it in the Author's own words; referring our musical Readers, for an explanation of the fubject, to the articles in our journal above alluded to. Suppose the two notes that are founded are the fifteenth and the feventeenth; their vibrations coincide at every fifth pulfe of the upper note, and at every fourth pulfe of the lower note: and when they confpire, the vibrations of each become more intense, fo as to be diftinguished by the ear. But their coincidence happens exactly at the fame intervals with the vibrations of the fundamental note, or unifon; and thence the unifon is heard as the third found. The lower tone would hit the unifon at every fourth vibration; the higher would hit the unifon at every fifth vibration. Now let the unifon be removed, and they meet each other where each would meet the unifon; and then the sensation of the unifon is excited. Whether there is a third sphere of undulations, produced in the air by the concurrence of the other two, is a queftion of fome difficulty; but without fuppofing it, the effect must be referred rather to the imagination than the fenfes.' In this difcourfe, the Author gives a well-authenticated account of the invention, or rather perhaps the re-invention, of the Eolian harp, by the late Mr. Otwald. To account for the production of the different tones in this aerial mufic, he fuppofes that air, like light, confifts of heterogeneous parts differently refrangible; and that as colours are produced by inflexions and refractions of the rays of light; fo mufical founds are produced by fimilar refractions of the air: the air, in fhort, becoming vocal, by a kind of refraction occafioned by its paffing over the edge of an aperture; juft as light prefents us with colours, not only by paffing through a prifm, but alfo by moving over the edge of a folid body. This whimfical theory has no other foundation than the wellknown, and, probably, merely accidental, analogy between the fpaces occupied by the feven colours in the folar spectrum, and the feven intervals which denote the tones and femitones of the octave, in the scale of mufic; or rather in a fcale which is not now in ufe. The Author however goes further, and perceives an analogy between three of the feven colours, viz. red, yellow, and blue, which he confiders as fimple and primary; and the three principal tones which conftitute the harmony of the octave, viz. the unifon, the third, and the fifth. For our part, we can fee no reason to fuppofe, thany thing happens, in the refraction or inflection of light, mat can july be faid to refemble any effects produced by the mere change of direction, which a current of air fuffers in paffing through a narrow paffage, or over the edge of a body. In this laft cafe, its inflexions are fuch as are common to any elaftic fluid, moving i in fimilar circumftances. We doubt not but that, under the ame circumftances, mufical tones would be produced by fixed or phlogiflicated air, or even by the elaftic vapour of water, from an eolopile: but we should not fufpect that any of these fluids would be decompounded, merely by their inflection, or change of courfe. The analogy too between the folar Spectrum, and the mufical octave, evidently fails, when we confider that a ray of light is not only actually decompounded by a prifm; but that the decompofition is permanent, and the parts remain feparate: whereas, even granting that the air may confift of heterogeneous particles of different magnitudes, &c.; neither the nitrous, or any other tel of the integrity or purity of air, has yet exhibited to our modern experimental philofophers any figns, or even induced any fufpicion, that that fluid is liable to be decompounded by a mufical inftrument, or an air-prifm, as the Author terms the Eolian harp-Were we to attribute to the air, thus fuppofed to be affected, the qualities ufually afcribed to air decompounded, we should be ready to apprehend, that an Eolian harp, placed at a window, would probably confume as much air as a lighted candle; and that huge air prijm,' the organ, would, if played upon, refract, and decompound as much air in an hour, as might ferve for the confumption of a moderate family for a whole week. We should not overlook a practical improvement of the Eolian harp, which is defcribed, and has been executed by the Author. -inftead of fixing the ftrings to the outfide,' fays the Author, I difpofe them upon a founding board or belly within fide at wooden cafe, and admit the wind to them through a horizontal aperture; fo that the affinity of the inftrument to an organpipe appears at firft fight: and thus it becomes portable, and ufeful any where in the open air, inftead of being confined to the houfe; which is a great advantage; and it is probable this new form may lead to fome new experiments.' We have not yet noticed thofe parts of the prefent Work, in which the Author takes occafion to combine natural and experimental philofophy with philology, theology, &c. Treating of the ufes and application of mulic, the Author makes his orthodoxy at leaft confpicuous, by citing, with complacency, a paffage from Symfon's Chelys; in which that writer, defcanting on the three fundamental notes of the octave-the unifon, third, and fifth-confiders them as affording us "a fignificant emblem of that fupreme and incomprehenfible THREE in ONE, governing, comprifing, and difpofing the whole machine of the world,. with all its included parts, in a moft perfect and ftupendous harmony." This phyfical trinity,' adds the Author, as an abfolute fact in mufic, muft be evident to every beginner in the science; and it is a trinity in unity: but it is a mirror, in which many eyes will discern no image ;. With me it is a matter of fmall fmall concern, how fuch an allufion would be relished by a Middleton, a Bayle, or a Voltaire, whofe minds were poisoned by a difaffection to truth, &c. &c.' In the 7th and 8th difcourfes, the Author treats of foffil bodies, with fome obfervations introductory to a theory of the earth;' and on physical geography, or the natural history of the earth.' Thofe who wish to acquire a knowledge of the principal marine fhells, and other animal and vegetable matters found in the bowels of the earth, will here mect with defcriptions of feveral fubjects, illuftrated with plates; together with reflections concerning the origin of marine fofils. The volume is terminated by a difcourfe on the appearances, caufes, and prognoftic figns of the weather." B...y. ART. lil. Two Letters to Dr. Newcome, Bishop of Waterford, on the Duration of our Saviour's Ministry. By Jofeph Priestley, LL. D. F. R. S. 8vo. 2 s. 6 d. Johafon. 