ve M4 ia ley ph ini : jit THE QUARTERLY JOURNAL SCIENCK, LITERATURE, AND THE ARTS. VOLUME XVII. LONDON: JOHN MURRAY, ALBEMARLE-STREET. ———. 1824. LONDON? PRINTED BY WILLIAM CLOWES, Northumberland-court. CONTENTS OF THE QUARTERLY JOURNAL, No. XXXII. ART. PAGE TI. On some Phenomena relating to the Formation of Dew on Me- tallic Surfaces. By Georce Harvey, M.G.S., &c.&e.. . II. Description of Two New and Remarkable Fresh Water Shells: Melania setosa and Unio gigas. By Witttam Swainson, Esq., F.R.S., M.W.S., &. . 2 +» ee ee ee III. On Indistinctness of Vision, caused by the presence of False Light in Optical Instruments ; and on its Remedies. By C. R. Gorine,, MEDPiu Ge oyowll’ b gigi! ogo 4,00, iegine 4% IV. The Characters of several New Shells, belonging to the Linnzan Volutz, with a few Observations on the present State of Con- chology. By Witt1am Swanson, Esq., F.R.S. &c. . V. Account of the Earthquake in Chili, in November, 1822, from Observations made by several Englishmen residing in that Coun- try. (Communicated by F.Puace, Esq.) . . 6. «, ;. VI. On Evaporation, By I, Freperic Daniett, Esq., F.R.S., Man Ol, ng ae SS ee ke le we VII. A Design for making a Public Road under the Thames, from the east side of the Tower, near Iron-Gate Stairs, to the opposite side of the River, near Horseleydown Stairs. By Samuen ee a en ae oS aes ae ie it eke oe VIII. An Account of the Overflowing Well in the Garden of the Horticultural Society at Chiswick. (Communicated by Josern Sapine, Esq., Sec. H.S., &c.). IX. On the Taylorian Theorem X. Astronomical Phenomena, arranged in Order of Succession, for the Months of April, May, and June, in the Year 1824... 13 17 28 38 46 it CONTENTS. Arr. PAGE XI, Astronomican ann Nautica, Conuectrions, No. XVII. i. Remarks on the Catalogue of the Orbits of the Comets that have been hitherto computed. By Dr. Ovpers . . . . . . . . + 85 “iil. Further remarks on the periodical Comets, (86 Olb.) with con- jectures on the effect of a resisting medium. By Professor ENCkR 96 iii. Comparison of the New Tables of Refraction, with observation 100 iy. Note on Refraction, addressed to Professor ScHumMACHER . . 103 - General Results of Observations on the Dipping Needle. By wv. Scopessyy Juni Baqi). swans dl anes Doth 2 wilfay 104 vi. Elements of the Comet of 1823-4, By various Computers . . 104 Xi. © © ° © AwALYsts oF ScrentiFic Books. i. Sur les Ichthyolites ou Poissons Fossiles. Par M. Blainyille, Article extrait.du. Noveau Dictionnaire d'Histoire Naturelle . . ~» 105 ii. Philosophical Transactions of the Royal Society of London, for the Year 2gBP'82< IORI AES GW PEAY IORONY Wer wg lye ( 182 iii, Letter to the Editor from Dr. William Henry . . . . © . 131 XIII. Progress or Foreign ScieNcR . . « 6 we ow o + 135 XIV: MISCELLANEOUS INTELLIGENCE. I, MgcHaANIcaL SciENCE. 1, Remarks on Tron-Wire Suspension Bridges. 2. Test for the Action of Frost on Building Materials, by M. P. Brard. 3. On the strength of Cast Iron, and other Metals. 4. On the Capillary Action of Fissures, &c. 5. Sound produced by opening a Subterraneous 147 Gallery. 6. Nautical Bye-tube, 7. Leghorn Straw Plait 2... If. CaraicaL Science. 1. On Fulminating Silver and Mercury. 2. On the unequal Dila~ tation of a Crystal in different directions, by heat, 3. Difference CONTENTS. : lil” Am i aaa PAGE of Crystalline Forms of the same Substance. 4. Supposed Effect of ~ Magnetism on Crystallization. 4. Thermo-magnetisu. 5. Electro-— maguetic Multipliers. 6. Plate Electrical Machines. 7. Improve- ment of the Leyden Jar. §. Electricity on Separation of Parts. 9. Electric Light. 10, Connexion of Phosphorescence with Electricity. 11. Phosphoresence of Acetate of Lime. 12. Preparation of Sul- phurons Acid Gas. 13. Preparation of Sulpburetted Hydrogen. 14. Preparation of Saturated Hydro-sulphuret of Potash or Soda, 15. Preparation of Kermes Mineral. 16. Action of Sulphate on Iron. 17. Economical Preparation of pure Oxide of Nickel. 18. White Copper. 19. Prussian Blac. 20, Crystallization’ of the Sub-car~ bonate of Potash. 21. Composition of Ancient Ruby Glass. 22. De- tection of Arsenic in cases of Poisoning. 23. Ou the Detection of Acetate Morphia in cases of Poisoning. 24. Test for Morphia. 25. Process for obtaining Strychnia. 26. Volatility of Salts of Strychnia. 27. Acid Tartaric Sulphate of Potash. 28. Pyroligneous Ether, or Pyroxilic Spirit. 29. Cafeine. 30. Conversion of Gailic Acid into Ulin, 31. An Aécount of an Electrical Arrangement produced with different Charcoals, and one conducting Fluid. . i ‘ . 158 Ill. Narurat Hisrory. 1. Vegetation at different Heights. 2. Irritability of Plants. 3. Notice of an undescribed Lava which attacks and devours Snails. 4. Hatching Fish. 5. Natural changes in Carrara Marble. 6. Note on the existenee of a Nitrate anda Salt of Potash in Cheltenham Water. 7. [odine in Mineral Waters, &c. $8. New Vesuvian Mine- rals. 9. Products of combustion of certain Coal Strata. 10. Ad- vancement of the Ground. 11. Existence of Free Muriatic Acid in the Stomach, 12. Usé of Sulphate of Copperin Croup. . . Wa On the Recurrence of the Smallest Light of the Variable Star Algol, By W. M, Moseley, Esq. p Puke ‘ ' * oe 184 XV. Meterologieal Diary beet Aten Re ed) Gerrg «AQT TO OUR READERS AND CORRESPONDENTS. We are much obliged by Cantab’s letter, and will look more sharply into those matters in future. At page 345, line 12, of our last volume, for “ invariably,” vad ** in= versely.” Hy 8 ** An old Subscriber,” who accuses us of “ puffing,” had better not stir the subject of his letter, least we should communicate information which might be very disagreeable to some of the gentlemen whose cause we presume he intends to advocate. No person or thing has ever been puffed in this Journal. The suggestions of ‘* Medicus” respecting the New Pharmacopeia, shall be attended to. Sir George Mackenzie's paper has duly reached us ; we regret that want of room obliges us to postpone its publication. The article on the Mechanic's Institution is too long for insertion. We are sorry again to postpone our Correspondent y- A. "The letter dated ‘* Glasgow, March 1,” shall have due consideration. Among Miscellaneous Intelligence our readers will find much that should have been placed under the head of Foreign Science. We have received many communications and inquiries respecting the Royal Institution, and feel much obliged for the facts which several of them contain. The Visiter's Report will shortly be laid before the Members, and will probably include the information sought for by some of our Cor- respondents ; if not, they shall be replied to in our next. The observations of F. R. S,, and those contained in-a letter dated ‘«* Kensington,” and in another signed ‘ Amicus Justitie,” are extrerhely pertinent and judicious, but we feel disinclined to enter into the subjects they touch upon if we can possibly avoid it. ‘The parcel from Manchester has just arrived. (March 29.) Preparing for Publication, in 1 Vol. Svo., A MANUAL OF PHARMACY. By W. T. Branoz, F.R.S, &c. CONTENTS OF THE QUARTERLY JOURNAL, No. XXXIV. ART. PAGE I. On the Horary Oscillations of the Barometer. By J. Freperic DET BES skalmoeinitel Secs watnemiepye) ih ed: mrcknd SO II. On the Alterations of Rate produced in Chronometers by the in- fluence of Magnetism. By Grorce Harvey, Esq., F.R.S.E., &e. 197 III. On Indistinctness of Vision caused by the presence of False Light in Optical Instruments, and on its Remedies. By C. R. Gorinc, M.D. (Continued from p. 28.) . . . . . . - 202 1V. Hints on the possibility of changing the Residence of certain Fishes from salt water to fresh. By 1. Mac Cuxuocn, M.D., 4 NE Rete el kee tes ere ys set sy) oe UD V. Mr. Cooper's Lamp Furnace, for the Analysis of Organic Bodies 232 VI. Description of a self-acting Blowpipe. By Mr. H.B. Lerson 236 VII. Astronomical Phenomena arranged in Order of Succession, for the Months of July, August, and September, in the Year 1824. By James Souru, F.R.S. (Continued from Page 84) 238 VIII. On the Soundings in the British Channel. [To the Editor of ihe’ Quarterly sournal| 9s. 2. se. < +. e -seue, es) ou 6 BHO IX. Some particulars respecting the Ornithorhyochus Paradoxus. PIO IE SOOT IRA Veh pa.) sina walang Ces! asthiaA Sad St se okies 240 X. Procerpines or rHE Royat SocreTy . .. +. 2 «© « « « 200 XI. Proceepincs or true RoyarlnstiruTion . ..... . 281 XII. Asrronomicat anv Navricat Coxrections. No. XVIII. . i. Extracts relating tothe Theory of Tides 2. 1 ee + 295, 1 CONTENTS. ART. PAGE ii, An easy Method of computing the Time indicated by any Number of Chronometers, with the given Time at a Station. By the Rev. Fearon Fallows, M.A., F.R.S., Astronomer at the Cape of GoodsHopesaiconts Mar eb SUBSE MOMENTA. ET Mn ot apa iii, Easy Approximation to the difference of Latitude on a Sphe- roid y.5 fret eGNS * WP eee ae a ee se ee iv. Extract of a Memoir on the Theory of Magnetism, read at the Academy of Sciences, 2 Feb. 1824. By M. Poisson . . . . 317 XIII. ANALYSIS OF ScrenTIFIc Books. i. Meteorological Essays and Observations. By J. F. Daniell, IBURAS.,, °" 3.\¥e00"s). ¢ ep ge deite hee ig ane is Otis Nc ps alles amas ii. A translation of the Pharmacopeia of the the Royal College of Physicians, 1824. With Notes and Illustrations. By Richard Phil- lips, F.R.S., Lon. and Ed. &e, &e. epee ow oy se BAD XIV. MIsceLLANEOUS INTELLIGENCE. I. MecHANICAL AND GENERAL SCIENCE. 1. Adhesion of Nails in Wood. 2. Levels in London above the highest Water-mark. 3. On the comparative Advantage of Coke and Wood as Fuel. 4. Vicat on burning of Limestone or Chalk. 5. On the Application of Muriate of Lime asa Manure. 6. Pre- paration of Caoutchouc. 7. Magnetic Intensity of a Chronometer. 8. Influence of Magnetism on the Rates of Chronometers. 9. On the adaptation of a Compound Microscope to act as a Dynameter for Telescopes. By C. R. Goring, M.D. : : 360 Il. Cuemican SciENCE. i. On a Reciprocity of insulating and conducting Action which the incandescent Platina of Davy exerts on the two Electri- cities. 2. On the magnetic Action of strong electrical Currents on different Bodies. 3, On Electro-motive Actions produced by the con- tact of Metals and Liquids. By M. Becquerel. 4. Measurement of the conductibility of Bodies for Electricity. 5. Distinctionof Positive and Negative Electricity, 6. Electricity produced by the Congelation of Water. 7. Hare’s Single Gold-leaf Electrometer. 8. Hare's Voltaic Trough. 9. Dobereiner’s instantaneous Light Apparatus. 10, Test CONTENTS. iii ART. PAGE of the Alteration of Solutions by contact with Air. 11. Odour of Hydrogen Gas extraneous ; Inodorous Hydrogen Gas. 12. Inflam- mation of sulphuretted Hydrogen by Nitric Acid. 13. Artificial Chalybeate Water. 14. Mereurial Vapour iu the Barometer. 15. Combustion of Iron by Sulphur. 16. Ammonia in Oxides of Iron. 17. Iodous Acid. 18. Preparation of pure Oxide of Uranium. 19, Uranium Pyrophori. 20. Atomic or Proportional Weights. 21. On the Acetates of Copper. By M. Vauquelin. 22. Dahline, or Inuline, in the Jerusalem Artichoke. 23. New Vegeto alkali, Vio- line. 24. Jalapine, or Jalapia. 25. MM. Leibeg and Gay-Lussac on Fulminic Acid and Fulminates. 26. Supposed new Metal, Taschium 27. Liquefaction of Sulphurous Acid : : 369 Ill. Naturat History. 1. On the different Manners in which Bodies act on the Organs of Taste. By M. Chevreul. 2. Action of Meconic Acid on the Animal Economy. 3. On the ditferent Masses of Iron which have been found on the Eastern Cordiliera of the Andes. By MM. de Revero and Boussingault. 4. Natural Ice Caves. 5. Glacier of Getros, Valley of Bagne. . . . . - 892 XVI. Meteorological Diary for the Months of March, iy and May, 1824 : : : E . 398 Inpex : : : : . . 399 TO OUR READERS AND CORRESPONDENTS. Several Papers remain on our hands, which, for reasons already com- municated to the respective authors, we are obliged to decline publishing. We shall be under the necessity of destroying these papers, unless they are immediately applied for. We regret that the Paper on the Analysis of the Holy-well Water is too long for insertion. F Mr. Stevenson s Paper is declined in consequence of the number of engravings requisite for its illustration. The drawings shall be taken care of. We suspect that our voluminous Correspondent upon the subject of London Bridge is not quite disinterested, andif he will favour us with his address, he shall be convinced that we have not neglected the ample consideration of his communications, The request of E. A. has been made known in the proper quarter. Mr. Bigsby’s Paper has reached us, and will appear in our next Num- ber. We never advocated the Repeal of the Salt-Tax, and cannot therefore conscientiously insert the Letter of our Correspondent at Liverpool. Mr. Walsh’s Letter reached us too jate for insertion. We cannot meddle in the matter alluded to by ous Correspondent at Edinburgh, who nevertheless has our thanks. Preparing for Publication, A MANUAL OF PHARMACY. BY W. T. Branbg, F.R.S., Ke. THE ‘QUARTERLY JOURNAL, April, 1824. Art. I. On some Phenomena relating to the Formation of Dew on Metallic Surfaces. By George Harvey, M. G..S.,.5:¢;. de. [Communicated by the Author.] It is a curious fact, mentioned by Dr. Wells, in his valuable Essay on Dew, that if a metallic substance be closely attached to ‘a body of some thickness, which attracts dew powerfully, the ten- ‘dency of the metal to promote the formation of moisture on its sur- face, instead of being increased from the circumstance, is dimi- nished, provided the metal covers the whole of the upper surface ‘of the body to which it is attached*. This principle he illustrated by the following experiment: Two pieces of very light wood, each four inches long, a third of an inch wide, and one tenth of an inch thick, were joined in the form of a cross ; and to one of its sides the non-metallic surface of a square piece of gilt paper was at= tached, by means of mucilage. On exposing the metallic surface ‘on a dewy night, by suspending it ina horizontal position, about six inches above the ground, he found after a few hours, that the parts of the metallic paper, not in contact with the wood, had minute drops of dew on their surfaces, while those in contact with the ‘cross, were perfectly dry. In repeating this experiment, I have employed gold and silver * Wells on Dew, page 22, second edition, Vou. XVII. B 2 Mr. Harvey on the Formation metallic paper, attached to frames of various forms; and by pro- secuting the subject under different circumstances of the atmo- sphere, I have met with some interesting and beautiful phenomena, which seem to merit a particular description. The metallic squares were sometimes suspended. a few inches above the ground, and at other times placed on surfaces of glass, or on the recently-mowed herbage. The particular situation of each will however be noticed, as the different experiments are described. In endeavouring to trace phenomena relating to the deposition of dew on the surfaces of polished metals, some perseverance is necessary ; as it is but seldom that the circumstances of tempera- ture and moisture are such, as to permit its ready formation. It would appear, that not only the depression of temperature, and the presence of moisture in the lowest atmospheric stratum, must be considerable ; but that the superficial dimensions of the metal have also an influence on the formation of moisture on it. ‘The dif- ference between glass and polished metals in this particular is sin- gularly remarkable. A small vitreous surface, when presented to a clear and tranquil sky, has its surface as readily covered with moisture as one of larger dimensions ; but in the case of metals of the same kind, of polished tin for example, a large metallic plate is sometimes more readily dewed than a small one ; whereas, under other circumstances, one of a small area is covered with a copious deposition of moisture, whilst a large one will preserve, during the whole night, a bright and unsullied surface*. I have thought it proper to introduce these remarks, in order to apprize the young inquirer of the disappointment to which he will be frequently liable, when prosecuting this interesting subject with relation to polished metals. Whenever the squares of silver paper were exposed for the pur= * ‘A large metallic plate, lying on grass, resists the formation of dew more powerfully than a very small one similarly situated. If a large and a very small plate be suspended horizontally, at the same height in the air, the small plate will resist the formation of dew more powerfully than the large.”’— Wexts on Dew, page 22; second edition. of Dew on Metallic Surfaces. 3 pose of receiving dew, it was remarked, that the first formation of moisture took place at the corners of the triangular portions of the metallic paper, not in contact with the wood; the particles beng exceedingly minute, and requiring the aid of a magnifying glass to discover them. As the radiation of the metallic surfaces was pro- moted by the influence of the clear nocturnal sky, those particles of moisture gradually increased both in number and size ; while other minute drops began at the same time to be deposited on the edges of the square; so that in the course of three hours, the metallic sur- face had assumed the appearance represented in fig. 1, Plate I. the shaded parts denoting the particles of dew, and the dotted lines the position of the cross to which the metallic paper was attached. After midnight, the farther deposition of moisture appears to have been suspended; as at half an hour before sunrise, the appearance of the metal was nearly the same as when the last observation was made. ~ It was most interesting to observe, during the progressive depo- Sition of the moisture, that the particles were disposed in triangular forms, similar to the right-angled triangles, into which the metallic paper was divided, by its contact with the cross ; and this was the case even when the triangles, from their minuteness, might be es- teemed of an almost elementary kind. And at the last observation, when the greatest quantity of dew for the night had been depo- sited, the triangular figures were perfectly well defined, their hypo- thenuses being bounded by the edges of the metallic surface, and their several bases and perpendiculars, respectively parallel to the arms of the cross. . So also the gradual accumulation of moisture in the small segments, whose chords coincided with the edges of the metal, was marked by the same uniform and progressive cha racter; the particles, during their increase in number and magni- tude, preserving a beautiful curvilineal contour to the figures which they formed. The parts of the paper in contact with the cross, had no dewy particles on them ; their junction with the wood appearing effectually to prevent the formation of moisture ; thus confirming the observation of Dr. WELLs. On another night, favourable to the copious formation of dew, B 2 4 Mr. Harvey on the formation the moisture was not confined to the small triangular and curvili- neal spaces alluded to in the preceding experiment, but was dif- fused over the whole surface, excepting the parts in contact with the wood. The metallic surface presented therefore a dry portion with well defined borders, in the form of the algebraic sign plus ; and four triangles of dew, formed of particles, beautifully distinct, but undergoing a minute diminution in size, from the edges of the paper to the vertices of the triangles, as represented in fig. 2, To contemplate these triangular formations of dew to advantage, it was necessary to place the eye in a situation to receive the impres- sion of the reflected light. In such a position the forms of the tri- angles were viewed to great advantage ; the innumerable atoms of dew presenting a pleasing contrast to the unsullied figure of the cross. On the same night a similar surface of gold metallic paper, simi- larly circumstanced, presented an appearance as in fig. 3, in some degree analagous to that represented for the silver paper im fig. 1. The moisture seemed however destitute of that uniformity which characterized the particles formed in the last-mentioned diagram, although some slight approach to it might be traced, in the forma- tion of the irregular patches of dew, in the angular portions of the figure. On the following night, portions of silvered paper attached to triangular and square frames, as denoted by figures 4 and 5, were presented to the nocturnal sky. In the former, the beautifully minute particles of dew were confined to the equilateral triangular surface, not in contact with the frame; the particles however seeming to preserve an uniformity of magnitude over the whole surface. To the middle of the non-metallic surface of fig. 5, a cir- cular piece of wood was attached, of the same thickness as the frame ; and during the abundant deposition of dew which took place in the course of the night, the moisture was strictly confined to the parts of the metallic paper, not in contact with the wood ; the small circular portion, although surrounded as it were with an atmosphere of moisture, presenting as effectual a -barrier to its formation as the external frame. of Dew on Metallic Surfaces. ; 3 During the prosecution of these experiments, J have had fre- quent opportunities of remarking that silver metallic paper per- mits dew to be deposited earlier, and in greater abundance on its surface, than gold. arly in the month of April, at nine p. m., a large pane of glass was placed on the green herbage, and on it the squares of gold and silver paper attached to their respective crosses. The clear and transparent sky, joined to the perfectly tranquil state of the atmosphere, indicated the possibility of a co- pious deposition of dew. At six the next morning the grass exhi- bited the appearance of a thick hoar frost, and the moisture which had been formed on the upper and under sides of the glass during the night, presented coats of transparent ice. On referring to the squares of metallic paper, that of gold was found removed from the glass on which it had been placed the preceding evening, to the distance of six feet; its change of situation having been probably produced by the force of some breeze during the night. ‘The me- tallic side was in contact with the grass, and on taking it up it presented four beautiful triangles, completely covered with innu- merable particles of frozen dew. Those parts of the metal which had their inferior surfaces in contact with the wood, exhibited the perfect and well defined form of the cross, represented in fig. 6, The appearance of the crystalline triangles, when contrasted with the golden surface ef the cross, was extremely beautiful ; and it was remarked, that as the gradually increased warmth of the morning dissolved the crystals of dew, the moisture was still confined to the same triangular surfaces: thus preserving completely the form of the cross. Minute crystalline atoms were also perceptible on the non-metallic side of the paper, and which, likewise dissolving, had a sensible effect on the rigidity of the paper. On examining the silver square which had preserved its situation on the glass, its metallic surface was found without the appearance of moisture, under any form, on its surface. A hasty consideration of this phenomenon might lead us to infer, that dew is more readily deposited on gold than on silver, con~ trary to what has been before remarked, as the result of extended 6 Mr. Harvey on the Formation observations ; but a farther investigation of the anomaly in question may lead to a satisfactory explanation of its cause. eee The appearance of the heavens at the time the metallic sure faces were placed in the meadow for observation, indicated, as be- fore remarked, the probability of a copious deposition of dew, during the night, and that a considerable quantity was deposited, the hoar-frost in the morning clearly proved. The temperature, and the hygrometric state of the air, were also, from other collate- ral circumstances, to be regarded as highly favourable to the for- mation of dew on metallic bodies; and that a breeze must have existed for some time during the night, sufficiently powerful, at least, to remove the metallic square, together with its attached cross, to the distance of several feet, is likewise apparent. These circumstances will account for the anomaly in question, * In the first place, dew was most probably deposited during the former part of the night, in a sufficiently copious degree, to cover the four triangles on each of the metallic surfaces. This deposition may be presumed to have taken place before the temperature of the lowest stratum of air, in contact with those surfaces, was de- pressed to that of the freezing point. The breeze removed the golden square, and left its metallic surface in contact with the short herbage, the temperature of which had been previously re= duced to 32°. This temperature necessarily caused the particles of dew already deposited on the triangular surfaces to crys- tallize ; and left the cross with its lustre undiminished. The same wind dissipated the moisture that had been deposited on the silver surface; for it has been remarked by Dr. Wells*, that ‘the dew which has formed upon a metal will often disappear, while other substances in their neighbourhood remain wet.” The breeze indeed may have continued the remainder of the night, and prevented any new formation of dew onthe silvery surface; but, at the same time, permitted moisture to be deposited on the non-metallic sur- face of the golden square ; because white paper has been placed by * Page Ql, Essay on Dew, hy De. Weta, second edition, of Dew on Metallic Surfaces. Y the last-mentioned philosopher among the substances that are even more productive of cold than wool*. Or it is possible that the breeze may have subsided, and the circumstances of temperature become such as to have allowed the deposition of dew on the paper, but not of its re-formation on the silver. Dr. Wells has also remarked +, that when dew forms upon me- tals, it ““ commonly sullies only the lustre of their surface ; and that even when it is sufficiently abundant to gather into drops, they are almost always small and distinct.” This observation, however, re- quires some limitation ; since, on nights that have been more than usually cold, and when the quantity of moisture in the air has been abundant, I have observed the dewy particles deposited on metals to attain a considerable magnitude ; and examples have even oc- curred of polished tin surfaces being completely covered with thin sheets of water, the result of the junction of the innumerable minute particles deposited on them. On one night, equal squares (their linear edges being one inch and half) of lead, zinc, brass, copper, and tin, were laid on a large plate of glass, and presented to the influence of a clear sky. At sunrise the next morning, the particles of dew on the different surfaces were found of variable magnitudes ; those on the lead being the largest, and of the size represented in fig. 7. Those on the zine were next in magnitude, as denoted in fig. 8; and the particles on the brass were still smaller, but much more numerous, as in fig. 9. The copper and tin, particularly the latter, seemed only to have had the lustre of their surfaces just dimmed, by the abundant moisture of the air. Lead, therefore, was at one extreme of the series, and tin at the other ; brass holding a middle rank between the two. - This relation, however, between the particles on lead and brass, was inverted on another night, when equal squares were laid on the recently cut herbage, the particles on the brass being of the size represented in fig. 10, and those on the lead as denoted in fig. 11, As the plates of metal were the same in both cases, it is reasonable * Page 21, Essay on Dew, by Dy, Wet1s, second edition, } Page 21, second edition, 8 Mr. Harvey on the Formation to infer that the opposite results, observed were produced by the substances on which they were respectively placed. A slight trace of moisture was perceptible on the zinc, but not the least degree on the copper and tin. » An example of the slowness with which polished tin permits moisture to be deposited on it, occurred when a concave mirror, formed of polished block tin, was employed as an /thrioscope, on the plan first suggested by Dr. Wollaston. The focus of the in- strument, at the time the experiment was performed, was 20 inches above the ground. The night was tranquil, and dew was copiously deposited on glass, a few minutes after it was presented to the chilling influence of the transparent sky. Atnine, vr. M. the ther- mometer in the focus of the Athrioscope indicated a temperature of 46°; the herbage being at the same time 44° ; and the air, seven feet above the ground, 494°. Observations, connected with some other phenomena, were made every half hour; but no trace of moisture was perceptible on the metallic surface, till two a. M., when it appeared slightly dimmed, although other substances had gained considerable increments of dew in the same time ; masses of wool, for example, having increased in weight from twelve grains to thirty. At the same moment, the focal thermometer indicated a temperature of 424°; that on the grass, 39°; and that elevated in the air, 45°. In five hours, therefore, the cold of the upper sky only underwent a change of 33°; whereas the grass lost by radia- tion in the same time 5°; and the eleyated stratum of air diminished its temperature 45°. From two o’clock to three, the thermometer remained stationary, but the moisture had sensibly increased on the surface of the Athrioscope, and increments amounting to se- veral grains, were likewise found on other substances ; a proof, that if the general temperature remains stationary, after the tempe- rature of a body is sufficiently lowered to permit the formation of dew on its surface, the farther deposition of moisture is not pre- vented. At four a.m. the whole metallic surface was covered with visible drops, the temperature, at the same moment (just before sunrise), indicating the maximum of cold, the focal thermometer of Dew on Meiailic Surfaces. 9 being at 40°; that on the grass, 37°; and that elevated seven feet above the ground, 414°. It is worthy of remark, that two plain sheets of polished tin, placed horizontally on the herbage, had not the slightest trace of moisture on them. On another night, however, when there was every prospect of an abundant deposition of dew, the influence of the grass in promoting its formation on metals, was clearly shown. At nine p. m. two plates of polished tin, one fourteen inches by ten, and the other six by two, were laid on very short grass. Another plate of the same di- mensions as the former was placed gently on the long grass. Its weight necessarily compressed the herbage on which it rested, so that the polished surface was surrounded on all sides by grass, reaching twelve inches above it. In fig. 15 the long grass is repre- sented on two opposite sides of the tin M N, together with the com- pressed herbage below it. At eighteen inches above the ground, or two inches above the average height of the grass, a similar plate, O P, was placed on slender props. The temperature of the grass at the moment the plates were exposed was 60°, and of the air 65°; being a difference of 5° in the small space of three feet. At five the next morning, a great quantity of dew was formed on the grass. A register thermometer on the short herbage, indicated the maximum cold to have been 52°, and of the air, at the elevation before mentioned, 60°. ‘The difference between these maximum depressions of temperature was, therefore, by no means considera- ble; and the copious deposition of dew observed was to be regarded rather as the result of the abundance of moisture in the atmo- sphere, than as a consequence of great difference of temperature. The metals presented the following particulars for observation. The plates resting on the short herbage had a few scattered patches of dew on their upper surfaces, but nothing like a regular and uni- form deposition, The plate M N, surrounded by the long grass, had its superior surface completely covered with minute but distinct particles of moisture ; but the plate O P, elevated above the grass, was perfectly dry. This difference in the results must be regarded as arising from the different conditions, under which the plates were situated, Tee latter surface, it will appear, had not its tem- 10 Mr. Harvey on the Formation perature depressed below that of the stratum of air reposing on it, during the night; but the former must have been considerably colder than the column of air hovering above it. The cooling power of the grass surrounding the plate MN, and on which it also rested, must have necessarily extended its influence to the me- tal; and by lowering its temperature considerably, have occasioned the copious deposition observed. The upper plate not being in contact with the grass, permitted the air to pass freely on each side of it; and being itself a bad radiator, attained no condition during the night favourable to the deposition of dew. With re- spect to the formation of dew being less abundant on the plates resting on the short herbage, than on that surrounded with the long grass, it may, in one point of view, be regarded as a consequence of the ‘curious fact observed by Mr. Six, that the temperature of short grass is always greater than that of long grass. The state of the herbage has always a considerable influence on the quantity of dew deposited, and the greater the body it presents, the more abundant it is likely will be the formation. That the quuntity of herbage has a considerable effect, may be inferred from the expe- riment, that when one mass of wool was placed on short herbage, and another of equal size and weight on the summit of a mass of recently cut grass, fifty inches above the ground, the moisture gained by the former during the night, was only fifteen grains, whereas the increment to the latter was twenty-three. In consequence of the plate O P having had its surface exposed to the entire canopy of the sky, but the view from the plate M N being confined to a comparatively small circular space, in the zenith of observation, it might be inferred from a principle adopted by Dr. Wells*, that the former would have gained more moisture than the latter. But the maxim of this ingenious philosopher is evidently limited to the consideration, that the bodies are in other respects similarly circumstanced. For instance, in one of the experiments * Essay on Dew, page 14, second edition. The principle here alluded to ig the following; * Whatever diminishes the view of the sky, as seen from the exposed body, accasions the quantity of dew which is formed upon it, to be fega than would have occurred if the exposure to the sky had heen complete,” of Dew on Metallic Surfaces. I! instituted by Dr. Wells, to illustrate the principle in question, by bending a sheet of pasteboard into the form of the roof of a house, and placing it with its ridge uppermost, and ends open, over a mass of ten grains of wool laid on the grass ; and at the same time placing another equal mass on the herbage, fully exposed to the sky, the former gained, during the night, an increment of only two grains, whereas the latter gained sixteen. In this experiment, the two masses were placed under the same circumstances, so far as con- tact with the grass was coucerned; but in the case relative to the plates of tin, one was not only in contact with the herbage, but also surrounded by it; whereas the other was completely detached. The gradual manner in which dew is deposited on the metallic side of gilded glass was pleasingly exemplified on another occasion. The parallelogram of glass was six inches by four, as represented in fig. 14. It was first exposed to the atmosphere with its metallic side uppermost, at half-past six, rp. m., being about three quarters of an hour after sunset. The atmosphere was clear, and highly charged with moisture ; and dew had formed on glass in a shady place, three quarters of an hour before the departure of the solar orb. A mild and gentle breeze prevailed also at the same time. No perceptible change took place in the metallic surface until eight, when minute particles of dew were visible at A, the leeward end. From the last-mentioned hour to ten, the moisture gradually in- creased from A to the middle part of the surface ; and distinct drops were likewise deposited at D, B, E,C. As the particles increased in size round the three edges, other minute drops were successively deposited, more distant from them ; and it was observed, that they accumulated with most rapidity at the leeward sides A and C. At eleyen, Pp. M., when the sketch represented in the figure was made, an oval portion of the metallic surface was found entirely free from moisture. The same figure was also perfectly visible at midnight, when the drops at A had increased to at least an eighth of an inch in diametey; those at C being rather less, The particles at the corners D and E also preserved their superiority in size above those at B, 12 Mr. Harvey on the Formation of Dew. The difference in the appearance of dew, when deposited on tin and on glass, is sufficiently remarkable to arrest attention, not only when the moisture remains uncrystallized, but also when it is frozen. In an example that occurred of the latter case, a decrease in the magnitudes of the frozen particles could be traced from its edge to the dry and unfrozen margin surrounding a parcel of wool, placed on the middle of the plate, as represented in fig. 13: the appear- ance of the frozen atoms partaking, in some degree, of the lustre of the tin. The parcel of wool, in the interval from nine P. m. to mid- night, gained four grains of moisture ; and from the last mentioned hour, to six the next morning, thirty-two grains ; thus gaining, in a double time, an eight fold quantity of moisture. The wool was frozen to the tin; and when the rays of the sun fell on the metallic surface, the crystalline particles became detached from it, and were readily col- lected together. The dew deposited on the glass presented an irregu- lar fibrous appearance, its colour partaking of the greenish hue of the crystal. The icy particles on the tin were first deposited as dew, and frozen before they had collected in sufficient numbers to run into each other, and form an uniform crystalline surface. But the dew on the glass being formed at an earlier period of the night, a sufficient quantity was deposited to cause the particles to mingle with each other, and thus to present to the action of the freezing tem- perature a wide spread surface of water. The unequal action of the glass, combined with the law which regulates the crystallization of water, communicated to the frozen surface of dew, the fibrous and irregular character represented in fig. 12. Soon after the solar rays had impinged on the glass, filaments of ice were detached from both its surfaces, that from the upper side being much the thickest. Plymouth, December 12, 1823. 