« AnteriorContinuar »
those diseases of the Tuba Eustachiana in which this method can be of moft service: some other objections, too, may be made, both to his quotations and cases. Art. 36. Tentamen Chemicum de calcis vivæ a&tione in falem vo
latilem alealinum. Auctore Johanne Alberto Schlosser, Ultrajeitino, M. D.
Dr. Schloffer observes, that there is no difference in volatile alcaline falts; but by the admixture of quick-lime, great part of their qualities are destroyed ; and therefore it is necessary to diftinguiih a salt thus prepared, by a different name. Boerhaave calls it an igneous spirit, from a kind of igneous property he imagined was communicated to it from the quick-lime; and this naine our Author has adopted.
Hutiinan, Boerhaave, Pott, Duhamel, Macquer, Malouin, Alfion, and Whytt, have made a great variety of experiments on quick-lime, from a careful comparison of which, particuTarly those of Boerhaave and Pott, the Doctor is persuaded, That quick-lime is a true fimple alcaline earth, brought to its utmost purity by the force of fire; that the salts extracted froin quick-lime do not properly belong to its original composition, but are derived from various acids, attracted from the atmosphere, and united with quick-lime, as a real alcaline earth ; and therefore, that the purélt and strongest quicklime watcr, is a fimple and well faturated folution of this alcaline earth. Adding, that if some of the above authors had read Pott, their experiments would have probably been con. ducted in a different manner.
In order to discover the nature and properties of the igneous spirit, our Author took a drachm of very pure volatile, alcaline lait, extracted from fal amoniac, by a fixed alcali, which he diffolved in a little distilled rain-water, Into this folution lie poured twelve ounces of strong quick-lime water filtrated; the mixture immediately became opaque and milky, and white flocculi precipitated to the bottom and fides of the 'veffel. As thele fiocculi precipitased, the milkiness disappeared, and the liquor recovered its trapparency. The same quantity of lime-water was again added, and the same phænomena followed. In this manner the addition was repeated, till fifty-four ounces of lime-water was poured into the volatile alcaline folution; the same phænomena succeeding each áfusion of the lime-water, but in a less degree, so that the lait affusion produced hardly any alteration,
On examining the liquor, the flocculi were found adhering so fast to the bottom and sides of the vesiel, as not to be reparated by agitating the liquor, so that our Author was obliged to make use of a small stick. The liquor was then filtrated through paper, by which means it was again rendered transparent, and the flocculi remained in the paper cone.
The filtrated liquor retained a small taste of the lime, but was not the least saline. It had a strong smell of an igneous spirit. Syrup of violets being mixed with it, scarce indicated any change to green. A very strong vitriolic acid mixed with it caused no effervescence; nor was there any effect produced by adding a fixed alcaline salt.
The flocculi in the paper cone being thoroughly and carefully dried, were found to have increased 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 increased till it attained a perfect ignition. It was then suffered to cool, and on examination it was found to have lost almost fixteen grains of its weight, and to have acquired an igneous taste, resembling quick-lime. Some pure distilled rain water being poured upon a few grains of this calcined salt, was immediately turned into a real quick-lime water, as sufficiently appeared from its taste and precipitating effect on the addition of some volatile alcaline falt.
Dr. Schloffer made several other experiments, both on the liquor and flocculi, from whence he concludes, that the ig
neous spirit is produced from the real volatile alcaline falt of § the quick-lime,',
Art. 37. Fifty-seven inches of intestine, 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 situation, were cut off by John Nedham, Surgeon, of North Wallham, in Norfolk. traordinary fact, with the boy's entire recovery, is witnessed by another surgeon.
Art. 38. In this article Dr. Brocklesby confirms some of Haller's experiments, with regard to the sensibility and irritability of the several parts of animals.--He also recommends the long continued rubbing in of sallad oil, as a remedy in rheumatisms. Art.
41. A mort account of some new Astronomical and Physical Observations, made in Afia; and communicated to Matthew Maty, M. P. F. R. S. by his Excellency Mr. Porter, his Majesty's Ambassador at Conftantinople, and F. R: 8.
