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Preached in the Parish Church of St. Matthew, Bethnal Green, November 22, 1778. For the Benefit of the Charity Children of the faid Parish. By Samuel Beazville, A. B. Minister of the French Church in St. John Street in the faid Parish. 8vo. Fry, &c.

It is impoffible to read this plain and well-adapted fermon without heartily wishing that the defign of its publication may be fully anfwered. There are fome inaccuracies in it, with refpect to ftyle, but these are well compenfated by the pious, grateful, and berevolent fpirit of the Preacher.

IN

CORRESPONDENCE.

To the REVIEWER S.

"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 Action; 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 traft 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 fenfible Correfpondent, 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 laft 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 paffage in queftion; nor do we pretend to justify even the smalleft appearance of local prejudice or vulgar attachment.-But it is difficult for a "True-born Englishman" to confine himself within the bounds of politenefs, when the machinations of those who are the avowed enemies of his country, are prefented to his obfervation.-If this apology is not deemed fufficient, we muft fubmit to the cenfare of the candid Public.

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

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

The Canadian Freeholder, Vol. II. the Conclufion of our account of Dr. Priettley's Experiments and Obfervations, and The Modern History of Europe,.will be inferted in our next

THE

MONTHLY REVIEW,

For

SEPTEMBER, 1779.

ART. I. Experiments and Obfervations relating to various Branches of Natural Philosophy, &c. By Jofeph Priestley, LL. D. F. R. S. [Concluded from our Review for June laft, pag. 441.]

TH

HE difcoveries and new obfervations relating to dephlogifticated air, contained in this volume, are too numerous and important not to require particular confideration. We shall accordingly, in this concluding Article, almoft wholly confine our attention to this interesting fubject.

In our account of the Author's fecond volume of Obfervations 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 difcovery. From that account it appears that he obtained dephlogisticated air from mercurius calcinatus, and red lead, by mere heat, and which they must have attracted from the atmosphere during their calcination. He afterwards found that dephlogifticated 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 fimilar circumftances, not having been attended with the production of this kind of air, he was naturally led to conclude that the nitrous acid was an effential or neceffary ingredient in the process.

At the time of the Author's last philosophical publication, he did not, nor could he reafonably, fufpect that fubftances buried in the bowels of the earth, where no nitrous acid is known, or even fufpected, to exift, and which cannot be fuppofed, in that fituation, to have attracted air from the atmofphere, fhould nevertheless furnish dephlogisticated air, merely by the affistance of heat, or without the addition of nitrous acid. In a courfe of experiments, however, made only with a view to discover what kind of air, and in what proportion, certain mineral fubftances would yield, on being expofed to a red heat; VOL. LXI.

M

he

he had the following refults, on fubjecting the mineral fubftance called Manganefe to this new mode of analyfis.

On putting an ounce of this fubftance into a small retort with a very long and narrow neck, and expofing it to a red fand heat, forty ounce meafures of air were expelled from it in different portions. Part of this air, in every portion, was fixed air, and at first almoft wholly fo: but four-fifths of the laft produce was the pureft dephlogifticated air. He was naturally much furprised at this refult; as the cafe does not appear reducible to either of thofe recited at the beginning of 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 expofed to the influence of the atmosphere :-unless indeed we recur to some unknown and very diftant era, in which it may poffibly have had a communication with the external air, and have acquired its dephlogifticated air, in a manner fimilar to that in which the precipitate per fe, and red lead, at prefent acquire their pure air, during the act of calcination, in our laboratories. According to this idea, we may fay that manganese (the nature of which is very little known) may probably be a metallic calx, which has undergone a calcination in volcanos, long fince extinct; but which may formerly have had a communication with the atmosphere. We fcarce need to add, that on re-calcining this calcined manganefe, moiftened with the nitrous acid, more fixed air, and pure or dephlogisticated air, were produced.