13 Arr. Il. Description of Two New and Remarkable Fresh Water Shells: Melania setosa and Unio gigas. By William Swainson, Esq., F.R.S., L.S., M.W.S., Se. [Communicated by the Autkor.] THE attention of several conchologists has been excited by a new and most extraordinary fluviatile shell, belonging to the genus \ Melania, recently brought from the Mauritius. Having been fa- voured with its examination, I now lay before the public the follow- ing description of the shell, drawn up from the only specimen which its discoverer, Mr. Warwick, was able to procure, after diligent and often repeated searches in the same locality. I take this opportunity also of recording the characters of another fresh- water shell of gigantic dimensions, equally unknown and interest- ing to naturalists. Mevania. Lam: Cuy. Specific character. M. testa ovata, ventricosa, spinis tubularibus seta bina porrecta ‘basi connexa emittentibus coronata. Shell ovate, ventricose, co- Tonated by tubular spines, each sheathing the ‘base of two pro- truded horny bristles, DeEscriprion. Length, one inch two tenths, of which the spire occupies very © nearly one half. In habit the shell resembles Melania amarula, (Helix amarula, Lin.) but the basal volution is more ventricose, the spire more conic, and the tip acute; it is also much thinner, and may be termed subdiaphanous; the whole shell is covered by an olive brown epidermis; the spiral volutions are angulated, and marked by from three to four transverse elevated striz ; the basal volution is without any indication of plaits, but is slightly im- pressed by narrow, transverse grooves, which are wide apart; these are crossed by very delicate and close-set longitudinal strie; but whether these last are only external and belong alone to the epi- dermis, could not be ascertained without injury to the specimen, The most extraordinary characteristic of this shell, I shall now proceed to detail. On the upper part (or shoulder as it is some- times called,) of the body whorl, is a row of coronated spines, 14 Mr. Swainson’s Description of perfectly tubular; these spines are very thin, and are placed parallel with and very near to the aperture; their summits are obtuse and their length variable, probably owing to some having been injared through their great delicacy; the longest measured nearly one- eighth of an inch; from the summit of each spine emerges two stiff erect acute bristles; closely adhering together, and projecting about two-tenths of an inch. The colour of these bristles is black, their surface polished, and their substance horny. They likewise possess some degree of elasticity, being easily bent by a slight pressure applied laterally ; although I doubt whether they would have sustained such pressure had it been applied horizontally. These bristles it will be perceived, are completely sheathed at their base by the tubular spines, but these latter are so thin that the lower part of the bristles are distinctly seen through them; rooted, as it were, in the substance {of the shell. I know not, positively, whether each spine contains ¢wo distinct bristles; or only one, forked or divided at about half its length, as this fact could only be ascertained by removing one of the spines, and tracing how far the division extended; but that portion which forms the lower half (and is enclosed within the spine) is so thick, as to favour the supposition of their being in pairs. These spines are continued round the middle of each volution of the spire to its apex ; but they are more remote, and the bristles much shorter, than those on the body whorl; sometimes, indeed they hardly project beyond the spines. The direction of the whole is slightly incurved. The aperture is pale; and, at the top of the outer-lip, is an indented sinus similar to that seen in M. amarula, Lam. Ob. 1. The extraordinary appearance of bristles protruding from the spines of a shell, a formation altogether unprecedented amongst this class of animals, might naturally excite, in some minds, a sus- picion that it was an ingenious deception. But this idea, I think will be abandoned, when the peculiar construction of the spines are well considered. In the genus voluta, we have many instances of shells being crowned with thin, vaulted spines, but no example can be produced, of such coronated spines being tubular; or com- pletely closed in their circumference, and pervious only at their two New Freshwater Shells. 15 summits. Now it is obvious, that this peculiar form, is of all others the best adapted to strengthen and protect the elastic bris~ tles which they enclose: both appendages, therefore, are in unison with each other, and leave not a doubt in my mind, (setting aside the personal testimony of its discoverer) that the whole shell is in a perfectly natural state. It is difficult to conjecture in what way the formation of the shell accords with the economy of its inhabitant. We know that testaceous mollusca, are the food of several kinds of fish, both ma- rine and fresh-water; may not these bristles be intended by nature to defend the animal from such enemies? they would certainly be very repulsive to the lips of any fish; and in all probability would penetrate, as deep as possible into the skin. The weapons of pro- tection or of defence with which nature has furnished different tribes of animals, are as various as they are wonderful. In the testaceous mollusca, they are confined alone to the shelly covering of the animal, who, as long as his castle is armed and entire, with- draws into its walls, secures the entrance, and remains passively secure. 0b. 2. Since the above was written, Mr. Broderip informs me, another specimen of this shell has come into his possession : “care- fully cleared, and every vestige of bristle removed, the hollow co- ronations remain.” Unio GiGas. Specific character. U. testa ovato-oblonga, depress4, anticé alata et sulcis obliquis, divaricatis subradiata; posticé brevissima; dente laterali (utri- usque valve) solitario; umbonibus brevibus, retusis. Shell ovate-oblong, depressed anterior side winged and marked by oblique grooves in different directions ; pdsterior side very short; lateral teeth, one in each valve; umbones small, retuse. Description. This is truly a gigantic shell; far exceeding in size any other yet discovered as inhabiting the fresh-water, and presenting cha- racters which leave no doubt that it has hitherto remained unknown to all conchological writers. Its extreme length is rather more 16 Mr. Swainson’s Description of than eight inches and a half; and its greatest breadth (from the ligamental to the basal margin,) five inches three-quarters. Its form is a broad oblong-oval; obtuse at both extremities; the anterior of which is broadest and sinuated, aud the posterior rounded, and so very short as to project only three quarters of an inch beyond the outer side of the cardinal teeth. The whole shell is remarkably flat but very thick in substance; and the umbones, which are unusually small have scarcely any convexity; the liga- mental margin is dilated, winged, and forming in its dilation nearly two equal sides; the horny part of the ligament itself, (with the in- ternal plate that supports it,) extends half way between the umbo and the extremity of the wing; the exterior colour of the epidermis, is dark brown, but the umbones (in this specimen) are decorticated for a considerable space around them. The sculpture of the an- terior part of the shell is very peculiar; it consists of four series of short oblique grooves, or of indented wrinkles, three of which are arranged in a direction with the umbonial slope *, the other is trans- verse; the first of these series consists in parallel grooves which cross the wing obliquely from left to right. The next is a range of broad and sinuated indentations, wide apart and having the same inclination as the former; the third range occupies the umbonial slope, and is formed by narrow sulcated grooves, placed nearly in a horizontal direction, and diminishing in length as they approach the umbones. The fourth and last consists of several transverse erooves situated near the basal margin, and the whole presents an appearance as if the shell had been indented, .in various di- rections, by some blunt instrument. The inside is pearly, white, tinged with flesh-coloured purple, and stained (as is frequently the case, in fluviatile bivalves) with olivaceous yellow spots; in a perfect state of the shell the colours, probably, would be more brilliant. The cardinal teeth are strong; deeply and irregularly striated and are obliquely transverse; in the right valve are two, and in the left valve, one; in each valve there is only one lateral tooth, a very unusual and discriminative character for the species; this *See Zoologi Ilust. two New Freshwater Shells. 17 tooth is very thick, minutely crenated, and is double the length of the ligamental plate, which latter is much elevated, broad, and terminates abruptly in a sinus extending to the point of the wing : adjoining the cardinal teeth are four deep muscular impressions, one of which is very large, and two of the others very small; the anterior impressions are slight and present nothing peculiar. Ob. Two odd valves of this unique shell came into the possese sion of Mr. G. Humfrey, A. L.S., many years ago; and were sold with part of this gentleman’s collection last spring; the shell then passed into the hands of Mr. Mawe; Mr. H. was informed it came from the river Oronokoo; this I think a very probable lo- ceality, for it has all the characteristics of an American species; its massy substance and uncommon size seems, moreover, in unison with the force and rapidity of such a vast river. I am not well satisfied as to the exact form of the dilated process on the anterior side; as in both these valves the edges had been injured and re= paired: in the perfect shell this part probably may be more di- lated, and may terminate in a form somewhat different from that which I have described. Warwick, 1824. Arr. II. On Indistinctness of Vision, caused by the pre- sence of False Light in Optical Instruments ; and on tts Remedies, by C. R. Goring, M. D. (Communicated by the Author,] Opricat instruments in general have within the last century been brought to so high a degree of perfection, that it may almost be doubted if there remain any real improvement to be made in them ; nevertheless, it has appeared to me, that in the humble depart- ment of their construction which provides against the admission of false light, there is still left some capability of a farther ad- vancement towards perfection, which may be effected with advan- tage, to the performance of astronomical refracting telescopes, Newtonian reflectors, and compound microscopes.—As it is neces = sary to understand the nature of an evil before we can cure it, as Vou. XVII. C 18 Dr. Goring on False Light well as to feel the utility of removing it, I shall here give a slight account of the indistinctness occasioned by fog, (as it is technically termed) to which I propose to apply a remedy. Thus, when we look through a telescope admitting false light at a printed bill, the plate of a clock, or other such object, especially if the day is clear, and the sun shines on it, we find, (however perfect the in- strument may be in other respects,) the letters or figures do not appear nearly so black and sharp, as they will when viewed by the naked eye under the same angle, but rather of a brownish colour; in other words, the effect upon the eye, is similar to that of looking through a mist, or through glasses dimmed by moisture ; in short, what an ordinary observer would express by saying, the instrument , did not shew objects clear and distinct*. Now, on examining the pencil of rays proceeding from the eye-piece of such a telescope, with a magnifier, it will (supposing no other source of indistinct- ness exists,) be found surrounded by a variety of foreign rays, forming different halyos about it, instead of appearing like a span- gle on a piece of black cloth, which it will do, when all the false light is stifled, as in Gregorian and Cassagrain reflectors by their eye-hole, and in refractors with erecting eye-pieces, which have a stop between the two bottom glasses, producing the same effect, by suffering nothing but the true and genuine pencil of light, from the object glass or metal, to teach the retina, Indeed, in these in- “struments the quantity of spurious rays would be so great, as ab- solutely to preclude any thing like distinct vision, without the stops and eye-holes in question, In those to which I propose to apply an equivalent contrivance for extinguishing fog, though there may not be the same imperious necessity for its application; still I think the advantage to be gained by the improvement, is not to be despised, but will rather be admitted to be highly useful and appropriate, as placing optical instruments one step nearer perfec- tion than they would otherwise be, by producing the maximum of distinctness and clearness of vision, of which they can be rendered susceptible, consistently with their excellence in other respects.— » * All cbjects are of course equally affected by the fog, but it is more striking in those I have designated than in others, in Optical Instruments. 19 Now, opticians have not been entirely insensible to the advantages, to be obtained by excluding all inefficient light ;—being aware that no kind of blacking applied to the inside of an optical tube, is sufficient to effect that salutary purpose, they have had recourse to other means, though inadequate to the end in view.—Thus it is common in a refracting astronomical telescope, to meet with one stop and sometimes two, placed in the interval between the object and eye-glass; the apertures of the magnifiers, are likewise con= tracted on the same principle. But these stops are never in suffi= cient number, or sufficiently contracted, or placed in such situa~ tions as they should be to be efficient, at least it has never fallen to my lot to see any such. It seems to me, as if they were pos= sessed of some superstitious dread of cutting off some of the light of the object glass by inserting stops; or perhaps have wished to shew their customers, that the apertures of their glasses were clear, it being a common trick to make a large object glass, and then to cut off the effect of the imperfect edges by a contrivance, such as has been mentioned, which ordinary purchasers are not aware of, and thus, suppose, the instrument to be much finer and better than it really is; at least it is not uncommon to meet with this species of fraud in the works of the continental artists, who are yery fond of making larger object glasses than the English work~ men. To enter into my subject, I shall here as succinctly as possible, describe the method which I have experimentally found to answer best for stifling fog in the astronomical refractor. It is a consideration which must obviously present itself, that if an eye= hole be placed at the end of a telescope, precisely of the size and precisely in the focus of the pencil of rays produced by any par ticular magnifier, that the end here proposed will be attained, as in the Gregorian and Cassagrain telescopes ; it will moreover, confine the eye truly to the axis of the tube, and thus prevent us from seeing any of that colour in the image, which may always be perceived in the best instruments, when the eye is a little removed from its true position. Nevertheless, I have after sufficient trial rejected this method, as less expedient than another which I shall point out, on account of the difficulty of executing it C 2 20 Dr. Goring on False Light properly with high powers, as well as that it confines the field of view, and is disagreeable to the eye. It is evident, that with high powers the pencils of rays will be exceedingly small, therefore if the aperture of the eye-hole is too large it will be ineffectual, if too small it will obstruct light : it must therefore be executed to a very great nicety, which is not always to be expected; besides in a case of such delicacy, if the eye-piece be not screwed on to a par- ticular mark on the body of the tube, or if any of the parts of which the magnifying apparatus is composed, be more or less screwed home than at the time of adjustment, it will be highly probable, that the eye-hole will be a little thrown out of its true situation, and thus do away with the sole object for which it was constructed. Thus it is, that what is perfect. in theory, will not always answer in practice. As to using eye glasses with very small apertures for the same purpose, (as contradistinguished from eye-holes, placed at the ends of the cones of light, drawn toa point by the magnifiers,) it is a method which cannot be made to exclude false rays with any degree of precision, even though their diameters are so much reduced as greatly to contract the field of view. I shall now give an account of the plan I have selected as most eligible, and which I have applied to a thirty inch and eigh- teen inch refractor with complete success, as it seems to me. Fig. 1. Plate II. isa drawing of the section ofarefractor, in which may beseen seven stops in the course of the tube and eye-piece, (exclusive of the field bar,) five of which are placed in such a manner, and of such apertures as to pinch the cone of rays proceeding from the object glass as tight. as possible, without intercepting any. It will be obvious that no foreign rays, or any that are not parallel, wilt be able to find their way to the eye, nor can any light be re- flected from the sides of the tube, so as to become visible. To execute this, use the following method; when the telescope is finished in the usual way, and before any stop is inserted, attach its lowest astronomical eye-piece to it, and find the true solar or sidereal focus of the object glass; when thus adjusted, measure carefully with a dynameter, the size of the pencil of rays proceeding frora the eye-piece, and note it down. Having then i / in Optical Instruments. 21 procured a plank of wood covered with paper of sufficient length, take the aperture of the object glass, and set it off at one end of the board, bisect it and draw a line at right angles to it, to the exact length of its focus: fix three strong needles into the three points of the focus and aperture of the object glass, and then stretch a fine thread over them, which will then represent the cone of light which forms the image; set off six or seven inches from the focal extremity, (an efficient stop cannot be placed nearer, without.contracting the field of view,) and ascertain the distance between the threads at this point, which will give the diameter of the fifth stop. Then divide the remainder of the focal length into five equal parts, (whatever it may be,) and the distance of the threads will give the diameter of four more stops, 4, 3, 2, and I, in the figure, all sufficiently correct for the purpose. The stops are then to be made and inserted into the tube in their proper places; it will not however be amiss to make No. 1, 2, 3, and 4, a little too large, and to confide the main business of stopping the false rays to No. 5*, which may be attached to the eye tube, and move along with it, in adjusting the focus of the magnifier. This will give the instrument the power of adjusting itself, to nearer objects on the earth, without losing any light from the effect of the stops, which otherwise must be adjusted to the shortest focus of the object glass, and supposed to act perfectly only with parallel rays. It will not be amiss to haye a very small eye-hole, placed correctly in the focus of the object glass, which will give a great facility of adjusting the stops, as it will shew by merely looking through the instrument, if they are correctly placed or not. Lastly, having fixed these, apply the eye-piece, carrying the lowest mag= * The way of regulating the aperture of this or any other stop to its situation in the course of the tube, will naturally be by pushing it up or down, till it strictly conforms itself to the size of the cone of rays at the point where it acts ; when once itis settled for the lowest magnifier,so that the image of its aperture, and that of the object glass correctly correspond, and shew no difference in measurement by the dynameter, the business is effected for all the ether powers, as they will always preserve the same relative proportion to each other, whatever may be the depth of the lens which is employed to form ay image of them, 22 Dr. Goring on False Light nifier as before, and again with the dynameter measure the size of the cone of rays at the eye; if it measures precisely as before, you may be quite confident you have cut off no true light*. I dare say it will be thought, there are already a very superabundant quantity of stops, but, I am sorry to say, that on examining the — pencil with a magnifier, it will most probably be found, that some false light is still reflected from the eye tube, to cure which two more stops will be necessary, (Nos. 6, and 7;) both of these how- ever, must be larger than No. 5, and No. 7 the largest of the two, or the field of view will be contracted in the low powers.—The higher the power, the nearer an efficient stop may be placed to- wards the focal extremity of the pencil, proceeding from the object glass; the lower it is, the farther the stop must recede, gradually of course, increasing in its aperture, (unless the length of the eye- tube is increased in proportion to the focus of the magnifier em- ployed.) I have pitched upon six or seven inches, which is a distance for the main stop, that will suit all telescopes, and all magnifiers which are not more than one inch focus. Here it seems proper to observe, that when once the false light is duly excluded from a telescope, in the manner I have here recommended, the eye glasses may be used of any aperture, and thus the field of view may be had of any size, even with a single eye-glass, which in my opinion, when high magnifiers are used is a great convenience, as it enables us to keep a celestial object in sight more easily, though we should only see it distinctly in the axis of the telescope; more- over, should it not be thought worth while after all, to have the false light as perfectly excluded, as it possibly can be under all cir- cumstances, the stops No. 1, 2, 3, and 4, may be rejected, and 5, 6, and 7 only executed; the consequence will only be, that some false light will be rendered sensible, when the eye is not con- fined to the centre of the eye-glass. *T think an instrument from which all the false light is utterly excluded, does not appear quite so luminous as it did before, for false rays are as capable of affecting the retina, as true ones. [If we were to turn out all the disagree- able people out of a room full of company, there would of course be fewer indi- viduals init, but the society would, I think, be indubitably improved by the measure. | in Optical Instruments. 23 ~T have given the full complement of stops, to render the exclu- sion as complete as possible. As good a way as can be devised of illustrating the effect of the stops, is the following. It is known thata terrestrial telescope with an erecting eye-piece of four glasses, would be rendered nearly useless by withdrawing the little stop placed between the two glasses which erect the image, by the quantity of fog which would be let in, (supposing the instrument constructed in the usual way.) But in a telescope furnished with such stops as I have described, it is of no consequence whether the little stop is introduced or not, the performance is precisely the same in point of distinctness in both cases. In performing this ex- periment, it is necessary however, that the aperture of the little stop should be correctly and truly accommodated to the size of the pencil, which is formed by the glass, in the focus of which it is placed, so that it shall barely admit the image of the object glass, without cutting any of the side rays off, otherwise the experiment will not be fair.—Opticians are apt sometimes to make these aper- tures so small, as to intercept some of the light of the object glass as effectually as a cap over the end of it would; for the achromati- city of an erecting eye~piece depends very much upon the size of the little aperture in question, Thus where the diameter of an object glass bears a very large proportion to its focal length, it will be impossible to admit the whole of the light proceeding from it into the eye-tube, without at the same time destroying the achro- matic property of the latter, by the necessity which would arise of opening this stop too wide to consist with it. In the experiment I have detailed, there is sufficient proof that the effect of my stops is equivalent, indeed more than equivalent, to that produced by the stop which is inserted in erecting eye-pieces for the purpose of procuring distinct vision. What then? is there any merit in having effected, by means of half a dozen stops, what may be done well enough by one? certainly not. But take away the erecting eye-tube, screw on an astronomical eye-piece, (either with or with- out a field bar,) and where I ask now, is that part of structure which is to do the work which was performed in the erecting com- pound magnifier, now removed, by the little stop of which I have said so much ; (supposing the telescope constructed in the usual 24 Dr. Goring on False Light manner, thatis to say, without stops in the course of the focal dis- tance of the object glass, or at least without effectual ones?) It cannot be asserted, that there is anything equivalent in the instru- ment in its present condition, to the former provision in it, for the valuable purpose of excluding false rays, though the expediency and utility of it in both cases, must be equally admitted or denied, and it is clear this can only be supplied in the astronomical teles- cope, by some such expedients as I haye resorted to. As I conceive no one can be hardy enough to assert~that there is no use in excluding false rays from a telescope intended to be used at night, for viewing the heavens, it will be superfluous for me, to set about proving that we shall see a celestial object the better, if no light, either direct or reflected, reaches the eye, save that actually proceeding from it. If the light of the heavens in a star-light night, and that of the bodies which produce it are very faint, still there is the same ratio between their brightness, and the false light they produce, (though not so conspicuous perhaps) as there is in that of terrestrial objects. Indeed it is perfectly well known to astronomers, that in the darkest night, wearing a black hood over the eyes, greatly facilitates the vision of very faint and delicate objects, such as nebule, &c., from the sensibility and tran= quillity induced by these means in the retina, rendering it sus- ceptible of the slightest impressions. Surely the effect of foreign light reaching the eye directly, or through the medium of a telescope, must be equally pernicious. It is in viewing the class of objects here designated, that the utility of the stops I have described will be found; no one will expect that they can render a telescope better able to define or divide a star, because these pro-= perties depend upon the perfection of an entirely different part of its structure. I shall take my leave of the subject, by asserting that if any one should choose to maintain a contrary opinion from myself on the affair of excluding false rays, he must, to preserve consistency, assert that there is no use in the eye-hole of the Gre- gorian and Cassagrain telescope, (if used at night,) and should therefore in using these instruments, content himself with such a one as is applied to common spy glasses, just to keep his eye in the axis of his instrument, ' in Optical Instruments. 25 I now proceed to the next part of my subject, which is the con- sideration of the Newtonian telescope. This admirable instrument, such as could only be expected from the genius of the immortal philosopher who invented it, has, (as a necessary consequence of its construction,) among its other valuable peculiarities, that of having less false light in it than any other kind of telescope.—The same striking effect, therefore, will not be manifest in excluding the trifling fog there is in it, as in another construction where it is more abundant. Nevertheless there is something to be done.—If we examine the pencil of rays proceeding from its eye-piece with the magnifier, it does not precisely represent the image of aspangle or a piece of black cloth, as it should do ;—a good deal of foreign light may be seen, formed partly by the side of the tube behind the diagonal metal, and partly by such portion of the end next the large mirror, as the plain one can reflect along with the image, toge- ther perhaps with some reverberated by the little tube which carries the magnifiers. In Fig. II. is represented the method I haye taken to remedy these imperfections in a 77-inch focus, and seven-inch aperture Newtonian*. The alterations from the common construction, are * On exhibiting these alterations to those celebrated artists, Messrs. Tulley of Islington, I learnt from them that they had lately made an arrangement of the same description, in a Newtonian telescope, made for Mr. Camfield of North- ampton. These gentlemen (whose unrivalled pre-eminence in their profession, needs not my feeble testimony, or eulogium) fully admit that the exclusion of the false light, makes a great difference in the performance of the telescope, in the day-time, but do not seem to think any alteration is to be perceived in viewing celestial objects. Iam aware, that I am paying myself an indifferent compli- ment in differing from such authorities. Ihave given my reasons for so doing, and cannot help still being of opinion, that it is scarcely possible to select any object in the heavens, and to view it without rays from a variety of others also finding their way into the telescope, and thus disturbing the singleness of vi- sion, which would exist was there but one star or object in the heavens to emit light. I think, in particular, that the double ring of Saturn, and its belts and shadows are not perfectly seen, unless the telescope employed to view them, will show black objects perfectly black, and white objects perfectly white, and of course all the intermediate gradations of shade correctly ; very few telescopes will shew the division between the rings of Saturn quite black, (as mine does,) owing to the false light so generally prevalent in them, 26 Dr. Goring on False Light as follows: the tube which carries the magnifiers is seven inches long, instead of being only two inches or perhaps less, as is usual —the diagonal metal is likewise placed nearer than usual to the large one, so that the length of the telescope is reduced about five inches; this is of course necessary to render the pencil of rays re= flected at right angles from the axis, long enough to act with the increased length of the eye-tube. (As the diameter of the spec- trum of the great mirror increases as we recede from its focal ex- tremity, more of the small plain one will in this case be called upon to act ; it however will still do the work without any increase in its size; mine is 1-3, inch of circular diameter, yet its entire surface is not employed.) By this arrangement a sufficient length of eye- tube is obtained to insert the stops 5, 6, and 7, as in the refractor, No. 5, is the efficient stop as before and is ;7; inch in diameter, The extrusion of the aberrant light is complete as long as the eye is in the axis of the instrument. It would of course be impossible to insert any stops similar to those, 1, 2, 3, and 4, in the refractor to render the effect more complete; nevertheless, I think, were it any object, a Newtonian would by the aid of the contrivance I have applied to mine, act sufficiently well with a skeleton tube only. It now remains for me to describe the new adjustment which the adoption of so long an eye-tube has compelled me to have recourse to, for it is evident that any want of centricity and parallelism in the lenses composing the eye-glass to the axis, which might be tolerated in a very short tube, will be perfectly insupportable when aggravated by a longer one: moreover, the stop No. 5, (which I suppose to be so ad- justed as barely to suffer all the light of the great metal to clear it) will, if not truly concentrical with the cone of light on which it operates, evidently impede some, as in such a case is perceptible by looking through the small eye-hole recommended in adjusting the refractor, or by examining the extreme pencil after it has passed the eye-glass with a magnifier. It is evident, I think, that the adjustment of a Newtonian is complete, when the pencil of rays which is reflected from the small metal, truly perforates the axis of the eye-tube, and the centres of the lenses composing it; it mat~ in Optical Instruments. 27 ters not, I conceive, at what angle or in what direction the said cone of rays proceeding from the large metal be thrown by the diago- nal one, provided these conditions are fulfilled, (supposing of course the position of the small metal to be the centre of the tube, so that it shall truly receive the whole of the light of the great one.) We may, therefore, either adjust the small metal to the eye-tube or the eye-tube to the small metal, or we may do both, which latter will probably be the most expedient, and is the method I have pre- ferred; I have effected it in a very simple manner, by having the tube made to fit loosely into another wider piece, which is screwed on in the usual way, to the side of the telescope:—the vacancy be- tween them is filled up with wax, the inner tube is tight at the bottom of the external one, by the interposition of a small setting chamferred at the edge, but admits of a slight rotatory motion to- wards the eye-glass by heating the wax with the flame of a candle - which is inserted into the external tube, and which unites them both together; time will be given to adjust it before the wax cools, when it will all set tight, and will not be liable to get out of order. Two small niches should be made, one in the shoulder of the screw of the external tube, and the other in that of the female screw to which it is applied, to be a guide that the two pieces may always be serewed home to a particular point: or it is very probable the adjustment may be spoiled, because it will be a chance if the eye- tube when fixed, is precisely at right angles to the side of the tele scope. A variety of methods of effecting this adjustment will pre- sent themselves to the workman, instead of that which I have used, which though it answers very well, yet does not look very elegant or scientific. Thus, instead of the wax, three screws might be used, fixed into the external tube; or such a contrivance as is repre- sented in Fig. II., by having counter screws to play against those by which the setting for the eye-piece is attached to the rackwork, on the side of the telescope, &c. Now it is not my intention to assert that this adjustment is absolutely indispensable, for I haye not a doubt but that a superior workman might execute a long eye- tube, such as I have employed, so that nothing but the usual adjust- ments would be required; still I think that no Newtonian would be 28 Mr. Swainson on the Characters injured by having such an apparatus to it as I have recommended, even though the eye-tube were only of the common length; it is certain it could do no harm at Jeast. I think I can, moreover, with confidence assert that increasing the distance between the small metal and the eye-glass, for the purpose of applying stops, will not be found to make the least sensible difference in the performance of an instrument, as far as the figure of the small metal is con- cerned, provided it is of the standard goodness*; if but imperfect such an alteration will evidently try it more, and this will be shewn by examining a double star which will probably vary slightly in the distance at which the stars appear separated, (ceteris pari- bus,) according as the eye-glass approximates to, or recedes from, an imperfect diagonal. To conclude, as an Herschelian telescope is nothing but a Newtonian, used without the interposition of a small metal reflector, whatever has been said of the latter, will equally apply to it, and the same principle in the eye-tube and ad- jJustment, will for the same reasons be equally adapted to both, though the manner of execution will be different; I have, however, made no experiments on this kind of telescope. [The portion of this paper relating to Microscopes is reserved for our next Number. ] eee ener teil Arr. IV. The Characters of several New Shells, belonging to the Linnean Volute, with a few Observations on the pre- sent State of Conchology. By William Swainson, Esq., F.R. and L.S. Tue study of conchology has now become so general, or, if I may be allowed the term, so fashionable, that the number of elemen- tary works is truly surprising. The new systems of the French conchologists have been translated, explained, and advocated, in various publications; while the admirers of the Linnzan method, * It is evident that if the diagonal metal were quite perfect, it could make no difference at what distance the eye-glass was placed from it; if decidedly im- perfect, it is no less plain that the nearer the eye-glass is placed to it the bet- ter, because the less of the edges will be called into action, which will of course be the worst part. of several New Shells. 