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red and florid colour, even when it is expofed to it out of the body; are propofitions which are at least rendered highly probable from the following as well as fome other experiments.

Pieces of the nearly black coloured craffumentum of the blood. of a sheep, inclofed in nets of open gauze or wire, having been introduced, through water or quickfilver, into inverted receivers containing conimon air, depraved the air; and at the fame time acquired, from their expofure to it, a florid red colour. This colour was further brightened, and the change fooner produced, on introducing them into the Author's pure, or dephlogiflicated air. On the contrary, the brightest red blood became black in phlogiflicated, or any other kind of air unfit for refpiration; but reaffumed its red colour, on being again exposed to pure air: parting, in this last fituation, with the ph'ogiston which it had acquired in the preceding.

That the blood communicates phlogifton to air, or that pure air is at leaft depraved by its prefence, while the colour of the blood is changed from black to red, is rendered evident by the following experiment: By fucceffively introducing fresh pieces of craffumentum into the fame portion of dephlogiflicated air, the Author vitiated it in a confiderable degree. At the beginning of the experiment, one measure of this pure ar, and two of nitrous air, occupied the fpace of no more than half a measure: at the end of it, the fame proportions of each occupied the space of a measure and half. He next fhews that this depravation was not produced in confequence of any tendency to putrefaction in the blood employed in this experiment.

It may be objected, however, that in the lungs, the blood, being contained within its proper vefiels, never comes into immediate contact with the air, as it does in the Author's experiments; and further, that the red globules feem likewife to be protected from the action of the air, in confequence of their being furrounded with ferum. On both these accounts, it feems reasonable to conclude, that in living animals, the air cannot thus act upon the blood, or be affected by it. The force of these objections appears to be intirely taken off by the following experiments:

Having inclofed and fufpended a large quantity of black blood in a bladder, moiftened with ferum, and tied very clofe, he found, next day, that the lower furface of the blood had acquired a coating of a florid red colour, probably as thick as if the bladder had not intervened between it and the air; or as if it had been exposed to the immediate action of that element. He found likewife that a deep covering of feveral inches of ferum was no impediment to the action of the blood and air upon each other. The ferum therefore should seem to be peculiarly organised for this purpose: for the flighteft covering of water

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or faliva effectually prevents the blood from acquiring its florid A fimilar portion of black blood, covered with ferum, and placed under an exhaufted receiver, underwent no change of colour.

We fhall only add that the Author, reverfing the preceding experiment, found that phlogisticated air would act upon red blood, through the depth of two inches of ferum, and change its colour to black.

Article 14 Experiments on Water obtained from the melted Ice of Sea Water, to afcertain whether it be fresh or not, &c. Alfo Experiments to find the Degree of Cold in which Sea Water begins to freeze. By Mr. Edward Nairne, &c.

Some writers, particularly Mr. Boyle *, have fuppofed that the great maffes of ice in the northern feas, which furnish fresh water on being thawed, do not confift of falt water frozen; but that they owe their origin to fnow, or to the immense quantities of ice brought down by the great rivers in the neighbouring continent. To determine whether the ice of sea water retains any falt or not, the Author, during the fevere froft in January laft, expofed fome fea water, taken up off the North Foreland, to the air. Having procured a fufficient quantity of ice from it, which he afterwards washed in fresh water, and then thawed; he found that the water thus obtained was, to his palate, perfectly free from any taste of falt.' Its specific gravity likewife was to to that of the sea water from which it was obtained, as 1514 to 1653. That of distilled rain water was at the fame time 1612.

From fome of the Author's other experiments it appears that the freezing point of fea water fhould be fixed, in Fahrenheit's fcale, at 28.5. In the courfe of his experiments on this subject he obferved fome fingular appearances. The mercury standing at 27, in a thermometer placed at the bottom of a jar of fresh water, fuddenly rofe to 32, when the ball began to be encom paffed with cryftals of ice. The crystals, fhooting upwards, foon reached the bulb of another thermometer placed just under the furface of the water; the mercury in which likewife immediately rofe from 27 to 32. In a fimilar manner, crystals of ice having rifen from the bottom of a jar of fea water, so as to cover the bulb of a themometer placed at the bottom of it; the mercury inftantly rofe from 25° to 28.5: the thermometer in the open air standing at the fame time at 19.5.

