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

Pieces of the nearly black coloured cralimentum of the blood of a sheep, inclosed in nets of open gauze or wire, having been introduced, through water or quicksilver, into inverted receivers containing conmon air, depraved the air; and at the fame time acquired, from their exposure to it, a forid red colour. This colour was further brightened, and the change rouner produced, on introducing them into the Author's pure, or dephlogisticated air. On the contrary, the brightest red blond became black in phlogisticated, or any other kind of air unfit for respiration ; but reassumed its red colour, on being again expoled to pure air: parting, in this last fituation, with the phlogiston which it had acquired in the preceding.

That the blood communicates phlogifton to air, or that pure air is at !caft depraved by its presence, while the colour of the blood is changed from black to red, is rendered evident by the following experiment: By successively introducing fresh pieces of craffumentum into the same portion of dephlogisticated air, the Author vitiated it in a considerable degree. At the beginning of the experiment, one measure of this pure alr, and two of nitrous air, occupied the space of no more than half a measure : at the end of it, the same proportions of each occupied the space of a measure and half. He next thews that this depravation was not produced in consequence 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 vesels, never comes into immediate contact with the air, as 'it does in the Author's experiments; and further, that the red globules seem likewise to be protected from the action of the air, in consequence of their being surrounded with serum. On both these accounts, it seems reasonable to conclude, that in living animals, the air cannot thus act upon the blooi), or be affected by it. The force of these objections appears to be intirely taken off by the following experiments :

Having inclosed and suspended a large quantity of black blood in a bladder, moistened with serum, and tied very close, he found, next day, that the lower surface of the blood had acquired a coating of a Ajrid red colour, probably as shick 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 likewise that a deep covering of several inches of ferum was no impediment to the action of the blood and air upon each other. The serum therefore should seem to be peculiarly organised for this purpose : for the flighteft covering of water

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or saliva effectually prevents the blood from acquiring its Aorid colour. A similar portion of black blood, covered with ferum, and placed under an exhausted receiver, underwent no change of colour.

We shall only add that the Author, reversing the preceding experiment, found that phlogisticated air would act upon red blood, through the depth of two inches of serum, and change its colour to black. Article 14. Experiments on Water obtained from the melted Ice of

Sea Water, to afiertain whether it, be fresh or not, &c. All 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 supposed that the great masses of ice in the northern seas, which furnith fresh water on being thawed, do not consist of salt water frozen; but that they owe their origin to snow, 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 salt or not, the Author, during the severe frost in January last, exposed some fea water, taken up off the North Foreland, to the air. Having procured a sufficient quanvity office from it, which he afterwards washed in fresh water, and then thawed; he found that the water thus obtained was, .80 his palate, perfe&tly free from any taste of falt.' Its specific gravity likewise was to to that of the sea water from which it was obrained, as 1914 to 1653. That of distilled rain water was at t::e same time 1612.

From some of the Author's other experiments it appears that the freezing point of sea water should be fixed, in Fahrenheit's scale, at 28.5. In the course of his experiments on this subject he observed some fingular appearances. The mercury standing at 27, in a thermometer placed at the bottom of a jar of frelh water, suddenly rose to 32, when the ball began to be encom, poffed with crystals of ice. The crystals, shooting upwards, foon rrached the bulb of another thermometer placed just under the furface of the water ; the mercury in which likewise immedia'ely rose from 27 to 32. In a similar manner, crystals of ice having risen from the bottom of a jar of sea water, so as to cover the bulb of a themometer placed at the bottom of its the mercury instantly rose from 25° to 28.5: the thermometer in the open air standing at the same time at 19.5. Article is. Easy Methods of measuring the Diminution of Bult,

taking place upon the Mixture of common Air and nitrous Air, &c. By John Ingenhousz, M. D. F.R S. Physician to their lmperial Majelties at Vienna.

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

It would be doing an acceptable service to philosophy, to improve the method of applying Dr. Priestley's excellent teft, to ascertain the salubrity of air, by an admixture of nitrous air : but we would not advise the most eager philosopher to put bis patience to so severe a test, as it must undergo in the attempt to make himself master of the Author's Easy Methods' described in this article. The most unremiuing attention will scarce fuffice, to conduct the Reader through the labyrinth of brass and glass tubes, and their connections; their male and female screws, and ftop-cocks, and other appendages, with which he is presented in the first of these easy methods. Without reckoning the other members, here is a brass tube,'' a short lateral tube, ' a long tube,' ' another short tube,' and a glass bent tube,'all closely following each other within the compass 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 said to have been fent with this Article, but it does not appear. But after all, surely Dr. Priestley's original method of mixing known quantities of the two airs together in a cylindrical vefiel, or simple tube, must be fuperior, both with respect to accuracy and fimplicity, to this complicated apparatus; or even to the two simpler methods next described. The Author afterwards adds some miscellaneous experiments on plaTina, principally relative to the magnetical properties which he afcribes to all the particles composing that substance. Article 10. An Account of the Success of some Attempts to freeze

Quicksilver, at Albany Fort, in Hudson's Bay, in the Year 1775, &c. By Thomas Hutchins, Esq; &c.