29 have not been backward in expressing their warm attachment to the plan of the great Swedish naturalist. It is not my present inten- tion to speculate upon the respective merits of these systems. In the study of no class of the animal kingdom have there been so few ab- solute facts discovered, whereon to build a truly natural system, as in that of the testaceous mollusca, In the history of those families which: are known, anomalies have been discovered, which bafile explanation, and obstacles almost insurmountable, from the very nature and hab:tat of the animals, conspire to retard that rigid in- vestigation of their economy, which must alone form the basis of their perfect arrangement. But while so many writers have been engaged in forming systems and constructing genera, the elucidation of species has compara- tively been neglected. An extensive acquaintance with species is the first step to a knowledge of natural divisions. In every branch of natural history those who have seen and studied the fewest individuals, will be most apt to create new genera; ‘‘ when they have seen more, they will discover the intermediate links which unite different genera; and thus be forced to join what they formerlyseparated*”. Iam fearful this has not sufficiently been considered by the authors and advocates of the French systems: it may be doubtful if their generic distinctions are not too much refined ; butit is certain that a know- ledge of the science is daily becoming more unattainable to all but professed naturalists. While this revolution of classification and of genera is going on, our cabinets are crowded by innumerable species, some of which we know not how to name, while others (well known by the figures of the older writers) remain undescribed: new species are con- tinually pouring in upon us to augment the number: and although the student may be perfect in the elements of his system, he knows not how to proceed, or where to turn, if he ventures on the inyesti- gation of species, The volumes of Lamarck (His. Nat. des Animaux sans Ver- tebres) have indeed done much to remedy this evil. They contain - * Wildenow, Principles of Botany, P, 175, “Sect, 163, 30 Mr. Swainson on the Characters a considerable increase of new species, and a more perfect eluci- dation of many of the old ones; but, on the other hand, the same over-refinement which marks the characters of his genera, will be traced in the discrimination of his species; this is more particu larly the case in his account of the genera Conus, Oliva, and Helix. Let me not, however, be misunderstood, as wishing to depreciate the merits of this great man. His general reputation could not be affected either by my praise or my censure. But obliged, as he has been, to employ the sight of another in finishing his latter volumes, it would perhaps have been better for his own sake, and that of the science, to which he has devoted his long life and great abilities, ifthey had never been published. - The importance of monographs, or complete histories of parti- cular tribes, or families, in every branch of natural history is un- questionably very great; for their object is, not only to ascertain the limits'of genera, and the affinities and analogies, which the indi- viduals of such genera bear to others, but likewise to include the history of all the species thereunto belonging. To accomplish this, however, is in the power of a very few. Access must be had to the rich contents of foreign museums, and of costly libraries, to supply what may be deficient in minor collections; and it is from this cause that nearly all the monographs of extensive families have proceeded from naturalists in the charge of public museums, or in the possession of immense private collections. From the labours of these men science has received the. greatest assistance. But, although few can enjoy the advantages such materials afford, con- siderable benefits will be derived from the labours of those, who frame a correct diagnosis of individual species ; particularly when relative characters are subjoined, and comparisons made between others to which they bear a resemblance. When it is considered how many rare and unknown shells have lain for years in the cabi- nets of mere collectors, and how much greater is the number of those species more usually seen, but which are likewise unrecorded, the value of these isolated descriptions will be rightly understood. They are the indispensable materials for completing a general suryey of the natural world, and constitute the ultimate object of of several New Shelis. 31 all systems; namely, such a knowledge of the individuals, as will enable the student to assign to each ‘‘a local habitation and a name,” I shall now proceed to describe several beautiful shells; dena of uncommon rarity, and apparently unknown to modern writers : the four first belong to the genus Voluta, as it is now restricted ; and the remainder to Mitra, a genus towhich I have long paid much attention, with the ultimate hope of illustrating it by a distinct monograph. Votura. Lam. (Diy. 1. Musicales.) Voluta chrysostoma. V. testa ovata, albente, lineis angulatis maculisque castaneis or= nat4; anfractibus spinis brevibus, concavis coronatis ; apice crasso, obtuso, levi; apertura aurea, _ Shell ovate, whitish, with angulated chestnut lines and spots ; whorls crowned by short concave spines; apex thick, obtuse, smooth ; aperture golden. Voluta chrysostoma. Sec. Exotic Conch. Fas. 5. ined. Voluta luteostoma? testa obovata, angulata, lineis et venis fus- centibus i in fundo albido undulata sub-perforata, anfractibus cinctis nodis conicis, apice obtuso, basi valde emarginata, columella pli- cata plicis quatuor solidis, fauce lutea. Chemnitz xi. p. 18, tab.177. F. 1707-8. DESCRIPTION. _ The shell in its habit, approaches V, vespertilio: its total length is about two inches, of which the spire occupies not more than half an inch: its form is oval, and its surface without sculpture: the basal volution, and the two first whorls of the Spire, are crowned by a row of short thin vaulted spines, rather acute, and resembling those on V. diadema, (Ex. Conch, Fas. 1.) The remaining three spiral whorls are perfectly smooth, the middle one being by much the largest, and the whole forming a thick and somewhat obtuse cone. The base is deeply emarginate, and the plaits on the colu- mella, (which are four in number) are very thick, The ground colour of the specimens before me is nearly white, with broad 32 Mr. Swainson on the Characters longitudinal shades of deep chestnut, broken into rows of angulated whitish spots of various sizes, and disposed in a longitudinal di- rection. The spire is white, with a few brown undulated lines on the lower whorls; the inner lip yellowish white, and the throat or inner aperture golden yellow. This shell, as far as regards English collections is unique. It is now in the possession of Mr. Mawe, I believe, and in all proba- bility may be found to inhabit the Indian Ocean. The Vol. luteostoma of Chemnitz,(a shell passed over by Lamarck, and all systematic writers,) bears a strong resemblance to this spe- cies, but I have many doubts if it be really the same. In this genus, the form and sculpture of the terminal whorls of the spire, afford the most certain specific distinctions; now in the V. luteos- toma, these terminal whorls are represented as graduating to an obtuse point, whereas in the shell above described, they are very thick and papillary. V. duteostoma is stated to be “* subperforata,” but this V. chrysostoma bears not the slightest indications of such a character, neither is the description, ‘‘ anfractibus cinctis nodis conicis,” applicable, if intended for the latter species. On the other hand, the two shells agree in their general form, habit, the golden colour of their apertures, and nearly the pattern of their markings. I have preferred however, for the present, to keep them distinct ; because every conchologist must be sensible, more perplexity has been introduced into the science, by creating too few species than too many. Votuta GRACILUS. V. testa oblongo-fusiformi, lineis undulatis picta ; spira producta plicata; labio exteriore subreflexi; columella 4 plicata. Shell oblong-fusiform, with undulated lines; spire lengthened, plaited ; outer lip sub-reflected; pillar 4 plaited. DerscriPrion. This is a most elegant shell, belonging to the same group as that filled by V. undulata and its allies; from all of which it may at once be known by the great prolongation of its spire, which is nearly the length of its aperture. The whole shell does not exceed of several New Shells. . 33 two inches and a half in extreme. length; the basal volution is smooth; but the three next whorls of the spire are plaited, and slightly nodulous; these plaits then disappear, and leave the ter- minal volutions quite smooth; the apex is obtuse, but not enlarged ; the base of the shell is contracted, and the emarginate notch rather slight; the margin of the outer lip is somewhat reflected, and on the columella are four slender and nearly equal plaits. The colour is pale brown, elegantly marked by longitudinal, slender, waved, and angulated lines of a deep fulvous brown; at the top, bottom, and middle of the basal whorl, these lines are more thickened and deeper coloured, so as to form three transverse bands. Another specimen of this species was covered over with a reddish tinge, which nearly obscured its markings. The brown lines are also continued on the spire, but are fewer and more remote. Ob. Two specimens of this elegant voluta were brought home by one of the South Sea trading vessels from the Bay of Island, they are now in the possession of Mr. Mawe. VoLuta CostaTa. V. testa ovato-oblonga, costis sub-mucronatis, pallida, lineis fulvis interruptis fasciata; basi granos4; spira mediocris apice levi, obtuso; columella multiplicata, plicis tribus inferioribus max- imis. Shell ovate-oblong, with sub-mucronate ribs, pale, and banded with interrupted lines of fulvous; base granulated, spire moderate, the tip smooth and obtuse; pillar many plaited, the three inferior plaits largest. The situation of this species, appears intermediate between the Vol. festiva and mitreeformis of Lamarck, but its form cannot be compared to any other. It is little more than two inches and a quarter in extreme length ; the spire is rather produced, and occu- pies oneinch, With the exception of the terminal whorl at the apex of the spire, (which is perfectly smooth and obtuse,) the whole shell is marked by numerous, regular, convex ribs, about the same thick- ness as the breadth of the space which occurs between them; these ribs form a row of short obtuse spines, which crown the summit of Vou, XVII. D 34 Mr. Swainson on the Characters each yolution; leaving between them and the suture an open chan- nel; at the base of the shell are deep striee, which cross the ribs, and produce a rough granulated surface. The ground of the shell is pale flesh colour, crossed on the ribs by bands of short slender fulyous lines; interspersed by a few orange spots: the aperture is also flesh-coloured, and the margin of the outer lip sharp and rather inflected. The upper part of the columella is crossed by numerous slender plaits, and at the lower part are three others much larger. Described from a specimen in the possession of Mr. Mawe. 0b. 1. The V. festiva of Lamarck, except from his description, is a species unknown to me. According to the writer, it differs from V. costata in being fusiform and ventricose, resembling in shape V. magellanica; it likewise appears destitute of the numerous small plaits on the columella, and of the obtuse coronations, formed by the summit of the ribs. These two shells with V, nucleus Lam. (which is Voluta harpa of Mawe’s Introd.) V. mitreformis, and another undescribed species in my possession, constitute a new group in the genus; characterized by having the principal plaits on the pillar, situated at the base of the aperture. Ob. 2. It may be necessary to observe, that although two shells already appear in the Linneean classification under the name of voluta costata, neither of them in fact, belong to this genus.as it now stands, One of these (the voluta nassa of Gmelin,) is a young shell of a species of Nassa Lam.; the other, (Vol. costata of Gmelin and Dillwyn,) is the Mitra Subulata of Lamarck. Mirra. Lam. Cuyv. Mirra tessellata, M. testa ovata, leevi, striis transversis remotis et punctis, al- bente, lineis fulvis transversis et longitudinalibus cancellata, labii interioris basi fusca; labio exteriore leevi. Shell ovate, smooth, with remote transverse punctured strie; whitish, cancellated by transverse and longitudinal fulyous lines; inner lip brown at the base, outer lip smooth. DrscriPrion. Habit of Mitra pertusa, but is much smaller in size, and less _ of several New Shells. | 35 ventricose; the spire also is shorter in proportion, but more thick- ened and obtuse; total length one inch three quarters; the whole shell is crossed by delicate remote striz, which are minutely punctured; the aperture is rather longer than the spire, and toge- ther with the inner lip is pure white, the base of the latter is how- ever stained by dark chestnut brown; the outer lip is rather inflected and is perfectly smooth; this latter character will at once distin- guish this species from all its allies; the pillar has four plaits. The colour is uniform yellowish white, with slender fulvous, transverse lines following the indented strice; these fulvous lines are crossed by others more broken and produce a singular resem- blance to the mortar divisions of brick work ; adjoining the suture is a row of small fulyous spots. This shell I only know from a beautiful specimen in the posses- sion of Mr. Mawe. Mirra GUTTATA. M, testa ovata, sub-fusiformi, levi, striis transversis punctis, fulvA maculis albis varia; labio exteriore crenato; columella 5- plicata. . Shell ovate, sub-fusiform, smooth with transverse punctured ‘striee, fulvous variegated with irregular white spots; outer lip cre- _ nated, pillar 5-plaited. shops DEscRIPTION. Habit of the last; but is a much smaller shell, having the base more contracted, and the tip more acute; the striz also are deeper and the punctures larger; it seldom exceeds an inch in length; the whole shell is brownish yellow, irregularly marked by white spots and blotches, these last spread over the spire, and form an irregular band across the middle of the body whorl; the aperture.is white, the outer lip crenated, and the pillar has five plaits. Ob. Two specimens of this species are in my own collection ; but I am unacquainted with its locality, Mirra Fusca, M. test crass4, ovata, leyi, fusci; spiree contracie sutura sub- tilissimé crenata; labio exteriore crasso, gibbo, lwyi; columella 4-plicata, D2 36 Mr. Swainson on the Characters Shell thick, ovate, smooth, brown; spire contracted, suture mi- nutely crenated; outer lip thick, gibbous, smooth ; pillar 4-plaited. DuEscRiPTION. Length one inch, habit of M. crassata Sw. the basal volution is thick and rather ventricose; the spire is short and abruptly slen- der, having the upper margin of the whorls projecting beyond the suture, and minutely but regularly crenated ; the whorls are likewise crossed by a few remote strize, the inner margin of the lip is thickened, and gibbous, except at the aperture, which is white. The whole shell is of a uniform fulyous brown; inhabits the In- dian ocean, and is very rare. Mirra Acuminata. M. test crassa, levi, albente ; spird contracta, attenuat&é acumi- nata, apertura longiore; labii exterioris crassi margine inflexo, levis; columella 4-plicata. Shell thick, smooth, whitish; spire contracted, attenuated, acute, longer than the aperture; outer lip thick, the margin inflexed and smooth; pillar 4-plaited. On a cursory glance this shell (if in an imperfect state) might easily be mistaken for the last; when perfect, it is about an inch and a half long (the spire occupying considerably more than half this length) and is faintly striated. The spire when unin- jured is long, abruptly contracted, and terminates in an acute point. This part is so delicate, that in two specimens out of three which have come under my notice, it was wanting. The whorls are crossed by delicate indented strie, but are not in the least convex ; this character gives the suture an appearance of being channelled ; the outer lip is somewhat inflexed, the margin smooth, thick and slightly gibbous within the rim; the base is ob- tuse, and the whole shell white, covered with either a yellow or reddish brown epidermis. Inhabits the Mauritius.—A small though beautifully perfect spe- cimen is in the possession of Mr. Mawe. Mitra Canrinata. M. testa gracili, fusiformi, fusca, anfractibus medio carinatis, juxta suturam striatis, columella, 4-plicata. ' Shell slender, fusiform, brown, whorls carinated in the middle, and striated transversely near the suture ; pillar 4-plaited. of several New Shells. 37 Drscrirtion. A remarkably slender fusiform shell, about an inch long ; the spire being of equal length with the aperture ; the shoulder of the basal volution, and the middle of the spiral whorls are crossed by a carinated ridge ; between which and the suture, are two or three elevated transverse strize; the rest of the shell is quite smooth; the aperture is white, and smooth within; the inner lip marginated, and the pillar 4-plaited. It is covered by a uniform brown epi- dermis, beneath which the colour is yellowish; base deeply emar- ginate, and slightly recurved. Inhabits Sierra Leone, from whence it was received by Mr. Mawe. It is a species at once distinguished by its crenated whorls, and should be placed in the same division as M. vulpecula and melongena. Mitra STRIGATA. M. testa levi, castaned, strigis longitudinalibus obsoletis, al- bentibus ornata; apertura spira breviore, alba; columella 4-plicata. Shell smooth, chestnut, with obsolete longitudinal whitish stripes; aperture white, shorter than the spire ; pillar 4-plaited. Habit of M. carbonaria, Sw. and M. melaniana, Lam: the specimen before us measures two inches in length, the spire occupies an inch and one-tenth and is rather thick. The top of each whorl where it joins the suture, is turned and prominent, every part of the shell is destitute of sculpture and very smooth; the base is contracted and the pillar has four teeth, with the indication ofa fifth. The colour is arich glossy chestnut, striped at unequal distances, with paler, narrow, longitudinal stripes, which form dots of pure white adjoin- ing the suture; the aperture and inner lip are also white. The only specimen of this beautiful mitre with which I am ac~ quainted, is in the possession of Mr. Mawe. Mirra Bicotor. M. testa leevi, fusiformi, alba, facia fusca lata cinctd, spira anfrac- tusque vasalis parte superiore striis cancellaiis punctis insculptis ; striis basalibus simplicibus. Shell smooth fusiform, white with a brown band; spire an ., 38 Mr. Swainson on New Shells. upper part of the body whorl with cancellated punctured strie; base with simple striz. DeseRIPTION. Shell about three quarters of an inch long, in shape, habit, ‘i even in colour, resembling M. casta (Zool. Ill. pl. 48.) but the brown band, (which in that shell is merely formed by an external epidermis,) in this is internal, and delicately waved with capil- lary longitudinal lines of whitish; the longitudinal striz are clouded and simple, but the transverse striee are more remote, and deeply punctured; those in the middle of the body whorl, and of the base are likewise simple; the plaits on the columella are four, and very prominent; the base of the pillar is tipt with brown. Ob. This shell, together with M. casta, olivaria, dactylus and oliveformis, constitute a particular group, distinguished by the plaits of the pillar extending far beyond the aperture. Inhabits the South Seas? mus, nost. Art. V.—Account of the Earthquake tn Chilt, in Novem- ber, 1822, from Observations made by several Englishmen residing in that Country. {Communicated by F. Piace, Esq.] Cur is a long narrow country, lying between the mountains of the Andes on the east, and the Pacific Ocean on the west. It ex- tends from 20° 20’ to 43° 50’ south latitude, and from 68° 50’ to 74° 20' west longitude from Greenwich, its length being about~ 1350 miles, and its average breadth about 130 miles. While under the dominion of Spain, Chili was visited by very few Europeans. Its great fertility, its abundance of metals and minerals, its agreeable and healthy climate, have, since it has been declared independent, induced a considerable number of English- men, and a few other foreigners, to become residents, and the number is continually increasing. j The country rises gradually but irregularly from the-sea coast to the mountains; it is exceedingly diversified, but the principal Account of the Earthquake in Chilt. 39 feature is its formation into valleys, surrounded by hills, many of them rising to a considerable elevation. . The whole country may be divided into two regions or climates, the one humid, the other dry, separated from each other by the river Maule, which in 35° 10’, falls into the Pacific Ocean. South of the river Maule the climate is variable; rain falls at intervals during the whole year, and timber trees are in abundance. North of the river Maule the rains are periodical, and fall only during a particular time of the year. At Valparaiso, the principal sea-port of Chili, and for about forty miles to the northward, the rainy season commences in May and terminates in September. Further to the northward, the rainy season is of shorter duration, diminishing gradually, until at the northern extremity of the coun- try, it totally ceases. To the southward of the Maule the time in which rain falls gradually increases, and, at the southern extre- mity of the country, there are but few intervals of dry weather. Chili is never free from earthquakes ; scarcely a week ever passes without one or more being felt, in some part of the country, but as the shocks seldom do any damage, the inhabitants pay but little regard to them. It is now nearly a hundred years since the former great earth- quake, and a persuasion seems to have prevailed among the peo- ple that no very considerable earthquake would happen oftener than once in twohundred years. Partial earthquakes, doing much damage, have always happened at intervals of a few years. The town of Coquimbo was nearly destroyed by an earthquake in 1820. The shock, was local, and produced no alarm in other parts of the country. On the fourth of November, 1822, the town of Copiapo, in S. lat. 27° 10’, was visited by a severe shock, which damaged many houses; this was followed, the next day, by a much more violent earthquake, which nearly destroyed the town, and did considerable injury to the town of Coquimbo, in 8. lat. 29° 50’. The great earthquake on the night of the 19th of November, 1822, was felt over the whole surface of the country, from the mountains to the sea, and from one extremity to the other. Its force seems to 40 Account of the Earthquake in Chili. have diminished in a pretty exact proportion to its distance from Valparaiso. is Its effects are thus described by an Englishman, tededinds at Concon, near the mouth of the river named in the maps ‘“ Rio Quillota.” Concon is about fifteen miles N.N.E. of Valparaiso, as _ the crow flies. “ At half-past ten, on the night of the 19th iauiedheal I felt the first oscillation. I was writing at the time; starting from my chair, I paused for an instant, expecting the shock would subside, as others had done; but the falling of glasses from the sideboard, the cracking of the timbers, and the rattling of the tiles from the roof, fully apprized the whole family of their danger, and all ran out of the house. The house was violently agitated, and was falling to pieces, but freed from the apprehension of being buried in the ruins, my attention was forcibly drawn to the phenomena, which I endeavoured to observe as accurately as possible. Scarcely, however, was this resolution taken, and before the first shock had entirely subsided, a second and much more violent one succeeded; this was accompanied by noise, which appeared to be deep seated in the earth, perpendicularly to the spot on which we stood. The duration of this shock was about two minutes; it was succeeded by a third, also accompanied by noise, less loud than that which accompanied the preceding shock. The shock was less violent than either of the two former shocks, and of less duration. These shocks occupied about five minutes of time. Shocks, at intervals, of four and five minutes, continued for nearly an hour, after which, they became less frequent during the remainder of the night, and of very different intensities, some being rather severe, and others hardly perceptible. The three principal shocks may be said to con- stitute the earthquake. “« At the commencement of the earthquake, the atmosphere was, as is usual at this time of the year in this country, quite free from clouds, the moon and stars shone with splendour; there was no atmospheric indication of change of any sort, either before or after the earthquake. Some persons say they saw an unusual light in the horizon to the southward, but I, who was expecting some Account of the Earthquake in Chili. 4] _ change, and was prepared to observe any that might have occur- red, saw none whatever. | “ During the earthquake the ground rose and fell with great vio- lence, and with almost inconceiveable rapidity. There was cer- tainly no undulatory motion, though many unobserving and unre- flecting persons suppose this to have been the case. I had astrong suspicion at the time, since confirmed by observation of its effects, that there was a powerful horizontal motion, but as I could not perceive it as coming from any particular point, I concluded at the time that I was mistaken. The circumstances which make me now conclude there was a horizontal motion, are observations I have since made in many places, in which walls, and even houses, have been partially twisted round, and from the fissures round the roots of the largest trees. At Quintero, ten miles to the northward of Concon, are several large palm-trees ; three of these standing so as to form an equilateral triangle, lashed one another like willow rods, and beat or shook off many of their branches. The motion of these trees seems to have been horizontal and circular, since each of them cleared a space in the ground round its stem, several inches wide, and this was the case also with other large trees in different places, “ The sensation we experienced during the earthquake, was pro- bably the same we should have felt had we been conscious that a mine had been sprung beneath us, and was about to blow us all into the air. . “On examination next morning, at daylight, I found the earth full of fissures, some of them very small, while others were from two to three feet wide. In many places sand had been forced up, and had formed small hillocks. In the most recently formed allu- vial soil near the river, water and sand had been forced up together, there being many large truncated cones of clean washed sand, each of which had a hollow in the centre, like the crater of a volcano. The same phenomenon was observed in several places; in other places, large quantities of soft mud had been forced up, and spread itself over the surface of the land. “ The surface of the country has been raised all along the coast, as far as my information extends. It seems to have been raised 42 Account of the Earthquake in Chili. highest at the distance of from two to three miles from the shore, diminishing both ways. The rise on the coast is from two to four feet; at the distance of a mile inland, the rise must have been from five to six or seven feet; for in the cut for the tail water course of amill, at the distance of about a mile from the sea, a fall of four- teen inches has been gained in little more than a hundred yards. “ At Valparaiso, near the mouth of the Concon, and along the: coast northward to Quintero, rocks have appeared in many places, where none before were visible. The high-water mark along shore is about three feet above the place the tide now reaches, and. a vessel, which had been wrecked on this coast, and which could only, be approached at low water in a boat, is now accessible on dry land at half tide *. “¢ At Valparaiso, not a single house escaped being damaged; it is somewhat remarkable, however, that although the ground was raised bodily, and considerably, those houses whose foundations were on the rocks, were less damaged than those built on the allu- vial soil. All the houses at Valparaiso are built of adobes (sun- dried bricks), cemented with clay. These were thrown into heaps of rubbish, or torn and rent in all directions. The town had the appearance of having suffered a heavy and long continued bom- bardment. Upwards of three hundred persons were buried in the ruins. Had the earthquake happened two hours later, very few of the inhabitants would have escaped. ‘* After the earthquake, the inhabitants encamped upon the hills above the scene of desolation, in the best way they could; this was thought less of a hardship than it would have been thought in most other countries, from the fine warm weather, the certainty as was concluded of dry weather, and the small quantity of dew which, at this season of the year, falls in Chili. To these hills goods of all sorts, furniture, and every thing else, were brought, and laid in the open air. The damage done to this thriving town will not be re- paired in many years. «« The church of La Merced presented a striking instance of the * There is very little variation of tides on this coast, the sea never rises anprG than four feet at the full of the moon, . Account of the Earthquake in Child. 43 violence of the earthquake; the tower, sixty feet high, which served as a belfry, was levelled to the earth. Its solid walls of burnt bricks; well laid in mortar, were shivered in pieces; the two side walls, full of rents, were still standing, supporting part of the shat- tered roof, but the two end walls were entirely demolished. On éach side of the church were four massive abutments, six feet square, of good brick work; those on the western side were thrown down, and broken to pieces, as were two on the eastern side; the other two were twisted off from the wall, in a north-easterly direc- tion, and left standing. ey te : bad 24 : . _ N i as BOG, Dy gy |} Church of | LaMorecd ~ “On board the admiral’s ship in the harbour, where more secure than ashore, the effects of the earthquake, so far as the situation permitted, observations were made with great accuracy. Tere three distinet shocks were felt, the second was observed to be by far the strongest, and its duration, as had been noticed at Concon, is stated at two minutes. The effect upon the ship was the same as would have been produced had she suddenly sunk down upon a rock. It appeared as if her bottom had been struck with prodigious force ; 44 Account of the Earthquake in Chilt. the vessel vibrated in an extraordinary manner, her timbers cracked, and she appeared strained throughout. “‘ At Santiago, the capital, at ninety miles distance from the sea, and about twenty miles from the mountains of the Andes, the earthquake was less severe; no houses were thrown down, al- though many, as well as the churches, were much damaged, but no lives were lost. Here, however, as in other places, the inha~. bitants removed from the town, and camped out in the open air. The effect of the earthquake atAconcagua, about fifty miles N.N.W. of Santiago, was much the same as at Santiago, Millipilla, sixty miles S.E. of Valparaiso, suffered less than either Santiago or Aconcagua; but, at Casa Bianca, not a single house or wall of any kind was left standing. At Mapel, the shocks were very severe, great part of the village was destroyed, and a pool of water was formed in the market-place. Quillota also suffered to a consider- able extent, many houses were destroyed, and all were more or less damaged. At Valdivia, in 39° 50'S, lat., one shock only was felt; it is described as having been “ pretty sharp,”’ but it did no damage. At the moment the shock was felt, two volcanoes in the neighbourhood burst out suddenly with great noise, illuminated the heavens and the surrounding country for a few seconds, and then as suddenly subsided into their usual quiescent state. ‘“« Although no atmospheric changes appeared at the time of the earthquake, there can be no doubt that very considerable changes took place. ‘The weather, after the earthquake, continued as usual; but on the evening of the twenty-seventh of November, just eight days after the earthquake, the country, for a great extent, was visited by a tremendous storm of rain, accompanied with heavy gusts of wind; the rain continued all night, producing terror and dismay among the people. Every thing saved from the earth- quake, was exposed in the open air, or under such temporary coverings as could be constructed with the few materials time and circumstances permitted. Few of the tents, under which part of the people lived, were water proof. Many were living in enclo- sures called ramadas, made of dried boughs and bushes, open to the heavens, and many had no other fence than could be formed of Account of the Earthquake in Chili, 45 their furniture or other effects. Rain towards the close of the month of Noveraber had been expected by no one, and no prepa- ration to defend either persons or property from its effects, had been made. Rain had never before fallen in the country, even at a small distance north of the river Maule, in the month of No- vember. The consequences anticipated from the rain, which, from appearances, was likely to continue, were of the most distressing nature. The total destruction of the houses which had been in- jured, as well as that of the goods, merchandize, and furniture, which had been collected, and of the growing crops, was antici- pated by all. Its immediate effects, had it continued, would have been intermitting and malignant fevers. These apprehensions caused the people to pass a night of indescribable agony. The rain, however, ceased suddenly towards morning, and the weather ‘became settled as usual. “The greatest force of the earthquake appears to have been felt at the distance of about fifteen miles N.E. of Valparaiso; the whole country, from the foot of the Andes to far out at sea, has been raised; the rise has, however, been very unequal. “As the earthquake was felt at Copiapo in the north, and at Val- divia in the south, its extent, from north to south, exceeded nine hundred miles. Where the shocks were most severe, the earth has been raised the highest, and its not subsiding again to its for- mer level has probably been occasioned by the innumerable fissures and multitude of small cracks caused by the repeated explosions, by which the sanity of the whole mass has been somewhat al- tered. “ Many persons to the northward of Valparaiso thought the di- rection of the shocks was from the south-west, while those to the southward thought they came from the north-west. If the princi- pal force, as it appears to have been, was exerted within a circle of about fifty miles diameter, the centre of which was a little to the __N.E. of Valparaiso, the direction of the shocks might have been, as those at a distance, to the north and south of that space, have de- scribed them. Most persons who live near the coast, suppose the shocks to have come from seaward, either to the northward or 46 Account of the Earthquake in Chili. southward, as had been mentioned, while those who resided within the circle described, conclude they were produced by ex- plosions, perpendicular to the earth’s surface. It does not ap- pear that the earthquake extended into the mountains of the An- des; no change whatever was observed in any of these mountains, except as has been related near Valdivia, and here the voleanie ridge is nearer to the sea and less elevated than in any other part of Chili. The surface over which, or rather under which, the earth= quake extended ashore, cannot be less than 100,000 square miles. “‘ During the earthquake the sea, for a considerable distance along the coast, receded and returned several times. At Quintero, the fishermen who live upon the beach, fled in terror to the sand-hills. At Valparaiso, a man-of-war’s boat, going ashore, landed at the door of the Custom-house, which is twelve feet above the usual high-water mark. Neither the recussion, nor the retrocession of the sea, were as violent as might have been expected. “Up to the end of September, 1823,the date of the last accounts, earthquakes continued to be felt; forty-eight hours seldom passed without a shock, and sometimes two or three were felt ving twenty-four hours.” Arr. VI. On Evaporation. By J. Frederic Daniell, ai F.R.S., M.R.L., &c. {Communicated by the Author.] Tue subject of evaporation has occupied, at various times, much of the attention of natural philosophers, and many accurate and interesting observations have been recorded of the formation and diffusion of elastic fluids, from various kinds of liquids. ‘The cir- cumstances, especially, attending the rise and precipitation of aque- ous steam in the atmosphere, are acknowledged to be important in the highest degree, as upon their silent influence depends the adjustment of those important meteorological phenomena, with which is connected the welfare of all the organized creation. The labours of De Lue, De Saussure, and particularly of Mr. Dalton, haye thrown considerable light upon this neyer-ceasing process; but Mr. Daniell on Evaporation. 