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SERMON. Preached in the Parish Church of St. Matthew, Bethnal Green, No.

vember 22, 1778. For the Benefit of the Charity Children of the said Parish. By Samuel Beazville, A. B. Minister of the French Church in St. John Street in the said Parish. 8vo. Fry, &c.

It is impoflible to read this plain and well-adapted fermon without heartily wishing that the design of its publication may be fully an{wered. There are some inaccuracies in it, with respect to style, but these are well compensated by the pious, grateful, and becevo. lent spirit of the Preacher.

IN

CORRESPONDENCE.

To the REVIEWERS. N the year 1776 came out a publication, entitled, “ Advice from

a Father to a Son, just entered into the Army, and about to go abroad into Alion; in Seven Letters.” I do not remember to have seen it taken notice of by you ; and as they have great merit, both for the advice they inculcate, and the manner in which they are written, you would greatly oblige one of your Readers if you could inform him who was their Author, and whether they were written from a father to a fon in the circumstances therein mentioned.

OXONIENSIS. Oxonienfis will find an account of the tract which he speaks of, in our Catalogue for October, 1776, Art. 28. We commended the performance, but of the Writer we are entirely ignorant.

A very sensible Correspondent, who figns D. D. has favoured us with a friendly admonition, on account of what he deems an illiberal and uncandid reflection on the courts of France and Spain : vid. our last Appendix, p. 556, 557. The Author of that Article, (one of our Foreign Correspondents) not being in England, has no immediate opportunity of replying to what D. D. has objected against the passage in question ; nor do we pretend to justify even the smallett appearance of local prejudice or vulgar attachment. But it is difficult for a.“ True-born Englishmanto confine himself within the bounds of politeness, when the machinations of those who are the avowed enemies of his country, are presented to his observation. If this apology is not deemed sufficienc, we muft submit to the censare of the candid Public.

txt Some just remarks of this Correspondent on National Perfidy, &c. will, probably, be, hereafter, adverted to: they are too good to be loft,

We.are much obliged by the letter signed L. 2; but it came to hand too late for more particular acknowledgement in this Month's Review. It will, however, furnith a paragraph for the faf page of our next Number.

The Canadian Frueholder, Vol. II. the Conclusion of our account of Dr. Prieilley's Experiments and Observations, and The Modern History of Europe, will be inserted in our next

THE

MONTHLY REVIEW,

For SETTEMBER, 1779.

భంధంతరంగార00000

ART. I. Experiments and Observations relating to various Branches

of Natural Philosophy, &c. By Joseph Prieitley, LL.D. F.R.S. (Concluded from our Review for June laft, pag. 441.) THE discoveries and new observations relating to dephlogif

1 ticated air, contained in this volume, are too numerous and important not to require particular consideration. We shall accordingly, in this concluding Article, almost wholly confine our attention to this interesting subject.

In our account of the Author's second volume of Observations on Air [See Monthly Review, February, 1776, p. 108] we related, pretty much at large, the steps by which Dr. Priestley was led to this memorable discovery. From that account it appears that he obtained dephlogisticated air from mercurius calci. natus, and red lead, by mere heat, and which they must have attracted from the atmosphere during their calcination. He afa terwards found that dephlogisticated air was producible from combinations of the nitrous acid with any kind of earth whatever. The trials which he had then made with the vitriolic and marine acids, under similar circumstances, not having been attended with the production of this kind of air, he was naturally led to conclude that the nitrous acid was an essential or necesary ingredient in the process.

At the time of the Author's last philosophical publication, he did not, nor could he reasonably, suspect that subftances buried in the bowels of the earth, where no nitrous acid is known, or even suspected, to exist, and which cannot be suppoled, in that situation, to have attracted air from the atmosphere, should nevertheless furnish depblogisticated air, merely by the affistance of heat, or without the addition of nitrous acid. In a course of experiments, however, made only with a view to discover what kind of air, and in what proportion, certain mineral substances would yield, on being exposed to a red heats Vol. LXI.

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he had the following results, on subjecting the mineral subItance called Manganese to this new mode of analysis.

On putting an ounce of this substance into a small retort with a very long and narrow neck, and expofing it to a red fand heat, forty ounce measures of air were expelled from it in different porcions. Part of this air, in every portion, was fixed air, and at first almoft wholly o: but four-fifths of the last produce was the purest dephlogisticated air. He was naturally much furprised at this result; as the case docs not appear reducible to either of those recited at the beginning ( this Article : for here no nitrous acid had been employed; nor had the fubftance, till it was dug out of the bowels of the earth, been exposed to the influence of the atmosphere :-unless indeed we recur to some unknown and very distant ara, in which it may poflibly have had a communication with the external air, and have acquired its dephlogisticated air, in a manner similar to that in which the precipitate per fe, and red lead, at present acquire their pure air, during the act of calcination, in our laboratories. According to this idea, we may say that manganese (the nature of which is very little known) may probably be a metallic calx, which has undergone a calcination in volcanos, long since extinct; but which may formerly have had a communication with the atmosphere.' We scarce need to add, that on re-calcining this calcined manganese, moistened with the nitrous acid, more fixed air, and pure or depblogisticated air, were produced.

The Author subjected likewise an ounce of lapis calaminaris to a red heat, without addition, and expelled from it about 316 ounce measures of air, the whole of which, however, was fixed air, except four ounce measures, which appeared to be nearly as good as common air.

