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The 28th and 20th plates exbibit Virws of the Town of SanNicole in the fame island, taken from different points of ob{ervation. In the explication of the 28th plate our Author makes farther observations on the island of Tenos, whose small extent of twelve miles in circuit is compensated by its fertility, and which contains near twenty thousand inhabitants, dispersed in about fixty villages. It bore formerly the name of Opbiulsa, from its being infested with serpents, and hence in Greece the viper is said to have been called Tenia. Its inhabitants are governed by their own magistrates; no Turkish officer renews by his presence the idea of their servitude, and they only feel one day in the year that they are under the yoke of despotism.

The 30th plate represents the hand and Town of Syra, formerly Syros. The traveller, says M. de Choiseul, who fails through the Archipelago, feels the most agreeable emotions in recalling to memory the great men, who once rendered these islands famous, and make us still behold them with a certain sentiment of homage and respect. The image of Pythagoras arises to his fancy, when he arrives at Samos, -- Lesbos recalls to him Alcæus and Sappho,-Ceos presents to him Simonides the master, and Bacchylides the rival, of Pindar. He pays homage to the Thade of Hippocrates when he comes to Cos, and to that of Archilochus when he arrives at Paros. Syros had the honour of giving birth to Pherecides, one of the most ancient philosophers, and the master of Pythagoras.

In the 31st plate we find a Plan of the Island of Delos. The ruins, says our Author, with which Delos is covered, proves the veneration of the ancients for that ille in a still more powerful manner than the Odes of Callimachus and Pindar. The fables, which ennobled the origin of Delos, excited the piety of the Greeks, who were always fond of the marvellous, to lavith on this island the richest oblations and presents. The azylum of Latona, the place which gave birth to Apollo and Diana, could not but be honoured with a universal worship. All the hiftorical details that regard Delos, are comprehended here in a moft animated description of the feasts that were celebrated of old in that island. This description is the composition of an anonymous Author, who detached it from a large work, and permitted M. de Choiseul to insert it here. It is rather too poetical with respect to style and imagery, but it has great merit as to erudition and eloquence, and will be read with pleasure by the lovers of classical antiquity.

For our accounts of the two former Numbers of this splendid work, see "Appendixes to our 58th and sgth volumes.

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ART. V. Nouveaux Memoires de l'Academie Royale des Sciences et Belles Lettres.

Annie 1776-avec l'Histoire,- New Memoirs of the Royal Aca. demy of Sciences and Belles Lettres of Berlin for the Year 1776, with the History relative to that year. Berlin. 4to. 1779.

HISTORY OF THE ACADEMY.
HE first thing we meet with in the historical part of this

volume (after some discourses on occasion of the reception of members, which we pass over in silence) is a letter of Dr. Wilson, of the Royal Society, to the Academy of Berlin, in which he communicates to that learned body his discovery of some new properties of light. We have also here the opinions of some of the principal Academicians concerning this discovery. Among these opinions, that of M. Beguelin is peculiarly interesting, and bears all the marks of that penetration, extensive knowledge, and amiable candour, that so eminently diftinguish this excellent philosopher. This discovery, we suppose, is well known, as also the experiments by which it was made ; it ftruck, indeed, the members of the Academy with great surprise, and appeared directly contrary, not only to the observations of Newton, but also to the known properties and nature of light. That the red or ubrific parts of a phlogisticated oyster-lhell, or phof phorus, fhould exhibit a feeble and pale red after having been exposed to the red rays of the solar beam alone, and should, on the contrary, appear with a red several shades deeper and more lively, when exposed to the green rays only, and with a still more lively and brilliant red when exposed to the blue ones, seemed to M. Beguelin, incompatible with the theory of the immutability of the rays of light; and this ingenious academician makes several acute reflections on the subject, as also on the series of experiments on the phosphori and their prismatic colours, of which the learned Author made a present to the Academy.