47 something appears to be still wanting to complete the investiga- tion, and to follow up the results to their ultimate consequences. The following observations, however inadequate to fulfil this desirable purpose, may possibly attract some attention to the sub- ject, and may be the means of indicating the points which most require elucidation. _ It is a well-known fact that water, under all circumstances, is - endued with the power of emitting vapour, of an elastic force proportioned to its temperature. It is also well understood, that the gaseous atmosphere of the earth, in some degree, opposes the diffusion, and retards the formation of this vapour; not, as Mr. Dalton has shewn, by its weight or pressure, but by its vis iner= tie. What is the amount of this opposition, and by what pro- gression it is connected with the varying circumstances of density and elasticity, have never yet been experimentally explained. It may facilitate the comprehension of the subject, to distinguish three cases with regard to the evaporating fluid: the first, when its temperature is such as to give rise to vapour equivalent in elas- ticity to the gaseous medium, and when it is said to boil; the second, when the temperature is above that of the surrounding air, but below the boiling point; and the third, when the tempe- rature is below that of the atmosphere. _ With regard to the first, all the phenomena have been accurately appreciated. The quantity evaporated from any surface, under any given pressure, is governed, in some measure, by the in- tensity of the source of heat, and is in no way affected by the motions of the aérial fluid. The elasticity of the vapour is ex- actly equivalent to that of the air, which yields en masse to its lightest impulse. When disengaged, it is immediately precipi- tated in the form of cloud, giving out its latent caloric to the ambient medium; and under that form is again exposed to the process of evaporation, according to the laws of the third division of the process. All the phenomena attending the process of boiling, have been ably investigated by Gay-Lussac, Dalton, Ure, and Arch-deacon Wollaston; but, as they have but little con- nexion with the atmospheric relations, which are the particular 48 Mr. Daniell on Evaporation. object of the present paper, I shall proceed to the second case of evaporation. When the evaporating fluid is of a higher temperature than the surrounding air, but not so high as to emit vapour of equal elas- ticity to it, the exhalation is proportionate to the difference of tem- perature. The gaseous fluid, in contact with the surface, becomes lighter by the abstraction of portions of the excess of heat, and, rising up, carries with it, inits ascent, the entangled steam. This, as in the former case, is precipitated, and, in the form of cloud, exposed to the third species of evaporation. This process is not only proportioned to the difference of temperature, and the elasti- city of the vapour, but is also governed by the motion of the air. A current or wind tends to keep up that inequality of heat upon which it depends, and prevents that equalization which would gradually take place in a stagnant air. Such is the evaporation which often takes place in this climate, in Autumn, from rivers, lakes, and sea, and which is indicated by the fogs and mists which hang over their surfaces. It is, however, the third modification of circumstances, which is the most interesting in the point of view which I have suggested, and from which I have merely distinguished the preceding, to free the subject from ambiguity. When the temperature of water is below that of the atmosphere, it still exhales steam from its surface; but, in this case, the vapour, neither having the force necessary to displace the gaseous fluid, nor heat enough to cause a circulation, which would raise it in its course, is obliged to filter its way slowly through its interstices; and the nature of the resistance it meets with in this course is the first object of investigation. The force of vapour, at different temperatures, has been deter- mined with great accuracy, and the amount of evaporation has been shewn to be ceteris paribus, always in direct proportion to this force. The quantity is also known to depend upon the at- mospheric pressure, but I know of no experiments which esta~ blish the exact relation between the two powers. I attempted to elucidate the point as follows:— Mr. Daniell on Evaporation. 49 By enclosing in a glass receiver, upon the plate of an air-pump, a. vessel with sulphuric acid, and another with water, and by pro- perly adjusting the surfaces of the two, it is easy to maintain, in the included atmosphere of permanently-elastic fluid, an atme- sphere of vapour of any required force; or, in the usual mode of expressing the same fact, the air may be kept at any required de- gree of dryness. The density of the air, in such an arrange- ment, may, of course, be varied and measured at pleasure. Now there are three methods of estimating the progress of evaporation in such an atmosphere: the first, and most direct, is to weigh the loss sustained by the water in a given time; the second, to mea- sure, by a thermometer, the depression of temperature of an eva- porating surface; and the third, to ascertain the dew point, by means of the hygrometer. Experiment 1. The receiver, which I made use of, was of large capacity, and fitted with a hygrometer. I placed under it a flat glass dish, of 74 inches diameter, the bottom of which I covered with strong sulphuric acid.. The glass bell but just passed over it, so that the base of the included column of air rested everywhere upon the acid. In the centre of the dish, was a stand with glass feet, which supported a light glass vessel of 2°7 inches diameter, and 1:3 inches depth. Water to the height of an inch was poured into the latter, the surface of which stood just three inches above that of the acid. A very delicate thermometer rested in the water, upon the bottom of the glass, and another was suspended in the air. It may be necessary to observe, that the sides of the vessel were perpendicular to its bottom, which was perfectly flat. The height of the barometer was 29°6, and the temperature of the water 56°. In twenty minutes from the beginning of the experi- ment, the hygrometer was examined, and no deposition of mois- ture was obtained at 26°. This being the greatest degree of cold which could be conye- niently produced by the affusion of ether, the experiment was re= peated, with a contrivance which admitted of the application of a Vou. XVII. E 50 Mr. Daniell on Evaporation. mixture of pounded ice and muriate of lime, to the exterior ball of the hygrometer. In this manner the interior ball was cooled to 0°, without the appearance of any dew. The temperature of the water and air were, in this instance, 58°, and the pressure of the atmosphere 30°5. From this experiment it appears, that in the arrangement above described, the surface of water was not adequate to maintain an atmosphere of the small elasticity of °068 inch; in other words, the degree of moisture in the interior of the receiver could not have exceeded 129, the point of saturation being reckoned 1000. How much less it was than this, or whether steam of any less de- gree of elasticity existed, the experiment, of course, did not deter- mine. We may reckon, however, without any danger of error in our reasoning, that the sulphuric acid, under these circumstances, maintained the air in a state of almost perfect dryness. Experiment 2, The same trial was made with atmospheres variously rarefied, by means of the pump. No deposition of moisture was, in any case, perceived with the utmost depression of temperature, which it was possible to produce; and the state of dryness was as great, in the most highly attenuated air as it was in the most dense. In the higher degrees of rarefaction, the water however became frozen. Experiment 3. The water, which had been previously exposed to the yacuum of the pump to free it from any air in solution, was weighed in a very sensible balance, before it was exposed to the action of the sulphu- ric acid under the receiver. Its temperature was 45°, and the height of the barometer 30°4. In half an hour’s time, it was again weighed, and the loss by evaporation was found to be 1'24 grains. It was replaced, and the air was rarefied till the gauge of the pump stood at 15-2; in the same interval of time it was re-weighed, and the loss was 2°72, but its temperature was reduced to 43°. The loss from evaporation, in equal intervals, with a pressure con- stantly diminishing one-half, was found to be as follows:— Mr. Daniell on Evaporation. 51 ‘Temperature, Loss Pressure Beginning Eud Grains ee ee ee ee es See ee en Me ee ea as ee a ee ee ete. ae ee er ae eee ae ae a | ee ce eae, Cee a eee ot ene es ee ts ee ee ee When the exhaustion was pushed to the utmost, the gauge stood at 0°07, and the evaporation in the half hour was 87:22 grains. During this last experiment, the water was frozen in about eight minutes, while the thermometer under the ice denoted a tempera-~ ture of 37. Now, before we infer from these experiments the state of evapo- ration, from different degrees of atmospheric pressure, it is neces- sary to apply to the results a correction for the variation of tem- perature which took place during their progress. The quantity of evaporation having been determined to be in exact proportion to the elasticity of the vapour, we must estimate the latter from the mean of the temperatures before and after the expcriments, and calculate the amount for any fixed temperature accordingly. This will, doubtless, give us a near approximation, although, from the last experiment, we perceive that the method of estimating the tem- perature of the surface water cannot be absolutely correct. The following table presents us with the former results so corrected for the temperature of 45°: Pressure, Grains. E12: Mem PE 1°24 LE i RTE RET aN 6 7°6 . . . . 5:68 3°8 . . . . 9°12 1:9, Sie Pie pale FRC u/s (piep, 96 ve), bolaiin ds 298d Lf OS NE «Lae sted ane het Oe 52 Mr. Daniell on Evaporation. Notwithstanding the slight irregularity of the above series, we can, I think, run no risk in drawing from it the conclusion, that the amount of evaporation is c@éeris paribus in exact inverse pro- portion to the elasticity of the incumbent air; and that De Saus- sure was misled by his hygrometer, when he inferred from its indica- tions, that a diminution of one-third the density doubled the rate. Before we proceed, it is necessary to say a few words upon the apparent discrepancy between the results of Mr. Dalton’s experi- ments and mine, as to the amount of evaporation, at the full pres- sure of the atmosphere. He found, upon the supposition of no previous vapour existing in the air, that the full evaporating force of water, of the temperature of 45°. would be 1:26 grains per minute, from a vessel of six inches in diameter. This amount re- duced in proportion to the squares of the diameters of the two ves- sels, would give 7°65 grains in half an hour, from the glass of 2°7 inches diameter, which I employed. It must, however, be recol- lected, that Mr. Dalton’s culculations were founded upon experi- ments made at a temperature very considerably above that of the surrounding medium, and that consequently a current must have been established in the latter which greatly accelerated the pro- gress. It is true, that he afterwards subjected his calculations to the test of experience, at common atmospheric temperatures; but then he expressly states, that ‘‘ when any experiment, designed as a test of the theory, was made, a quantity of water was put into one of them (vessels), the whole was weighed to a grain; then 7 was placed in an open window, or other exposed situation, for ten or fifteen minutes, and again weighed, to ascertain the loss by evaporation.” In this way he ascertained, that with the same evaporating force, a strong wind would double the effect. The difference, however, even after these considerations, is still very striking; but, from several repetitions of the experiment, I have no doubt of its exactness. Experiment 4, The arrangement described in the last experiment, having been found adequate to maintain in the receiver a state approaching to Mr. Daniell on Evaporation. 33 that of complete dryness, I had no opportunity of judging whether the elasticity of the vapour, as it rose from the surface of the water, varied in any degree with the pressure of the air, or whether any part of the increase of evaporation were dependant upon such vari- ation. To determine this point, I placed the sulphuric acid in a glass, of the diameter of 2°8 inches, so that its surface was very little more than equal to that of the water. The vessels were placed, side by side, upon the plate of the air-pump, and covered with the receiver. The temperature of the water and air was 52°, and the height of the barometer 29°8. The following table shews the dew point, which was obtained, at intervals of half an hour, at different degrees of atmospheric pressure :— Barom. ~— Temp. of Water and Air Dew Point 29 8 se SL agebllee been lla pics: ay, 2 apa teed cg: ~ ge nl they t all Sante © be gear aude tute Oo tine dbinga ei 86 yee pepe nga FLO mean i amie hari agate 7 nr arthaaneideert aterm barn 2 2 ne aga atte et 2 deter deter gamba 2A peta et atts ent aint, ylde ages pong The differences of these results are so extremely small, and are moreover so little connected with the variations of density, that there can be no difficulty in regarding them as errors of observa- tion, and we may conclude, that the elasticity of vapour, given off by water of the same temperature, is not influenced by differences of atmospheric pressure. The equal surfaces of sulphuric acid and water here made use of, maintained, at the temperature of 52°, a degree of saturation equal to 570. I repeated the experiment, at the temperature of 61°, and the following are the results:— Barom. Temp. of Water and Air Dew Point 29-6 12 ie) a a atl A ia a RS RS Prgirivegay sow) © gipile, aagdgrgmaly: 96g Gay Dank ey sien Barris Meals V6 gD pepe el 30st) OPT yep gag POA OLE HBO IN WA 4S Tike PION ATS Var EB yt as o4 Mr. Daniell on Evaporation. Under these circumstances, the amount of saturation was 651; an increase evidently dependant upon the force of the vapour, but not in exact proportion to its augmentation. Experiment 5. Being now desirous of ascertaining in what degree the tempera- ture of an evaporating surface would be influenced by differences in the density of the air, I made the following disposition of the apparatus:—To a brass wire, sliding through a collar of leathers, in a ground brass plate, I attached a very delicate mercurial ther- mometer; this was fixed, air-tight, upon the top of a large glass receiver, which covered a surface of sulphuric acid of nearly equal dimensions with its base. Upon a tripod of glass, standing in the acid, was placed a vessel containing a little water, into which the thermometer could be dipped and withdrawn by means of the slid- ing wire. The bulb of the thermometer was covered with filtering- paper. At the commencement of the experiment, the barometer was at 30:2 inches, and the temperature of the air 50°. Upon withdrawing the thermometer from the water, it began to fall very rapidly, and in a few minutes reached its maximum of depression. The following table presents the results of the experiment, for different degrees of the air’s density; the intervals were each of twenty minutes :— Barom. Temp. of Air Temp. of wet Ther. Difference 1 a alt al dat tee: aia a ee al LT ee ee, ae Ca ae PA ee, FEOP (PO ER Re BRO AEG Se a OS eee SO Aa See 1G 82? OY SR eo (See oh: si: = Sola le Mian a ae ok yrs Se RI Oe ot SSR ote Here, in an atmosphere which a former experiment has proved to be in a state of almost perfect dryness, we find that, at the full atmospheric pressure, the wet surface of the thermometer was re- duced 9°, It is worthy of remark, also, how small a quantity of water is required to produce this effect. It has been previously Mr. Daniell on Evaporation. 50 shewn, that a surface of 2:7 inches diameter, only lost 1:24 grains in half an hour. This would have been 1:41 grains at the tempe- rature of 490. The surface of the wet thermometer could not have exceeded ;1,th of that of the evaporating vessel, and the maxi- mum effect was produced in ten minutes, or 4 of the time, so that the weight of water evaporated in this case was not more than (:0094 grains) one-hundreth of a grain. It will be seen, that the depression increased with the rarefaction of the air, but in the pro- portion only of the terms of an arithmetical progression to those of a geometrical. The increase is attributable, not to the augmented quantity of the evaporation, but to the decreased heating power of the atmosphere. MM. Du Long and Petit, in their experi- ments upon the cooling power of air, determined it to be nearly as the square root of the elasticity; but whether the heat which it is capable of communicating to a cold body, follow the same pro- gression, the experiments above detailed are not sufficient to de- termine with precision, We may, however, certainly conclude from them, that the temperature of an evaporating surface is not affected by the mere quantity of evaporation. It is right to remark that, in the last experiment, care was always taken to station the evaporating thermometer in .the same place in the receiver, for I found that, when the air was highly rarefied, a greater degree of cold could be produced by approxi- mating the wet bulb to the surface of the acid. No difference, however, could be perceived from such a change at the full atmo- spheric pressure. I also ascertained that no change of relative position in the surfaces of the acid and water produced any al- teration in the dew point under any circumstances. _ The few simple facts above determined appear to me to be in- timately connected with the solution of some very important at- mospheric phenomena, and I shall endeavour briefly to indicate their relation. _ The aqueous fluid is so abundantly spread over the face of the earth, that there can be no doubt that the permanently-elastic atmosphere, which surrounds it, would very speedily be saturated With its steam, did notgome cause, analogous to the sul phuric acid 56 Mr. Daniell on Evaporation. in the receiver, prevent its universal diffusion. This never-failing cause is inequality of temperature. As in the small experiment we found that the degree of dryness was proportioned to the energy of the absorbent mass, and that the existing vapour was equally diffused between it and the exhaling surface; so, in the larger operations of nature, we shall find that the state of saturation is dependant upon the point of precipitation, and that the aqueous atmosphere is nearly uniform between it and the source of steam. Now, it is well understood that the temperature of the gaseous atmosphere in its natural state must decrease with its density as we ascend to its upper parts; so that a great degree of cold is at all times to be found within a very moderate distance from the surface of the waters. It is this low temperature which determines the tension of the aqueous atmosphere ; and it is evident that the evaporation which is thus caused at the base of the aérial fluid, must be accompanied by a simultaneous and equal precipitation above. What then becomes of the precipitated moisture? Let us endeavour to trace the order of this phenomena. We will first suppose a calm state of the atmosphere, a temperature of 80°, and the barometer at 30 at the surface of the earth. By a calm state of the atmosphere is here meant, one that is free from any lateral wind, and in which, the only currents being in an ascending and descending direction, evaporation would proceed at the rate ex- hibited in the first column of Mr. Dalton’s table. The dew-point at the surface of the earth is 64°, and this is determined by the temperature at the height of about 5000 feet, where the barometric column would maintain itself at 24 inches. The degree of satura- tion below would therefore be 600, and the amount of evaporation 1-74 grains per minute from a surface of six inches diameter. This quantity we therefore suppose condensed at the height before named. But the state of saturation in the atmosphere, above this point of precipitation, is again diminished; for we may suppose the force of the vapour to be determined by a temperature of 31° at a height of 15,000 feet, where the barometer would stand about 16 inches. ‘The force of evaporation would, therefore, be 1.71 grains per minute, at the full atmospheric pressure ; and this amount Mr. Daniell on Evaporation. 57 increasing as the pressure diminishes, would give 2°13 grains per minute ; so that the power of evaporation at this stage exceeds the supply of moisture, and no cloud could possibly be formed. Above the second point of condensation let us now suppose the force of the vapour to be determined, in still loftier regions, by a temperature of 120. The force of evaporation would then be 0°44 grains, increased in the proportion of 16 inches to 30, or 0°82 grains. Here, then, the power of evaporation would be insufficient to diffuse in the upper regions the whole of the moisture supplied from the surface of the earth, and a cloud, it might be supposed, must consequently result. But another modification of the pro- cess now ensues; the precipitated moisture has a tendency to fall back into the warm air below it, and consequently would again assume the elastic form with a rapidity proportioned to the rare- faction of the stratum in which it is diffused. There is, I think, no difficulty in supposing that no visible cloud, or one of extreme tenuity, would be formed during this double process of evapora- tion. A yery important re-action, however, must take place upon the strata of vapour beneath; the elastic force being increased aboye, enables the water below to maintain an atmosphere of a higher degree, and the quantity of evaporation must decrease as the point of saturation rises. A different arrangement of the points of precipitation would ensue in the progress of these effects. An important distinction must here be drawn between the ulti- mate effects of the superior and inferior evaporation denoted above. In the first, the whole weight of water is condensed and simul- taneously exhaled ; and although it constitutes steam of an in- ferior degree of force, there is little or no difference in the quantity of its latent heat, and no effect is tierefore produced upon the temperature of that portion of the atmosphere in which the change takes place. But in the second, the condensation happens at one spot, and the vaporization at another inferior to it; the latent heat is therefore evolved at the former and communicated to the air, while at the latter the process is reversed, and the air is cooled. The process of this operation would, therefore, tend to equalize the temperature of the atmosphere, 58 Mr. Daniell on Evaporation. We will next imagine that the surface of the earth is swept by a high wind, and that the atmosphere instead of resting calmly upon its base, moves laterally with great velocity. Under these cireum- stances experience has shewn that the amount of evaporation will be nearly doubled; but the force of evaporation is not altered in the upper regions. The inferior exhaling surface being immove- able, the motion of the air perpetually changes, and renews the points of contact, and prevents accumulation at any one place; but in the heights of the atmosphere the exhaling surface of the cloud is borne upon the wind, and their relative situations never change. The progress of precipitation must, therefore, necessarily, under these circumstances, outstrip that of evaporation, and the dis- turbance of the atmospheric temperature will be greatly accele- rated. There is another cause which would also quicken evaporation below, without equally increasing its power of diffusion at any given height above; and that is a decrease in the density of the air at the surface of the earth. Under the circumstances of our first supposition imagine the barometer to fall to 28 inches, the evapo- ration would be increased from 1°74 grains per minute, to 1°86 grains; but this decline of two inches at the surface would indi- cate a contemporaneous fall of little more than one inch at the height of 15,000 feet, and the rate of diffusion would vary accord~ ingly. When it is considered that great falls of the barometer are generally accompanied by high winds, and that this disparity is multiplied by the force of the current, it is easy to appreciate the influence of this local increase of the power of evaporation. The facility of evaporation in the rarer regions of the atmosphere will also go far to account for the state of saturation in which the air of mountainous countries is generally found, and many minor meteorological phenomena might probably meet with their expla- nation from variations of the same cause; such as the fogs which frequently accompany a very high degree of atmospheric pressure, and that peculiar transparency of the air which often precedes | yain, and is accompanied by a falling barometer, But te return Mr. Daniell on Evaporation. 59 again to the more general and extended influence of the vapour upon the boundless strata of the atmosphere :—that the phenomena of evaporation and condensation, as we have been contemplating their progress, have not been described with any bias to theoreti- cal considerations, but are in strict accordance with facts and ob- servations, any one might easily convince himself with less diffi- culty than would at first be supposed. To prove the assertion I shall extract the following passages from the works of De Luc, who was probably one of the most accurate observers of nature that ever existed, and who seldom, indeed, allowed any hypothe- tical considerations to warp his description of what he had ob- served. They will afford a complete illustration of the preceding remarks, although they were penned by him to support a very different hypothesis. “Si Von ne fait qu’une légére attention a la surface de ces brouillards vus des montagnes pour en jouir comme d’un beau spectacle, on peut penser qu’ils sont permanens ; que l’évaporation est arrivée 4 son maximum 4 la surface des eaux, parce que l’air est parvenu 4 l’humidité extréme ; et que les vapeurs vesiculaires qui troublent la transparence de cet air restent les mémes durant des semaines ou méme des mois; cest-a-dire, tant que le bro- uillard se conserve 4 une méme hauteur. Mais le phénoméne différe beaucoup de cette premiére apparence: l’evaporation con- tinue 4 la surface des eaux, les vapeurs vésiculaires qui s’en forment montent sans cesse et une nouvelle évaporation a lieua Ja surface des brouillards. C’est un spectacle aussi amusant qu'instructif, que celui que fournit cette surface, vue d’un lieu peu élevé audessus d’elle, et dans une grande vallée ou l’on ait A quelque distance, des montagnes rembrunies par des foréts de sapins. Une telle vallée éclairée par les rayons du soleil semble étre comblée de coton, filé dans toute sa surface par des étres invisibles en fils invisibles: il s’y fait par-tout des tumeurs, sem- blables a celle que produit une fileuse sur sa quenouille en tirant Je coton pour former son fil, et elles disparoissent successivemeng en se dissipant dans Pair. Quelquefois ces tumeurs s’allongent et fe separent de la masse en tendant & monter; on les voit alors 60 Mr. Daniell on Evaporation. s’étendre comme un paquet de gaze qui se déploie et peu a peu elles disparoissent. Les brouillards se forment done constamment 2 la surface des eaux et du sol; mais constamment aussi ils se dissipent dans I’air supérieur: et cependant on n’appergoit point que l’humidité y augmente.”—TJdées sur la Metéorologie, Tom. 11, p. 78. “‘ Depuis que mes idées ont changé sur la cause de la pluie, j’ai fort souvent fixé mon attention sur les nuages et j’ai reconnu trés évidemment, qu’ils s’évaporent méme tandis qu’ils grossissent. Si l’on fixe ses regards sur leur bord découpé qui, lorsqu’il a pour fond l’azur du ciel, presente mille figures singuliéres, celles que V’'imagination leur préte alors, peut aider 41’examen dont je parle, en rendant leurs changemens plus frappans. II arrive souvent, que la partie sur laquelle on fixe son attention se dissipe au lieu méme ov l’on a commencé a I’cbserver: souvent aussi on la voit s’étendre, sans que la totalite du nuage se meuve, et elle ne se dissipe pas moins durant cette extension. Quelquefois, tandis que l'un des festons du nuage se dissipe on en voit d’autres se former, s’étendre, produire eux-mémes de nouveaux festons ; par ou le nuage grossit: d’autres fois il diminue; et alors tous ses festons s’évaporent successivement et il n’en acquiert de nouveaux, que parcequ’il se découpe : on appercoit en méme tems, qu'il devient plus mince et il disparoit enfin totalement. “ C’est ce qui m’a conduit a penser qu’il y a en effet dans Vair, une source générale de vapeurs qui en fournit en certaines circon= stances; que ces vapeurs sont produites au lieu meme ou se forme un nauge; que c’est par la durée de cette production de vapeurs, que les nuages subsistent, s’aggrandissent méme, quoiqu’en s’évaporant tout le tour; et que lorsqu’ils se dissipent c’est que leur evaporation n’est plus réparée par la formation de nouvelles vapeurs.”—J0. p. 117. I shall now conclude this paper with an observation which is in- timately connected with the subject of the preceding pages. It has been argued that the quantity of heat which would be commu- nicated to the air by the condensation of atmospheric vapour would be trifling, and inadequate to produce those expansions in Mr. Daniell on Evaporation. 61 the aérial currents to which, in my essay upon the constitution of the atmosphere, I have ascribed the fluctuations of the barometer. Now, I have therein shewn how the gradual spread of a small in- crease of temperature, through a considerable stratum, is sufficient for the purpose ; and a very little consideration will, I think, con- vince any one that the evolution of caloric is by no means so small as has been supposed. ‘The following rough calculation will place the facts in a striking point of view :—The latent heat of steam has been proved to be somewhere about 970°, and it is known that, whatever be its den- sity, or the temperature at which it is produced, the amount will differ but little from this estimate. The condensation, therefore, of a pound of steam of any degree of elasticity would be adequate to raise a pound of water 970°. The capacity of atmospheric air, of mean density, for heat, compared to that of water, is as ‘2669 to 1; therefore the same quantity of heat which would raise a pound of water 1°, would raise a pound of air 3°7. The conden- sation of a pound of steam would, therefore, elevate the same weight of air to 3589°. A pound of air is equal to about 11 cubic feet, so that the evolution of heat from the condensation of a pound of steam, would be sufficient to raise the temperature of 3657 cubic feet of air 10°. When we now look to the depth of water which falls upon the surface of the earth, and recollect that this is not the sole measure of the effect we are endeavouring to estimate, but that the unceas- ing precipitation and exhalation of the clouds is perpetually ex- tending this influence to the most inaccessible heights, we shall, perhaps, have a juster notion of the prodigious power of atmo- spheric vapour ; and it will, I think, be granted that I have not over-rated the impulse which it is calculated to impart. 62 _ Mr. Ware’s Design for Arr. VII.—A Design for making a Public Road under the Thames, from the east side of the Tower, near Iron-Gate Stairs, to the opposite side of the River, near po one down Stairs. By Samuel Ware, Esq. [Communicated by the Author.] The carriage-road . . . 28 feet wide. Internal Dimensions | The height above the road . 18 feet. of the The foot-paths . . . . 14 feet wide. Arche The greatest width . . . 42 feet. The greatest height . . . 21 feet. The following particulars of the Esrrmare describe the mode of erecting the arch-way :— Compensation for the ground and buildings on the north side of the river, and for the ground and buildings on the south side, to form the approaches; cofferdams, in ten successive lengths or removes, to keep out the water; and strutting, to keep up the ground. Steam-Engines, to keep the works within the cofferdams dry, and subsequently for draining the’ road, should there be occasion. Digging out a channel, in the bed of the river, for the arch-way, and the ground for the approaches. Removing the refuse earth ; claying, filling in, and level- ing, two feet above the extrados of the arch. Yorkshire Ledgers for the foundations of the arch-way, and walls of the approaches and embankments, and piling as occasion may require. Stone-work, cut in voussoirs, of the arch, and counter- arch. Lining with lead, 10d. to the foot superficial, enveloping these arches. Super-arch of brick-work, lined externally with tiles in cement. ‘ a Public Road under the Thames. 63 Centering for the arches. Forming and gravelling the road, ascending one foot . perpendicular to twenty feet horizontal. Drains, pipes, foot-paths, and lamps. Embankments, and other walls and parapets, in the ap- proaches *. Facings to the entrances to the arch-ways, and toll- _ houses. Estimated amount of the above works .... . £250,000 Pecuniary Advantages. A small part of such a revenuet, as would be derived from the number of passengers and carriages which has been estimated to pass London Bridge daily, calculated at the tolls allowed to the Southwark Bridge Company, would be ample to compensate the cost of this arch-way. The taxes arising out of the materials of the buildings likely to: be erected, together with the assessed taxes arising out of them when built, in the ways to and through the lower road to Deptford, and in communicating with the Kent Road, consequent on such a connexion between the two sides of the Thames, would be a great source of revenue to the government, probably more than sufficient to compensate the cost of this arch-way. * This mode of approach is also applicable to a road descending from a bridge ; is cheap, by lessening the expense of compensation for the buildings and ground required and damaged in making an inclined plane ; and is con- venient, because the foot of the inclined plane is at the river. Y BRIDGES. Average|Toll| £. 5. London Biackfriars Westminst. d, + Foot Passengers - - 7 ¢| 89640 | 61069 |. 37820 | 62813 | 1 | 261 17 Waggons - - - - - -- 1s 769 533 173 492] 12] 24 12 Carts and Drays - - - la 2924 | 1502 963 | 1796] S|] 52 17 Coaches ------- 1240 990} 71} 1133] 9] 42 9 wo Gigs and Taxed Carts | 3] 485] 500} 5669] 518] 4] 8 12 Horses not drawing - 2 & 764 522 615 633 | 14 3 19 a See Month. Mag. March, 1816, and Morn, Chron, May 26, 1812. 6 £400 per day, or £146,000 per annum, 64 Mr. Ware’s Design for The saving in time, and in the wear and tear of carriages, horses, and men who would otherwise go over London Bridge, or cross the river in boats, would be a compensation for the tolls to be paid at this arch-way. The carriages and passengers are those coming from the streets adjacent to the site of the proposed arch-way, those going into or through Surrey from the East India, West India, and London Docks, from the Commercial Road, and from the Counties of Hert- ford, Cambridge, Norfolk, Suffolk, and Essex ; also those going to the above-mentioned places from the counties of Surrey and Kent. The necessity of increasing the width of the intended new Lon- don Bridge, by this diminution of the number of passengers and carriages, may be obviated, and a large sum of money thereby saved. . Political Advantages. The communications, by this road, between the officers of govern- ment, and the Mint, Trinity-House, Custom-House, and the 'Tower, may be facilitate d. A readier transfer of soldiers, arms, and stores, to and from the counties north and east of London, and the Tower, to and from Woolwich, Chatham, and Sheerness, by land, will be obtained by this arch-way. This arch-way may be made a military pass, there being pro- posed a private way to it from the Tower. Observations. It seems remarkable, considering the great advantages to be obtained in populous cities by opening a communication between the shores of a navigable river, for foot-passengers, horses and carriages, without interrupting the navigation on the river, that the passage under the Euphrates, constructed by Semiramis, at Baby- lon, is the only one upon record. The account Diodorus the Sicilian gives of it may be translated thus :— “In the low ground of Babylon, Semiramis sunk a square pond, 35 feet deep, each side being 300 stadia in length, the banks a Public Road under the Thames. 