This Gentleman has determined the latitudes of Aleppo, Mount Cassius, Seleucia in Syria, Antioch, Diarbekir, and
Bagdad; and observed an occultation of a star in Virgo, marked w in Bayer's catalogue, by the moon, on June ro, 1755. He is persuaded, that the vast number of stars imagined to be seen in Europe, in a clear winter's night, are not, as gene-. rally supposed, mere scintillations, but real stars. He says, that nitre is produced by a combination of the universal acid with the natrum of the antients; that affa fætida 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 some bear spicaceous flowers, both male and female, and others only female ones: and that the country is so dry, that electrical experiments often succeed, without any ftand of bitumen, pitch, filk, glass, &c. Art. 42. Some observations proving, that the fetus is in part nourished by the liquor amnii. By Malcolm Fleming, M. D.
From hairs being constantly found in the meconium of Tipe calves, Dr. Fleming concludes, that the liquor amni, which detaches them from the skin of the calf, contributes in part to the alimentary support of the fætus. Besides 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 discovery of these hairs, he has since found, that Swammerdam, in his Biblia Nature, and Slade, an Amsterdam phyfician, under the feigned name of Aldes, in his Epiftola contra Harveium, had observed the fame phænomenon, but without making any physiological applications. Art. 45.
This article is no improper fupplement to one by the same author (Dr. Brackenridge) in the last volume of the Tranfactions * -From the number of houses, and quantity of wheat used in England, the Doétor concludes, that this kingdom contains rather less than six 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 fishing, 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 support half a million
• See Review, Vol. XIII. p. 428.
The whole globe, if fully improved; might maintain twenty-fix times its present inhabitants. The annual increase of the people of England is computed
18,000; which, tho finall, is not unreasonably fúloete
be much diminifhed, by the emigrations of great numbers to our American colonies, and other settlements; and by our wars, and losses at sea ; 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 inconsiderable, if any at all, which, by the
way, 'fhews the reasonableness and good policy of encou• Taging foreigners to settle among us.'-This is an ingerious paper, and the calculations, as well as data, feem very just.
Art. 48. Informs us, that the exact representation of the fish, called an Old Wife, in the West Indies, was found in the heart of a stone, dug out of a quarry on the side of a mountain in Antigua, two miles from the sea, and 300 yards higher than high water mark. The stone was 'fent over to England, and we have here an engraving of it. Art. 51. Electrical Experiments, made in pursuance of those' by
Mr. Canton, dated December 3, 1953. With explanations, by Mr. Benjamin Franklin, communicated by Mr. Peter Collinjon, F. Ř. 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 separate, and repel each other.
2. An electric atmosphere, not only repels another electric atmosphere, but will also repel the electric matter contained in the substance 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 nas tural quantity of electricity, repel each other, (or at least ap
pear to do so, by a mutual receding) as well as those elec trified positively, or which have elec?ric atmospheres.
Art. 52. Extract of a letter concerning Ele&tricity, from Mr.
B. Franklin, to Monf. Delibard, inclosed in a letter to Mr. i Peter Collinson, F. Ř. S.
In this letter Mr. Franklin observes, that his meaning with regard to the effect of points in drawing the electric matter from the clouds, and thereby securing buildings, &c. has been but imperfectly understood. I have mentioned it in several
of my letters,' says he, and except once, always in the (alternative, viz. "That pointed rods erected on buildings, • and communicating with the moist earth, would either pre
vent a stroke, or, if not prevented, would conduct it, so as that the building should suffer no damage. Yet whenever my opinion is examined in Europe, nothing is considered but the probability of those rods preventing a stroke, or explofion; which is only a part of the use I proposed from them; and the other part, their conducting a stroke, which they may happen not to prevent, seems to be totally forgotten, thoof equal importance and advantage.'
That pointed rods are of great use in conducting the stroke of lightning, appears from an accident which, Mr. Franklin tells us, happened at Newberry, in New England. And also from another, which happened at Darking, in Surry, related
in article 53
Art. 57. Extract from a Letter of Thomas Barker, -Esq; to
the Rev. James Bradly, D. D. Astronomer royal, and F. R. S. concerning the return of the Comet expected in 1757, or 1758.
This article is illustrated with a copper-plate, on which a circle, representing 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, inewing where the Comet may be expected to begin to appear in any month, as the theory of Comets is not yet brought to such 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 Agita
tion of the IVaters, tho' without any perceptible motion of the earth, observed 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 so extenprvely affected many very distant parts of the globe. In several Letters transmitted to the Society.