1781. THE 6 THE firft of thefe Letters was prefixed to Dr. Priestley's English Harmony of the Evangelifts; and our Readers will find an account of it in our Review of that publication. It is here reprinted, that the whole correfpondence might be before the Reader in a more convenient form.' To this letter Dr. Newcome publifhed an anfwer, in which, agreeably to Dr. Priestley's wilhes, his Lordship entered into a particular confideration of the fubje&t, ftated the facts and circumftances upon which his opinion refpecting the duration of our Lord's miniftry was founded, and made obfervations upon some of the principal arguments which the Doctor had alleged in favour of Mr. Mann's hypothefis. We gave our Readers an account of his Lordship's publication in the Review for June laft. The fecond letter before us is in reply to Dr. Newcome. Dr. Priestley begins with expreffing the pleafure it gives him to find his Lordship enter fo fully into the difcuffion of the fubject, and his hope that fome new light may be thrown upon it, even though it should not be decided to general fatisfaction. He next apologizes to the Bishop for not making a reply fooner,. declares the high refpect that he entertains for him, and affures him, that he esteems it an honour to difcufs a question fo interefting to many Chriftian crities, and which has never been properly difcuffed before, with a perfon of his Lordship's learning and candour. And then, after a few curfory reflections on the incidental advantages attending fcriptural inquiries, he obferves, that, in order to introduce as much diftinctness as pof. fible into the conduct of the argument, and to render it less tire Review for February, 1781, p. 84. fome fome both to his Lordship and to their readers, he shall, in this, and all fubfequent letters on the fubject, difcufs the feveral articles comprized in it in feparate fections. The articles fpecified by Dr. Priestley in this letter, and which he has difcuffed in feparate fections, are, The teftimony of the Chriftian Fathersthe conduct of Luke in giving a date to the preaching of John the Baptift-the ignorance of Herod, and of other Jews, concerning Jefus, at the time of the death of John the Baptift-the interpolation of the word Paffover, in John vi. 4.-the tranfpofition of the 5th and 6th chapters of the Gospel of John-journies fuppofed to be omitted in his, Dr. Priestley's, Harmony-the number of miles that Jefus has been fuppofed to travel per day - references to more than two Paffovers in the Gospel of Matthew, Mark, and Luke-the ar•gument for the probable duration of our Saviour's miniftry from the objects of it-the tranfactions of the first Passover-the ftay that Jefus made in Judea after the first Pafover-the journey from Judea to Galilee-whether Jefus vifited Capernaum or Nazareth firft -and, the harmony of the Gospels according to the ancients, efpecially Eufebius and Epiphanius, and fome of the moderns who have moft nearly followed them. To thefe the Doctor has added a fection under the title of Mifcellaneous Obfervations, containing the following articles, The first excurfion from Capernaum-the time of the journey to Nain-the fecond Sabbath after the first-and, the difciples of John. As it is not in our power to go over all these fections in their order, we fhall felect fuch particulars as may connect with our former extracts and remarks on the fubject, or enable our Readers to form an idea of the ability and spirit with which Dr. Prieftley continues to fupport his argument. In order to prove, that the fpace of fifty days was not fufficient for the tranfactions fuppofed to have taken place between the Paffover, John ii. 13. and the Feaft of the Jews mentioned, John v. 1. Dr. Newcome drew out a plan of our Lord's journies during that period; by which it appeared that he must have travelled eight miles a day, including Sabbaths. As Dr. Prieftley's obfervations refpecting this reprefentation contain both his Lordship's plan and his own correction of it, and are followed by fome curious remarks on our Lord's manner of travelling, we fhall give them at length. Having mildly infinuated a charge against his Lordship on account of his mixing their two fchemes together, fpecifying journies which he, the Doctor, does not allow to be included in the period alluded to, and extending others beyond his idea of their length, he proceeds: That we may examine this bufinefs with more attention, I muft beg your Lordfhip to turn to p. 93 of your Letter, and we will look over the lift that your Lordship has there drawn of our Saviour's journies, and I will point out what articles I admit, and what I object to. I will then allow the reft in your own numbers, that you may not think that I will contend for trifles; and we fhall fee how the account of his daily progress really stands upon my hypothesis, unmixed with your Lordfhip's. No. 6 I. 2. 3. Miles. Granted. 50. Granted. {Granted in part 30." "From Jerufalem to Judea 25." "From Judea to Cana "From Cana, through Nazareth, to Capernaum because I do not fuppofe Jefus to have paffed through Nazareth; and for this, according to your Lordship's map, I ought to deduct more than I do, when I allow 20 miles. 4. "The circuit about Galilee 70." I deduct from this article at least twothirds, because I confine the circuit to the places in the neighbourhood of Capernaum, chiefly to the north of that town. I therefore call it 30 miles. "From Capernaum to Je-65." 5. rufalem in the cities of Galilee Granted in part. Not granted. Granted. Not granted. Granted. 20." Granted. 33." Granted in part. This journey I confine to the neighbourhood of Nazareth, and therefore fhall not allow much more than half the number of miles, or 20. REV. Jan. 1782. C • If |