65 whereof were lined with bricks well cemented with bitumen *, she then turned into it the water of the Euphrates t. Across the chan- nel of the river, thus made dry, she then made a passage in the nature of a vault from one palace to the other. The arch was built four cubitst thick, of firm and strong bricks, plastered all over on both sides with bitumen. The walls supporting the arch were 20 brick § in thickness, and 12 feet high from the floor to the springing of the arch, and the breadth of the passage was 15 feet. * Dr. Hulme, (Archzologia, vol. xiv. page 57,) analyzed the cement adher- ing to a brick brought from Babylon, and found it to be bitumen. + Strabo, (lib. xvi. page 738,) states the width of the Euphrates to be one stadium, which is generally taken at a furlong, or 660 feet. M. Gosselin shows that there were two stadia; one used by Herodctus, called the short stadium, about 329 feet English: the other of Archimedes, about 438 feet English. Ctesias, from whom Diodorus had his account, used the stadium of Archimedes, Herodotus used the short stadium. In this way the discordance of Herodotus and Ctesias, in respect to the wall of Babylon, has been re- conciled. $A cubit royal of Babylon was estimated, by Romé de Lille, at 22575 inches English. § There is a brick in the British Museum, brought from the site of ancient Babylon. That described by Dr. Hulme, in Archzologia, vol. xiv. page 55, is 133 inches square, and 3 inches in thickness, and weighs 38 1b. 11 oz. avoir- dupois. He analyzed the material, and found it to be pure clay, and not burnt.. Dr. Henley, in the same volume, page 205, deciphered the inscription on it, “ a brick baked by the sun.” Pocock measured some of the bricks of the brick Pyramid at Saccara, built by king Asychis ; he found some 133 inches long, 6% broad, and 4 thick ; and others 15 inches long, 7 broad, and 4} thick. In Rennel’s Geo. Sys. of Hero, section 14, page 356, is the following note : © Diodorus describes a vaulted passage under the bed of the Euphrates, by which the Queen Semiramis could pass from one palace to the other, on dif- ferent sides of the river, which was a stadium in breadth, (according to Strabo, page 738,) without crossing it. This serves, at least, to show, that the palaces were very near the river’s banks.” “ Ata time (1800) when a tunnel, of more than halfa mile in length, under the Thames (at Gravesend) is projected, it may not be amiss to mention the ‘ reported dimensions of the tunnel made by Semiramis, under the Euphrates ; which, however, was no more than 500 feet in length, or less than 1-5th of the projected tunnel under the Thames. That of Semiramis was said to have been 15 feet in breadth, 12 feet in height to the springing of the arch, perhaps 20 in all. The ends of the yault were shut dp with brazen gates, Diodorus had an Vou, XVI. r 66 Mr. Ware’s Design for This work was finished in 260 days, and then the river was turned into its ancient channel; so that Semiramis could go privately from one palace to another, under the river. She made also two brazen gates at each end of the vault, which continued to the time of the kings of Persia, the successors of Cyrus.” In 1798, atunnel, 900 yards in length, was projected to pass under the Thames, to unite Tilbury, in Essex, with Gravesend, in Kent, at an estimate of only £15,955. Subscribers were obtained to promote the undertaking, by whose means an engine-house and steam-engine were erected, and a shaft dug, about 146 feet deep, when the engine-house was burnt, and the operations were aban- doned. In 1805, an Act of Parliament (45 Geo. 3. cap. cxvii.) was obtained, to construct a tunnel under the Thames, at the Old Horse Ferry, about 23 miles below London Bridge, and to raise £140,000, and a further sum of £60,000, in all £200,000. A shaft, 76 feet deep, was sunk, and a driftway, 5 feet high, 3 feet wide at the bottom, and 2 feet 6 inches at the top, was extended, under the direction of Mr. Trevetheck, a Cornish miner, 1011 feet from the south shore, under the bed of the Thames, when sand and water burst in upon the workmen, and further progress was suspended. The powers given by this act are now, by lapse of time, void. In 1809, notice was given, idea* that the Euphrates was 5 stadia in breadth, see lib. ii, c,1. The Eu- phrates was turned out of its channel, in order to effect this purpose. Hero- dotus, who is silent concerning the tunnel, says, that the river was turned aside in order to build a bridge. Diodorus describes a bridge also. ‘here is an absurd story told, in both these historians, respecting the disposal of the water of the river during the time of building the bridge. According to them, the water was received into a vast reservoir, instead of the obvious and usual mode of making a new channel to conduct the river, clear of the work con- structing in its bed, into the old channel, at a point lower down t.” * Diodorus merely states, that the bridge built by Semiramis was 5 stadia in length. Bridges are frequently five times aslong as the width of the river they stride. + This story, from the vastness of the reservoir, may be true. Local circum: stances may have compelled Semiramis to adopt this apparently extrayagant mode of removing the water of the Euphrates from the site of the tunnel. - a Public Road under the Thames. 67 by public advertisement, that the directors were desirous of re- ceiving designs for proceeding again in this work, and they offered a premium of £200 for the plan which should be adopted, and a further premium of £300 upon the execution of it. Since that time the project has lain dormant. Lately a pamphlet has ap- peared, entitled “ A New Plan of Tunnelling, calculated for open= ing a Road-way under the Thames, by M. T. Brunel, Esq., in order to the raising a capital of £ by transferable shares of £100}each,” for commencing again this project. Mr. Brunel describes his plan as follows: ‘* The character of the plan before us consists in the mode of effecting this excavation by removing no more earth than is to be replaced by the body of the tunnel, retaining thereby the surrounding ground in its natural state of density and solidity.” Mr. Brunel proposed that the excavation, 34 feet wide by 18 feet high (external dimensions), consisting of 33 such drift-ways as that before mentioned, moving simultaneously, worked by 33 men, at the rate forward of three feet per day, followed by a brick tunnel at the same pace, should pass in a stratum which he states, * has been found to resist infiltrations,” so that the crown of the tunnel will have a head of earth on it, from 12 to 17 feet in thick- ness, quite undisturbed, as he expects. ' The method proposed by Mr. Dodd, at Gravesend, by Mr. Vazie, at Rotherhithe, and by Mr. Brunel, is by mining. Other methods may or have been proposed, such as to dredge out a channel in the bed of the river by machinery in vessels, and afterwards to sink therein caissons with brick or stone tunnels in them, to be after- wards secured together and perforated; or to sink large iron cy- linders or boxes, the size of the proposed tunnel, with moving, lapping, and closing joints, let down, one after another, on strong iron mooring chains, into the channel so dredged out; the junc- tions to be facilitated by means of the diving-bell: but these schemes are of a very adventurous character, and might be tried perhaps with propriety in the case of a small passage under a river, The apparent cheapness of such methods seems calculated F2 68 | Mr. Ware’s Design for to obtain subscribers to such a project, but not to effect a dry and secure passage for men and carriages under the Thames. The method of Semiramis was simple in design and certain of success. Troughs holding water, such as the canal aqueducts over rivers, are to be seen in all parts of the country; and there can be no doubt, that such an arch-way as that before described * in the estimate commencing this statement, executed in the open air, and uninterrupted by water during such erection, by means of cofferdams, would have a successful issue, and be perfectly dry under a river, for a thoroughfare for passengers and carriages. In modern times, a cheaper way of rendering the bed of a river dry has been discovered than that of Semiramis, which was by means of a reservoir to receive the waters of it, or even than that of Trajan, in building the bridge across the Danube, which was by making a temporary new channel to receive its stream. We have lately seen the piers of Waterloo Bridge and of Southwark Bridge laid dry, in the bed of the Thames, by means of cofferdams, the use of which, in keeping the space enclosed in them free from water, has been greatly extended by the facility obtained by means of steam- engines; and by similar means may an arch-way be constructed of almost any useful dimensions under the river, and with the same success, and not with more interruption to the navigation of the Thames than would be caused by one of the vessels in the pool getting athwart the stream, and remaining so for a few months. Since the foregoing statement was made, an advertisement has appeared of the intention of applying to Parliament for leave to bring in a bill to erect a patent wrought-iron bar bridge of sus- pension, from some part of the parish of St. Botolph, Aldgate, over the Thames, to some part of St. Mary, Bermondsey, of such * The following account of the suspended gardens of Nebuchadnezzar, at Babylon, extracted from Diodorus, will show the care used by him, to render the rooms under them dry. ‘ On the walls were laid stones, 16 feet long and 4 feet broad ; these were covered with reeds coated with brimstone, on which were laid double tiles, cemented together, and on them were laid sheets of lead.”, a Public Road under the Thames. 69 a height as to admit vessels to pass under it at prin: tides, pith out lowering their masts. These repéated attempts to obtain a road-way for passengers and carriages eastward of London Bridge, across the river, together with the almost impassable state of London Bridge, from the crowds on it, in the middle of the day, show that there is a demand for such a communication between the sides of the Thames, east= ward of London Bridge. The questions to be considered, are, First, what method of obtaining such an object is the best? Secondly, how that method can be carried into effect with certainty? Thirdly, what is the best site for sucha road-way? Fourthly, whether such a work, in the site hereby laid down, would not be of such political importance, facilitated as the execution thereof would be by a possession of the ground necessary for the northern approach, as to warrant the State in undertaking the work, leaving to the public the use, subject to certain tolls and restrictions, as may accord with the uses of it by Government? Fifthly, as to time, should the cofferdams necessary to resist the deep water in the erection of the new London Bridge be of such a size as to cause an impetus to the river, or alteration of the mid-stream, so as to destroy the pre- sent bridge, or render it impassable, (it being intended that it shall remain until the new one is passable), would not then such a way as the one hereby proposed be a great relief to Southwark Bridge, until a temporary bridge be supplied? And, comparing generally the expediency and cost of carrying into effect this design with the expediency and cost of rebuilding London Bridge *, ought not this work to have the precedence ? SAMUEL WaRE. 5, John Street, Adelphi. . * See this Journal of Science, Roy. Inst., Nos. 29, 30, and_3], 1823; and Tracts on Vaults and Bridges, 1822, 70 Art. VIII. An Account of ihe Overflowing Well in the Garden of the Horticultural Society at Chiswick. (Com- ~ municated by Joseph Sabine, Esq., S.H.S. &c.), [The specimens adverted to in the following paper are deposited in the Mineral Room, at the Royal Institution. ] In consequence of the success which had attended the opera- tions of several persons in the vicinity of Chiswick in boring for water, it was determined by the Council of the Horticultural Society that an attempt to procure an overflowing well should be made in the society’s garden, for the purpose of obtaining a supply of water for various purposes; but more particularly to form an ornamental canal in the Arboretum for the growth of hardy aquatic plants. After the necessary inquiries had been made, it was determined. that Mr. John Worsencroft, a person who had previously suc ceeded in making an overflowing well for Messrs. Bird, of Ham- mersmith, should be empioyed to execute the experiment. He commenced his operations upon the first of September last; and after boring for five weeks without material interruption, tapped the spring on the 18th of October, and finally completed his task on the following day. The depth from which the water first rose was 317 feet, and the whole depth of the well, when completed, was 329 feet; the additional 12 feet of boring having been made in order to gain a perfect opening into the bed of the spring, which flowed when first tapped less copiously than after the final depth was obtained. The chalk from which the water immediately comes is soft, but the bottom of the well is in hard chalk. The water in all the neighbouring wells appears to have been obtained at about the same depth; and the strata through which the perforations were made are nearly similar to those met with in the present instance, The tackle and instruments used were very simple. A scaffold- ing was raised 20 feet above the proposed orifice of the well, on which a platform was fixed to support a windlass, by which the Overflowing Well at Chiswick. 71 rods used in boring were lowered into, and raised from, the well. These rods were of tough iron, about an inch and a half square, and ten feet long ; the ends of each screwing on to, or unscrewing from, the top of the next, as they were lowered into, or raised from, the hole. The instruments fixed as occasion required to the lowest extremity of the series of rods when in action, were augers of various dimensions for boring, steel chisels for punching, and a hollow iron cylinder, (called a shell,) fitted with a valve at its lower end, for bringing up soft mud. The rods, when an auger was attached to them, were turned round by means of moveable arms or dogs, which were made to lay hold of the part of the uppermost rod at the top of the hole; the auger being thus forced through the stratum of clay or sand, was drawn up as soon as its cavity was filled with the substance it had loosened. The chisels were employed for punching through stones, hard sub- stances, or hard chalk ; the rods, when these were attached, were moved by means of a powerful beam acting as a lever, and worked by four men. The water is discharged at the surface of the ground after the rate of six gallons per minute, and is capable of being carried 20 feet above the ground level; and even then supplies a copious stream. The well is lined for the first 186 feet with cast-iron pipes, with a three-inch bore, jointed by means of wrought-iron collars, which are rivetted into the pipes; the succeeding 77 feet 6 inches are lined with copper pipes, with 23 inches bore, soldered into a single length, and resting in the chalk, through which the remainder of the hole is bored, and in which no pipes were used. The whole series of pipes was introduced at once, the hole having been prepared for receiving them as soon as it avas ascertained that the augers had reached the chalk stratum. The land springs in the gravel, above the blue clay, were kept out in the first instance by extra iron pipes. The spring which was found in the sand below the blue clay, and above the chalk, rose to within a few fect of the surface, but did not overflow. The whole of the water of this spring is, however, excluded from the well by the pipes with which it is lined, a2 Mr. Sabine on the The cost of the well, including that of the pipes, boring; and every other expense whatever, did not exceed 130/.; and the’ manner in which it was executed, was, in every respect: satisfac- tory. Indeed it is impossible to speak too highly of the care, attention, and dexterity of Mr. Worsencroft, and the workmen: whom he employed. Turnham Green, November 27, 1823. Memoranda of the various strata bored through. Feet. 19 Gravel. 162 Blue clay. Specimen No. 1. At the depth of 59 feet from the surface asmall stone, sp. No. 2, four inches thick was found; another at 149 feet was found six inches thick, but it was pounded to dust by the chisel ; a third was found at the depth of 153 feet; it is marked sp. No. 3. At 162 feet from the surface the clay became veiny, and intermingled with very minute glittering fragments; this is sp. No. 4. At 173 feet the clay became more sandy, sp. No. 5, and continued so ull it altered into the next kind. 30 Coloured clay; varying from brick-red, mixed with blue and yellow, to many shades of dull purple ;. sp. 6, came from 190 feet; sp. 7, from 200 feet; sp. 8, from 203 feet; sp. 9, from 211 feet, when the seam changes into the next which is more yellow. 22 Clay, with nearly an uniform colour of yellow ochre, occa~ sionally mixed irregularly with grey. Sp. 10. This was more sandy than the previous stratum. Among this water rose in some quantity. 28.6 Soft soil, apparently composed of clay and sand. It varied very much in colour, being sometimes bright green, other- wise yellow intermixed with green, or sometimes beauti- fully veined with dark red and yellow. Many specimens are sent, v2z. : : sp. 11, 240 ft. sp. 12, 242 ft. sp. 18, 248 ft. sp. 14, 244 ft. sp. 15, 246 ft. sp. 16, 246 ft. sp. 17, 247 tt. sp. 18, 2565 ft. sp. 19, 261.6 ft. Overflowing Well at Chiswick. 73 » The last specimen is of the soil immediately above the chalk. ' Two stones were met with in this stratum; one like those formerly mentioned, of which no specimen could be pre~ | served; the other a flint, sp. 20, at 257 feet. 67.6 Chalk; among which many flints were scattered. Of these, one, sp. 21, was one foot in thickness, and so unusually hard’ as to occupy the workmen three days in punching before they could force a way through it. The water was found at the depth of 317 feet, in a bed of soft chalk, mixed with small flints; the hole was bored 12 feet among the water, so that the total depth of the well is 329 feet ; / and it is supposed by the workmen that the last piece of chalk that was brought up sticking to their punch, was from the upper surface of a new layer of chalk in which there is no water. Specimen 22, is a morsel of a hard stone, apparently containing ore, which was brought up in the auger from among the chalk, at the depth of 274 feet. Specimen 23, is of the first chalk which was found at 261.6 feet. -Specimen 24, is from 317 feet, when the first water was found; it was saturated with moisture when first brought up; sp. 25, is the last piece of chalk brought from 329 feet, and supposed by the workmen to be from the upper surface of a new and dry layer of chalk ; sp. 26, various fragments of large flints broken by the punch at different depths in the ground ; sp. 27, morsels of flint and pebbles washed out of the chalk raised from the water-source, and supposed not to have been broken in punching, but to have laid among the water in their present condition. In cutting a solid piece of chalk, which had been brought up in the auger, a morsel of flint, exactly like these specimens, was observed, with every appearance of not having been forced into its place in the chalk by violence. The principal impurity discovered in this water by the action of reagents is common salt, of which it contains about four grains and a half in the pint. When evaporated to dryness, the residue 74 Overflowing Well at Chiswick. contains a sufficient quantity of carbonate of soda to render it very manifestly alcaline ; this is also the case with the waters of the other deep wells in and about London. J. L. Art. IX, On the Taylorian Theorem. [To the Editor.] Trinity College, Dublin, October 11, 1823. Sir, I lately communicated to you a demonstration of the Taylorian Theorem given to me at lecture in this University by Mr. Edward Wilmot, a gentleman-commoner, and under-graduate of this col- lege. The same gentleman has since given me an extension of this to functions of several variables, which I now enclose. The simplicity of the proof, and the elementary nature of its principles, must render it very valuable to the student. You will observe that it is independent of the Theorem of Maclaurin, and gives it as a corollary. It is also free from the functional reasoning so ob- jectionable in other proofs of this theorem. I am, Sir, Sc. Sc., Dionysius LARDNER. Let u = F (2,2',2",....+), , 2,0", §c., being independent variables, Let =F (r+ Aaa’ + Ax, a" + AB", ....0-) And let this be supposed to be expanded according to the di mensions of x + A a, Sc. w= A(x + Ax) + A’(2’ + Ax’) + A’ (a" + Aa")....- + A, (a+ Ax)? + Ay (u’+ Ac’) + A," ike ey alee + B’ («+ Ax) (a’+ Ax’) + B (w+ Az) ("+ Ax’) + B Ce ACE AE) i avetis's + A, (z+ day + Ay (2'+ Avy + A,” (2° + Ax’) ytite. On the Taylorian Theorem. 75 Hence u= Aa’ + A'e' + A”2' uw Aya? + Asx og Ng pay. Ce B" xa + Bax’ + Ba'a" Ax + Aja? + A,r... Foeernen 8) This being successively differentiated for each of the variables, gives dt ng + Bae + = Sits di dx x = Aw {A+2A,¢+B'r'+B'a"+3A,27 ..... } + Ax {A'+2A,’c'+B’e+Ba"43A,'x'2 .... 3 + Ax’ {A"4+2A,"c"4+Ba'+Bia+3A,"2"2...4 § d2u Ax? du =Ax® Pe dus Aa’? , a dx? 1.2 oie | ose Hast At fA, +t SAg ty» wir. giriaiiere ee CR eae Bh ee ks t> F TED RSE Se) Wee a a ar te eee OREM AE Pete Dt ca teiny feu) BEAL deus AT Aa ss Na) Ie Ae 7 dxda 1 dz dz” 1 dat dah Ns = Ag. Ag {B’....... } ee RB. Tae} ee eae 1 Ree ae } . . ° . . (E) The sum of the series (D) and (2) may evidently be expressed thus, d?u f Ax ra Ax 12 eda da’ meh ms 76 On the Taylorian Theorem. And hence if the series (A) be arranged by the dimensions of the quantities, Aw, Aa’, Ax", ..... and the substitutions sug- gested by the series (B), (C), (D), (E), Sc., being made, the re- sult will be du Ax d2u Az \2 d3u eee (a2) ae is i aoa a da 1.2.3 (s a a.’ Raeee dx In which the symbol S = signifies dx Ar Ax Aa’ dg age Ge The meaning of the symbols we ( e222 )' §c., is suffi- 1.2 dx ciently obvious. Ne 8 dx dx The series of Maclaurin may easily be inferred from it by sup- This becomes identical with Taylor’s series when S posing « = 0 and changing Az into a. a . 79 Arr. X. ASTRONOMICAL PHENOMENA arranged in Order of Suc- cession, for the Months of April, May, and June, in the Year 1824. (Continued from Page 297.) APRIL. Plaviet’s or ie #| Sidereal Planet’s or Planet’s or = 2| Sidereul Planet’s or -. Star’s re Star’s x Star’s a5 > Star’s T2| Name, &c. |&“| Time. Declination. = Name, &c a! Time. » Declination, ie A e Se {a j=? a =° ! H. M.D. M. H.M. OD. M. #1} Sun... .. 043 4 38N Im.Jupiter 12 28or 1132’ mr. | Mars... 12°11. 2’ 8N Im. * 7. .| 7| 12 460r11'49 mr. \ Juno... 14418 2198S ¥’s R.A. 615’ Decl. 23° 32’ N (2’S) Venus .. 2255 8145 Im. * 8. .| 7| 12 5lorl]"54’ mr. } | Mercury . 013 0 46S ¥’s R.A. 6"15’ Decl. 23° 25’ N. (1/S) #2} Sun ... 047 5 IN Im.¥9..| | 12 58o0rl21’ wr. 4 Im. ¥. . 17.81 10 47or10"3’ mr. *s R.A. 6"15’ Decl. 23°48’ N. (cont.) *’s R.A. 3614’ Decl. 21° 25’ N. (0’) Em. Jup,. 12 220r12"25’ mr. Em... . 11 330r10"49’ mr. (4’N.) Em. *7. 3 35o0rl12" 38’ mr.(4N) Mars... 1210 2 16N Em. ¥ 8 ° 13 36 0r12"39’ mr. (5’N) Juno... 14 17 age Juno ..° 1415 1498S Venus .. 23 0 =%747S Venus .. 23 14 6387S | Mercury . 020 0 5N Mercury . 040 240N 3} Sun.... 0 50 ST OEN 6} Sun... 1 1 633N ‘| Im. ¥. . |7.8;) 9 400r 8! 51’ ut. Moon... 7.3, 22 "GN x's R.A. 4" 9’ Decl. 23° 36’ N. (4’S.) Mars... 12 4 242N Em. ... 10 3lor 9542 mr. (0') Juno... 1415, 1418 Mars... 12 8 2 23N Venus .. 23 18 6°0°S Juno... 1417 2 48 Mercury . 048 3&8 34N Venus .. 23 4 7208S TieSEmi aed. 1 5 655N } | Mercury . 026 0 56N Moon. . * 8 4 18 30N 44) Sunn... 054 547N 20 Canc. .| 6] 813 18 53N Em. 2 Sat.| | 11 480rl0 55’ mr. (98) CT ae 5-6] 8 22 18 41N Mars... 12 7 229N VII. 112.) 8} 8 28 19 53N Juno... 1416 1568S Im. *1..] 71 8 400r 7 36 mr. Venus .. 23.9... 6538S ¥’s R.A. 8 4’ Decl. 18° 12! N. (16/S.) Py. 033 147N Em. * 1 | 9 13o0r 8" 9’ mr.(11'S.) BsiSon... . 058 610N Im. *¥2.. 9 200r 816’ Mr. Moon. . | 6 0 24 11N *’s R.A. 8" 6’ Decl, 18° 5’ N. (14’S.) Im. ¥* 1. {1.8} 7 520r 6556’mrT. Em. 3 Sat. 9 38or 8'34’mr.(+100) %s R.A. 6h 3’ Decl. 24° 2’ N. (7S.) Em. * 2 . 10 Tor 816 mr. (5'S.) Em.*¥1 . 8 44or 7" 48’ mr. (1S) Em. 1] Sat, 11 150r10"11’m7.(+100) Im. * 2. | 7| 8 47or 751’ mr. Mars... . 12 3 2 48N %’s R.A. 6" 6 Decl. 24° 1’ N.(2’S.) Juno... 14 14 1 348 Im. * 3. .| 7| 9 180r 8) 22’ wr. Venus .. 28 23 «5 33S %’s R.A. 6" 6 Decl. 23° 47’ N. (12’S.) Mercury . 0-55. 4. 27 Em.*2 . 9 450r 8 49’ mr.(5N)]] 8} Sun... Te oO 7 Te Em. *3 .- 10 lor 9" 5’ mr. (7S) Moon.. . 9 3 18 38N Im.*4 .| 8].10 Sor 9° 7 mr. IX. 55. /7.8) 912 13 51N %’s R.A. 6" 8 Decl. 23° 40’ N. (14S.) Im. 4 Sat. 9 13o0r 8" 4’ mr.(+100) | Im. %5. 7.8] 10 130r 9" 17 mr. (9S.) IX. 84 .-+/7.8} 917 15 4N ‘| Em. *4 . 10 360r 9'40’mr.(11’S.) IX. 120. .|7-8} 9 25 13 26N Em.*5. 10 520r 9"56’ mr. (9’S.) Mars... 12 1 2 54N Im.*.6 .| 8] 11 20 orl0 24’ mr. Em. 4 Sat. 12 6o0rl0"58'mr.(+101) #s R.A. 6! 11’ Decl. 23° 50° N. (5’N.) Juno... 1413 1278 Em. * 6 12 8orll!?mr.(11/N) Venus .. 2397, 5 "5S Mars aia | 12,5. 2 86N Mercury . 13 52N Days. Magnitude of Stars. 9} Sun... . ] IX. 202, .| Sie .9 m Leonis .|4-5| 9 Moon... 9: 43 Leonis| 6} 10 Mars ... 12 JUNO ye wie 14 Venus .. 23 Mercury . 1 SUN, sss 1 Mercury . 1 Moon... 10 65 Leonis.|5.6) 10 69 Leonis.|5.6) 11 he: hae 11 JUNG, > 14 Im. ¥. . 6.7] 16 xs R.A. 115 6’ Em.x* .. 17 Venus .. 23 SUN, ay. we ] XI. 148. ./6-7} 11 MLwbie of Shel) Moon... 11 GE 2 Oy | a Mars... 11 JUDGEe ss 14 Venus ,. 23 SODy. wo 4 1 Mars... 11 Moon... 12 Em. *.. 9 Mars... « 11 75. Virg. | 6| 13 XII. 139 | 8} 13 83 Virg. | 6) 13 Moon... 13 Juno... 14 Venus . . 23 Sun aa «4 ] Mercury . 14 Em. 3 Sat. 10 H. 55 Leonis | 6| 10 « 49 Virg. |5.6] 12 52Virg.. | 8} 13 XIU. 25.7.8) 13 JUNO. + «= 0 14 Venus .. 23 SOD a5 0 « 1 Mercury . 1 Im. %.. 6.7] 8 Planet’s or é! Sidereal Star’s / Name, &c. Time. 12 833or 15°16’ MT. Decl. 0° 17’ S. (14’ S.) 17 orl5" 59’ MT. (38.) 32 39 or 7 11’ mt. x’s R.A. 13 31’ Decl. 15° 33'S. (16'S.) 190r MSY mr. (8'S.) 55 93 28 35 39 9 50 a 50 or 918’ 7r.(+100.). no Ode oR ROD _ _ woonovweo © 9 Planet’s or Star’s Declination. M 40N 54N 128 10S 24N n ZDP 4N $ 20N 278 838 178 188 508 478 30N 59N = SO OWE EO SD RY 60 2 =) COTE Astronomical Phenomena. APRIL. a — Planet’s or |= “] Sidereal Planet’s or " Star’s 28 . Star’s = Name, &e. | Time. Declination. Z = H. M. D. M. Mars... 1154 8 24N Juno... 14 9 0 48S XIV. 116.| 7} 14 25 19 49S Moon. 14 36 20 428 10 Libre .| 7] 14 42 17 87S Im. ¥. . .| 7] 14 45 0r13" 12’ mt. x’s R.A. 14 37’ Decl. 20° 35'S. (cont. XIV. ay 4 14 47 20 36S Im. ¥ 7.8| 19 590rl8" 25’ mT. x’s R.A. 14.47’ Decl. 21° 26'N. (5N.) Em. *. 20 48o0r19"14’mr.(10'N Venus .. 93 54 2198 15} Sun.... 134, “9 5IN Mercury .« 147 10 54N Mars... 1153 $8 30N RU wis 14 8 0368S Im. ¥ . 6| 14 16 0rl2" 40’ wr. xs R.A. 15" 34’ Decl. 23° 50’ N. (2’S.) Em. * . . 15 24 0r13'47 mr.(6N. 42 Libre .|5.6} 15 30 23 148 Moon... 15 35 23 50S XV. 192 || 6] 15 43 23 27S XV. 213 7.8} 15 48 23 18 Im. ¥.. -| 6| 20 4o0r18" 27 mr. ¥’s R.A. 15" 43’ Decl. 24° 0’ N. (cont. Venus .. 23 59 +1518 TEL Sian ots ile 138 10 129N Mercury 155 11 50N Mars . LY 52 38 31N Im. ¥. . .!7.8] 13 49or12" 9 (mr) ¥'s R.A. 16" 29’ Decl. 25° 42’S. (15'S Em.*..- 14 2orl2'22’mr.(14'S,, Juno.. 14 7 0298 ; Venus .. 0. 3). 4-335 ¢ 17] Sun... ‘] | 142. 10 88N ; Mercury - 2.8, 12 48N Mars... 11 51 8 35N JUDD, ous 14° 6. 022958 Venus... (Oa Pe 1S) Sat cece 145 10 54N Mercury . 2 31, 18 37-N Mars. «.. 4 1150 $3 38N Im. ¥ ... .|7.8}.13 21orl1533’ ur. ¥s R.A..18" 20’ Decl. 25° 0’ N. (5S.) Juno... 14.5.0 Tas Em. * .. 14 18 o0rl2"30° mr. (5S. Venus .. 012 0268S 19} Sun. 149 11 15N Mercury . 219 14 40N Mars... 1150 340N Juno... 145) OO oe : Im. % 1. .]7.8) 14 190r124 27’ mr. ror ~—— 2 > 21) 22 23 24 Astronomical Phenomena. APRIL. = Planet’s or |5 | Sidereal Planet’s or itar’s as Star's . Name, &e. x! Time, Declination. =a Be 4 M. D..M. #’s R.A. 195 14! Decl. 22° 54'S. (4S.) Im. * 2. .]7.8] 14 51orl2h59’ wr. #s R.A. 198 15! Decl. 22° 47’ S. (1'N.) Em.¥1 . 15 140r13" 99’ mr.(8’S.) Em. * 2 15 57orl4" 5’ mr. 3’S.) Venus .. 017 O 2N 26 Sun. ... 153 11 36N Mereury . 227 15 19N Mars... 1149 3 43N Juno... 14\i4' 0.28 ‘Im. *¥1. .| 8] 14 530r12" 57 mr. 27 %’s R.A. 20" 5’ Decl. 19° 44’ S.(5’N.) Em.*1. 15 540r13"58' mr. (2’S.) Im.¥ 2. .| 81.16 Oorl4' 4’ mr. #’s R.A. 20" 6! ne 19° 26'S. (cont.) Venus .. 0 21 0 30N 28 Sun... . 157 11 56N Mercury . 235 16 8N Mark ii. 4 1148 8 45N Junge 14 3 0 4N Venus .. 026 0 59N 29 Suns: : 2 0 12 16N Mercury . 243 1657N Mary 2/.. 4 1147 347N Juno... 14 2 011N Venus .. 030 127N 30 Sune 2. 4 2 4 12 36N Mercury . 251 17 41N Em. 1 Sat. 10 38or 8"3)’mr. ceibod “Mars... 1147 38 48N Juno... 14 1 O17N Venus .. 034 1 56N Buns ar. 5 2. 8) 12 SEN Mereury . 259 18 24N Mars. . 1146 3 49N JUNG. §) » 14 1 0 23N Venus .. 039 2 24N 79 Planet’s or = | Sidereal Planet’s or Star’s aie Star’s Name, &e, Ee Time. Declination. = 9 H. M. D. M. Sunde. 2 212 13 16N Mercury . Se): 19. ween i Mars... 1145 3 50N ' Juno . 13 0 O 29N Venus . 043 2 58N Sune %."% 215 13 35N Mereury . 3:14 19 44N Mars .. J 1145 $3 51N i Juno... 1359 O 85N } Venus .. 047 +3 Q1N i Sun... 219 13 54N | Mercury . 3 21 20 20N } Mars... 1144 $8 51N Juno... 13 58 0 41N . Venus .. 052 3 50N Sun. . 223. 14 18N Mercury . 3.28 20 56N Mars... 1144 351N { Juno... YSP58! 10 “4a | Venus .. 056 418N Sun... 227 14 32N Mercury 3 386 21 27N Mars 43.1 1144 $51N Junot, 2h. 13 57 0 53N P| Venus 11 4 46N Suny gat 231 14 51N Mercury . 3.43 21 57N Im. ¥1. .J7.8} 9 59o0r 7) 24’ MT. x’s R.A. 3 49" Decl. 23° 7’ N, (cont.) Im. * 2. .|T. 8 10 220r 7 47’ ur. ¥’s R.A. 8h 50! Decl. 22° 42’ N. (3/8. Em. * 2 11 8or 8" 33’ mr. a) Mars... 11/43) 3 50N Em. I Sat, 13 lor 10"26’mr.(+100) Juno... 13 56 0 58N Venus ., Tf “Sy 4). eee Planet’s or Star’s Name, &e. Venus .. Sun.. Mercury .« Moon. . | Sidereal Time. Magnitude of Stars. H. M. 1 32 2 57 4 24 10 36 80 Astronomical Phenomena. MAY. Planet’s or = #| Sidereal Planet’s or 5 Star’s ras , Star's. : > Name, &c. oe Time. Declination. 2 4 Be A H. M. D. M. 1} Sun. . 234 15-9N Mereury . 349 22 23N 7 Mars... 1143 3 49N Im. *.. | 6] 13. 3 orl0% 24 wr. #’s R.A. 4" 57 Decl. 24° I'N, (1'S.) Im*... Planet’s or Star’s Declination, D. M. 8 ON 16 53N 24 11N - 3 35N 6| 10 37or . 34 Mr. Em. 13 47 or]1" 8 mr. (0’.) *’s R.A. 10" 36 Decl. 3° 15’ N. (7S. J Venus .. 110 5 43N X.172 . | 8] 10 42 4 31N 2} Sunk ii. % 288 15 27N 58 Leonis] 5] 10 51 4 34N Mercury . 355 22 45N XK. 2B" 1055 4 35N Mars . 1145 3 48N Mars 11°42; 8 83TNiws Im. ¥ 1. .| 8] 12 8or 95 95’ wr. Em. * 11 49or 846’mr ae %’s R.A, 5 55’ Decl. 23° 39’ N. (12’S.) Venus 137 8 28N Im. * 2. || I 12 23or 9" 40’ mr. 8} Sun . $ 1 17 9N %’s R.A. 5h 56 Decl. 23° 39’ N. (11’S.) Mercury . 4 8 24 19N Em. ¥1 , 12 42 or 9°59’ mr.(8S.) 87 Leonis}4.5] 1121 2.28 Em.*2 , 13° 2orl0" 19’ wr. (68.) Moon... 1128 2 36S Venus .. 114 610N Mars... 11/42. 3 34N 3} Sun... , 242 15 44N XI. 179. .| 8} 1145 2 48S Mercury . 4 1 23.6N XI. 213. J T)11'52) 0 478 Mars... 1143 3 46N Venus 142 8 55N Im. *¥.. .| 7] 13 340r10"47 wr. 9] Sun . 30 Sy 1h) 250) *’s R.A. 6! 0’ Decl. 21° 33’ N. (9'S.) Mercury . 433 24 27N Em. ... 14 2lorll" 3¥ mr.(1’S.) Mars 11%42 38 30 Venus . . 119 6 S8N 14 Virg. |6.7] 12.10 7 56S 4; Sun. 246 16.2N Moon... 1221 8233S Mercury . 4 7 23 28N 22 Virg. |5.61 12 25 8 29S Im. * 1. .|7.8} 10 350r 74 45! wr. 31 d/l... 4.6]'12433 . 8 «2.8 x’s R.A. 7 51’ Decl. 18° 49’ N. (cont.) Im. *. . .| 7! 16 48 0113 37’ mr. Im. ¥2. || 7| 10 350r 7 45° Mr. *’s R.A, 12) rita 2° (1VS.) ¥’s R.A. 7 59" Decl. 18° 43 N.(15'S.) Em. 49 or 14°37 Mr(1/N. Em. * 2 J1 190r 8 29’ mr.(7’/N) Venus .. A 46 9 2I1N Mars .. 1142 3 44N 10) ‘Sune sit 34 9) l%:4la Im.* 3. .| 6] 15 Torl2h16' mr. Mercury . 4 37 24 35M *’s R.A. 84 2’ Decl. 18° 10’ N. (9'N.) Mars... 1143 3 27N Em. x3. 15 tle hn tt XIII. 19 7-8 13 4 12 32S Venus 23 7. SN Moon 1315 14108 a Sn oY 250 16 19N 75 Virg. .| 6] 13 23 14 27S Mercury . 413 23 42N XII. 177 |7.8, 13 35 18 20S Moon... 845 14 59N Venus .. 151 9 48S Mars®.” >. 11 42 3 42N 11} Sun. 313 17 56N Venus’. | 28 Rasa, Mercury . 441 24 37N 6} Sun. . 250 16 19N Mars. . 1143 3 23N Mercury . 413 23 42N XIV.22 | 6114 6 17 23S Moon... 941 9 34N Moon.. - 1411 18 56S Im. *¥1. | 8] 11 35or 836’ mr. XIV.116.) 7; 14 25 19 40S xs R.A. 9h 45’ Decl. 8° 54’N (19'S ) 10 Libre | 7| 14 42 17.378 Mars. . 11 42 3 39N Im.*¥ 1. J7.8 16 28 o0r13"9 mr. Em. ¥ 1 12 41or 9542’mr.(3'N.) ¥s R.A. 14h 16’ Decl. 19° 10’ S.(12’/N. Im. ¥2.. 12 57or 9958’ Mr. Im. * 2. .| 7] 16 300r13" 11 wr. *s R.A. 9" 47’ Decl. 8° 30’ N. (16’S.) Em. 2 Sat. + 35 or10"36’m1(+100.) Em. * 2 13 39 or]0"40’mr.(15’S.) ¥s R.A. 14" 16’ Decl. 199(10’S, )(12°N. Em. *1. 16 520r13" 33'mr.(16'N Em.*2 . 16 520r1333'MT.(15'N. :, Astronomical Phenomena. 14 MAY. Planet’s or |S #| Sidereal Planet’s or Star’s ee s = Star’s z Name, &c. ua Time Declination. 2. ES a H. M.D. M. Venus .. 156 1015N Sun.... 317 18 12N Mercury . 445 24 39N Mars... 1143 3.19N XIV. 262 | 7) 14 56 22 38S XIV. 282.) 6} 15 0 2318S Moon... 15 9 22 34S XV. 65.. 15 16 2045S Venus .. 2 0 10 41N Sun.... 321 18 27N Mercury - 4 48 be 41N 17 Mars... 1143 3 15N Im. * 1. |7.8) 14 16 0rl0" 49’ mr. x’s R.A: 16" 6) Decl. 25° 0’ S. (15/S.) Im. * 2. .| 7| 14 20 orl0"53' mr, %'s R.A. 16! 4’ Decl. 25° 1’ N. (cont.) Em. ¥ 1. . 14 37o0rl11"10'mvr.(13’S.) Moon... 16.7 2453S 18 oScorpii .|5.6) 16 10 23 44S Poet Dy le 15° 23° "2S SoC. s al 6) £6.20 24.425 Im. *.. 1 4117 29or14! nur. 19 %'s R.A. 16" 10’ Decl. 25° 10’ S. (10'S.) Em.* .. 4 250114558’ mr.(7S.) Venus . 5 11 8N Sun’... ee 18 41N Mercury . 451 24 38N Mars~... 11 44 3 10N XVL.248 | 6] 1649 2449S 20 28 Oph. | 7| 16 53 25 26S Moon. 17 6 25 48S 6 Oph. . 3.4) 17 11 24 49S Venus 210 11 33N 21 Sun... . 329 18 55N Mercury : 454 24 34N ‘Mars. . 1144 3 5N Im. * 1. .J 7! 14 180r 10°44’ mr. #’s RA. 17 58 Decl. 25° 29 S. (13'S.) Im.*¥2..| 7| 14 24 0r10! 50’ MT. ¥’s R.A. 17 58 Decl. 25° 29’ S. (19'S.)| 22 Im. *3 . 6 14 240110" 50'mr. Em.*1.. 14 560r11"21’m7v.519’s.) %’s R.A. 174 58" Decl. 25° 29'S. (12'8.) Em, *2 & 3 15 1lorl1'26’mr.(19'S.)},.23 63 Oph. 6.7] 17 44 24 51S 4Sagit.. | 5| 17 49 23 478 XVII. 342] 7] 17 54 24 248 Moon. . 18 3 25108 24 Venus .. 214 11 58N Son. ,. 31387 19 “ON Mercury . 457 24 31N Mars :.. 1144. 8 ON vies Vou. XVIT. G 2 Planet’s or | 4] Sidereal Planet’s or Star’s 2s tar’s. Name, ke. | #“| Time, Declination. SS Lae D. M. Im. * 1. .[8.9} 13 S4orl0" 16 MT. ¥s R.A. 18" 51! Decl. 23° 28'S. (13'N. ) bm. * 1 . 14 29 orl0*51mr.(12‘N.} Im. * 2. 17 51orl4" 12’ wr, x's R.A. 18" 58! Decl. 23° 27'S. (1/S.) Im.x%3. J | 18 250r14"46 mr x's R.A. 18" 59! Decl. 23° 28" 8. (4’S.) Em. * 2 19 9orl5'30! mr. (1’S.) Em,* 3 . 19 330r15" 54’ wr. (9S.) Venus .. DAN |.19-93iNi Sun..-. 3 37 19 23N Mercury . 459 24 22N Mars .. 1145 2.55N Im. *¥.. .| 8] 18 57orl5" 14’ Mr. %’s R.A. 19" 50’ Decl. 20° 20! S. (4’S.) Em. *.. 19 530r16 10mr.(9'S.) Venus . 224 12 48N Sun: elie 3 41 19 36N. Mars... . 5 1). 24 14N Mercury . 1145 2 49N Venus .. 228 13 13N Sun... 3.45 19 49N Mercury . 5 2 24 5N Mars... 1146 2 44N Im. ¥. 17 4o0rl3413’mr. x’s R.A. 21h 93' Decl. 13° ’S.) 1'N.) Em.*¥ ..[ | [| 18 Torl4"16’mr.(10'S.) Venus .. 2 33 13) -38 Sum. ... 349 20° 2N Mercury . 5 2 23 52N Mars . 1146 2 38N Venus 238 14 1N Sun... ; 3 53 20 14N Mercury . 5 3 23 40 Mars, . 11 47. 2 31N Im. *¥. . 18.9] 17 300r13%31'mr. *’s R.A. 22" 51’ Decl, 3° 23'S. (1'N.) Em... 18 28o0rl4%29’mr.(10'S.) Venus 243 14 24N Sun... 38 57 20 26N Mercury .« 5 3 23 27N Mars... 11 47 .2-25N Venus ., 247 14 47N Sun. 4 1 20 38N Mercury . 5 3 23 11N Mars... 1148 ¢%18N Venus 2 52 15 11N DGD, f5'75,74 4 5. 20:49N Mercury . 5 2, 22 54N Mars . 1149 212N Im. %.. Ins 19 240r15"13' wr. #'s R.A. 1" 9! Decl. 12° 19".N, (14'N.) 82. Astronomical Phenomena. n Planet’s or Star’s Name, &e. ‘| Sidereal Planet’s or Planet’s or Star’s a Star’s Time. Declination. 2 | Name, &e. Magnitude of Stars gnitude of Stars: Ma, H. M. D. M. | Em. * .. 19 33o0r15"29’m7.(13'N.) Mercury . Venus .. 257 15 .34N Mars ... Sun.... #19 )21, ON Venus. .. Mercury . 5 2 22 38N SON ufphous Mars... 1150 2 5N Mercury .- Im. %.. .| 7| 18 590r14"45’ mr. Mars... *’s R.A. 250’ Decl. 16° 24’ N. (8'N.) Venus ., Em.%... 19 500115" 36’ mr. (2’N.)) 30] Sun. . . Venus .. 3 2 15 57N Mercury . Sun;.Gdck. 21 10N Mars... 27N Mercury . 22.19N Im. %.. ./6.7| 14 370r10" 3’ mr. Mars... 157N %'s R.A. 6" 41' Decl. 22° 0’ N. (6/S.) Venus .. 16 18N Em. *¥.. 15 20 orl0"46'mr.(4'N.) DUD ey. Dol ® 21 20N Venus .. 327 1740N Mercury . 22 ON 31} Sun. ... 33 21 57N Mars... 1 50N Mercury . 53 20 42N Im. 3 Sat. 13 40or9"19’m7r.(4+100) Mars... 55 118N 421 21 30N Venus .. 