Article 15. Easy Methods of measuring the Diminution of Bulk, taking place upon the Mixture of common Air and nitrous Air, &c. By John Ingenhoufz, M. D. F. R. S. Physician to their Imperial Majefties at Vienna.

Shaw's Abridgment, vol. I. page 635.

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It would be doing an acceptable fervice to philosophy, to improve the method of applying Dr. Priestley's excellent teft, to ascertain the falubrity of air, by an admixture of nitrous air: but we would not advife the moft eager philofopher to put his patience to fo fevere a teft, as it must undergo in the attempt to make himself master of the Author's Easy Methods' defcribed in this article. The most unremitting attention will fcarce fuffice, to conduct the Reader through the labyrinth of brass and glass tubes, and their connections; their male and female fcrews, and ftop-cocks, and other appendages, with which he is prefented in the first of these easy methods. Without reckoning the other members, here is a brass tube,' a fhort lateral tube, a long tube,' another short tube,' and a glafs bent tube,'all closely following each other within the compafs of eight or nine lines. A drawing would have explained in what manner, and why, this goodly company of tubes is brought together; and one is here faid to have been fent with this Article, but it does not appear. But after all, furely Dr. Priestley's original method of mixing known quantities of the two airs together in a cylindrical vefiel, or fimple tube, muft be fuperior, both with refpect to accuracy and fimplicity, to this complicated apparatus; or even to the two fimpler methods next defcribed. The Author afterwards adds fome mifcellaneous experiments on platina, principally relative to the magnetical properties which he afcribes to all the particles compofing that fubftance.

Article 10. An Account of the Success of fome Attempts to freeze Quickfilver, at Albany Fort, in Hudson's Bay, in the Year 1775, &c. By Thomas Hutchins, Efq; &c.

In the only fuccefsful experiment related in this Article, the thermometer ftanding in the open air at 28° below o, in Fahrenheit's fcale, the quickfilver contained in the bulb of another thermometer, immerfed in a frigorific mixture, was found to be frozen when the mercury in a ftandard thermometer had fallen to 430° below o. It bore the repeated ftrokes of a hammer, and was flattened by them; giving a deadifh found like lead.' We wish that the Author had informed us, whether the quickfilver had been diftilled in water; as fome philosophers, though probably on infufficient grounds, have attributed the congelation of mercury folely to water adhering to it.

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PAPERS relative to ASTRONOMY, NAVIGATION, &c. These papers will not require any further notice than the bare transcription of their titles, or the giving a very short account of their contents.--Article 2 contains Tables of the Variation of the Compafs; exhibiting the refults of 17:9 obfervations made in voyages to and from Guinea, the East and Weft Indies, &c. by Mr. Robert Douglas, from the year 1721 to 1735. The manufcript had been perufed and recommended by Dr.

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Halley.

Halley.-Article 3. Propofitions felected from a Paper on the Divifion of right Lines, Surfaces, and Solids. By James Glenie, A. M. &c.-Article 3. A new Method of finding Time by equal Altitudes. By Alexander Aubert, Efq; F. R. S. By this method the observer is lefs liable to be difappointed, or led into error, by intervening clouds, or variations of the refraction.Article 6. Short and eafy Theorems for finding, in all Cafes, the Differences between the Values of Annuities payable yearly, and of the fame Annuities payable half yearly, quarterly,or momently*. By the Rev. Richard Price, D. D. F. R. S.-Article 11. Aftronomical Obfervations made in the Aufirian Netherlands, in 1772 and 1773. By Nathaniel Pigott, Efq; F. R. S.