This is followed by the observations of M. SULZER on a brass nail found in a quarry of lime-stone near the port of Nice in Provence, and by the eulogies of the deceased Academicians, GUISCHARD (called Quintus Icilius), Heinius and Kuster.

MEMOIRS.

EXPERIMENTAL PHILOSOPHY. Concerning Friction, considered as diminishing Motion and opposing it. By M. Lambert. Second Memoir.

Concerning the Powers of the Human Body. By the same. Part first. These are considered here as moving and accelerating powers; but both the extent of the piece, and the series of the reasoning, sender this memoir incapable of abridgment.

Chymical Researches concerning the Topaz of Saxony. By M. MARGRAFF. This stone is found, in considerable quantities, in Voigtland, about two miles from Averbach, in the crevices of a yery hard rock, where it is mixed with a kind of yellow marl

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and with rock-crystal. With respect to its internal texture, it is.compact, but foliated like the diamond; its form is prismatic, and has four unequal angles; it is also hard, and has a vivid luftre. M. MARGRAFF, having observed, that hard stones, and more efpecially those which are placed in the class of precious ftones, are not composed of homogeneous earths, but of earths of different kinds, thought proper to begin his researches on this fubject by examining the topaz by the means of diffolvents, and subjecting it to the trial and operation of acids. In order to execute this design, and to discover the different kinds of earth which enter into the composition of the topaz, he chose the three acids of the mineral kingdom, those of vitriol, nitre, and falt, and having pulverized his topazés (a circumstance necessary when hard stones are to be subjected to chymical operations) he began his experiments, which are: here circumstantially related, are very curious, and shew that the topaz contains a calcareous and an argillaceous earth.

An Inquiry into a Point of Physiology, relative to the State of the Pelvis or Bafon of Women, in the Circumstance of Child-birth. By M. DE FRANCHEVILLE. This subject of inquiry is curious and important. The question is, whether or no, at the time of delivery, the Pelvis in lying-in women yields and is dilated in order to facilitate the paslage of the child! The greatest part of the medical faculty answer this question in the negative; several, however, are for the affirmative, in consequence of their own observations: from whence it is natural to conclude, that this dilatation does not actually take place in all women, but that it may happen, and that it has happened, and this is what the learned academician proposes to prove, and has fully proved, in this memoir, both fron the construction of the bason in women, and from the testimonies of the most celebrated Anatomists and Phyficians both of ancient and modern times.

Experiments on the Electrophorus, together with a Theory of that Instrument. By M. ACHARD. The instrument, here mentioned, is of late invention, and its fingular and unexpected effects have excited, in a peculiar manner, the attention of the observers of nature.

The construction of this instrument and the manner of using it, as also its preserving its electricity for a confiderable space of time, are well known. It was to discover the manner in which the electrophorus acts, and produces its effects, that M. ACHARD made the fixteen experiments related and described in this excellent memoir, and which do such honour to the fagacity and abilities of that celebrated naturalift. For an account of these experiments we'must refer the Reader to the volume before us; but the conclusions and results deducible from them, and which M. ACHARD deduces from them in effect, with the clearest evidence, are, ift, that it is not ne