32 18 ON JUNE, H. M. D. M. H. M. D. Ms 1} Sun... 487 22 5N Mercury . 442 19 5N Mercury . 451 20 21N Ot SUD ve bens 454 22 35N . Georgian . 9 e6 (2s Ts Moon... 12 5 6558 Venus .. $3 37 18 21N Im. #1. .|7.8| 14 390r 9" 49’ mr. 2} Sun... 441 22 14N %’s R.A. 12" 8’ Decl. 7° 48’ S. (15'S.) Mercury . 449 20 1N Im. ¥2. .| 8| 15 180r10"16' mr. Im. x. . .| 7] 15 560r]11" 11)’ ur. *’s R.A. 12" 9’ Decl. 7° 55S. (16S.) xs R.A. 94 36’ Decl. 9° 41’ N. (5'N.) Em. ¥ 1] . 15 150rl0" 18’ m7.(8’S.) Bim) oe ia « 16 350r11"50’mr.(14’°N))|” | Im. ¥ 3. 15 3lorl0"34’ arr. Georgian . 19°. G6) 23° US x's R.A. 12" 10’ Decl. 7° 56S. (14’S.) Venus .. $ 42 18 38N Em. *3 . 15 490rl0'52’ mr. (5'S.) 3} Subp. j<: 445 22 21N Em. * 2. 15 5lorl0"54’ m7. 10'S. | | Moon... 1018 5 15N Georgian . 19 15° 2%, (25 Im... .[6.7] 15 240r10"35’ wr. Venus .. 2 57 19 :3uUN x's R.A. 108 27’ Decl. 4° 27’ S. (cont.) Mercury. . 440 18 50N Georgian . 1.26) 24°08 6) Sun. ,..- 457 22 41N Venus - . 3.47 18 56N Moon... 12 57 12 328 Mercury . 444 19 292N Georgian . 19 5 23 28 4] Sun.... 449 22 28N Venus .. 4 2 19 48N Moon... a1 71); @ 538 Mereury . 439 18 35N Im. ¥ 1. .{7.8' 15 40 0rl0 47 mr. 7] Sun... . 572722 40 %’s R.A. 11" 20’ Decl. 2° 1’ S. (8'N.) Moon... 13 51 17 288 Im. ¥ 2. .|4.5| 16 llorll§18’ mr. XII. 317 | 6} 14 1 15 28S %’s R.A. 11" 21’ Decl. 2° 2’S. (1’S.) XIV. 22 | 6} 14 6 17 23S Em.¥1 . 16 40 orll'47/mr.(7S.) XIV. 38 J7.8) 14 10 17 4258 Em. *2 . 17 6orl2"13M7.(19S.) Georgian . 19%: 5; 2B 28 Georgian . 19,5 28 28 Venus . . 4 7 20 6N Venus .. 3 52 19 13N Mercury . 4 37 18 20N > P cS | ¥’s R.A. 16! Astronomical Phenomena. #’s R.A. 15! 59’ Decl. 24° 31'S. (4’S.) Em. * 4 ° Venus’ ..: Mercury . Sun.... Im. *1.. *’s R.A. 16" 36’ Decl 25° 19’S. Em.* 1. Im.¥2.. 20 290rl15"15’mr. (3’N.) 4°17. 20. 35.N 433 17 58N 514 23.3N 6] 12 240r 748’ mr. (2N.) 13 23 or 87’ mr. (6N.) 15 Sor 95)'mr. %’s R.A. 16" 41’ Decl. 25° 18'S. (7'N.) Im. *3. .| | 15 21orl0°4’ mr. #’s R.A. 16" 41’ Decl. 25° 17'S. (8/N.) Em.*2 . Em. * 3 Im.% 4. . 25 Scorpiil 6 18 Oph. | 6 Moon... 26 Oph. || 6 Em. *4 . Georgian . 16 17o0r11"0’ mr.(11’N.) 16 17orl11'0’ mT.(11/N.) 16 320r11"15/ mr, 44’ Decl. 25° 32’ S. (3’S.) 16 36 25 12S 16 39 24198 16 43 25 33S 16 49 24 43S 17 300rl2 137. (1’S.) 19 4 28 88 G2 15 Im. #1. .}7.8] 14 83 JUNE. Planet’s or ¢ 2] Sidereal” Planet’s or Planet’s or z | Sidereal Planet’s or 's aS Star’s Star’s ie Star’s Name, &e. me Time. Declination. S Name, &e uP Time. Declination. ae A ere H.™M, OD. M. H.M. D. M. Sun.... 5 6 22 53N Venus 4 22 20 49N Im. *#1.. 14 13or 9" 5’ mT. Mercury 4 32 17 47N ¥’s R.A. 14" 47" Decl. 219 26'S. (2S.) {|11] Sun. . 5 18 23 7N XIV.171.) 7) 14 37 20 35S Moon... 17 40 25 318 Moon... 14 47 21 248 63 Oph. .|6.7} 17 44 24 51S XV.19../6.7/ 15 6 2144S 4 Sagit.. 15] 17 49 23 47S Im. ¥ 2. .|7-8] 15 Sor 9459’ ur. XVII. 342] 7] 17 54 24 9458 #’s R.A. 14" 49’ Decl. 219 41’ S. (10’S.)]]_ | Georgian . 19° 4 23-38 XV.65..) 8) 15 16 2045S Venus .. Al2T) 21°.38N Em. * 1 15 25o0r10" 16’ mr. (8'8.) Mercury . 431 17 41N Em.*2 . 16 I4orll*5’mr.(@S.) |]12 Sun.... 5 22 23 11N Georgian . Tg 57 2b 9 Im. *. . .| 8] 15 390r10" 14’ mr. ‘Venus .. 412 20 20N *’sR.A. 18" 32’ Decl. 24° 6’ S. (15’N.) Mercury . 435 18 9N Em.¥ .. 16 Sorl0'43’mr.C14'N.) Sun.... 5 10 22 58N XVIII.129] 6] 18 28 23 39S Im. ¥1. ‘ 6| 14 29or 9°16 mr. XVIII.141] 6] 18 31 23 598 *’s R.A. 15" 43’ Decl. 24° 0’ S. (6'N.) Moon... 18 37 24 9§ Im. *2..| | 14 45o0r 95 39’. vSagit.. | 5] 18 44 99 57S x's R.A. 15" 44’ Decl. 24° 9’ S. (5’N.) Georgian . 19 4 23 38 Em.*¥ 1. 15 23o0r10"10’7.(12'N.) Mercury - 430 17 36N 42 Libre .|5.6] 15 30 23 14S Venus .. 432 21 17N XV.149 .I7.8) 15 33 24 51S 13) Sunn 0. 527 23 14N Moon. . 1545 24 9S Georgian . 19 4 28 4S Em.*2 . 15 47o0rl10"34’mT.(11’N.) XIX.138 | 6} 19 20 2140S KV 2225 4°3|'15"50 227) 7's. XIX. 166., 7] 19 25 21 9S Im #3. .'6.71 17 4orll1"51'mr. Moon... 19 30 21 87S %’s R.A. 15" 48’ Decl. 24° 20'S. (1’S.) 56 Sagit. .| 6] 19 36 20 10S Em. #3 . 18 150r13"2’mr.(3'N.) Mercury . 429 17 30N Georgian . 19%). 23 h3'S Venusy. * 4 37 21 32N Im.*4. | 7] 19 270r1414’mr, 14, Sun.... 5 31 23 18N 52o0r 920’ wr. ¥’s R.A. 20" 11’ Decl.18° 52'S. (9'S.) 15 15 Em. ¥* 1 Im. ¥ 2. | | 48 orl10"16 mr.(2’N.) 53orl0hel’ ur. *’s R.A. 20 13’ Decl. 18° 54’ S. (0’) 59 orl 1) 26’ m'r.(7'S.) 0 orl3h27 wr. *’s R.A. 20 17’ Decl. 18° 46’ S. (cont.) Em. * 2 | 16 Im. ¥8. | 5] 19 Georgian | 19 Im.*¥ 4. .} 5] 19 4 938-4§ 39 0r14" 6 wr. %’s R.A. 20" 19’ Decl. 18° 23’ S. (3’N.) Im. ¥5. .|7.8| 19 43 orl4! 10’ mr. *’s R.A. 20" 19’ Decl. 18° 27’ S. (1’S.) XX. 45. | 8] 20 Moon... 20 XX. 194 | 7} 20 XX. 240. 20 Km. * 5 ./6.7) 20 Em.*4 . 20 Mereury . 4 Venus .. 4 MUN. os 5 6 1649S 31 1645S 53 0r15"20'mr.( 11'S.) 56 o0r15" 23’ wr. (9'S.) 30 17 30N 42 21 48N 85 23 20N 84 Astronomical Phenomena. a a = = 20 21 Planct’s or z 2) Sidereal Planet’s or Star’s 2g Star’s 5 . Name, &e. =? Time. Declination. 2 hy a H. M. D. M. Georgian . 19 4 23 48 22 Im. * 7. .| 7] 19 5lorl4'14’ wr. #s R.A. 21" 8’ Decl. 14° 0’ S. (19’N.) Em. * . | 21 lorl5" 24’ wr. (0’) Mercury . 431 17 30N 23 Venus . 447 2154N Sune tre 5 39 23 22N Im. ¥ 1. |7.8] 16 550rl1514’ wr. *’s R.A. 215 48’ Decl. 10° 24'S. (1VS.), Em. ¥ 1 17 14or11"33 mr.(15’S.) Georgian . 1953) 23.458 Im. * 2. |7.8, 20 440r15" 3’ wr. 24 #’s R.A. 21" 54’ Decl. 9° 21’S. (13’N.) Em. *2 . 21 48orl6" 6’ mr. (1’N.) Mercury . 4 31 17 30N Venus .. 452 22 5N 25 Son. : 5°43 23 24N Georgian . 19% 53)923 HS Mercury . 4.32 17 36N Venus .: 4:57). 22. 15N 26 Sun. . 5 47 23 26N Im. *- . .| 61°18 58o0r13" 9 wr. xs R.A. 23! 18’ Decl. 0° .10’N. (7S.) Georgian . 19:3 323 25S 27 Em.%... 19 55o0r14" 6 mr. (0’.) Mercury . 432 17 41N Venus .. 5°12" )22 26N Suny oe 4 5/52) 23 27N 28 Georgian . 19° 3) 23 .5S Mercury .« 433 1747N Venus .. 5 £189.220/3/ Sade sy : 5 56. 23 28N 29 Georgian . 19) (8...23 \6)S Mercury . 435 17 57N Venus .. 513 22 44N Songs’ j-°< 6. 0 23 28N 30 Georgian . 19 vis fle: AS Mercury . 438 18 8N Venus .. 5019) 22 5)N > Sl ce Planet’s or | 2 ¢| Sidereal Planet’s or Star’s ote Star's. Name, &c ep Time. Declination. se = H.M. D. M. » Sun... 6 4 23 28N Georgian * 19. 3 23 6S Mercury . 440 18 18N Venus . . 5 24 22 58N Sun. . 6 8 23 27N Georgian . 19 3 23.78 Im* . . {6.7} 20 130r14"5! wer. x's R.A. 3" 28’ Decl. 22° 5’ N. (19’S.) Em. *.. - 20 47orl14" 38' mr. (7'S.) Mercury . 443 18 32N Venus .. 529 23 4N Sun. 2. ¢ 612 23 26N Georgian 19" 2) 2a" ins Mercury - 445 18 46N Venus 535 28 11N Sun... 616 23 25N Georgian . 19)°2¢ 23 .%S Mercury . 448 19 ON Venus . 5 40 23 18N Sunisytné 6 21 23 23N Georgian . 19 2 23 7S Mercury - 452 19 16N Venus . 5 45 23,21N Sun... 6 25 23 20N Georgian . 19 2 23 "8S Mercury . 456 19 32N Venus .. 5 51 23 25 N Sun 629 23 18N Georgian .« 19; 2. 23 8/8 Mercury .« 5 0 19 48N Venus .- 5 56 23 28N Sun.. 6 33 23 15N Georgian . 19 1.93. 8S Mercury .« 5 4 20 6N Venus . 6 1 23 32N SUiiet sae 6 37 23 11N Georgian . 19 1 23 9S Mercury . 5 9 20 24N Venus... 6 7 23 36N nti a 85° ~ Arr. XI; -ASTRONOMICAL AND NAUTICAL COLLECTIONS. No. XVII. i. Remarks on the Cavatocut of the Orbits of the Comets that have been hitherto computed. By Dr. Orzers. Tue Catalogue of the Orbits of Comets is founded on that which Delambre has given in the third volume of his Astronomy, p. 409. Many errors of the pen and of the press, in Delambre’s Catalogue, are corrected, and those orbits are added which were-unknown to Delambre, or over- looked by him, or which have been computed since the termination of -his catalogue in 1813. Where several persons have computed the orbits of the same comets, some of their results have been omitted, when they have been manifestly incorrect, or derived only from a construction, or given merely as examples of computation with inadequate observations, and by no means intended to represent the correct orbits. Perhaps, however, too many in- accurate computations have still been retained: but this has been done with the intention of affording a conjecture how far the orbit may be more or less remote from a parabola: and where the orbit has been found deci- dedly elliptical, it is interesting to compare the difference of the parabolic and the elliptic elements. And since so many orbits have now been com- puted as elliptic or hyperbolic, a separate column has been added for the eccentricities, Where this is left blank, the eccentricity is supposed to be = 1, or the orbit to be parabolic. The eccentricity shows whether the orbit is elliptic or hyperbolic, and thus renders the elements complete, since the greater axis is easily found from the eccentricity and the least distance. The logarithm of the mean motion is assigned in all cases, on account of its utility in computing the true anomaly, even in the cases of elliptic and hyperbolic orbits. For this logarithm of the mean motion we have retained, on account of uniformity, the constant logarithm 9.9601283, which has hitherto been commonly used, as the logarithm of the mean motion of a comet, of which the least distance is=1. This value supposes properly that the mass of the comet is equal to that of the earth: but if this mass, which is indeed unknown, but which is certainly always very inconsiderable became = 0, the logarithm should be 9.9601277:-so that if we required the ee possible accuracy, it would be necessary to diminish the tabular ogarithm of the mean motion by 6 in the 7th place of decimals. With respect to the following remarks on the table of comets, I must gratefully acknowledge the assistance that I have received from the excel- lent notes which the Baron von Zach and the Baron von Lindenau have respectively added to their tables. But for the sake of brevity, IT have omitted many references which may be found in Pingré, or in other works here quoted, and very extensively circulated. r No. Year. J 1. 240. Chinese observations. A very uncertain orbit. Mon. Corr. X. . 167. 2. 539. ae Chinese observations, without any latitudes. Mém. prés. 4 l'Inst. I. p. 290. Mon, Corr. II. p. 415. XVI. p. 498. _ 8. 565, Deduced from two Chinese observations only, upon the two suppositions, that the curtate distance of the comet, at the time of the first observation, was either = 1,2 or = 1.3, Al- 86 Astronomical and Nautical Collections. No. Year. though the elements have some resemblance with those of the comets of 1683 and 1739, yet Burckhardt found that neither of these two orbits would accord with the observations of 565. Mon. Corr. X. p. 162, 4. 837. Chinese observations. Pingré Com. I. p. 340. 5. 989. Chinese observations, A very uncertain orbit. Mon. Corr. X. p- 167. 6. 1066. Very uncertain orbit. Pingré I. p. 373. 7. 1097. From Chinese observations of the 6th, 16th, and 17th October. Say. Etr. L p. 290. Mon. Corr. If. p. 417, XVI. p. 501. 8. 1231. Chinese observations. Pingré I. p. 401. 9. 1264. Phil. tr. XLVII. p. 281. Pingré I. p. 406. Mém. Par: 1760. p. 195. Struyck Vervolg Amst. 1753. p. 108, 109. The identity with the comet of 1556 is uncertain from the want of precision in both orbits. 10. 1299. Two European observations, and one Chinese: a third Euro- pean record does not agree. Pingré I. p. 418. 11. 1301, Pingré has applied a correction to the European, and Burck- hardt to the Chinese observations, which could not otherwise be reconciled. Hence the diversity. Pingré I. p. 420, Mon. Corr. X. p. 164. 12. 1337, Pingré I. p. 432. The orbit of Pingré is preferable to that of Halley, since it represents both the European and the Chi- nese observations tolerably well, while Halley's differs as far as 208 fromthe latter. 13, 1351. Even the few elements, which Burckhardt has been able to assign, are very uncertain. Pingré I. p. 487. Mon. Cor. IIL. p- 415. Mem. Say. Etr. I. p. 290. There are only four Chinese observations, of the 24th, 26th, 29th, and 30th No- vember, without latitudes. On the whole we ean place no manner of reliance on the orbits of the comets of 240, 539, 565, 989, 1066, 1097, 1231, 1299, 130], 1351, and 1352. 14. 1362. Mon. Corr. X. p. 166. Three Chinese observations. The two orbits are derived from different. suppositions respecting the latitudes. 15. 1456. The celebrated comet of Halley, of which the period amounts. to about 76 years. Pingré I. p. 459. 16. 1472. From the observations of Regiomontauus, Pingré I. p. 475. (15.) 1531. Halley's comet as observed by Apian. Pingré I. p. 488. See also especially Halley’s ‘Tabule Astronomice, and his essay there inserted, De motn cometarum elliptico. 17. 1532. Pingré I. p. 492. The once supposed identity of this comet with that of 1661 must be abandoned. Méchain, Meém. Prés. X. p. 333. Olbers in Hindenburg’s Magazine for Ma-. thematics 1787. p. 440. ' 18. 1533. Pingré L. p. 496. The total diversity of the two orbits suffi- ciently shows the uncertainty of both. Struyck, 1753. p. 24. Astron. Jahrb. Berl. 18009. (9.), 1556. From the observations of Paul Fabricius between the 4th and the 17th of March, which cannot be considered as certain ; so that we can place little reliance on the resemblance to the still less certain elemenis of the comet-of 1264. Pingré f. p- 502. Astronomical and Nautical Collections. 87 No. Year. 19. 1558. From three observations of the Landgrave of Hesse, and one of ¢ Cornelius Gemma, the latter being corrected in what is, very probably, an error of the press. Gemma de Nature Divinis Characterismis. Book II. ch. i. p. 33. See Berl. Astr. Jahrb. 1817, p. 176. 20. 1577. From Tycho’s Observations. Pingré I. p, 511. 21. 1580. Halley from Méstlin, Pingré from Tycho’s better obscrvations. Pingré L. p, 521. 22. 1582, Both orbits uncertain, since they are founded only on three observations of Tycho, of the 13th, 17th, and 18th of May ; that of the 18th giving a double result, whence the two orbits are derived. The first elements seem the most probable, Pingré I. p. 544. 23, 1585. From the observations of Tycho and Rothmann. Pingré I. . 550. 24, 1590. Tycho’ observations, from 23 February to 6 March. Pingré . p. 554. 25. 1593. Bocrlat to the observations of Chr. J. Ripensis, at Zerbst. Mem. Par. 1747, p. 562. Pingré I. p. 557. 26. 1596. Halley from Méstlin, Pingré from Tycho’s observations : hence the latter elements are preferable. Pingré L. p. 562. (15) 1607. Halley’s comet. Pingré [I. p. 3. Halley's Tab. Astr. First supplement of the Berl. Astr. Jahrb. Mon. Corr, X. p. 425. 27. 1618. From Kepler's imperfect observations. Kepler de Cometis. Pingré II. p. 4. 28. 1615. Bessel’s orbit is far the best, being founded on the observations - of Harriot, Longomontanus, Cysat, and Schnellius. Berl. Astr. Jahrb. 1808, p. 113. 29. 1652. From the observations of Hevelius between the 20th December and the 8th January. Hevelius’s observations are not only in the second volume of the Machina Celestis, which is very rare, but also in his Cometographia, 30. 1661. The observations of Hevelius from the 3d February to the 28th March. Machina Ceelestis [., and Cometographia. Mém. pres X. p. 350. 81. 1664, Hevelius'’s observations in the Prodromas Cometicus, or better in the Mantissa Prodromi, and in the Machina Cel. II, p. 439. Pingré LI. p. 10. 32. 1665. From Hevelius's observations from the 6th to the 20th April, which are found in the Deser. Comet. 1665, Mantissa Prodr. Com. and Mach. Ceelestis IL. 33. 1672. According to Hevelius’s observations from the 6th March to the 21st April. Mach. Cel. IL. p. 593. 34. 1677. According to Hevelius’s observations from the 29th April to the 8th May. Flamstead observed it also twice. Mach. Col. IL. p- 292, Flamstead Hist. Cel, Br. Ed, 1712, p. 103. Ed. 1725. I. p. 103. 35. 1678, From Lahire’s observations, which are only estimated, and from the chart in the Hist. Cél. of Lemonnier, p. 238. See particu- larly Struyck, 1753, p. 88, 39. 36. 1680, Euler's elliptical elements are to be considered merely as an example of calculation, and require no further consideration. It is only the elliptical orbit of Encke that is of any value at present ; itis taken from his masterly prize essay on this comet 88 No. Year. Astronomical and Nautical Collections. (Zeitschrift fiir Astr. 1818), in which all the observations are collected and discussed. The first orbit of Encke is the para- bola which agrees best with the observations. The longi- ee are reckoned from the mean equinox of the 15th Decem- er, 1680. (15.) 1682. Halley's comet: observed from 25th August to 19th September. 37. 38. 39. 40. 4). 42, 43. 44, 45. 4s. A9. Flamst. H. C. Br. I. p..108. Hevel. Ann. Climact. p. 120. Halley in Tab. Astr. de mot. com. ellipt. 1683. According to Flamstead’s observations, from the 23d July to the 5th Sept. Flamst. p. 110. 1684, According to Bianchini’s observations, from the Ist to the 17th July. Phil. Tr. N. 169, p. 920. Acta erud. 1685. p.241. 1686. Seen first in August in the East Indies, then in September, in Europe. Orbit not very certain. Pingré II. p. 28. i 1689. Very uncertain observations, Pingré IL. p. 29. » 1695. Burckhardt computed his orbit from manuscript observations left by Delisle in the Dépdt de la Marine.. What was before known of this comet Pingré has collected. p. 33. Conn. des tems, 1817, p. 278... : 1698. The observations of Lahire and Cassini, the only ones that we have of this comet, are deficient in accuracy. Anc. Mém. II. p- 341, X. p.'742.. Mém. 1701, p. 117. 1699. Observed by Fontenay at Pekin, and by Cassini and Maraldi at Paris. The observations extend from the 17th February to the 2d March. Mem. Par. 1701, p. 47. 1701. From observations made by P. Pallu at Pau, which had lately been recovered, and from the observations of P. Thomas, at Pekin. Conn. des tems, 1811, p. 482.. Noel Obs. Phys. Math. in India fact. p. 128. 1702. The observations between the 20th April and the 5th May not very exact, Struyck, 1753, p. 50. Pingré II. p. 38. Mem, Inst. UH. p. 28. Mon. Cor. XVI. p. 511. - 1706. Cassini and Maraldi, from the 18th March to the 16th April. Mem. Par. 1706, p. 91, 148. Pingreé IL, 39, Struyck, 1753, 5 p. 54. . 1707. The observations extend from the 25th. November to the 23d January, 1708. Mem, Par. 1707, p. 58S, and 1708, p. 89, 323. On the orbits see Pingré Li. p. 40. Struyek, 1753, p. 54. The orbit of Hottuyn, given imperfectly by Struyck himself, depends only on a construction. 1718, From Kirch’s observations, which are not particularly accurate. Misc. Ber. III. p. 200. Phil. Trans. XXX. XXXII. Pingré II. p. 41. Struyck Inleiding de Algemeene Geographie, p: 295. Struyck, 1753, p. 57. 1723. Was seen in the East Indies as early as the 12th October. The orbits are principally founded on the observations made be- tween the 20th October and the 18th December by Halley, Bradley, Pound, and Graham. Phil. Trans. XXXII. n. 382, _p. 41, n. 897, p. 223. The second orbit, ascribed to Struyck, is only found in the astronomical tables of Berlin. Pingre If. -p. 42. Burckhardt’s hyperbolic. orbit. . Conn. des tems, 182i. 1729, Discovered by Father Sarabat the 31st July, 1729, and observed until the 18th Jan. 1730. Pingreé IL. p. 42, Struyck, 1740, p. Astronomnteat and Nautical Collections. 89 No. Year. 2 297, 1753, p. 58. Mém. Par. 1730, p. 284. The hyperbolic and parabolic orbits of Burckhardt. Conn. des tems, 182]. 51. 1737, Computed from Bradley's own observations, extending from 26 Feb. to 2 April. Phil. Trans. N. 446, p. 111. Pingré II. p- 45. Struyck, 1740, p. 301. 52, 1737, The observations made at Pekin were published in the Mon. Corr. XXL. p. 316. Conn! des tems. 1812, p. 409. 53. 1739. The observations are by Zanotti, from the 28th May to the 18th August. N. Acta Erudit. 1740, p- 166. Comm. Inst. Bon. II. p. ili, p. 73. Struyck, 1753, p. 64. The second orbit, by.Za- notti, is only a first approximation, still remaining imperfect. 94. 1742. For the numerous observations of this comet see Pingré II. 47. 59. 1743, In part. very imperfectly observed. The observations are j principally collected in Struyck, 1753, p. 75. 56. 1743. Observed imperfectly, and by Klinkenberg alone, from 18 Aug. oa to 13 Sept. Struyck, 1753, p. 76,77. The observations, which are also inserted by Pingré I, p- 52, differ sometimes 1° and more from the elements assigned. 57. 1744. Besides the observers and computers of this celebrated comet quoted by Pingré, IT. p. 52, and Struyck, p. 78, some valuable matter may be found in Chéseaux Traité dela Cométe, Laus. 1744, and Hiorter Trans. Swed. Acad. of Sciences. _58. 1747. Discovered by Chéseaux the 13th Aug. 1746, and last ob- served by Maraldi the 5th Dec. 1746. The orbits of Ma- raldi and Lacaille are the best. Pingré II. p. 57. Struyck, 1753. p. 92. 59. 1748. Especially observed by Maraldi, Mém. Par, 1748, p. 229. 60. 1748, Observed only three ‘times imperfectly by Klinkenberg, the 19th, 20th, and 22d May. Struyck, 1753, p- 96. Bessel has reduced the observations with greater care. Berl. Astr. Jahrb. 1809, p. 99. The imperfect elements, time of the Perihe- lium, 1748, 22d April Q 9°, 24°, Inclination 76°, Least distance 0.5, Motion retrograde, which Delambre as- cribes to Burckhardt, and respecting which I can find no further information, cannot possibly belong to either of the computed comets of this year: so that they must have been derived from the alleyed observations of the silly Kinderman, which deserve no credit whatever. 61. 1757, Bradley's observations and elements are preferable to the rest. Phil. tr. L. Part. i. p. 408. The other observations may be found collected by Pingré, Mém. Par. 1757, p- 97. 62. 1758, Messier observed the comet from the 15th Aug. to the 2d Noy. _Mém, Par, 1759, p. 154, 1760, p. 165, 463. (15).1759. Celebrated and predicted re-appearance of Halley's comet. Pingré IL. p. 63, gives references to works in which the ob- servations and the elements may be found. Burckhardt's ___ orbit, preferable to all the rest. ‘Conn. des tems, 1819. 63, 1759. Pingré prefers his own elements. The comet was observed from the 25th June to the 16th March 1760. Pingré I. 5 p- 68. 64. 1759. Observed from the 8th Jan. to the Sth Feb. 1760, Pingré II, p- 70. ; 65. 1762, Discovered by Klinkenberg the 17th May, observed to the 2d July. The refraction had been neglected in the reduction of 90 Astronomical and Nautical Collections. No. Year. the observations, and hence all the computed orbits varied several minutes from the observations. Burckhardt reduced them with greater care, and hence obtained the last elements, which are more correct. Mém. Inst. VIL. p. 226. Mon. Corr. XVI. p. 515. wit. 66. 1763. Discovered by Messier the 28th Sept., observed before the pe- - vihelium from the 30th Sept. to the 25th Oct., after the perihelium from the 12th to the 25th Nov. Pingré and Lexell could not represent the observations sufficiently well by any conic section. Pingré II. p. 106. Acta. Ac. Sc. Petr. 1780. Pt. ii. p. 324. Burckhardt has corrected the observations of Messier, which were distorted by some errors in the places of Flamstead’s stars, and he has employed the observations of St. Jaques de Silvabelle, which were made public more lately. Mon. corr. X. p. 507. Conn. des tems. XIII. p. 344. 67. 1764, Discovered by Messier, and observed from 3d Jan. to 11th Feb. The third orbit is that which has been corrected from all the observations. Pingré IT, p. 74. 68. 1766. Discovered by Messier the Sth March, and observed for eight days only. Pingreé If. p. 75. 69. 1766. Observed by Messier at Paris only five days, from the Sth to the 12th April. La Nux at the Isle of Bourbon followed it from the 29th April to the 13th May. Pingré IL. p. 76. The imperfect observations of La Nux, Pingré could not satisfactorily combine with the Parisian observations, and Burckhardt has attempted to do this by means of an ellipsis. Conn. des tems. 1821. 70. 1769. Discovered by Messier the 8th Aug., and observed before the perihelium to the 15th Sept. ; after it from the 24th Oct. to the Ist Dec. The principal observations are found Mem. Par. 1769, p. 49; 1770, p. 24; 1775, p. 392. Maskelyne Astr. Obs. I. On the various orbits, besides Pingré II. p. 83, see especially Euler Recherches et Calculs sur la comeéte, 1769; 4 Pet. 1770; the two rare works of Asclepi De cometarum motu exercitatio ; 4 Rom. 1770, and De come- tarum motu Addenda, Rom. 1770; besides Bessel’s excellent prize memoir in the Berl. Astr. Jahrb. 1811. That Bessel’s elliptic orbit is preferable to all others, scarcely requires to be observed. The nodes and perihelium are determined by Bessel as at rest with respect to the stars for the Ist Jan. 1769. 71. 1770. This comet, celebrated for an orbit deviating so greatly from the parabolic form, was discovered the 14th June by Messier, and observed till the 24 Oct. The observations have been collected by Messier, Mém. Par. 1776, p. 597. The short period of this comet, little exceeding five years and a half, which appeared so paradoxical when it was first computed by Lexell, was fully confirmed by Burckhardt’s investigations in his valuable prize memoir. Mém. Inst. 1806, p.1. Therea- son why the comet has not re-appeared since 1770, has been very satisfactorily explained in Laplace's Mée. Cd. vol. [V. -72. 1770. Was observed only four times at Paris, between the J0th and 20th of Jan. 1771. Mem, Par.1771, Pingré II. p. 90. 73. 1771, Discovered by Messier the Ist April, and observed by him until the 19th June ; but by St, Jaques de Silvabelle at Mar~ Astronomical and Nautical Collections. 9] No, Year. : dias seilles till the 17th July. The orbit appears, according to the investigations of Burckhardt and of Encke, to be truly hyper- bolical. The parabola. of Encke, however, affords also : results varying but little from the truth. Mon. Corr..X. p- 510. Conn. des tems XIII. p. 344, Von Zach Corresp. astr. 1820, Encke reckons from the mean equinox, Ist Jan. 1771. ‘74, 1772. Discovered by Montaigne the Sth March, observed by Messier four times only, the 26th, 27th, and 30th March, and the 1st April. The computation of the elliptic orbits was undertaken on account of the similarity of the elements of the second &, comet of 1805. These more correct investigations render the identity of the two comets highly improbable, and it is accordingly rejected by Bessel, as well as by Burckhardt, who was able to employ the rediscovered observations of Mon-~ taigne. Mon. Corr. XIV. p. 73, 84. Conn. des tems 1811, - 486. K 75. 1778. Dieddwerceh by Messier the 12th Oct. 1773, and observed until “A the 14th Apr. 1774. Burckhardt, who employed also obser- vations of St. Jaques de Silvabelle, found the orbit not sensibly different from a parabola. Mém. Par. 1774—1777. Acta Petr. 1779, p. 335. Conn. des tems XIII. p, 343. Mon. ie Corr. X. p. 540. 76. 1774, Discovered by Montaigne the 11th Aug. observed till the 25th Oct. Mem. Par. 1775, p. 445. Conn. des tems 1821. 77. 1779. Discovered by Bode the 6th Jan. observed till the 17th May. Mem. Par. 1779, p. 318. Pingré, IL. p. 94, seems to prefer the orbit of Dangos before the rest. 78. 1780. Discovered by Messier the 27th Oct. and observed till the 29th Nov. Mém. Par. 1780, p.515. Act. Petr. 1780, p. ii. p. 347. Berl. Astr. Jahrb, 1784, p. 141. 79. 1780. Discovered the 18th Oct. by Montaigne and Olbers, and ob- served very imperfectly three times only. The elements are therefore very uncertain. Mém, Par. 1780, p. 515. Berl. Astr. Jahrb. 1804, p. 172. 80, 1781. Discovered by Méchain the 28th June, observed till the 15th July. Mém. Par. 1781, p. 349; 1782, p. 581. Berl. Astr. Jahrb. 1785, p. 166. $1. 1781. Discovered by Méchain the 9th Oct. observed till the 25th Dec. Mém. Par. 1781, p. 360; 1782, p.587. Legendre Nouv. Méthode, p. 41. 82. 1783. Discovered by Pigott the 20th Nov. observed till the 21st Dec. Mém., Par. 1783, p. 123, 648, Phil.tr. LXXIV. Conn. des tems 1788. But respecting Burckhardt’s orbit, sec especially beaten Conn. des tems 1820, p. 305. ; ‘83. 1784, Seen by Dela Nux at the Isle of Bourbon the 15th Dec. 1783, in Paris not till the 24th January, and observed there till the 11th March, Afterwards it was again visible, and observed from the 9th to the 26th of May. Mém. Par. 1784, p. 313, 358. The first elements are the most correct. The comet hitherto inserted in the tables, as the second of 1784, is a shameful forgery of the Chevalier Dangos, as Pro- ad fessor Encke has shown in the Corresp. Ast. for 1820. Cah. v. p- 456. ™ ‘A ' - 92 Astronomical and Nautical Collections. r No. Year. 84, 1785. Discovered by Messier and Méchain the 7th Jan. observed till the Sth Feb. Mém. Par. 1785, p.646. Berl. Astr. Jahrb. 1789, p. 142. Conn. des tems, 1788. 85. 1785, Discovered by Méchain the 11th March, observed till the 17th Apr. Mém. Par. 1785, p. 646. Berl. Astr. Jahrb. 1789, p. 143. 86. 1786. Was discovered by Méchain the 17th Jan. and could only be observed once more on the 19th, by Méchain and Messier. Mém. Par. 1786, p. 95. But since the identity of this comet with those of the years 1795, 1805, and.1819, has been de- monstrated, Encke was able todetermine the orbit from these two observations. Berl. Astr. Jahrb. 1822. Corresp. Astr. 1819. Conn. des tems, 1819, p. 224. 87. 1786. Discovered the 1st Aug. by Miss Caroline Herschel, observed till the 26th Oct. Mem. Par. 1786, p.98. Maskelyne, Astr. Obs. II. p. 29. Ephem. Milan. 1789. Conn. des tems, 1789. 88. 1787. Discovered by Méchain the 10th April, observed at Paris till the 20th ; at Marseilles till the 26th May. Mém. Par. 1787, p. 70. Conn, des tems, 1790. . Berl. Astr. Jahrb. 1791. La Nux observed it at the Isle of France from the 25th May ; to the 21st June. $9. 1788. Discovered by Messier the 25th Nov. observed till the 29th Dec. Mem. Par. 1789, p. 663. Conn, des tems. 1791. Berl. Astr. Jahrb. 1793. 90. 1788. Discovered by Miss Herschel the 21st Dec.: observed last by Méchain the 18th Jan. 1789. Phil. tr. LXX VII. p. 1. Mém. Par. 1789, p. 681. Maskelyne Astron. Obs, for 1788. Berl. Astr. Jahrb. 1793. p. 119. 91. 1790. Discovered by Miss Herschel the 7th Jan.: observed only four times ; the 9th, 19th, 20th, and 21st Jan. Mém. Par. 1790, p. 309. The first orbit agrees best with the longitudes ; the ; second with the latitudes. 92. 1790. Discovered by Méchain the 9th of Jan. and observed till the 22d. Mém. Par. 1790, p. 313. Conn. des tems, 1792, p. 355. Berl. Astr. Jahrb. 1794. 93. 1790. Discovered by Miss Herschel the 17th April, and observed till the <9th June. Mém, Par. 1790, p. 320. Conn, des tems 1792, p. 355. Englefield on Comets, Lond. 1793, p. viii. 94. 1792. Discovered by Miss Herschel the 15th of December 1791: ob- served last by Maskelyne on the 25th Jan. 1792. Berl. Astr. Jahrb. 1795, p. 184, 201; 1796, p. 148; Conn. des tems 1793, p. 374, Englefield on Comets. The first elements, by Méchain, are those which have been corrected from all the observations. 95. 1792. Discovered by Méchain the 10th Jan. 1793; also by Piazzi; observed till the 19th Feb. Piazzi della spec. astr. book v. Berl. Astr. Jahrb. 1797, p. 136 ; 1799, p. 192. Conn. des tems, 1795, p. 286. 96. 1793, Discovered by Messier the 27th Sept. observed till the 11th Oct.: then seen again the 80th Dec. and observed till the 4th Jan. 1794, Conn. des tems, 1795, p. 287. (To the best of my knowledge, Messier’s observations of this comet, as wellas of some others, have not yet been printed, Their entire publication would be highly desirable.) Astronomical and Nautical Collections. 93 ? No. Year. 97. 1793. Discovered by Perny the 24th September, observed till the 3d December. Conn. des tems, 1795, and especially Conn. des tems, 1820. Burckhardt leaves it doubtful whether this comet : is or is not identical with that of 1783. (86.) 1795. Discovered by Miss Herschel, the 7th November, and ob- served till the 27th. The observations chiefly rather inac- curate. ‘This is the second appearance of Encke's comet. Phil. Trans. 1795. | Berl. Astr. Jahrb. 1799. 1814. More especially see Berl. Astr. Jahrb, 1822, p. 183. Von Zach Corr. Astr. 1819. Encke computes from the mean equinox of the 18th November, 1795. 98. 1796. Discovered by Olbers the 31st March, and observed till the 14th April. Berl. Astr. Jahrb. 1799, p. 106. 99. 1797. Discovered by Bouvard the 14th August, and observed till the : 3lst. Berl. Astr. Jahrb. 1800. Allg. Geogr. Ephem. I. p- 127, 366, 604. 100. 1798, Discovered by Messier, the 12th April, and observed till the 24th May. Mém. Inst. IL p. 430. Alle. G. Eph. I. p. 679, 692, 694. II. p. 79, 95. Berl. Astr. Jahrb. 1801, p. 231. 101. 1798. Discovered the 6th December by Bouvard, and the sth by Olbers, and only observed till the 12th. Berl. Astr. Jahr L 1802, p. 195. Allg. G. Eph. III. Conn. des tems, 1804, p- : 373. 102. 1799. Discovered the 6th of August, by Méchain, and observed till the " 2ist October, Ally. G. Eph, IV. Berl. Astr. Jahrb. 1802, ~ 1803. Mon. Corr. I. IT. 103, 1799. Discovered the 26th Dec. by Méchain, and observed by him till of the 5th Jan. 1800, Mon. Corr. I. p. 191, 299, Mém: Inst. IT. p- 153. Berl. Astr. Jahrb. 1803. Conn. des tems, 1804, p- 376. Méchain thinks that this comet may possibly have been identical with that of 1699. 104, 1801. Discovered almost the same hour by Pons, at Marseilles, and Messier, Méchain, and Bouvard, at Paris, on the 12th July: observed last by Méchain, the 23d. Mon. Corr. IV. p. 179. Berl. Astr. Jahob. 1805, p. 129. Conn. des tems, An. XIII. p. 344, 484. 105. 1802. Discovered by Pons the 26th August: observed till the 3d Octo- ber. Mon. Corr. VI. Conn. des tems. An XIII, p- 236, 374, Berl. Astr. Jahrb. 1805, 1806, p. 129. 106. 1804, Discovered by Pons the 7th March: observed till the Ist April. ma Conn. des tems, XV. p. 374: 1808, p. 336. Mon. Corr, IX. Berl. Astr. Jahrb. 1807. ; (86.) 1805, Third appearance of the comet of Encke. Discovered at the same time by Bouvard, Pons, and Huth, the 20th October - observed till the 15th, and seen on the 19th November. Mon. Corr. XIII. XIV. Conn. des tems, 1808, 1809. Berl. Astr. Jahrb. 1899. But especially see Berl. Astr. Jahrb. 1822, 1823. Corresp. Astr. 1819. 107. 1805, Discovered by Pons the 10th Nov. and observed till the 9th rit Dec. Its supposed identity with the comet of 1772 has given oceasion to many computations, ‘This identity has not been confirmed ; but Gauss found that the observations agree better with any ellipsis that has its greater semiaxis longer than 2,82, than with a parabola. Mon, Corr. XIU. XIV, XXVU. &: Gg, No. 108. 109. 110. 111. 113. 114. 116. 117. Year. Astronomical and Nautical Collections. t p-360, 490. Berl. Astr. Jahrb. 1809. Conn. des tems. 1808, 1809. ‘ : 1806. Discovered by Pons the 10th November: observed first till the 20th Dee., and then again from the 17th Jan. to the 12th Feb. 1807. Mon. Corr. XV. XVI. Berl. Astr. Jahrb. 1810. Conn, des tems, 1810. p. 298, 1819. 1807. Great comet. Observed from the 22d Sept. 1807 to the 27th March, 1808. Most of the observations are collected in Bes- sel's Untersuchungen tiber den grossen cometen, 4, Kénigs- berg, 1810. Besides this classical work see also Mon. Corr, XVI. XVII. XVIII. XIX. Berl. Astr. Jahrb. 1811, 1812, 1813, 1814. Cacciatore della cometa di 1807. Conn. des Tems, 1809, 1810, 1811, and Phil. Trans. 1808. 1808. Discovered by Pons, the 24th June, and somewhat uncertain, 1810. . 1811. ‘Isil. 1812. especially with respect to the declinations: observed only at Marseilles, from the 26th June till the 3d July, Mon. Corr. XVIIL. p. 245, 359. Berl. Astr. Jahob. 1812, p. 129. j Discovered the 22d August by Pons, and observed very doubt- fully at Marseilles only from the 29th Aug. to the 21st Sept. Mon. Corr. XXIIL. p. 802., XXIV. p. 71. Berl. Astr. Jahrb, 1814, p. 179. Discovered by Flauguergues the 26th March, and observed in Europe before the perihelium till the 2d June, after the peri- helium from the 20th August to the 11th Jan. 1812: lastly rediscovered by Wisniewski, at New T'sherkask, the 31st July, 1812, and observed again from the Sth to the 17th of August. Upon this great comet, very remarkable even in its form, and observed by almost all astronomers, besides the Mon. Corr. XXUI. XXIV. XXV. Phil. Trans. 1812. Berl. Astr. Jahrb. 1815, 1816. Conn. des tems, 1820, and so forth, see especially the excellent treatise of Dr. F. W. A. Argelander, Ueber die Bahn des grossen cometen von 1811, 4, Kénigsberg, 1822. The orbit of Argelander, inserted in the table, is that which he considers as the most probable : but the observations made at the different times of the comet's appearance could not be quite satisfactorily represented by any orbit governed by the Keplerian laws. Argelander reckons from the place of the mean equinox the 12th Sept. 1811. Discovered by Pons the 16th November, and observed last at Bremen, the 16th February, 1812. Conn. des tems, 1820. Mon. Corr. XXIV, XXV, and especially XXVII. Nicolai reckons from the mean equinox on the Ist Jan, 1812. Discovered by Pons the 20th July, and observed till the end of September. Mon. Corr. XXVII. XXVIII. Con. des tems, 1820: but see especially the Zeitschrift for 1817. Encke reckons the longitudes from the mean equinox of the Ist Sep- tember, 1812. 5. 1813. Discovered by Pons the 4th February, and observed till the 11th March. Mon. Corr. XXVII. Conn. des tems, 1820. 1813. Discovered by Pons at Marseilles, and Harding, at Gottingen, the 2d and 3d of April: observed till the 29th. Conn, des tems, 1820. Mon. Corr. XXVU. XXVIII. 1815, Discovered by Olbers the 6th of March: observed last by Gauss, the 25th of August. Bessel has taken the perturbations into Astronomical and Nautical Collections. 95 No. Year. 38 -aecount for his elliptical orbit. Period, according to Nicolai, 74.7893 years ; according to Bessel, 74.04913. Bessel com- putes, that taking all the perturbations into account, the comet will reach its periheliam again in as early as 1887, Feb. 9.4, that is $24.5 days earlier than the period of the simple elliptic orbit. Berl. Astr. Jahrb. 1818, 1819. Observations at Konigsberg, If. Zeitschrift for 1816. Trans. Berl. Acad. . 