the p oft-diluvian earth, as he fays, was inferior in many re fpectsnto the Adamitic, is very probable; and agrees with the doctrine of the longevity of the ante-diluvian patriarchs. He appeals to the form of the earth's furface, as a proof that it received its cavities and flexures from vaft currents of de, fcending waters; and has given two views of a rude valley in Derbyshire to illuftrate his meaning. From this principle he derives the beauty of our profpects, and all the prefent water-courfes of the earth, from the highest mountains of inland countries, down to the level of the fea. He argues that the earth's diameter ought to be shorter at the poles than the equator, from the state of the elements, as well as other confiderations: and here he makes a reflexion on the incom

menfurability every where obfervable in nature. In treating of the internal difpofition of the earth, he observes, that the matters it contains are no where difpofed in the order of their gravities; and fhews how the ftrata of the earth are broken for the lodgement of metals, the formationof caverns, with the horizontal expofure of a tract in Caldy Island, in Pembrokeshire. From the folids of the earth he proceeds to the fluids, and enquires into the origin of fprings, which, as he contends, are not to be accounted for from falling vapours, but rather from an internal heat fimilar to that which produces perfpiration. This leads him to fire-damps, volcanoes, and earthquakes, the caufes and effects of which are copiously treated of; with the ftrange phænomenon of the flickenfideftones in Derbyshire.

He next recounts the changes the earth has undergone from different caufes; particularly the feparation of America; and concludes with the evidences, facred, profane, and philofophical, of the farther change which yet awaits it. Philofophical arguments have been taken from the ftate of things in the earth to fhew its antiquity; thefe Mr. Jones confiders, and makes fome useful remarks on the hiftory of language and letters. In the diftribution of the land and fea over the globe, he has found that fea on one fide has land in the antipodes but what is most observable in this discourse is the fuperiority of the northern hemifphere compared with the fouthern It has more land, more fun, more heat, more light, more arts, more fenfe, more learning, more religion ;' and he goes regularly through all these articles of the comparifon, fhewing at leaft how this difference agrees with the defigns of Providence.

Under every divifion of his work, that will admit of it, he introduces the ancient mythology; but here he gives a more extended view of the heathen cofmogonies, and endeavours to

fhew

fhew how they have preserved the tradition of the Mofaic. The mundane egg, and the trinity of Hermes, make a confiderable figure, and are commented upon at large from the ftores of mythology.

The last difcourfe of this work is on the Appearances, Caufes, and prognoftic Signs of the Weather. In this fubject all men pretend to fome degree of skill, and therefore every reader will find fome trite obfervations which he knew before. But the weather is not a low fubject: it affords an agreeable and ufeful walk in philofophy; it has an important relation to the health of man and the bufinefs of life. The changes of the elements, as the author truly obferves, prefent us with all that is great and wonderful in nature.' When we follow the weather into different regions of the world, we find many curious phænomena, which a pen with the power of defcription may dwell upon to advantage. Mr. Jones first examines into the caufes of the rifing and falling of vapours, the fufpenfion of the clouds, thunder-ftorms, the aurora-borealis and its kindred meteors. He thence proceeds to the origin of the winds; and fhows, by many examples and authorities, that thofe aerial currents iffue from the body of the earth. Boerhaave and Woodward had two different theories to account for the changes of the weather, which are here explained. Other caufes of the weather are the fun and moon; hence the trade-winds, tide, weather, &c. The arctic weather near the pole exhibits some wonderful scenery; from which the author conducts us to the weather of the torrid zone, and defcribes the waterfpout, &c. He fhews how the weather is affected by tracts of mountains, woods, and forefts; how blafting winds are derived from fandy defarts; and how the air is tempered by the waters of the ocean; which gives a physical reason why there is fo large a proportion of sea in the globe.

The figns of the weather, as Mr. Jones has collected them, are from the barometer, vapours, clouds, dew, the face of the sky, the fun, moon, and stars, the winds, meteors, and the motions of animals. The relation of the weather to the human body is a matter of great concern to the comfort of life, and is here particularly confidered. The whole is concluded with a moral reflexion, by the obfervation of which thousands might have been faved who have died prematurely. Having defcribed the circumftances moft neceffary to form a wholfome fituation, the author fubjoins : • There may health fix her feat: but let no man think that his fituation will preferve him, unless he has the prudence to preferve himself. All the varieties of the weather, all climates, all

the feafons, and all the elements, are at war with the indolent and the intemperate.'

In our account of this publication we have confined ourfelves to the principal contents of it, without deviating into questions concerning the orthodoxy of the author's philofophical opinions, fome of which cannot easily be admitted; though his general principle of the agency of the elements feems clear enough. Upon the whole we may venture to say, that Mr. Jones has offered to the public a work, in a style and method which has given a new face to natural philofophy, and made it more interesting as well as more intelligible to readers of a liberal education.