The Author fubjected likewife 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 thefe 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 purfuing this train of experiments, he found this kind of air produced from green vitriol, and likewife from the blue and white vitriols. Sufpecting however the purity of the vitriols of the fhops, which might have acquired fome mixture of fpirit of nitre, he prepared fome green vitriol himself, by diffolving clean iron filings in oil of vitriol diluted with water. Diftilling the matter in a retort, he had the fame refults as in his preceding experiments: the dephlogisticated air which came over laft being very turbid, and exceedingly pure.

He now fufpected the purity of his oil of vitriol, which, at prefent, is generally procured from fulphur with the addition of nitre. He therefore next employed the vitriolic acid prepared

in Newmann's manner, in which no nitre is ufed: but dephlogifticated air was ftill produced from the combination of iron filings with this purer acid. And left the mixture of these two fubftances might be fufpected to have attracted pure air, in confequence of their expofure 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 fufficient quantity of pure cil of vitriol, which had been carefully prepared for this purpofe by Mr.Winch, fo as to be free from any admixture of the nitrous acid. The diftillation was performed in the very fame retort in which the folution had been made, and in the continuation of the fame procefs; fo that all communication with the external air was moft effectually precluded.

Conducting the procefs, with thefe attentions, and diftilling the folution to drynefs, in a long necked retort, the fucceeding products were, first, the common air a little phlogisticated, and then a little fixed air, and much vitriolic acid air; and laftly 18 ounce measures of dephlogifticated air. The refiduum, or ochre, ftill weighed more than the iron filings originally employed; fo that it probably retained a quantity of the oil of vitriol, and had the heat been increased, more air might yet have been procured.

Adding fresh oil of vitriol to this refiduum, and treating it as before, but in a gun-barrel, a ftill larger quantity of dephlogifticated air was produced: fo that the oil of vitriol appeared capable of generating dephlogifticated air, on its admixture with iron, toties quoties, as well as the nitrous acid with red lead and other fubftances, 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 ftage of his trials: though at that time he was totally ignorant of its nature. [See his firft volume of Obfervations, page 155, and Vol. II. page 86.]

A combination of the vitriolic acid with mercury likewife furnished the Author with a notable quantity of dephlogisticated air. For on diftilling, in a green glafs retort, an ounce of pure quickfilver diffolved in vitriolic acid; though fome 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 expulfion of a great quantity of vitriolic acid air, and fixed air, about 50 ounce measures of dephlogifticated air. More dephlogifticated air was afterwards procured, on expofing to the heat a fecond time the white matter which had fublimed into the neck and fides of the retort. M 2 Left

Left it might be fufpected that, in confequence of the break. ing of the retort, this dephlogifticated air might poffibly have been imbibed from the atmosphere; the Author repeated the experiment with a view to this circumftance; and accordingly kept the neck of the retort conftantly immerfed either in quickfilver or water, from the time of putting the materials together, to the end of the process; which nevertheless was interrupted by the melting of the retort. Before this accident, however, 20 ounce measures of dephlogifticated 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 propofition relating to the conftitution of atmospherical air, which had been deduced from the Author's former experiments, will require fome modification, or extenfion; and that we should now fay that the acid, confidered as a component principle of atmospherical air, is not neceffarily the nitrous acid, as fuch, or the fpirit of nitre of the fhops; but is, in fome cafes, the vitriolic: or that the latter, in the abovementioned procefles for procuring dephlogisticated air, is converted into the former; or, in fhort, that the effects are produced by fome acid, or substance, that bears an equal relation, or is common, to both.

We shall only add further, on this fubject, that the marine acid feems to differ effentially from the other two mineral acids, with respect to the production of dephlogifticated air: for though Signor Landriani had informed the Author that he had procured this kind of air from corrofive fublimate, 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 expofed to a red heat.

From the various experiments refpecting Vegetation, contained in this volume, we fhall felect only one very remarkable observation relating to a particular plant called the Willow Plant, [the epilobium hirfutum of Linnæus] which was found by the Author to poffefs the fingular quality of abforbing a very confiderable quantity of common air, or any other kind of air to which it was expofed, in a glafs jar ftanding inverted in water. In the common phlogistic proceffes, fuch as the calcination of metals, refpiration 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 expofed: but this plant, in a growing 6

ftate,

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