lemand extravagant prices from us, upon the fuppofition that our lependence upon them obliges us to pay whatever they demand. Thinking in this manner, he often expreffes great furprife that Britain does not take immediate measures to secure herself against the precarious and felfifh friendships of the Scandinavian nations. The following paffage, which we select because it is fhort, will ferve to fhow how he feels and reasons upon this matter.

It is matter of no small astonishment that Great Britain, fo celebrated for her political wisdom and commercial prudence, which has rifen her to power and confequence in the world, chiefly by her maritime ftrength, fhould grofsly have neglected cultivating within herself a great part of her naval ftores, the very foul and finews of her greatnefs and preservation, particularly after the many falutary admonitions at an early period, and the attempt at monopoly by foreign powers, the armed neutrality in 1780, and the confederacy of the North in 1800. Great Britain makes herself dependent, as it were, upon thefe nations for the very articles on which her existence depends, and neglects thofe domeftic refources which the might fo advantageoufly carry into effect, not only to a national, but individual bencfit.'

p. 489. With a view to fuch an improvement of our national refources, he treats, first, of the fisheries; and maintains, that no fcheme for their extenfion will be effectual that does not enable poor people to enter into that trade. Bounties, he fays, are of no ufe; for they do not enable any one, who has not the means otherwise, to undertake fishing. He propofes, therefore, that boats and tackle fhould be provided at the fishing stations, and hired out for a fum juft fufficient to pay intereft, tear and wear, under the direction of the minifters and elders in the Scotch parishes, and by the fuperintendants of the poor in England.

He next recommends, in terms of extreme urgency, the cultivation of timber at home, and even proposes compulsory measures for that purpose. This is his great refource, indeed, upon all occafions; for Mr Oddy is one of thofe who think that governments ought to interfere in every thing. Meantime, he is of opinion the timber trade might be advantageously transferred to our North American plantations. The forefts there contain abundance of excellent timber, which he fays can be brought to this country a great deal cheaper than from the Baltic, with the additional national benefit of employing double the number of seamen, and double the tonnage of shipping. Some details are given upon the fubject, which must be extremely valuable to fuch as may engage

I 4

in

*The Swedes, in 1703, refufed to let England have pitch and tar, unless received in their own fhips, at their own price.'

In this trade. We were furprifed, however, to find the author dutuelle adimitting, that the price of wood in the countries round the Baltic is regulated by the common principles, after having do esfion complansed of the arbitrary monopoly demands of the northern merchants. Some of his reafonings on this point remind as of the declamations of certain French writers against our grievQua #ays of colonial productions.

tiaal-existages won'3, in Mr Oddy's erinion, accrue to the stat tage, bat particularly to Ireland, froca a more extend

between Europe and America, Britain' fhould become the magazine of the univerfe.

• Let all foreign grain, then, be allowed importation at all times under the King's lock, upon the principle of an entrepôt, there let it lay the pleafure of the owner for a market. We are better fituated for it than Holland was; if any demand should be made from the fouthern markets, our own fhips can be got out from our ports at all seasons of the year, which is not the cafe in Holland.

We fpeak from fact and our own knowledge, that, was fuch a principle adopted, the corn-dealers in the north of Europe, and thofe who have long been in the trade in other quarters, would cheerfully avail themselves of it. But it is not only from the Baltic that confiderable fupplies of grain would be fent to fuch an entrepôt, but from America; their confcious fecurity of the country, although they were feeking for markets, would always induce them, as they now often do, to touch at Ark or Falmouth, to learn the fate of the European markets, or call for orders. Great numbers of the American merchants, and they are moftly bold and enterprizing, would at once fend their produce here for a market, and take our manufactures in return.

From foreign grain being stored in this manner, would arife a certain advantage to the country. If, whilft our watte lands are getting into cultivation, any failure of our crops fhould take place, the flock in hand might be brought into the market by the regulations of the present, or some more judicious act. Monopoly, which is fo much cried down, would not exist in the face of a large unknown ftock; and if the price advanced under these circumftances, it would rife from an actual deficiency in the country, to fupply which we should then always have a ftock in ftore: for want of fuch a tock, prices frequently rapidly advance here, and the advance is anticipated abroad; fo that it coits - us enormous prices unneceffarily created. P. 51, 512.

The fhort view which we have given of the contents of this book, leaves us but little to add upon its general merits. The author is never profound or philofophical in his views; nor does he feem to have powers for clear or comprehenfive reafoning. He' is often vague, redundant, defultory, and inconfiftent; and his diction is mean and clumfy. But he is a man of great experience, and no small practical fagacity; and has produced a book more fuited to the wants and to the capacity of ordinary traders, than the greater part of those which are founded upon jufter maxims of policy.

