafe of the people of England is computed not to
fufpected 18,000; which, tho' fmall, is not unreasonably
fufpected to be much diminifhed, by the emigrations of great numbers to our American colonies, and other fettlements; and by our wars, and loffes at fea; whence the Doctor pertinently infers, that if it was not for the acceffion of foreigners, and those who come from Scotland and Ireland, the increase would be very inconfiderable, if any at all; which, by the way, fhews the reafonablenefs and good policy of encou→ raging foreigners to fettle among us.'-This is an inge nious paper, and the calculations, as well as data, feem very just.
Art. 48. Informs us, that the exact reprefentation of the fifh, called an Old Wife, in the Weft Indies, was found in the heart of a stone, dug out of a quarry on the fide of a mountain in Antigua, two miles from the fea, and 300 yards higher than high water mark. The ftone was fent over to England, and we have here an engraving of it.
Art. 51. Electrical Experiments, made in purfuance of thofe by Mr. Canton, dated December 3, 1753. With explanations, by Mr. Benjamin Franklin, communicated by Mr. Peter Collinfon, F. R. S.
The ingenious Mr. Franklin has given a series of curious and well adapted experiments, to fupport the three following principles.
1. Electrical atmospheres, that flow round non-electric bodies, being brought near each other, do not readily mix and unite into one atmosphere, but remain feparate, and re⚫ pel each other.
12. An electric atmosphere, not only repels another electric atmosphere, but will alfo repel the electric matter con*tained in the fubftance of a body approaching it; and with out joining or mixing with it, force it to other parts of the body that contained it.
3. Bodies electrified negatively, or deprived of their natural quantity of electricity, repel each other, (or at least appear to do fo, by a mutual receding) as well as thofe electrified pofitively, or which have electric atmospheres.
Art. 52. Extract of a letter concerning Electricity, from Mr. B. Franklin, to Monf. Delibard, inclosed in a letter to Mr. Peter Collinfon, F. R. S.
In this letter Mr. Franklin obferves, that his meaning with regard to the effect of points in drawing the electric matter from the clouds, and thereby fecuring buildings, &c. has been but imperfectly understood. 'I have mentioned it in several
of my letters,' fays he, and except once, always in the "alternative, viz. That pointed rods erected on buildings, ⚫ and communicating with the moift earth, would either pre• vent a stroke, or, if not prevented, would conduct it, so as ⚫ that the building fhould fuffer no damage. Yet whenever my opinion is examined in Europe, nothing is confidered but the probability of thofe rods preventing a ftroke, or explofion; which is only a part of the ufe I propofed from them; and the other part, their conducting a ftroke, which they < may happen not to prevent, feems to be totally forgotten, tho' of equal importance and advantage.'
That pointed rods are of great ufe in conducting the stroke of lightning, appears from an accident which, Mr. Franklin tells us, happened at Newberry, in New England, And alfo from another, which happened at Darking, in Surry, related in article 53.
Art. 57. Extract from a Letter of Thomas Barker, Efq; to the Rev. James Bradly, D. D. Aftronomer royal, and F. R. S. concerning the return of the Comet expected in 1757, or 1758.
This article is illuftrated with a copper-plate, on which a circle, reprefenting the Orbis Magnus, is divided into degrees, and the parabolic path of the Comet delineated; by which means the Comet's place, at any time, may be found. To this Mr. Barker has added a table, fhewing where the Comet may be expected to begin to appear in any month, as the theory of Comets is not yet brought to fuch perfection as to enable us to calculate exactly, the time of the returns of these planetary bodies.
Art. 58. An account of an extraordinary and surprising Agitation of the Waters, tho' without any perceptible motion of the earth, obferved in various parts of this island, both maritime and inland, November 1, 1755, chiefly about the time that the more violent commotions of both earth and waters fo extenfively affected many very diftant parts of the globe. In feveral Letters tranfmitted to the Society.