tainly not boiled in the liquid, as Grew fuppofed, fince the feathers are not at all corrugated, nor indeed materially changed from their natural appearance." P. 268. A plate accompanies this paper, which exhibits the above-defcribed mummy in its natural fize; but divested of its bandages, as well as of the bituminous or refinous fubftance. XIX. Obfervations on the fingular Figure of the Planet Saturn. By William Herichel, LL. D. F.R.S. There is not, as this author juftly obferves, an object in the heavens, which prefents fuch a variety of extraordinary phenomena as the planet Saturn. Its feven fatellites, its double ring, its equatorial belts, its flattened figure, its rotatory motion, &c. render it, among all the celeftial bodies, the moft interefting to aftronomers. Notwithstanding all thofe particulars which have been afcertained by the induftry of aftronomers, and principally by Dr. H. himfelf; a confiderable addition to the knowledge of that planet's peculiarities is contained in the prefent paper. This relates principally to the figure of the planet. In April, May, and June, 1805, Dr. H. had the opportunity of examining Saturn, in a very advantageous manner, through the molt perfect of his telescopes, and in the courfe of this examination he remarked, that the ring re fects more light than the body of the planet, fo that when the latter appears yellowith, the former appears more white, hence it may be diftinguifhed in that part which croffes the difk. The belts of Saturn cover a much larger zone than the belts of Jupiter generally do. The figure of the planet is moft deferving of attention; for, though flattened at the poles, yet it is not fpherical like that of Mars or Jupiter.--Some other caufe (probably the attraction of the ring) renders it fomewhat like a paral lelogram, "one file whereof is the equatorial, the other the polar diameter, with the four corners rounded off, so as to leave both the equatorial and polar regions flatter than they would be in a regular fpheroidical figure." This author diftinguithes three diameters of Saturn; viz. that which paffes through the points of greateft curvature is the longeft; the equatorial diameter is the next, and the polar diameter is the fhorteft. From a variety of micrometrical measurements, Dr. H. was enabled to determine, that 1 that the lengths of thofe diameters are 36, 35, and 32 refpectively. The latitude of the longeft diameter is 43°. 20'. A plate exhibiting the planet Saturn, as it appeared in the courfe of thefe obfervations, follows this paper. XX. On the Magnetic Attraction of Oxides of Iron. By Timothy Lane, Efq. F.R.S. This author commences the prefent fhort paper by faying, that he has found, by experiment, that hardened iron is not fo readily attracted by the magnet as foft iron.-He might have feen the very fame thing ftated, and the cause of it explained, in almost every work upon magnetifm. He was thence induced to examine what magnetical properties iron poffeffed when free from inflammable matter, and for this purpofe he inftituted feveral experiments, the refult of which is expreffed in the following paragraph. "My intention," he fays, "in this communication is to prove, generally, that mere oxides of iron are not magnetic; that any inflammable fubftances mixed with them do not render them magnetic, until they are by heat chemically combined with the oxides, and that when the combuftible fubftance is again feparated by heat, the oxides return to their unmagnetic ftate. magnetic oxides cannot be diftinguished from calcined oxides by their colour." P. 283. That We shall barely add, that Mr. L. might have found the effential part of thefe obfervations in a variety of works on magnetifm, if he had given himfelf the trouble of looking into them. XXI. Additional Experiments and. Remarks on an artificial Subftance, which poffeffes the principal characteristic Properties of Tannin. By Charles Hatchett, Efq. F.R.S. This additional paper, which is much longer than the first on the same subject, is divided into feven fections, wherein Mr. H. defcribes a great number of experiments which were inflituted with various views, though all relating to the tanning principle. In the first place he defcribes fome experiments on the comparative effects produced by nitric acid on thofe fubftances which contain the most notable quantities of tannin. Thefe experiments were fuggefted by the difference which exifts between the natural and the artificial tannin; namely, that the nitric acid which produces the latter, deftroys the former. Mr. H., however, finds that the de ftruction ftruction of the natural tannin, by the action of the nitric acid, is a work of considerable time and difficulty. In the next place Mr. H. tried the application of the fulphuric, and of the muriatic acid, to the artificial tannin. "When fulphuric acid," he fays, "was added to a folution of artificial tannin fubftance, the latter became turbid, and a copious brown precipitate fubfided, which was foluble in boiling diftilled water, and then was capable of precipitating ge latine." "The fame effect was produced by muriatic acid; fo that in these particulars, the artificial tanning fubftance was found to refemble, precifely, the tannin of galls and of other natural fubftances." Other fubftances, fuch as the carbonate of potash, ammonia, &c. were applied to the artificial tannin, and their effects are described. A curious circumflance is related in the course of thofe defcriptions, which is, that the abovementioned artificial tannin, although prepared from vegetable. fubftances, when placed on a hot iron, emits an odour much like that of animal fubftances, fuch as