Experiments and Obfervations made with a View to point out the Errors of the present received Theory of Electricity, and which tend in their Progrefs to establish a new Syftem, on Principles more conformable to the fimple Operations of Nature. By the Rev. John Lyon. 4to. 125. in Boards. Dodfley. MR. Lyon begins his work with an explanation of the tech

nical terms used by electricians; he then proceeds to give an account of the different fystems advanced by philofophers, to account for electric attraction and repulfion: this part of his work he concludes with Dr. Franklin's theory of the Leyden phial, from which he argues, that the whole system depends on the impermeability of glafs to the electric fluid, and the impoffibility of the fluid's paffing over the surface of glafs. He proceeds with giving two experiments, to prove the abfurdity of the latter fuppofition. As to the first of thefe, when we confider how much of its accuracy depends on the dryness of the air, and the glass he made ufe of, we think it affords no teftimony in his favour. In refpect of the fecond, where he makes use of a tube, and a pair of pith balls at the bottom of it, we are convinced, from our own experience, that the phenomenon depends not on the power of the glass to convey the fluid over its furface, but on a quantity of moisture, which it is almoft impoffible to remove from the infide of a tube. We would recommend to Mr. Lyon the use of a glass ftem wiped very dry, by which alteration in his experiment, it is probable he will find a refult very different from what he has defcribed; we would advife him likewife to take care that the atmosphere of his conductor does not extend as far as his pith balls, which we have found to be affected at a very great diftance from the conductor, when the cylinder we employed was not of very confiderable magnitude.

The

The author proceeds to give experiments, fhewing that glafs is permeable by the electric fluid- Take, says he, a pane of glafs, ten or twelve inches diameter, more or lefs, according to the fize of your jar, and place it upon a wire, under the end of the conductor, where you fix your jar. Let the end of the wire be hooked to a fharp pin, placed perpendicularly to the horizon, with the point close to the under furface of the pane, and oppofite to another sharp point upon the upper furface of the glafs, upon which also the phial or jar is to be placed, fo as to be in contact with the last mentioned point. Fix one end of a large conducting bow, with a glass handle, to the other end of the wire lying under the glafs, and, when the jar is charged, if you fuddenly touch the knob of the jar with the other end of the conducting bow, the jar will be discharged with a spark, and a fnap.'

We cannot coincide with Mr. Lyon in regard to the refult of this experiment: we have often tried it without even a semblance of what he describes. We always took care to have the glafs well dried, a circumftance which Mr. Lyon feems to have induftriously excluded from his electrical ceremonies. Indeed, by blowing with the breath only on the glafs, the operator may communicate a shock to it, and we must fuppofe that fomething of this kind deceived Mr. Lyon. To fet the matter, however, beyond all doubt, we used a fine lamen of talc, inftead of the pane of glass, as we knew this fubftance to be incapable of attracting much moisture from the air; in this cafe, the fhock ftruck through, but there was always a perforation juft oppofite to the points; we also discovered, that a fingle ípark from a very fmall conductor would have the fame effect: hence, nothing can be clearer than the impoffibility of paffing the leaft portion of the electric fluid through glass, without breaking it. This chapter contains many other experiments, which, in our opinion, when divefted of all obfcurities, may with the greatest ease be accounted for, on the principles of Franklin's theory.

The fourth chapter contains an examination of the present theory of electric attraction and repulfion: the author examines the feveral particulars of this theory; and profeffes to prove by experiment, that they are erroneous through the whole. Nothing, however, is combated but the received mode of accounting for one experiment. We are far from agreeing with him, that this fingle experiment is the bafis, or the key, to what he calls the present hypothetical fyftem of attraction and repulfion; we would recommend to him to read and confider fome curious facts on this fubject in lord Mahon's work; and not to be fo much out of humour with the prevail

ing hypothefis, till he has by his own accounted for those phenomena.—We have not fagacity enough to fee, or conjecture, what Mr. Lyon means by the long quotation from the Principia, which he has given in this chapter. We wish he had been lefs profufe of his fplendors, in other cafes where they are not fo much wanted as in the present.

Chapter fifth gives a description of the author's apparatus, which we think harmonizes moft admirably with his experiments and speculations. He feems to be ignorant of the very fimple machines used by modern electricians, and from the reprefentation given, we have reason to believe that he does not make use of fome very important improvements in the mode of exciting glass.

Chapter fixth is defigned to overturn Dr. Franklin's method of accounting for the Leyden phial: which, the author fays, depends wholly on the fuppofition, that when any additional quantity of the fluid is thrown into the infide, an equal quantity must be loft from the outfide of the phial,' and vice verfa. But, fays he, those who favour this system have ftumbled at the threshold, and have not hit upon the principle on which the phials act. Experiment: take two jars, charge them by their knobs, at the pofitive conductor. While they are ftanding with their knobs in contact with the conductor, and at fome diftance from each other, form a communication between the outside of one of the jars and the infide of both of them, and both the jars will be difcharged. How, continues the author, is the equilibrium reftored in this experiment to that jar whose infide has no communication with its outfide? The jars are both apparently in the fame state after the discharge was made, as they were before they were charged.' We are amazed at the want of fagacity which Mr. Lyon displays in this experiment, and the fubfequent remarks: it is wonderful that a man, who has thought at all upon the subject, fhould not perceive the cause of what he has described in the preceding quotation. The abfence of the fluid on the outfide of both the jars, depends on the additional quantity which is thrown on both their infides: this is the only cause which operates here; and, we think, when this caufe is removed, the effect can no longer exift: the infide is in this cafe discharged; for, agreeable to Dr. Franklin's theory, the outfide is fupplied with what it wants from the table and other bodies connected with the jar; if the jar were infulated, the phenomenon would be wholly different from that defcribed by Mr. Lyon, the charge would exift in the infulated phial, notwithstanding a thousand phials in contact with the fame conductor were charged and difcharged.

Experi