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cessary, that the brass-plate should touch exactly and in all its surface the circular glass plate' which is originally electric; for our Academician having placed horizontally a circular plate of glass, a line and a half thick and a foot in diameter, upon a plate of tin, which touched the glass only in a few places, the upper surface of the glass being electrified by rubbing, produced all the effects of the electrophorus :-2dly, that the metallic plate, or the board of the electrophorus covered with tin-foil, is not effentially neceffary to the production of the effects which have been observed in that inftrument, and that when the electrophorus is deprived of it, it retains nevertheless all its properties:-3dly, that the property which this instrument bas of retaining its electricity longer when it is insulated by a substance, which acqùires, by rubbing, an electricity contrary to that which is given i by rubbing," to the ele&ric plate, is not peculiar to the electrophorus, but is common to all substances which are originally electric:- 4thly; that in order to draw sparks from a conductor, it is not necessary that it thould touch or communicate with the metal'or tin-foil, that covers the inferior surface of the electrophorus, as fome affert; all that is required for this purpose is, that the conductor be touched by a body, which is adapted to transmit to it a portion of the eletrical fluid :-5thly, that the electrophorus can never render the conductor electric, unless it be touched by a body, that is non-electric by itself:-6thly, that the electrophorus never electrifies the conductor, but so far as the latter receives or loses a quantity of electrical fluid :7thly, that the conductor, as soon as it is placed on the electrophorus, acquires a small degree of electricity, which it loses at -the approach of a finger, and recovers the moment that it is taken away from the electrophorus :- 8thly, that the electrophorus, whose inferior metallic coating, or whose conductor is electrified, produces the effects of the Leyden phial :-9thly, that to render the instrument under confideration electric, it is not necessary to rub it directly; electricity by communication -being sufficient for that purpose, as it produces the same effect:Iộthly, that the moment that the conductor is placed upon an electrophorus of fealing-wax, it acquires 'a weak positive electric city, and acquires a weak negative electricity when it is placed upon the same inftrument made of glass :itthly, that if we touch the conductor, 'after having placed it on an electrophorus of fealing-wax or glass, it loses all its electricity :- 12thly, that when, after having placed the conductor on an electrophorus of sealing-wax, and touched it, we take it away from the instru-ment, it'acquires, the very moment it is lifted up, a pretty strong negative electricity; but when the electrophorus, employed, in this experiment, is of glass, the electricity of the conductor is positive,

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The explication which this ingenious Academician gives of the effects of this celebrated instrument, is recommendable for its fimplicity; his description of some new electrophori, corstructed upon the principles which have been here ascertained by the most accurate experiments, is very curious, though succind; but it would be difficult to render it perspicuous to the Reader without the affiftance of the plates.

Concerning the Nature of the Earth, which is the Basis of the vegetable and animal Creation. By M. ACHARD. When ang portion of animal or vegetable matter is subjected to the combined action of air and fire, there remains, after the intire dispersion and evaporation of the volatile parts, a fixed residue of a grey colour, which, by a calcination, continued for some time longer, becomes intirely white. This residue is a mixture of fixed alkali (united sometimes with other falts), and of the earth

, from which the part of the vegetable or animal, that was burned, derived its solidity. In order to obtain this earth alone and see parated from all other matter, nothing more is necessary than to lixiviate the residue with distilled water. By this process all the saline particles are removed, and the earth, that formed the basis of the calcined vegetable or animal matter, remains alone in its most perfect state of purity. This is the method that has been followed by our ingenious Academician. He gives us accordo ingly a circumstantial account of thirteen experiments

, which be made in order to discover the earth that constitutes the bafis of vegetables--but of these we can only specify the results. Isto the earth, already mentioned, dissolves, with effervescence, in all acids :--2dly, it forms, with the marine and nitrous acids

, salts per deliquium, that are not fusceptible of crystallization :3dly, the marine acid adheres so closely to the earth of vegetables

, that the action of fire, alone, is not sufficient to separate them -4thly, the marine salt, of which this earth is the basis

, is fulceptible of decomposition by the vitriolic acid, and all the faline alkalis, except the caustic volatile alkali;--the case is the same with the nitrous salt which has vegetable earth for its basis: Sthly, heat alone is sufficient to carry off the nitrous acid that is united to the earth of vegetables :-6thly, this earth, saturated with the nitrous acid, acquires, by calcination, the property of shining in the dark, provided it be previously exposed to the light:-7thly, the vitriolic acid, in conjunction with this vea getable earth, forms a falt, which shoots into small crystals, and requires a large quantity of water to dissolve it: Sthly, the action of fire alone is not sufficient to separate from the vitriolic falt (whose basis is vegetable earth) the acid, that is necessary to the preservation of its faline properties :-gthly, the vegetable earth decompounds cinnabar, by uniting itself with its fulphur

, and disengaging the mercury, with which it was mineralized :

Irthly,

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