horn, feathers, &c. This, however, is not the only inftance of vegetable products yielding that odour; for vegetable gluten gives the fame odour. In the feventh fection this author defcribes three methods of forming the artificial tanning fubftance, viz. "ift. That which is produced by the action of nitric acid upon any carbonaceous fubftance, whether vegetable, animal, or mineral. "2dly. That which is formed by diftilling nitric acid from common refin, indigo, dragon's blood, and various other fubftances; and, "3dly. That which is yielded to alcohol by common refin, elemi, afafoetida, camphor, &c. after thefe bodies have been for fome time previously digested with fulphuric acid." P. 306. For farther particulars refpecting thofe proceffes, and likewife for the various ufeful remarks which accompany them, we must, unavoidably, refer our readers to the paper itself. XXII. On the Discovery of Palladium; with Obfervations on other Subftances found with Platina. By William Hyde Wollafton, M. D. Sec. R. S. An account of various peculiar circumftances which this author obferved in the course of his purifying a confiderable quantity quantity of platina by precipitation, forms the fubject of the prefent paper: and as the various fubftances which accompany that ore are poffeffed of diftinét properties, fuch as having different fpecific gravities, being more or lefs, or not at all, foluble by certain acids, &c. fo their exiftence, their qualities, and their nature, were manifefted in the course of the abovementioned operations. Of thofe extraneous fubftances, the metal called palladium is that which is principally treated of in the prefent paper. It being impracticable to give a diftinct idea of the abovementioned operations, and of their refults, in a very concife manner; we fhall only add the titles of the fix fections into which this paper is divided; viz. I. Ore of iridium. II. Hyacinths. III. Precipitation of platina. IV. Separation of palladium. V. Reafons for thinking palladium a fimple metal. VI. Additional properties of palladium. XXIII. Experiments on a mineral Subftance formerly fuppofed to be Zeolite; with fome Remarks on two Species of Uránglimmer. By the Rev. W. Gregor. Two fpecies of this fuppofed zeolite are found in a mine called Stenna Gwyn, in Branwell, Cornwall. "The first, and most common one, confifts of an assemblage of minute crystals, which are attached to quartz crystals, in tufts, which diverge from the point of adherence, as from a centre. "The other fpecies of this mineral confifts of an affemblage of cryftals clofely compacted together in the form of mammillary protuberances, in general, of the fize of small peas, intimately connected with each other." P. 331. This author describes the external characters of this mineral, and his analytical experiments upon it, the refult of which shows that it principally confifts of alumina, with a fmall proportion of filica, and a much smaller portion of lime. With respect to the Uran-glimmer, Mr. G. fays, "I fhall add a few defultory remarks upon the yellow and green cryftals, which frequently accompany this foffil. "I confidered them to be two fpecies of Uran-glimmer, which had been examined by the celebrated Klaproth. "The yellow cubic crystals are light. Their specific gravity aken at the temperature of 45° Fah. was 2,19. "Expofed to the flame of the blowpipe on charcoal, they decrepitate violently.. A piece of this fubftance is taken up by. phosphate phosphate of ammonia and foda, without effervefcence, and communicates a light emerald-green colour to the fufed globule, By expofure to a red heat, this fubftance lofes nearly a third part of its weight. It then becomes of a braffy colour." It is foluble in the nitric and muriatic acids; but I could procure no cryftallized falt from the folution of either of them." "By evaporation to drynefs, and rediffolving the mafs, fome filica is feparated." P. 344. Mr. G. then defcribes the experiments he made upon this fubftance, by expofing it fucceffively to a variety of chemical agents, operations, &c. After which he fays, "The fcarcity of this beautiful mineral has precluded me from operating on fuch a fufficient quantity, as a regular and rigid analyfis required." "The fubftance, which is held in folution by ammonia, has" fome peculiar properties that feem to diftinguish it from uranium. And if this mineral be the uran-glimmer, I have cer tainly detected the oxide of lead, lime, and filica in it, which have not hitherto been confidered as ingredients of that foffil. The green cryftals differ in no refpect from the yellow, except in containing a little of the oxide of copper." P. 348. After the papers here noticed, this fecond part of the Philofophical Tranfactions for the year 1805, contains a lift of the prefents made to the Royal Society, with the names of the donors, from November 1804, to July 1805, and the index for the whole volume. ART. II. A Defcription of Latium, or La Campagna Di Roma, with Etchings, by the Author. 4to. Price 11. 1s. Long man. 1805. THE author of this work we understand to be a female," but so much extenfive knowledge is difplayed, various reading and familiar acquaintance with the beft writers of ancient times, as would have reflected no difhonour on a profeffed and accomplished scholar. It is truly observed in the introduction, that travellers, and particularly thofe among our own countrymen, who vifit Italy from the curiofity and veneration infpired by their early ftudies, from want of time or opportunity, or from not having the fcenes pointed out, which are more particularly worthy of their attention, fatisfythemfelves with merely vifiting a few of the towns and vil Jages |