1812, 1815. Math. Class. Wonn. des tems, 1520. Bessel reckons the longitudes from the mean equinox of the Ist Jan. Nicolai from the 26th April, 1815. 118. 1818. Discovered by Pons the 26th Dec. 1817: observed last at Bre- men the Ist May 1818. The comet was on account of the faintness of its light very dificult to be observed, and ap- peared to be gradually dissolved. Berl. Astr, Jahrb. 1821. Zeitschrift for 1818. Conn. des tems, 1821. 119. 1818, Discovered by Pons the 29th Nov. 1818 ; afterwards by Bessel the 22d Dec. Last observed by Harding the 30th Jan. 1819. Berl. Astr. Jahrb. 1821, 1524, Conn. des tems, 1821. Corresp. Astr. IL. p. 187. (86.) 1819, Reappearance of the celebrated comet of Encke, by which its short period of 1207 days was first ascertained. Discovered by Pons the 27th Nov. 1818: observed last the 12th Jan. 1819. Only the last elliptic orbit of Encke is to be considered as the true one. Corr. Astr. 1819. Berl. Astr. Jahrb. 1822, 1823. Conn. des tems, 1522. Encke reckons the longitudes from the mean equinox of the 1st Jan. 1819. 120. 1819. Appeared suddenly in Europe emerging from the sun’s rays in the beginning of July, of a considerable magnitude. Last observed in October at Dorpat and at Bremen. Is remark- able, because, according to the elements, it must have passed over the sun’s dise on the 26th of June. Corr. Astr. 1819. Berl. Astr. Jahrb. 1521, 1822. Conn. des tems, 1822. 121. 1819. Discovered by Pons the 12th June, and only observed at Mar- seilles and in Milan till the Joth July. Only the last orbit, by Encke, agrees with the observations, which cannot be re- presented by any parabola. Corr. Astr. 1819. Berl. Astr. Jahrb. 1822, p. 243; 1823, p. 221. Efem. Milan. 1820. Encke computes from the mean equinox of the Ist Jan. 1819. 122, 1819. Discovered by Blanpain at Marseilles the 28th Nov. : observed _ last at Milan the 25th Jan. 1820. Observed also at Bologna, and especially at Paris. he great deviation of the orbit from a parabola is not to be doubted ; but the limits of the time of revolution have not hitherto been found assignable, on account of the too short interval between the observations which have been published, and which are in some degree of deubtful accuracy ; those of Marseilles not having been ob- tained by the most earnest entreaties and demands. Corresp. Astr. 1820. Berl. Astr. Jahrb, 1824, Conn, des tems, 1824. Encke reckons from the mean equinox of the Ist June, 1820. 123. 1821, Discovered at the same time on the 2lst Jan. by Nicollet at Paris, and by Pons at La Marlia. Was observed in Europe till the 7th March, and after the perihelium, from the Ist April till the 3d May at Valparaiso, by Captain Basil Hall, Lieutenant W. Robertson, and Mr. H. Forster. Its apparent Astronomical and Nautical Collections. motion was very slow throughout the time of the European observations. Brinkley’s first elements are founded only on the observations at Valparaiso: the second he has com- puted from the observation of the 30th January at Bremen, and those of Capt. Hall, made the Sth April and the 3d May. Rosenberger was able to represent both the European and the American observations sufficiently well by his parabola. The rest of the ‘vrbits are founded on the European observa- tions alone, The orbit seems to differ very little from a true parabola. Corr. Astr. 1820. Conn. des tems, 1824, Berl. Astr. Jahrb. 1824. Phil. Tr. 1822, Pt. i. Edinb. Phil, Journ. N. xiv. p.382. Schumacher Astr. Nachr. N. 2, p. 17. N. 11, p. 166. N. 24, p. 425. 124, 1822. Discovered by Gambart at Marseilles the 12th May, by Pons at Marlia the 14th, and by the Oberlieutenant Biela, at Prague, the 16th: observed till the end of June. Zach Corresp. Astr. 1822, cah. ili. iv. v. Schumacher Astr. Nachr. N. 19, p. 298. N. 20, p. 309. Berl. Astr. Jahrb. 1825. (86.) 1822. Orbit corrected by Encke from Riimker’s observations at Pa- ramatta. Schumacher Astr. Nachr. N. 27, p. 39. Thelon- gitudes relate to the mean equinox of the 24th May. 125. 1822, Discovered the 13th July by Pons, at Marlia: observed till the 22d October. Only the second ellipsis of Encke is founded on the whole apparent are described : but the second parabo- lic orbit of Nicolai, and the third of Hansen represent also the whole of the observations hitherto published in the most satisfactory manner. Perhaps we may expect to receive from the Cape of Good Hope, or from New Holland, some observa- tions of the two last comets, as well as of that which was dis- covered on the 31st May, by Pons, at Marlia, near 6 Piscium, and which was little observed in Europe, and has not yet been computed, Zach. Corr. Astr. cah. v. Schumacher Astr. Nachr. N. 20, p. 307.; n. 21. Suppl. ; N. 22, p. 361, and 1. Suppl. ; N. 23, p. 393, and Suppl. ; N. 24, Suppl. Nicolai supposes the mean equinox of the 23d Oct.; Hansen in the second orbit, the Ist Sept. ; in the third the Ist October, and Encke, the 25th Oct. 1822. [See also Gambart in Conn. des tems, 1826. T'r.} ii. Further Remarks on the periodical Comer (86 Olb.) with conjec- tures on the effect of a resisting medium. By Professor Encxr. Bode's Alm. 1826, p. 124. The observations of Mr. Riimker have removed every possible doubt respecting the identity of the comet, and made it certain that future Astronomers will be able to recover it even if it should remain invisible for several revolutions. Fortunately, however, there is no reason to apprehend that it will escape us in its next Astronomical and Nautical Collections. 97 visit. Dr. Oxzers first pointed out to me that if it passed the perihelium later than the 10th of September, it will be visible to Europeans in August. From a cursory computation of the per- turbations, I find that its perihelium will be about Sept. 16.4, and its places will be nearly these: A.R. Decl. Log. Dist. 1825 aatiy iF iets © = Aug. 1.6 82 31 32 1N 0.023 0.162 6.6 90 23 32. 9 9.988 0.141 11.6 99 1 3] 44 9.948 0.123 16.6 108 19 30 36 9.903 0.107 21.6. 118 9 28 37 9.852 0.097 26.6 128 14 25 40 9.792 0.092 31.6 138 23 21 46 9.724 0.093 Its next return to the perihelium will be in Dec. 1828, or per= haps in the beginning of January 1829: and it will then be easily visible, unless its light should prove to be gradually dimi- nishing. In attempting to compute the perturbations, it becomes necessary to employ higher powers of the quantities concerned than those which are sufficient for the planets, and no precautions or suppo-. sitions respecting the masses of the disturbing bodies are capable of representing the successive revolutions from each other without errors of several degrees. For example, we represent the five perihelia of 1786, 1795, 1805, 1819, and 1822, most conveniently by taking the mass of Jupiter 71; less than that which is assigned by Laplace: but errors exceeding a whole day in the interval will still remain: and the middle three of the five considered alone afford still greater irregularities, although the actions of the planets which are neglected would have a very inconsiderable influence on this combination. Comprehending the effects of 8, 9, and ©, the best result is obtained by increasing the mass of Jupiter about 4: but the ele- ments thus corrected give the perihelium of 1786 two days too early, and that of 1822 a day and a half too late: nor will any Vou. XVII. H 98 Astronomical and Nautical Collections. other planetary perturbation, that ca be imagined, enable us to remove this error. I therefore think myself entitled to consider it as demonstrated, that an alteration of the supposed masses of the planets alone is not sufficient for the purpose; and in the predictive computation of the places for 1822, which has now been verified, I was induced by this conviction to assume an empirical correction proportional to the square of the time. Such a correction of the epoch corresponds to a mean angular motion increasing directly as the time, and points at once to the possibility of an explanation of its foundation. From Newton down to Laplace, a number of the most acute mathematicians have investigated the influence which any substance, scattered through space, might have on the motions of the heavenly bodies. The resistance of such a medium would necessarily occasion a continual shortening of the greater axis, and consequently an increase of the mean motion, and a diminution of the eccentricity; while the longitude of the perihelium would undergo only periodical changes compensating each other in the time of a revolution; and the nodes and inclination, which affect only the plane of the orbit, would be perfectly exempted from its influence. Now these are exactly the changes which are observable in our comet; for the decided change of the eccentricity, in the year 1822, may at least, in great measure, be attributed to some extraneous cause: though the earlier observations would not agree so well with a rapid change of this element. Before it had been shown by these computations that the various returns of the comet could not be reconciled to each other without some such hypothesis, Dr. Olbers had already pvinted out the pro- bability of a similar alteration in a letter to Mr. von Lindenau. He wrote again to me on the subject in these words: ‘ ‘The ex- emption of the dense and solid bodies of the planets from any sen- sible effects of resistance, in the interplanetary spaces, proves nothing with respect to comets, which occupying, perhaps, a volume 1000 times as great, may have masses 1000 times as small: and with respect to this comet of ‘ Pons,’ such a resistance Astronomical and Nautical Collections. 99 seems to be almost demonstrable @ priori: for it moves, during a considerable portion of its period, in that part of the open space of the system, in which the visible substance of the zodiacal light, or solar atmosphere, is found. It is this same comet, through the middle of which Herschel, on the 9th Nov. 1795, saw a small double star of the twelfth or thirteenth magnitude, with very little diminution of its brightness. This fact seems to demonstrate that the density of the comet bears some finite proportion to that of the zodiacal light, and that the substance causing this light may afford some sensible resistance to the motion of the comet. If then all the rest of the space surrounding us were to be considered as per- fectly void and free from resistance, which I do not believe, still the substance of the zodiacal light, which does certainly exist, is sufficient to explain the phenomena of a diminution of the periodi- cal time, and of the eccentricity of the orbit.” Dr. Olbers further remarks that this ethereal medium may na- turally be supposed to revolve with the planets from west to east, so as to exhibit little or no influence on their motions, while those of the comets, being more discordant, may suffer a very material disturbance from its resistance. [Upon a probable supposition respecting the law of the density of the resisting medium, Professor Encke proceeds to calculate the places of the comet for 1795, 1805, and 1819, in such a manner as to reduce the sum of the errors to less than half their amount upon the most advantageous suppositions respecting the planetary per- turbations. For 1822 the improvement does not appear to be so considerable. ] The times of the successive passages through the perihelium, as affected by the perturbation, are assigned in this table, and those, which have been observed, are distinguished by an asterisc. *1786 Jan. 30.1 Parisian M.'T. *1805 Noy. 21.5 1789 May 18.7 1809 March 11.9 1792 Sept. 4.1 1812 June 26.3 *1795 Dec. 21.4 1815 Oct. 12.7 1799 April 11.1 *1819 Jan. 27.3 1802 Aug. 1.9 *1822 May 24.0 100 Astronomical and Nautical Collections. The comet of 1766, which has been suspected to be the same, is recorded to have been very bright to the naked eye, and its motion was retrograde. iii. Comparison of the Nuw Tasirs of Refraction with Observation. Rerractions observed by Mx. GroomBrince. (Coll. XTIT.i.) M.Corr. Red. to Ivory Obs. App. Alt. Fahr. forl® Refr. B.30 469.5 N. A. Error. 509. Error” 16 218 49.6 49.2 $.5 2223.3 99 39.7 22 16.2 —16.5 22 10.2 —10.8 25 @& 30. 9,5,.38.1 3.3. .91,38.0,.91 10.2 2), 6.1 — 4.1.20 58.7 = 7.2 17 2 0 8.1 52.9 2.7 1811.1 18 28.3 18 28.5 +0.2 1819.0 — 0.4 [44] 217 35.2 31.9 9.4 17 38.9 17 4.0 1710.7 + 6.7 17 1.5 F 2.6 13 2 3053.4 56.7 2.3 1551.6 1615.0 1618.6 + 3.6 16 8.5 — 2.3 9 241 2.2 56.3 2.1 15 18.3 15 38.8 15 39.3 + 0.5 15 29.9 — 5.1 5 2.51 34.5 28.7 2.1 15 32.7 1455.3 15 2.6 + 7.3 14 53.3 414.2 12 $ 229.9 38.9 2.0 ..14 44.7 14 99.5 14 27.0 —-2.5 1418.0 + 2.7 10 $6 50;9 54.8 2.0. 19 58:5 14.10... 14.19.98 070) 14) beater 1). 8 $3 53°87c5, 89.8 1.6. 1217.4. 12 6.7-,12 6.2 — 0.512 Ove 7. 2,6 10 “47 “ova "s90°8" 1.56 12+ 1.6 11°40.2- 11 36-2 — 4.0- Itol.9 —t 3.5 15 449 8.7 °38.6 1.33 10 21.7 1011.2 1016.4 + 5.2 1011.8 + 3.8 12 455 27.2 43.5 1.30 10100 10 5.4 10 5.2 —0.2 10 1.04 1.1 16 455 55.7 38:8 1680 10 19.8 109%2.1..10..4,4.>.2.28 On Osim, 5. 1 +56.8 + 62.6 + 1.2 +25.4 7 5 917.7 58.2 1.25 999.8 944.4 943.0+1.4 9 39.2 #06 11 5 2758.5 ‘33.8 1.20 928.5 913.8 913.8 +0.5 911.7 + 2.1 13 5 44 33.2 53.8 1.13 841.4 849.7 853.04 3.3 849.3+0.3 13 5 4755.9 33.6 1.12 857.5 843.1 847.6 + 4.5 8 44.8 + 1.1 29 613 12.7 38.5 1.05 820.8 812.4 8162+ 3.8 814.1 +1.8 23 6 30 26.4 58.3 .98 746.4 1757.5 757.1— 0.4 7551+ 1.7 7 YG 85.0887 <9 67 g1s4 (7 19.8!) 7 20.5. Oly © Woeeeseol 7 94 792 13.6 61.8 .88 658.0 711.5 7 60—5.5 7 5.2 + 2.3 13 8 20 21.3 39.9 .82 636.5 622.9 620.8—2.1 619.9 + 2.0 Int. Int. 50° Br.22 7 $13 66.0 .89 6542 7 84 7 96+1.2 7 8.8 P.156 1343 0 45.0 .47 $57.0 354.6 354.6 0.0 3 54.9 The mean refractions of the Nautical Almanac are here com- pared with the observations as reduced to the standard tempera- ture of 46.°5 for the exterior thermometer, by taking a mean of the English and French corrections, for the reasons explained in the Astronomical and Nautical Collections. 101 thirteenth number of these collections. Mr. Ivory not having pre- cisely assigned the temperature at which his tables may be sup- posed to represent the results of the exterior thermometer, the errors of the New Tables have been copied from his own comparison of these tables with Mr. Groombridge’s observations, and it is obvious that the New Tables, thus compared with the phenomena, do not at least possess any advantage over those of the Nautical Al- manac ; though they can scarcely be said to be decidedly inferior, with regard to the lower altitudes: but at 45° it appears to be highly improbable that the refraction, at the temperature of 50°, or even of 48°, can be so much as 57.36. . Professor Brssxx has given us, in the Berlin Almanac for 1826, the results of his latest observations on the refractions near the horizon, which show, very satisfactorily, what was. perfectly well known before, that his table is founded upon an inadequate theory, and that it is of no particular use where any correct theory at all is wanted. The comparative results of the different determinations may be exhibited in a short table. Comparative Results, Barometer 30. N.A. N. A. Alt. apn ai 5z° Int. Ivory Dift- Bessel F, A. tet Corr. oO / / “a , uw J Mu 7 ‘ “ v “ uN 0 0 3351 33 34.8 34 17.5 +42.7 36 36.1 36 0 —36 0 30 28 37 28 24.8 28 40.8 +16.0 29 51.4 29 27.3 —24.06 1 0 2425 2415.6 2421.8 +6.2 24 58.2 24 44.6 —13.60 1-30-21 7 20 59:2 20 59:6 +0.4 21 18.3 21° 7.9 —10.35 2 0 1829 18 22.6 1819.6 —-3.0 18 28.8 18 23.3 -— 5.46 230 1621 1615.6 16 10.89 —4.7 1615.1 1613.9 — 1.19 8 0 14 35 14 80.4 14 26.04 —4.4 14 27.5 14 26.1. — 1:42 830 18 7 18 3.0 12 59.51 —-3.5 1259.5 12 58.7 — 0.77 4 0 11 52 11 48.6 11 47.15 —1.1 1146.4 11 48.4 + 1.97 430 10 50 1046.9 10 46.03 —0.9 10 44.9 10 48.2 + 3.30 5 0 958 955.2 9 583.84 —1.4 952.5 9 52.4 + 0.05 6 0 8 82 829.7 8 29.80 +0.1 8 28.5 Berl. Astr. Jahrb. 7.0. 227 7.25.0, .7 25.40 +0.4. |7 24.2 1826. 8 0 635 683.3 6 34,68 +0.4. 6 33.6 9 0 554 5.52.5. 5 58.79 +1.8 . 5 52.8 10 0 520 518.6 520.19 +1.6 519.4 15 0 8 34.8 8 93.4. 384.70 +1.3 8 84.3 102 Astronomical and Nautical Collections. N. A. Nw A. Alt. es fe 52° Inte Ivory Diff. Bessel F. A. oO 0 238.72 381 239,16 $1.2 ‘2 28.9 anh 9 4.29 5.1 2 4.65 +1.0. 2° 4,4 30 0 1 40.5 1 40.1 1 40.85 +0.7 1 40.7 35 0 23.0) 1) 225% 1 23.25 +0.5 123.1 40 0 1, [9.841 $9.0 1 9.52 +0.5 1 9.4 45 0 58.1 57.9 58.36 +0.5 58.27 50 0 48 8 48.6 48.99 +0.4 48.91 60 0 $3.6 33.0 33.72 +0.2 33.67 70 O SN ty lie 3 Ness 21.26 +0.16 21.23 80 0 10.2 10.2 10.30 +0.10 10.29 The results of the Nautical Almanac are reduced to 52°, im order to compare them the more readily with those of Mr. Ivory. For the mean probable error of a single observation, Professor Bessel and Mr. Rosenberger have found at Alt. Error Alt. Error Alt. Error oO r a“ °o V/ , a“ 630 26.0 230 53 £30. 2.0 prego spg7eod3g)%6 23, oP syg me, 214.7 130. 10.6.....3.30..sid@ Gadelpathondiian 2 0 Py ea ae oa ae Boe Ge And the probable ultimate errors of their determination of the mean refraction, at 1° and 2°, are found to be 2”.5 and 1” re- spectively. : With respect to the refractions below the horizon to which the table of Bessel extends, it will always be amply sufficient to take the mean horizontal refraction, and to increase it by its excess above the refraction computed for an altitude equal to the de- pression, and for the actual state of the atmosphere; except that if the temperature at the surface of the sea were known to be ele~ vated or depressed, it would be proper to correct the mean hori- zontal refraction accordingly. The whole of this comparison has been instituted in order to ascertain the propriety of retaining or suppressing the remark sub- joined to the table in the Nautical Almanac, that it ‘‘ appears to agree more perfectly with the latest observations than any other table that has been published,” explained as it is by the admission in the preface, that the “ deviation from the French tables in the Astronomical and Nautical Collections. 103 mean value of the refraction,” is altogether inconsiderable. If the new table had been decidedly shown to exhibit results more ex- actly conformable with the actual determinations of astronomers than those of the Nautical Almanac, it would have become the duty of the editor to adopt them; but for the present there can be no question that such a change would at least be premature. iv. Note on Rurraction, addressed to Professor SCHUMACHER. My dear Sir, I was much surprised the other day to observe, that in copying the explanation of my Table of Refractions from the Nautical Al- manac, you had omitted, without assigning any reason, the words “¢ which would be more consistent with the theory;” an expression which I had employed in speaking of the use of the external ther- mometer, in preference to the interior. I am the more disposed to remonstrate with you on this occa- sion, because I observe that a great number of astronomers, and among them some who do not usually act without reflection, have inconsiderately taken it for granted that the correction ought to be made according to the height of the interior thermometer, as nearest to the place of observation. Now, with regard to the theory, it is perfectly obvious, that the computation extends only to such changes of density as take place between the different strata of the atmosphere considered as hori- zontal; and that its results must necessarily terminate where this regular constitution of the atmosphere ends; that is, owtside the observatory, or other building, containing the instruments; while the change of density between the external and internal air, taking place in general at surfaces more nearly vertical than horizontal, at least when the object is but little elevated, and certainly never at horizontal surfaces, will either have no effect at all in increasing the refraction, or as great an effect at higher as at lower altitudes; so that this little irregular addition or diminution can never require to be considered as a part proportional to the whole original mean refraction. With regard to practice and observation, I need only refer to 104 Astronomical and Nautical Collections. Mr. Delambre’s remarks in the Connazssance des Tems, for 1819, where he shows that for Mr. Groombridge’s observations, the mean error of the exterior thermometer is only five sixths as great as that of the interior. Rishi v. General Results of Observations on the Dipping Needle. By W. Scorzssy, Jun. Esq. 1223 «Time Place Mean dip, Mar. 29 Liverpool 71°33' 0” June 10 La.71°31' 14” N. Lo, 12° 7'15" W. 78 36 July 5 71 38 0 17 37 0 79 07 or 79 67 (M.) The mean dip is the mean result of observations with and with- out a sphere on the needle: the last result, (M.) is obtained by the formula of Professor Mayer. vi. Elements of the Comer of 1823-4. By various Computers. 1. The first received by the Editor were from Mr. J. Taylor of the Royal Observatory, Greenwich.. 2. The second are by Pro- fessor Nicolai Schumacher, Astr. N.N. 48. B. 3; giving the greatest error in A. R. + 18”,indecl.+ 11”. 3. The third by Mr. Hansen, A. N. 48, B.3. 4. The fourth by Carlini. 5. The fifth by Dr. Brinkley. 6. The sixth by Mr. Richardson, of Greenwich. a 1823 Dec. 9.36974 Greenwich 9.4380 Manheim 7 spe 9.47193 Altona Passage of Perihelium ( 4° 9.4792 Greenwich 5. 9.2168 Greenwich 6. 9.4521 Greenwich 1. 302° 56’ 34’ 4, 303° Ae Longitude of 9 4 2. 303 1 18 5. 303 0 40 Sey OVSarx 47122 6.-..803,, -1p¢48 so» 28)48,, 64 4, 1. 284/26 43°8 — Periheliumy 2. 23 43 45 6. 29. 18 BO 3. 387 99! 56 6. 28 20 6 if 1. 9.38598242 4, 9,.3545000 Log. nearest distance, 2. 9.3579600 5. 9.3689400 | 3. 9.3553934 6. 9.3536855 Le: 75° 6545" 4.28 96° \A2lin SOY Inclination. .., 2. 76 9 40 5. %6 cl AGs | ae, 20. MA 22 Gs AGES ae Motion retrograde, 105 Arr. XII. ANALYLIS OF SCIENTIFIC BOOKS. Sur les Ichthyolites ou Poissons fossiles, Par Monsieur Blainville. Article extrait du Nouveau Dictionaire d'Histoire Naturelle. Vol. 28. Paris, 1822. Tur reputation and the success of Cuvier in that department of Natural History which respects the animals of a former state of the globe, and his comparative omission of that branch of these researches which relates to fishes, seem to have stimulated the author now before us to the present undertaking. The ambition is laudable, but we fear that we cannot say the same of the execution. Though this is far from being the first work which has pretended to treat of fossil fishes, it is the first which has been exhibited as a complete system of the present state of knowledge on that subject. That it is both faulty and imperfect, is sufficiently obvious ; and we are much inclined to think, that if Cuvier had considered the subject as capable of being undertaken to any purpose, he would not have left it to his ambitious imitator, We fear we must say that this is an instance, among many now too common, of that desire to shine or glitter in a new science, which is the disease of the day, and which has rendered geology the victim as it is the butt of every tyro, who, incapable of dealing with the accurate sciences, hopes to acquire some notice by evacuating on the unlucky public, the records of observations and speculations which, like their authors, have scarcely cracked the shell, and are desirous of flying before they have learned to walk. - There are reasons however for our faith in all cases ; and we owe Monsieur Blainville the politeness of shewing what his claims to authority on this question are. ‘The work must rather be considered a compilation from the writings and observations of others, than an original production ; and therefore the authorities are rather those of Scheuchzer, Haller, Volta, Faujas de St. Fond, Lametherie, Lamanon, Cuvier, and others, than those of the writer himself. Thus far, different measures of confidence will be allotted to them: confidence regulated, partly by the weight of the several persons quoted, and partly by the state of know ledge of the periods at which they severally wrote. Besides, and in aid "at this, Monsieur Blainville has had access to the collections in the Museum of Paris, and thus has had the power of comparing, in many cases, the printed descriptions with the specimens. ~ But somewhat more than all this is required for a just or luminous compilation on such a subject ; H and here, our author, we are sorry to say, is entirely deficient. It is one thing, even admitting that could be done in the present case, to ascertain the comparative anatomy of 106 Analysis of Scientific Books. the animals in question, and another to assign them truly to their geological situations. It is not sufficient that every fragment of bone, whether of land animals or of fishes, should be referred to an indi- vidual species or genus; but it is most essential that the true geologi- cal situations in which they occur, should be accurately understood and accurately described. We do not want to know merely what animals have existed, but when, where, and how they lived. .Doubt- less, it is important to know that many animals lived at all in a former state of the world, which are living in it no longer ; it is im- portant to know what these were, and how many ; what species and genera have disappeared. ‘This is a question however, which, ab- stractedly taken, concerns zoology only. The geologist is anxious for much more. He desires to know at what period of the globe they were in existence, in what lands or waters they lived, when they were buried and preserved, and how. And he desires to know all this, because he makes use of it as evidence respecting the history of the globe and its revolutions. Hence, he ascertains, or at least addu~ ces collateral evidence towards ascertaining, the nature, and order, and places, and comparative times of its revolutions; and thus he acquires knowledge which, judiciously combined with the history of the mere rocks themselves and their various phenomena, enable him to make nearer approximations to a true theory of the earth. It is indispensable therefore that the comparative anatomist should in this case be a practical, expert, judicious, and experienced geolo- gist. He should be as replete with sound logic as he is free of system; should be as accurate an observer of geological facts as well stored with observations ; and should be able, from his general know- . ledge, to exercise a critical and sound judgment on the reports and observations in zoology as in natural history, of those from whom he is compelled to borrow what he has not possessed the means of ascer= taining from personal observation. We wish we could say that Cuvier, much as we respect his sound- ness of mind and minute knowledge in comparative anatomy, were able equally to stand this test in geology. We wish we could say this in a far minor degree of Monsieur Blainville ; but he is no geologist. Judging from his book, we are entitled to say that he has as little knowledge of this important part of his duty as is well possible. He is no observer, and he cannot be a critic. Hence every thing from which the geologist ought to have derived assistance, all that he would have turned to for light, only leaves him in darkness, the same or worse than before. Monsieur Blainville copies, without discrimination, from the descrip- tion of those who wrote before geology had been rescued from its ancient state of night and chaos; and, unable or unwilling to verify or rectify the observations of his remote predecessors, leaves every thing where he found it, or rather, adds to the confusion which per- vades their remarks. M. Blainville on Ichthyolites. 107 Such a work could not have been executed as it ought to have been, either in Paris or in the Paris Museum. It ought not to have been attempted, but by him at least, whose experience in geology rendered him competent, from other knowledge, acquired in other places, to verify the probable truth or detect the fallacy or imperfec= tion of the reports of places which he was unable to visit. That the attempt has consequently failed in its most essential part, is but too plain. We wish that, what we have said, (and we might say much more did our limits permit,) would impress, not only on our neighbours but on the geologists of our own country, the necessity of keeping a steady regard, in their investigations, on the ultimate purposes to which these ought to tend or be directed. Geology itself, the history of the globe of the earth, is a difficult, severe, abstruse and laborious study. It requires much personal labour, much time, much acute- ness, some reading, much freedom from system and prejudice, and an earnest desire for truth; with a cautious, rigid, severe, logic, and trained habits of a close and strict reasoning, which partakes often as much of moral and metaphysical, as of mathematical thinking and induction. It is not the collecting of specimens, or the forming of sections in the closet, and of coloured maps from the imagination, or from much conjecture and little observation, which constitute geolo- gy; and, this abstracted, there is little in it to satisfy the craving desire for ease and amusement united, and for some poor temporary fame to be acquired by papers in transactions and systems of Scot- land or Siberia, on which the dilettantes in science live. Hence the labour is shunned; and the study evaporates in the far easier task of collecting bones and shells, in marvelling at the crocodile and rhino- ceros which occupy the place since held by the two kings of Brent- ford, or at the kyena who proves the hardness of his jaws upon the bones of Yorkshire rats, and at the nature of A/bum Grecum. But we must reserve our general criticisms on the present state of this science for a fairer opportunity, and return to Monsieur Blainville. We have said that he was no geologist, and that he was incompe- tent to his subject, because deficient in that most essential part of it. But we have a serious objection also to make, to the other department of his work ; to the rigidly zoological or anatomical part of it. All the world has marvelled, and with some reason, at the ingenuity with which Cuvicr has contrived to erect new genera and species, and to produce entire animais which were never yet seen, and never will be, from fragments of rotten bones; constructing a Megzetherium from a maxilla, and a Hyena from an os hyoides, With this we have nothing at present to do; satisfied with the ingenuity of the Zadig of the day, and, as far as authority can avail, quite as willing to allow him the dictatorship in this matter as any other person. There is always a latent delight in surrendering ourselves to the marvellous, But even to this delight there are bounds ; and when these are ex- ceeded, we are aptto feel a twinge of the “ incredulus odi.”” Unquese 108 Analysis of Scientific Books. tionably, the skeleton of a fish may be good evidence for the fish itself, as far as we may be satisfied without regaling on it, or are contented with guessing how it might have looked in a drawing, or skinned, varnished, and stuffed with plaster of Paris. This mode of assigning a species or a genus, will be still more satisfactory, when the naturalist has had the means of comparing the preserved skeletons of former days with those of existing species and genera to a sufhi- cient extent. But who need be told that there is such a simplicity and general uniformity in the skeletons of fishes, that the limits to this mode of investigation are very narrow indeed. They have no legs nor arms, no scapulee nor knee-pans, no os coccygis nor ster- .mim, nor phalanges, nor any of those multitudinous and ever varied parts from which the comparative anatomist derives so much facility in his researches on quadrupeds. There is something in the number of the spinal bones, there is something in their forms and propor- tions; and there is still more in the bones of the fins and in those of the skull. But all this is little; and while but little evidence can be derived from fragments, we are particularly determined to distrust Monsieur Blainville on points which neither he nor any one else could have ascertained, namely, the erection of new genera and new species from the contemplation of fragments, and these fragments often distorted by the effects of pressure and the other causes of change and injury to which fossil bones are exposed. When we said that Monsieur Blainville was ignorant of geology, we might also have said that he does not seem to have formed any conception of its nature and meaning, and of the relations of his own subject to it; considering this, as we do, rather a branch of zoology than of geology properly so called. He speaks as if the strata were only casual substances which might or might not be studied, but as being “* often useful.” We would gladly know how they are not always necessary instead of being often useful, at least in our view of the subject. If the object is merely to ascertain lost animals, they are neither necessary nor useful ; whence it is plain that when M. Blainville speaks thus, he is thinking of geology, not of his fishes, and thinking too, to little purpose. When he asserts that the nature of the organic remains offer the most ‘* unequivocal methods of establishing geology on indisput- able bases,” he is only saying what others have said before him, but which is not a bit the more true because it has been often said. In the first place, we will admit this, and then ask to what extent the science of geology can be based on the knowledge of organic re= mains? In many countries they do not exist; in many rocks they never occurred. ‘They are limited to a small portion of the geogra- phical globe, and they are confined to a small depth of the geological one. What would become of the theory and history of the primary rocks, of the trap rocks, of the volcanic rocks, if their history and theory depended on their organic remains? The organic remains M, Blainville on Ichthyolites. 109. are connected mainly with. the last revolutions of the globe ;—uni- versally with the later ones, And yet among these later, we must except the latest of all, which are the whole of the two classes of rocks produced by fire, the traps and the volcanic rocks. As to all the rocks which precede coal, with little exception, we should never obtain any knowledge of their theory, did we depend on the evidence to be derived from organized bodies. That they prove many things, is unquestionable; but it would be a defective system of geology indeed, and we might well despair of attaining any knowledge of that science, if we had no more knowledge and no wider views than Monsieur Blainville, and, (we might add,) many more, seem to possess on this question, We are equally ready to deny, and to prove it, had we room, that even the order of the succession and the true theory of those very strata in which organic remains exist, can be proved by means of them. This has been a favourite theory to the present day, and it has a large body of abettors still. But we could prove, by their own evidence and shewing, that it is unfounded; by quoting their own catalogues of the strata and their included shells, and by shewing. that the same genera, and the same species in many cases, occur through all the series, in positions the most remote. We could even prove it @ priori from zoological considerations. Were the assertion true in geology, or in organic mineralogy, (to use a better phrase,) then it would have been a necessary preliminary that. all climates should have produced, at different remote times, similar families of animals; that all these should have followed each other in a certain unvarying order, and that the same order and kinds should have existed and succeeded every where in one manner. It would have been impossible that there should now have been, had the same laws prevailed formerly as now, oysters at Milton, and muscles at Hastings, and cockles at Margate, and periwinkles at Dover, But we have not time for what well deserves a separate discussion ; and having thus far disputed Monsieur Blainville’s preliminaries, shall proceed to make a few remarks and extracts from a book which we might have ¢asily disputed at every page. As we cannot afford to quote a great deal, we must try to be con~ tent with a few passages, and shall take the following in the first instance. We insinuated this author’s want of logic; and surely it was an unjust insinuation, since the arrangement would do justice even to Jeremy Bentham. There is a Tudesqueness in it which is quite delightful, and which bespeaks the genius of a German pro- fessor crazed with the logic of Kant and Burgersdyck, and the reading of the schools, rather than the cestrus of a lively Parisian skipping through the dry bones of the Musée. If it is along passage, we can only say in its defence, as Horace Walpole did after Gray, and of other passages, that it ** leads to nothing.” 