MISCELLANEOUS ARTICLES. Article 1. On the Nature of the Gorgonia. By John Ellis, Efq; F. R. S. &c.-The Gorgonia has by fome been placed in the vegetable kingdom; while others feem to confider it as of a mixed nature between animal and vegetable. The Author endeavours to fhew that it is an animal of the Polype kind; but differing from that clafs, in the remarkable circumstance of producing from its own fubftance a hard and folid support, ferving many of the purposes of the bone in other animals.In Article 5. William Clayton, Efq; gives an account of the climate, productions, &c. of Falkland's Iflands; containing all the remarks which he made while he commanded on that barren, dreary, defolate, boggy, rocky (pot, in 1773 and 1774.'— Article 7. An Account of the Romanish Language. By Jofeph Planta, F. R. S.-Article 8. A Supplement to a A Supplement to a Paper, entitled, Obfervations on the Population of Manchefter. By Dr. Percival.In Article 9. Dr. William Scott relates the hiftory of a cafe, in which violent asthmatic fits were brought on by the effluvia of ipecacuanha, while it was powdering. Article 16 contains An Account of three Fournies from the Cape Town into the Southern Parts of Africa; undertaken for the Discovery of new Plants, towards the Improvement of the Royal Botanical Gardens at Kew. By Mr. Francis Mafon, one of his Majefty's Gardeners. In these three journies, performed in the years 1773 and 1774, in which the Author penetrated between 3 and 400 miles into the country, he met with and collected an immenfe number of new and curious plants; and paffed through woods

A reader not intimately acquainted with the fubject might imagine, as fome Critics have done, that the word momently is mif. printed for monthly; but it here fignifies an annuity payable not every half year, or quarter, or month, but every moment. Such an annuity is conceivable; and it was proper to determine its value, because it is the limit to which the value of an annuity continually approaches, as far as the value depends on its being payable more or less often in the year,

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confifting principally of trees hitherto unknown to botanists.The 17th and laft Article contains the meteorological journal kept at the houfe of the Royal Society, for the year 1775. In confequence of a new and very proper regulation, it commences with the month of March; in order that the journal of the meteorological year may consist of one entire fummer, and one entire winter. The mean of the obferved variations of the magnetic needle was 21 degrees 43 minutes; that of the dip was 72 degrees 30 minutes.

ART. II. The Border History of England and Scotland, deduced from the earliest Times to the Union of the two Crowns, comprehending a particular Detail of the Tranfactions of the two Nations with one another. By the late Mr. George Ridpath, Minister of Stitchi!l, revifed and published by the Author's Brother, Mr. Philip Ridpath, Minister of Hutton. 4to. l. 15. Cadell. 1776.

S in the intercommunity of good offices between the two

A kingdoms, as well as in the more frequent retaliation of

bad ones, the scene of action must have lain chiefly on their refpective borders, it might be expected that a work of this denomination fhould comprehend a confiderable part of the general history of both nations; and this is the plan purfued.-The Author commencing with the operations of the Romans, carries down a continued outline of history to the union of the two crowns, arranging, as he proceeds, the correfpondent reigns of the English and Scottish kings on oppofite pages, and filling up his outline with fuch a ftore of circumftances as either formed an immediate part of his fubject, or bore fome collateral relation to it. Thus, when he comes to the battle of Flodden, the greatest conflict that ever happened on the borders, he finds it neceffary to acquaint his Readers with the political views of France and England at the time, that they may know why Henry the Eighth fought by his general, and why James the Fourth, who married his fifter, fought at all. As here is a fuller local detail of this memorable battle than we meet with in any other Hiftorian, we fhall prefent it as a fpecimen of the work.

On the last day of June, 1513, Henry paffed the fea to Calais; and on the 26th of the following month, James fent his principal herald to him, with a letter containing his complaints of the injuries he had received from Henry and his fubjects, and a declaration of his purpose to fupport his ally the French king, and to take fuch measures as he hoped would oblige the king of England to defift from his hoftile enterprifes against him; which he at the fame time entreated and fequired him to do.

In the letter of James, juft mentioned, he takes notice of the fpightful withholding of the bequeft to his queen, notwithstanding repeated promifes to fatisfy that demand. He mentions alfo the flaying,

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