ART.

ART. X. Effuys, chiefly on Chemical Subjects. By William Irvine, M. D. F. R. S. Ed., Lecturer in Materia Medica and Chemistry in the University of Glasgow; and by his fon W. Irvine, M. D. 8vo. pp. 490. London, 1805.

IT has often been regretted by thofe who have paid attention to that interesting part of chemical fcience, which relates to the more abftrufe doctrines of heat, that the theory propofed by the late Dr Irvine was never fully brought before the public. He himself gave no account of it, but in the chemical lectures which he delivered in the Univerfity of Glafgow; and although the heads of it have been stated by Dr Crawford, who was well qualified to do it justice, the statement was only incidental, fubordinate to his own views, and, of courfe, unaccompanied by thofe details and illustrations which its author could have beft given it, and which were neceffary on a fubje&t in fome measure obfcure. From this caufe, although the outline of the theory has been generally known, its real merits have fcarcely ever been fairly appreciated; it has often been mifunderitood, nor has it yet had that rank affigned to it in chemical fcience to which it appears to us to be entitled.

Having long been accustomed to confider this theory of the diftribution of heat in bodies, and of its abforption during liquefaction and vaporization, as the moft philofophical that has yet been fuggefted, we turned to the perufal of this work with much curiofity and expectation. We have ftill to regret, however, that we have not the author's own ftatement and illuftration of his peculiar views, or have them only in a very imperfect manner. In the preface, we are informed that Dr Irvine's manufcripts, at least in what relates to this subject, were in no refpect fit for publication, and were even in fuch a state, that no fatisfactory account of the experiments and theory could have been compiled from them. To Dr Irvine, junior, the editor of this publication, there only remained the alternative of availing himself of them as far as poflible, in explaining and illuftrating what he knew from other fources of his father's opinions; and although this is not precifely what thofe interested in the difcuffion would have wifhed, nor what we are perfuaded it would have been the wifh of the editor to prefent to the public, it is but juftice to him to acknowledge, that he appears to be intimately acquainted with the fubject; that he has bestowed on it much attention; and has conveyed to us fome interefting information on his father's experiments. If fome tincture of enthufiafm may, as he remarks, be expected in a fon, who treats

of

of his father's labours, we have not obferved any want of candour, or any undue partiality to the doctrines he defends.

Dr Black was the difcoverer of the important truth, that when a body is heated to the point at which it begins to melt, it is not fufficient to communicate to it merely a little more heat to produce an entire change in its form; but that as the change proceeds, it abforbs a large quantity of caloric, which has no effect in increafing the temperature of the fluid, and which exifts therefore in the body in this new form, in a state not difcoverable by the thermometer. And again, that when the liquid is heated to the point at which it paffes into vapour, a fimilar abforption of caloric, unaccompanied with any augmentation of temperature, takes place. The heat exifting in this ftate Dr Black termed latent, to distinguish it from fenfible heat, or that by which the temperature of the body is raised.

In fpeculating on this important truth, Dr Black supposed that the caloric which thus difappears is the caufe of the change of form; that the latent heat, exifting in a fluid or vapour, is that which preferves it in thefe ftates; and that the vapour cannot be condensed, nor the liquid congealed, without this latent heat being withdrawn.

Dr Irvine viewed these phenomena in a different light; he regarded the abforption of caloric, not as producing, but as arifing from the change of form. Dr Black had established, from an experiment related by Boerhave, the important general conclufion, that in different bodies the fame temperature is not, as we might perhaps be difpofed to imagine à priori, produced by the fame quantity of heat or caloric, but that one body will require a very different quantity from that required by another; and that, therefore, at any given point in the fcale of the thermometer, different bodies, in equal quantities, whether estimated by weight or volume, contain very different quantities of this principle; a fact which came to be expreffed, by faying that different bodies have different capacities for heat.

Now, it occurred to Dr Irvine, that the abforption of heat which attends both the melting of a body, and its tranfition into the elastic state, might be owing to an alteration in its capacity. When a folid becomes liquid, or a liquid is converted into vapour, he fuppofed that its capacity or power of containing heat may be enlarged; and if this happen, the neceffary confequence must be the abforption of a quantity of caloric to keep up its temperature to the point in the fcale of heat at which the change takes place. By faying that the capacity of a body is enlarged, nothing more is meant, than that, at a given temperature, it is capable of containing more caloric than formerly. If fuch an enlargement happen,

therefore,