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t? An Account of the Mathematical and Aironomical Articles, contained in this and the following Part of this volume, fhall be given in a subsequent Number.

ART.

Art. VI. Philosophical Transactions of the Royal seria, of London. Vol. LXX. For the Year 1780. Part II. Davis, &c. 1781.

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Article 19. Account of an Ossification of the Thoracic Duči : By

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Article 33. Continuation of the Case of james jones: By the same.

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A similar piece of copper wire was shortened only 1-20th of an inch by a similar discharge. A more singular difference between the two wires was observed by the Author. The same charge which caused the iron wire to appear red hot, in a bright day, did not affect a similar piece of copper wire, so as to make it appear of a red heat, though the room was made dark. If the battery was but a little more charged, the iron wire would be melted; but no such effect was produced on the copper Wire.

* This seems to point out,’ says Mr. Nairne, “that iron wire resists the passage of the electric fluid much more than copper; and also, that the culinary fire and eleētrical fire have different effects on iron and copper: for malleable iron, I am informed, is one of the most difficult metals to melt by the culinary fire, and requires a much greater heat to melt than copper; whereas, on the contrary, the iron is melted with a much less charge of elečtric fire.”

M 1 s c E L L A N E O U S ART I c L E s.

Article 23. On the Degree of Salubrity of the common Air at Sea,

compared with that of the Sea Shore, &c. By John Ingen

House, M. D. F. R. S. &c.

The Author of this Article, an account of whose curious experiments relative to the dephlogisticated air emitted by vegetables we not long ago communicated to the Public, here gives an account of some of the trials which he made on the air, in his passage from hence to the continent, and elsewhere. The purification of phlogisticated air, by agitation in water, rendered it probable that the air at sea might be made purer, by its vicinity to a great body of water.

The Author's method of putting air to the test consisted in introducing into the inverted glass tube one measure of air, the space occupied by which was divided into 100 equal parts; and then adding to it an equal measure of nitrous air. At the Author's country refidence, ten miles from London, while he was making the experiments here alluded to, the two measures above mentioned occupied between io9 and 109 divisions in the glass tube; instead of 200, which would have been the space occupied by the mixture of a measure of nitrous air, and another of perfe&tly phlogisticated or noxious air.

The purest sea air which the Author seems ever afterwards to

have met with occurred in his very first trial, in the mouth of the Thames, between Sheerness and Margate, on the 3d of November. Formerly, on his return to town, and to his former lodgings in Pall Mall Court, in the vicinity of trees, he had been surprised to find the common air purer in general, in October, than he used to find it in the middle of summer, in the country: for one measure of common air, and one of nitrous

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