In the only successful experiment related in this Article, the shermometer standing in the open air at 28" below o, in Fahrenheit's scale, the quickGlver contained in the bulb of another thermometer, immersed in a frigorific mixture, was found to be frozen when the mercury in a standard thermometer had fallen to 430 below o. It bore the repeated strokes of a hammer, and was flattened by them; giving ' a deadilh sound like lead.' We will that the Author had informed us, whether the quicksilver had been diftilled in water; as some philosophers, though probably on insufficient grounds, have attributed the congelation of mercury solely to water adhering to it.

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 thort aċcount of their contents.--Article 2 contains Tables of the Variation of the Compass; exhibiting the results of 17:9 observations made in voyages to and from Guinea, the East and West Indies, &c. by Mr. Robert Douglas, from the year 1721 to 1735. The manuscript had been perused and recommended by Dr.

Halley.

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Halley.--Article 3. Propositions selected 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 ty equal Altitudes. By Alexander Aubert, Efq; F.R.S. By this method the observer is less liable to be disappointed, or Jed into error, by intervening clouds, or variations of the refraction.Article 6. Sbort and easy Theorems for finding, in all Cases, the Differences between the Values of Annuities payable yearly, and of the same Annuities payable half yearly, quarterly, or momently *. By the Rev. Richard Price, D.D. F.R.S. -Article 11. Aftronomical Observations made in the Aufirian Netherlands, in 1772 und 1773. "By Nathaniel Pigott, Esq; F.R.S.

MISCELLANEOUS ARTICLE s. Article 1. On the Nature of the Gorgonia. By John Ellis, Esq; F.R.S. &c. -The Gorgonia has by some been placed in the vegetable kingdom ; while others seem to consider it as of a mixed nature between animal and vegetable. The Author endeavours to thew that it is an animal of the Polype kind; but differing from that class, in the remarkable circumstance of producing from its own substance a hard and solid support, ferving many of the purposes of the bone in other animals. In Article 5. William Clayton, Esq; gives an account of the climate, productions, &c. of Falkland's Islands ; containing

all the remarks which he made while he commanded on that barren, dreary, defolate, boggy, rocky spot, in 1773 and 1774.'

An Account of the Romanish Language. By Joseph Planta, F.R.S.--Article 8. A Supplement to a Paper, entitled, Obfervations on the Population of Manchester. By Dri Percival. In Article 9. Dr. William Scott relates the history of a case, in which violent afthmatic fits were brought on by the effluvia of ipecacuanha, while it was powdering. Article 16 contains An Account of three Journies 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 Mason, one of his Majesty'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 immense number of new and curious plants ; and passed through woods

. A reader not intimately acquainted with the subject might imagine, as some Critics have done, that the word momently is mis. printed for montbly; 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,

confifting

Article 7:

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

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ART. II. The Border History of England and Scotland, deduced from

the earlieft Times to the Union of the two Crowns, comprehending a particular Detail of the Transactions of the two Nations with one another. By the late Mr. George Ridpath, Miniter of Stitchi!l, revised and published by the Author's Brother, Mr. Philip Ridpath, Minister of Huston. 410. il. is. Cadell. 1776.

S in the intercommunity of good offices between the two

kingdoms, as well as in the more frequent retaliation of bad ones, the scene of action must have laip chiefly on their refpe&tive borders, it might be expected that a work of this deno. mination should comprehend a considerable part of the general history of both nations; and this is the plan pursued. 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 correspondent reigns of the English and Scottish kings on opposite pages, and filling up his outline with such a store of circumstances as either formed an immediate part of his subject, or bore fome collateral relation to it. Thus, when he comes to the battle of Flodden, the greatest confia that ever happened on the borders, he finds it necessary to acquaint his Readers with the political views of France and England at the time, that they may know why Henry the Eighin fought by his general, and why James the Fourth, who married his liter, fought at all. As here is a fuller local detail of this memorable battle than we meet with in any other Historian, we shall present it as a specimen of the work.

• On the last day of June, 1513, Henry passed the sea to Calais; and on the 26th of the following month, James sent his principal herald to him, with a letter containing his complaints of the inju. sies he had received from Henry and his subjects, and a declaration of his purpose to support his ally the French king, and to take such measures as he hoped would oblige the king of England to desist from his hofile enterprises against him; which he at the same time entreated and tequired him to do.

• In the letter of James, juft mentioned, he takes notice of the {pightful withholding of the bequest to his queen, notwithstanding repeated promises to satisfy that demand. He mentions also the flaying, 3

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