In the course of these experiments, and afterwards, in conformity with a communication from Signor Landriani, the Author found that the presence of nitrous acid, qua nitrous acid, was not neceffary to the production of dephlogisticated air from combinations of metallic earths with mineral acids. While he was pursuing this train of experiments, he found this kind of air produced from green vitriol, and likewise from the blue and white vitriols. Sulpecting however the purity of the vitriols of the fhops, which might have acquired some mixture of spirit of nitre, he prepared some green vitriol himself, by diffolving clean iron filings in oil of vitriol diluted with water. Distilling the matter in a retort, he had the same results as in his preceding experiments : the dephlogisticated air which came over last being very turbid, and exceedingly pure.

He now suspected the purity of his oil of vitriol, which, at present, is generally procured from sulphur with the addition of nitre. Ac therefore next employed the vitriolic acid prepared in Newmann's manner, in which no nitre is used: but dephlogisticated air was still produced from the combination of iron filings with this purer acid. And left the mixture of these two substances might be suspected to have attracted pure air, in confequence of their exposure to the atmosphere, during their combination, he conducted the experiment in the following fcrupulous manner :

He diffolved five pennyweights one grain of iron in a fuficient quantity of pure cil of vitriol, which had been carefully prepared for this purpose by Mr.Winch, so as to be free from any admixture of the nitrous acid. The distillation was performed in the very same retort in which the solution had been made, and in the continuation of the same process; so that all communication with the external air was most effectually precluded.

Conducting the process, with these attentions, and distilling the solution to dryness, in a long necked retort, the succeeding products were, first, the common air a little phlogisticated, and then a little fixed air, and much vitriolic acid air ; and lastly 18 ounce measures of dephlogisticated air. The refiduum, or ochre, still weighed more than the iron filings originally employed; so that it probably retained a quantity of the oil of vitriol, and had the heat been increased, more air might yet bave been procured.

Adding fresh oil of vitriol to this residuum, and treating it as before, but in a gun-barrel, a ftill larger quantity of dephlogisticated air was produced : so that the oil of vitriol appeared capable of generating dephlogisticated air, on its admixture with iron, toties quoties, as well as the nitrous acid with red lead and other substances, in the Author's former experiments. In fact, it now appears that he had formerly produced dephlogisticated air from compounds containing the vitriolic acid, particularly blue vitriol and alum, in a very early stage of his trials : though at that time he was totally ignorant of its nature. [See his first volume of Observations, page 155, and Vol. II. page 86.]

A combination of the vitriolic acid with mercury likewise furnilhed the Author with a notable quantity of dephlogisticated . air. For on distilling, in a green glass retort, an ounce of pure quick silver diffolved in vitriolic acid ; though some of the matter was loft, by the breaking of the retort, yet on expofing it, in a fresh retort, to a red heat, he got from it, after the expulsion of a great quantity of vitriolic acid air, and fixed air, about 50 ounce measures of dephlogisticated air. More dephlogisticated air was afterwards procured, on exposing to the heat a second time the white matter which had sublimed into the neck and sides of the retort.

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Left it might be suspected that, in consequence of the break ing of the retort, this dephlogisticated air might possibly have been imbibed from the atmosphere; the Author repeated the experiment with a view to this circumstance; and aceordingly kept the neck of the retort constantly immersed either in quicksilver or water, from the time of putting the materials together, to the end of the process; which nevertheless was interrupted by the inelting of the retort. Before this accident, however, 20 ounce measures of dephlogisticated air had been expelled, which had evidently been produced from the materials, without the help of any thing that could have been communicated to them from the atmosphere. - From the preceding as well as many other experiments of a fimilar kind, it appears that the propolition relating to the conftitution of atmospherical air, which had been deduced from the Author's former experiments, will require some modification, or extension, and that we should now say that the acid, confidered as a component principle of atmospherical air, is not neceffarily the nitrous acid, as fuch, or the lpirit of nitre of the fhops; but is, in some cases, the vitriolic: or that the latter, in the abovementioned procefles for procuring dephlogisticated air, is converted into the former; or, in short, that the effects are produced by some acid, or substance, that bears an equal relation, or is common, to both.

We shall only add further, on this subject, that the marine acid seems to differ essentially from the other two mineral acids, with respect to the production of dephlogisticated air: for though Signor Landriani had informed the Author that he had procured this kind of air from corrosive sublimate, or a combination of the marine acid with mercury, Dr. Priestley has not yet been able to procure any, either from this fubftance, or fea falt; or from iron or quicklime diffolved in the marine acid, and exposed to a red heat.

From the various experiments respecting Vegetation, contained in this volume, we shall select only one very remarkable observation relating to a particular plant called the Willow Plant, [the epilobium birfutum of Linnæus] which was found by the Author to possess the singular quality of absorbing a very considerable quantity of common ai!, or any other kind of air to which it was exposed, in a glass jar standing inverted in water. In the common phlogistic processes, such as the calcination of metals, respiration of animals, &c. the diminution of air has not been found to exceed one-fourth of the whole quantity. Indeed the Abbé Fontana has lately found that ignited charcoal has the property of absorbing a very great quantity of any kind of air to which it is exposed : but this plant, in a growing

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