110 Analysis of Scientific Books. ** Sous le rapport de la composition chimique ou anatomique,” (he is speaking of organic fossils.) J’ai divisé les corps organises fossiles ; A. en ceux qui n’ont éprouvé aucun changement dans leur tissu, dans leurs compositions chimique et mineralogique; B. en ceux qui ont perdu seulement et entierément la matiére animale; C. ceux qui ont la méme composition chimique moins la matiére animale, mais qui ont perdu de plus leur structure et leur forme; D. ceux qui n’ont perdu que la partie organique, mais dont la por- tion inorganique a pris une disposition toute différente de la Spathifica= tion E. qui ont éprouvé des changements dans la tissu anatomique et dans la composition chimique, méme dans I‘acide du sel terreux qui les fermait ; F. ceux qui n’ayant rien perdu dans la structure organique. ont été entiérement changés dans la composition chimique; de la Petrification: G, fossiles qui sans avoir éprouvé de modifica- tions ont été imprégnés d’une substance metallique ; de U' Impregna- tion ; H. des corps incrustés ; I. des corps succinisés,” This reminds us of a modern Act of Parliament: a trap set to catch all the modifications of possibility, and somewhat more; but which is still so ill-constructed, that lawyers, rats, and criminals con- trive to escape it. A German engrafted on a Parisian, forms a heteroclite-enough animal; somewhat, we should conceive, like Monsieur Blaiiville’s own paleobalistums and paleorynchuses. But such is the conse- quence of going to school at Freyberg. We thought that the Pope had been dead, for, like his namesake in John Bunyan, his nails had been pared some time ago; but it seems that his ghost still walks. The earth, says our author, is divided and subdivided. This is highly instructive ; and firstly of the second, which are the organi- ferous strata, and of which the subdivisions are thus stated. We would have translated this logical and luminous passage for the benefit of our English readers but we want words. The divisions in French therefore are, ‘‘ lre. ‘Terrains zootiques les plus antiques, trés antiques et antiques: 2me. Terrains les plus ancicns, trés anciens, et anciens: 3me. Terrains modernes, comme d’alluvion, des tourbiéres : and lastly, 4. Terrains recens ou terrains meubles et couches super- ficielles.”” We have condensed the quotations, and hope they are the more intelligible. As to the first or the grand division, it is zootique and azootique. It is a fine thing to understand Greek and Logic; and the author’s positive, comparative and superlative, antic and ancient strata, remind us of the ‘‘ heavy not particularly light,” and the * intermediate between hard and semi-hard inclining to the soft,” with the “ scopiformly divergently radiated,” and so forth, which argue the metaphysical aud delicate profundity in language and thinking, which distinguishes another of the luminaries of this science. But we have said enough of this author’s general views, and must give a few specimens of his details. Of these, after the geological M. Blainville on Ichthyolttes. 111 confusion which we have already sufficiently noticed, the leading character is the ambitious desire of creating new species and genera ; apparently, with the design of rivaling Cuvier in his own peculiar walk, and for the sake of displaying his profound knowledge of Greek. As this language constitutes rather a novel science in France, we must excuse Monsieur Blainville for his wish to prove that he is actually the possessor of a Greek Lexicon. Whether the strata of Glaris are to be considered as most antique or very antique, or antique, or whether they are most ancient or very ancient, or ancient, to which of these two sets, in short, of positive, comparative, and superlative entities they belong, Monsieur Blainville has not told us, and we cannot guess, But we must try if we can Conjecture to what rank they belong in the vulgar language. We sincerely wish that geologists would use the same words as other people, to express such ideas as they happen to possess, If matters proceed much further in this way, what with German nomenclatures and French nomenclatures, books on geology will become as intelli- gible as the treatises for digesting sol with luna under the red dragon per ‘‘ pemset remsen ame muc senvu saltrafi,” Scheuchzer, as well as Ebel and many others, have examined this place, and many collections have been formed fromit. It is situated to the south-east of Glaris, in a small valley, at a distance of about five miles, in « part of the mountains called the Plattenberg. The including rock is a blackish fissile schist, containing some mica, and interstratified with thin lamin of limestone. It is, as he says, the Grauwacké schiefer of the Germans, and, what is worse, the Phyllade pailletée of Brongniart, as if one hard name was not enough. The specimens here are very imperfect, being only the impressions of the fragments of skeletons; one side of which has formed a sort of bas- relief in the schist, while the other is very ill-defined. _ Now Haller, a name not to be spoken of lightly, even by Monsieur Blainville, mentions the impressions of ferns as being found in the same places; but this he thinks improbable, because Brongniart found none in the collections which he examined, and chooses to call it a transition rock. Here the question of the geological nature of this deposit becomes inost important. Our author, making up his mind that it is a marine formation, determines that all his specimens are sea-fishes, We have abundance of respect for Brongniart, but have also good reasons for not giving implicit credence to his geolo- gical opinions. Cuvier thinks it is marine, because it contains the remains of a tortoise, and because that tortoise must have ‘been a marine one. We should be very glad to know whence this necessity arises: there was formerly the same compulsion on all the Lacerte, the crocodiles, to helong to fresh-water ; but, unluckily, Lieutenant Kotzebue finds that there are sea crocodiles in the Pellew islands. Here then we have a contest of evidence: the ferns which Haller saw, against the tortoise that must have lived in the sea; and, further, 112 Analysis of Scientific Books. the opinion of Andrza, who says that it is a fresh-water formation, against that of Brongniart. We do not intend to decide between dis- agreeing doctors, but it is a justice to our readers, if they are readers also of Monsicur Blainville’s Ichthyolithology, to dissect these para= graphs for their use. Eight species of fish are described as being found here. Of two of these, Monsieur Blainville makes new genera, by the names of Anenchelum and Palzeorhynchum ; the others are supposed to belong to Clupea and Zeus. The first of these was formerly imagined to be aneel; and although that opinion was probably wrong, we cannot see, how, from the miserable evidence which the fragments are ad- mitted to afford, itis possible to make a new genus for it. But this naturalist finds less difficulty in constructing a genus out of a fin or a tail, than Linnzeus did with the whole living races before him : according to the well-known adage, ‘‘ Qui ad pauca respiciunt de facili judicant.” Here is the way, for example, in which Paleeorhyn- chum (old Snout, for the benefit of the unlearned) is made. “ Quoique cet Ichthyolite, dont nous n’avons vu que la figure de la partie anterieure, dans l’Herbarium diluvianum tab. 9, fig. 6, nous soit trop insuffisament connu pour appuyer notre opinion, il ne nous paroit nullement probable que ce soit notre aiguille ; (sox bellone,) ainsi donc, jusqu’ 4 des circonstances plus favorables, nous propo- serons de la designer provisoirement sous le nom de Palzorhynque de Glaris.””’ We shall really be glad to know how such trifling as this can conduce to the study of ichthyology, or geology, or any other Ology in the whole circle of the sciences, Scheuchzer takes another of these fishes for a bleak ; not an un= likely conclusion, if this same deposit contains ferns; but our author chooses to make it a new clupea. A fourth was esteemed a pike, and this also he makes a clupea; which judgment being deduced, not from a specimen, but from a figure by Knorr, it is very satisfac-~ tory to be informed that it is uncertain whether that appertains to the rock of Glaris or not. On such principles as this, we are likely soon to abound in Ichthyolitologists and Ichthyolitologies. There is a third clupea, with a new title also; all of which is matter of course, since it was predetermined that this was a marine formation. Next comes the genus Zeus, of which he finds three new species. To show how satisfactorily these points are settled, in the first place, the first species is determined to belong to Glaris, not because it was- found there, but because it lies ina similar slate: as if similar rocks of all kinds were not found all over the world. This may very well be a marine fish, if he pleases ; but how does it follow that it has any thing to do with Glaris, or that it proves this to be a marine deposit ? As to its own characters, it has ‘* des rapports avec le Zeus, ou genres voisins ; mais c’est ce qu’on ne peut assurer, parce que la téte toute entiere manque.” Then “ toujours est il constant que c’est un poisson marin.” Very possible. And so for the others. M. Blainville on Ichthyolites, 113 The fossil fish of what is called the metalliferous slate, are well known to be abundant, in numbers at least, if not in kinds; and they occur in many different places. The most noted of these are the Palatinate, the Voigt, and Thuringia; and they have often been de- scribed by different authors, such as Kruger, Friesleben, and others. It is somewhat remarkable with respect to these specimens, that they are almost always much distorted and injured ; not even being com= pressed and preserved laterally, as is the most usual case in the fossil fishes, It is equally so, and important at the same time in investi- gating the species, that the impressions are those of the skin and sub- stance of the animal, not of the skeletons. With respect to the nature of this deposit, we have no objection to be convinced that it is a marine one, if it appears that any one of the fish is marine, or that any one sea-shell is contained in it. It may very probably be so, although no such evidence is produced. But if we are willing to believe quietly and without any evidence at all, we do not choose to be obliged to believe by that which is not evidence ; and this, not on account of any concern we feel about the bitumino- metalliferous schist of Mansfeld, but because of the very testimony itself. We have a mortal aversion to corrupt evidence in all its modes, and do not choose to pass any attempts to introduce any more. of it into geology, where there is already an abundance. These strata are determined to be marine because they lie beneath calcareous rocks containing ‘‘ ancient” (or modern) marine shells, such as belemnites, entrochites, and ammonites, of the same kind as those that belong to the limestones of the Apennines and Alps, toge= ther with gypsum accompanied by sea-salt, gypsum without sea-salt, sandstone, and so forth. Now these strata are the exact counterparts of the red marl and lime of England; particularly where they are somewhat intermixed. We have no objection, either to their marine origin, or to their antiquity, if that will give Monsieur Blainville any satisfaction ; but neither of these will prove that the strata below them are of marine origin also. Our own coal strata are situated in this very position; and no one now, it is hoped, since the theories of Dr. Hutton and of Kirwan on this subject are forgotten, will imagine that a series which contains terrestrial vegetables in abundance, and which never was known fairly to include a seashell, is of marine origin. ‘Thus much for what is possible respecting this deposit of ichthyolites. Monsieur Blainville has made twelve species and three new genera out of this collection. The new are palzoniscum, paleothrissum and stromatcus : the old ones clupea and esox. In general we may remark on these determinations, that they are more free from objec tions than some of the preceding ; as the author had access, in many instances at least, to more perfect specimens. How far, however, his arrangements are justified, we cannot pretend to decide. We may Vou. XVII. 114 Analysis of Seientifie Books. nevertheless remark, that he has here attempted to give generic characters, which, in some other cases, he has oddly enough seemed to have thought unnecessary. Surely if a genus or a name is to be erected for an ichthyolite, or any other kind of lite, the purpose is, if there be any purpose at all, to allow others to refer to it, and to arrange their discoveries under the appropriate division. If this is not to be, if there is only to be a paleeo—something, without characters, we do not see what natural history, ichthyology, or geology is to profit by such a coinage of crabbed words; while we do see that, on the same principle, we may shortly have as many genera as there are specimens; a proceeding likely to be attended with no con- venience that we know of to compensate for the vexation of such a catalogue, except that of inducing gentlemen to turn the leaves of the long-forgotten Lexicon ; that unlucky book, thumbed in the Anglo Greek division by every projector who wants to dazzle our under- standings with a Diatalaiporou, a Therapolegia, an Anthropomono- troche, « or an Apolepsia alexicacon. Of these new genera we shall give the characters of that in which our author has been most successful and appears most justified, asa compensation for some of the others which we have noticed. “« Paleothrissum.” “ Ila pour caractere essentiel: d’etre abdominal, malacopterygien, de n’avoir qu’une scule nageoire superieure située devant \’anale, entre les pelviennes et elle, et surtout d’avoir la queue bifurquée, et le lobe supéricur ordinairement beaucoup plus long que Yinferiecur, et couvert d’ecailles dans toute sa moitié supérieure.” There are four species of this: but Kruger thinks that one of them is a pike; it is doubtful if two of the others are not the same, though each one has its own name; and, what is worse, the geological rela- ‘tions of the rock in which these are found is doubtful. That one which follows is called stromateus ; but, as is most usual, has no generic characters assigned. How species are to be established before a genus is determined, rather surpasses our comprehension ; nevertheless there are three, with the names major, gibbosus, and hexagonus, (surely the love of arrangement is a terrible disease,) and two more without names, the genera of which, are, however, left in doubt, We shall extract a few words from these descriptions that naturalists may see what marks they may have to deal with when they take to the investigation of ichthyolites, No. 11.—On trouve encore & Eisleben une autre en d’ichthyo- lite, mais qui jamais, ou fort rarement est entiére: d’aprés la grandeur de sa téte, on suppose quelle pouvoit avoir prés de trois pieds: sa peau etoit, dit on, comme chagrinée. D’aprés cette indication, je - supposerois volontiers que les ‘oryctographes indiquent par la un poisson fossile, dont j’ai vu l’empreinte d’une partie de la peau dans Ja collection de Monsieur Brongniart. On y peut reconnoitre a ce qwil m’a semblé, une assez erande nageoire dorsale; mais ce me v M. Blainville on Ichthyolites. U6 cette peau offre de remarquable, c’est d’etre entitrement, récouverts * despéces de petites écailles, comme trifurquées a leur pointe, et qui semblent formées par deux chevrons disposes en sens inverse. Je n’essaicrai aucune conjecture sur le genre de poisson a laquelle cette peau a appartenu; mais je ferai l’observation que l’espéce d’ecusson qu’ on voit souvent a la racine des nagecires, dans les fossiles que j’ai designés sous le nom de Palzothissum, ressemble beaucoup a ces sortes d’ecailles.” We have no objection to this manner of contemplating the subject. It is proper that specimens, be they never so imperfect, should be preserved, and figured, and described ; because by the comparison of fragments at some period, a species or a genus may really be deter- mined: it is not often that our author is so moderate: and, to con- tinue, we shall give his equally prudent remarks on No, 12. ‘‘ Enfin, on cite encore, comme d’Eisieben, quelques restes, dont la peau est lisse comme celles des anguilles, Je crois avoir vu, dans la collection de Monsieur Brongniart, l’empreinte d’une portion de peau, qui a du appartenir a cette espéce. Le peu que j’en ai observe, et qui me paroit provenir des environs de |’anus, indique évidemment un poisson anguilliforme: toute la partie superieure offre des stries nom-= breuses verticales ; et l’autre moitié ou inferieure, est couverte de trés petites ecailles, fort luisantes, serrées, ovales, qu’on ne voit aisément qu’a la loupe,” 7 _ So much for the fishes of this deposit. But we must add that Leibnitz thought that he had found in it a mullet, a perch, anda bleak ; ruger also describes a pike; so that it may yet be a doubt whether these are marine or fresh water fishes; because, even if we were to grant Mons. Blainville all his new genera and species, it does not at all follow that they are marine ones. A word or two on this part of the subject will not be misplaced ; as the determinations of our mo- dern zoo-geolists on many parts of their investigations are very mainly and materially guided by certain notions which they have formed respecting the distinctive character of marine and fresh water species. Let us put the very simple case that the salmon, the sea-trout, the sturgeon, or the sterlet, were found in a fossil state, we should be very glad to know how it is to be determined whether these are marine or fresh water fishes; they are both the one and the other, — _ But we will carry the matter a little further and say, that there are no marks in the anatomy or natural characters of a fish by which its habitation can be known @ priori. It is a pure matter of experience now; and there is no experience about these ancient animals. For any thing to the contrary that we can ever hope to prove from natural characters, these ichthyolites may have been the inhabitants of fresh waters, or of the salt ocean, or of great inland lakes, such as are the lakes of Switzerland now, or such as the basin of Paris assuredly was long ago, In the same way, oe gn have attempted ta decide € ye 116 Analysis of Scientific Books. upon fossil shells, inhabitants of the sea and similar objects, the natives of fresh water. That also in matter of experience, and of that only ; and of the past, the so long past, there can be none, There is no character by which these can be recognised : it is not to be found in their tenderness, or the reverse, as once imagined. Itis not found in generic characters, because there are species in one genus, some of which are inhabitants of the sea, and some of lakes and rivers, just as much as there is a sea eel anda rivereel; a Murena anguilla and a Mureena conger. Indeed with respect to the shell fishes, Mons. Freminville has lately shown that sea and fresh water kinds all live together in the same place. But we need not pursue this point fur- ther, and shall return with Mons. Blainville to his next geolosical division, the ichthyolites of what he calls the ** Calcaire compacte.” As his method of division is geological, we think it would have been as wellif he had satisfied his readers first of the propriety of his geo- logical arrangements. ‘ Calcaire compacte” may mean a great deal. The geological characters of the former strata, were merely doubtful: those of the present cannot possibly be right. The first locality, for example, is Granmont, situated at four leagues frem Beaune in Bur- gundy ; and the rock is the “ calcaire ancienne, contenant des gryphites et des belemnites,” which is “ situé audessus du gres rouge, et que V’on croit presque aussi ancien que celui du Jura.” The next is Italy, where, without any other evidence than the colour and look of the detached stone, one is decided to belong to the Apennine lime- stone; we have no hesitation in admitting that some of them actually do so. If “ calcaire compacte” is to comprise such rocks as these, and if it is thus to be considered as one geological formation, we ought to have been furnished with more accurate geological information res- pecting them, that we might have judged of the propriety of this arrangement. If there is any object in dividing the ichthyolites accord- ing to the strata in which they are found, it is for the purpose of inquiring into the somewhat interesting question of their relative antiquity. This is what Cuvier has properly done with respect to the Paris district ; and Mons. Blainville, while he was about it, might as ‘well have imitated him in that too, had he not been solely occupied on fish bones, thinking, doubtless, ‘*in tenui labor at non tenuis gloria.” But we must inquire about the Ichthyolites themselves, There is first a new Elops, the macropterus, from Granmont, which may or may not be an Elops; and then there is another called incognitus, imbedded in a ‘pierre calcaire dure, assez com- pacte, grise, et formant une sorte de noyau dont j’ignore la loealité et le gissement.” ‘This is not a very accurate geological arrangement at any rate. The fish of Italy are left pretty nearly as they were found, but our author takes, or makes, an opportunity of cutting off Brieslak’s head with a golden hatchet. We cannot pardon Brieslak any more than M, Blainville, because he has a troublesome way of thinking for M. Blainville on Ichthyolites. 117 himself, and of professing that he does not understand the mystical language in which the French geognosts shroud their oracles :— ‘¢ Brieslak fait l’observation, qui nia été confirmée par Mons. Menard de la Groye, que on ne trouve dans cette localité qu’ une seule espece de poisson fossile, que l’on regardé 4 Naples, et méme parmi les savans, comme analogue du sparus quatracinus, appelé dans cette ville, spara- glioni. | Comme l’observateur dont je viens de parler, en homme qui sait agir dans ces sortes de recherches, a raporté 4 la fois ce fossile et Panalogue présumé, j'ai pu, grace asa complaisance, m’assurer que ce rapprochement est tout-a-fait erroné. En effet, le poisson fossile me paroit appartenir au genre Zee, ou a l'une des subdivisions qu’ y a introduites Mons. La Cépede; aussi la hauteur de son corps surpasse Ja moitié de sa longueur, tandis que, dans le sparus quatracinus, elle est environ le tiers.” So much for Breislak and his sparaglioni. The next geological formation is the chalk, which includes Brussels, Maestricht, Paris, and Perigueux. The first ichthyolite mentioned affords a good specimen of ichthyolitologistical reasoning. | M. Bur- tin begins by giving ‘‘des figures assez bonnes.’”’ —M. Blainville “ n’ en apas vu lui meme,” therefore it is, first ‘* Zeus auratus?” “ que je croirois volontiers du genre Pleuronecte, et peut etre la Barbue, ou mieux encore le poisson de St. Pierre.” John Dory after all. But then M. Burtin, who has drawn this very “‘ figure assez bonne,” sees fins, and ears, and sculls, and jaws, and teeth, and orbits, and clavicles, and scapula, and vertebree; while M. Blainville sees ‘‘ rien de tout cela dans la figure.” And then M. Burtin “ veut je ne sais trop pour= quoi,” that this isa Chtodon. But enough of the chalk formation. There is more of the same kind of useful information respecting the “ formation du Calcaire grossier, infériéur au gypse.” Cuvier seems to have been too wise to attempt it, and we shall spare our readers the sparus that may be a labrus. | _ Then succeeds an account of the fishes of Pappenheim, but we cannot afford to enter on the details in the same manner. The only remark we shall indulge ourselves in making, is, that in describing five species in the genus clupea, which seems a particular favourite with our author, he has borrowed from Knorr’s figures, instead of consulting the specimens themselves. Thus the probabilities in favour of truth are, that, in the first place, Knorr himself is correct; next, that his painter has figured impressions of fish bones so accurately, when the value of the subject was not understood, as to enable M. Blainville to determine different species of clupea, and the genus itself from them; and, lastly, that the author has no favourite system res- pecting his genera, the contrary of which is evinced in every page of his work. ‘The proof of this latter is, that all the figures which do not chance to suit the fashion of the moment, are pronounced bad; and that when they happen to suitit, they serve the purpose, with him, of demonstrating what such figures are totally incapable of proving, 118 Analysis of Scientific Books. His rage for maintaining his system at all hazards, is equally proved by another decision in this very case of Pappenheim.’ He finds a figure in Knorr, but without a locality assigned; yet he determines that it must belong to this spot, because it seems to lie in a similar stone. Weshould be glad to know how any figure can represent a stone, so as to render its locality certain, or even probable, We are sure that no figure of Knorv’s is capable of distinguishing any one stone from another, far less the slates of Pappenhcim from the’ slates of Shropshire or America. If thus M. Blainville’s geology is stndied and ascertained, we cannot have too little of it. As to the general geology of this celebrated spot, it is derived here from the description of Reuss and Humboldt; and a worse piece of geological observation and reasoning, we will venture to say, was never printed. ‘That it is a fresh water formation appears almost certain, so far from being what is represented; and that the observers have confounded and misrepresented the relative positions of the fresh water and marine strata, is equally so, though we cannot here enter into the reasons for this opinion. As to the ichthyology, it is ofa piece with the geology, which is Jess pardonable, since the author’s claims in this department are more decided. The figure is that of a sturgeon, and yet he chooses to decide that it is an unknown pike, to which he gives the name of Esox acu- tirostris. Stromateeus and Pecilia, from the same place, are deter- mined on grounds as slender. The specific name of the latter is Dubia; and if we were inclined to make a very low jest, we should say that it was applicable to three fourths of the whole collection. Mons. Blainville has entered into considerable length on the subject of the celebrated fishes of Monte Bolea, and we are glad to say that in this part of his treatise he has been of real service to the cause in hand, It is, in truth, the most valuable, and we had almost said the only valuable part of his book. With the double advantage of the splendid work, published at Verona under Volta’s direction, and of the ecol- lection itself procured, (plundered, as ‘Ttaly asserts,) from Count Gaz- zola, he has been enabled to rectify the more glaring errors of the Italian naturalists, and to give somewhat like a rational list of the specimens. Out of Volta’s forty-four genera, including a hundred and five species, he has admitted only ninety-three species, and it is quite plain that they would allow of still farther purification. This subject, however, is so extensive that we dare not enter it. We have no room for a criticism on genera and species, which in- deed could not be rendered intelligible without the figures. But we are bound to say, on the geological question, that the Italian theory which collects these fishes from all parts of the world, is purely gra- tuitous; and thus while it is geologically impossible and groundless, it is contradicted icthyologically by the specimens themselves, which are now, in part, and in former times have probably all been, natives and residents of that sea which now washes the land in which their M. Blainville on Ichthyolites. 119 remains are preserved. It would be easy to state a rational theory of this formation, and its relations to parallel phenomena in many parts of the world: but they are in a good measure superseded by the present more rational views of the history of the supramarine or ganiferous strata. We said before, that it was incumbent on an author, professing to give a general treatise on ichthyolites, or of any other branch of this .science, to make himself acquainted with the facts at least which are accessible, or to acquire such knowledge as would enable him to profit by the observations of others. The defect of our author in these respects is peculiarly sensible in what follows, where he has copied careless observations in a careless manner, and rendered the confusion more offensive and troublesome by the systematical and decided form in which he has placed it. Mount Lebanon, Cerigo, Antibes, and many other localities are discussed in this slovenly man~= ner, from Faujas de St. Fond, and others; and where we ought to have certainty we have only useless guessing. We consider that an author who thus professes to write a syste- matical work, is bound to make it really systematical, as far as that is possible. Icis a different thing to write single essays, or to describe those separate localities and partial facts from which geology ulti- mately derives assistance towards its general views. Hence our author is equally deserving of censure, that when he quotes Sicily, Malta, Iceland, and other well known countries, where fossil fishes have been found, he is scarcely ever at the trouble of ascertaining what has already been written about them, or of trying to extract something like truth from a balance of testimonies. As a specimen of this unpardonable carelessness, he quotes Antibes as a locality, and then doubts whether itis not Antigua. Nor could any thing but the same ambition to make a book and a system, which has led him to give genera without descriptions and species, under such imaginary and nominal genera, have tempted him to muster in his arrangement the fossil fishes of China, of which he knows nothing. On those of England he is equally unsuccessful; whereas he might have found something to his purpose, had he taken the trouble to seek for it. We have already shown our suspicions that many of Mons. Blain- ville’s marine formations, and marine ichthyolites, are really fresh water examples ; but we have a detail in the latter part of his essay of those which are indisputably such, and which he chooses to call Po- tamiens, “‘ apparemment,” because Tora is a river, and that these strata have been produced in lakes. We may pass over the Italian examples, as unsatisfactory: those of France are better known, and are here better described. ‘The deposit of Aix is well known to consist of five marked beds, reaching toa depth of near sixty feet, consisting of marl, limestone, bitumi- nous marl slate, and gypsum. ‘The fishes which it contains are one species in the genus perca, acyprinus, and the mugil cephalus or 120 Analysis of Scientific Books. grey mullet. Thislatter is a sea fish, and an inhabitant of the Medi- terranean ; though, as we formerly remarked, it can live in fresh water ; and since this is a decided fresh water formation, here is a remarkable fact in proof of what we have already advanced on the uncertainty which attends this subject, and which, if Mons. Blainville had not been so strenuous a theorist, might have led him to be more cautious in many of his decisions on this subject. The basin of Paris has been so thoroughly described by Cuvier and Brongniart, that little has been left for our author to do; and that des- cription is also known to every one sufficiently, to render it unneces= sary for us to enter into any details respecting it. These specimens are not numerous, and they are generally very imperfect and ill preserved. As our geological readers must know, they have been described by Lamanon, Faujas de St. Fond, and de la Metherie, as well as by Cuvier. The species are limited to seven, and they are all so ill de- fined that no very satisfactory conjecture respecting them has yet been made. We shall not quote what has been said, as it is of no mo- ment in the present review of Mons, Blainville. Yet we must be indulged in one remark on Cuvier himself in this case; professing, at the same time, that respect for his attainments which it is almost superfluous to profess. When the fishes of Veste- nu nuova were first described, it was the fashion to suppose that the world had been turned upside down, and inside out, and if there were two ways of explaining a fact, itseemed to be the fashion and the am- bition to reject the easiest and most natural solution, for the sake of adopting what was marvellous, incredible, or impossible. This has indeed been one of the leading diseases of /geology and geologists.— Because it was impossible that obsidian and pumice could be formed by water, they were to be aqueous productions: because the identity of volcanic rocks and trap rocks was so absolute that we could almost suppose we had seen the latter formed by the same class of fires which produced the former, it was resolved that they were gene- vated from water. Thus, at Vestenu nuova, because there was no difficulty whatever that the crowd of fishes which inhabit, or inhabited, the Mediterranean should have been elevated from the bottom of the sea, entangled in its mud, and indurated in rock, just as they have been before our very eyes in Iceland, it became necessary to collect them from the four quarters of the globe. The simple solution was not marvellous enough, and the dreams of Volta and his party have been triumphantly repeated and re-echoed, in our own clearer day, by those who prefer doubt and difficulty, to conviction and facility, and would rather that truth should not be attained than attain it by the easy road which all may apprehend. Of this, we fear, we must accuse Cuvier himself in the case of Pacilia vivipara, (as he chooses to suppose it,) of the Paris basin, a fish figured by Bloch, and a native of Surinam, For what possible pur- pose should we resort to Surinam for a fish for this situation? The M. Blainville on Ichthyolites. 121 theory is as purposeless as the voyage of the living fish itself to th Seine would be at this day, unless his object were to attract the praises, in a Bechamel sauce, of the Gastronomes who sit in judgment at the tables of Beauvilliers. The very theory of the Paris basin, to speak seriously, renders this supposition nearly as impossible as it is unreasonable, and it would-surely be a more rational conclusion that the fish in question was either a lost native of the Parisian seas, or that the imperfection of the specimen was the cause of a resemblance far too slight and doubtful to give the slightest justification to such a useless and violent supposition. We are fully aware at the same time of the argument in favour of such a view, which may be founded on the existence of vegetables with intertropical characters or analogies, in the same climates in which the Paris basin is situated, But this whole question, as far as it relates to change of climate, or an alteration in the position of the earth’s axis, is very obscure, or more than obscure: and were it not so, it must be remembered that the coal strata belong to a far remote period of the earth, antecedent by many and by millenarian revolu- tions to the basin and deposit in question. We have no right to argue thus, and it is only to perpetuate the vice from which geology has already suffered so severely. But it is time for us to bring this article to a close, and to take our leave of Mons. Blainville and his ichthyolites. We wish that we could have spoken more favourably of a performance which contains far more of conjecture and trifling than of useful and solid information, and which is not calculated to add much to our stock of knowledge. We do not undervalue this particular pursuit; on the contrary, we think it highly desirable that every organic fragment of a former world, in every department, should be collected, studied, and described: but geology, geology itself, the history of the structure and revolutions of the earth, has also its claims; and such collections and systems more than double their value when they are caused to bear and throw light on this important subject. This is what Mons. Blainville has yet tolearn, We still hope and expect that he will look at his subjectin this view; that he willturn from the poor ambition of shining in a catalogue of new and useless names, to that of improving the sciences which he has undertaken; and that, substituting study for guessing, and close investigation and careful reasoning for compilation and ca- talogue, he will appear before us again, at some future day, a new man, to receive the praise which we shall give with far more pleasure than we have passed the censure. 122 Analysis of Scientific Books. Il. The Philosophical Transactions of the Royal Society of London, for the year 1823, Parr. Il. - 1, On a New Phenomenon of Electro-Magnetism. By Sir Hum- phry Davy, Bart. Pres. R.S. This is a contribution of a curious fact to the new and interesting science of electro-magnetism, and it is by such contributions alone that this infant science can, at present, be expected to make any progress to maturity. Sir H. Davy found, that when two wires were placed in a basin of mercury, perpendicular to the surface, and in the voltaic circuit of a buttery with large plates, and the pole of a powerful magnet held either above or below the wires, the mercury immediately began to revolve round the wire as an axis, according to the circumstances of electro-magnetic rotation, discovered by Mr. Faraday. Masses of mercury, of several inches in diameter, were set in motion, and made to revolve in this man- ner whenever the pole of the magnet was held near the perpendi- cular of the wire; but when the pole was held above the mercury, between the two wires, the circular motion ceased, and currents took place in the mercury in opposite directions, one to the right and the other to the left of the magnet. Other circumstances led to the belief that the passage of the electricity produced motions independent of the action of the magnet, and that the appearances “were owing to a composition of forces. The form of the last experiment was inverted, by passing two copper wires through two holes, three inches apart, in the bottom of a glass basin; the basin was then filled with mercury, which stood about the tenth of an inch above the wire. Upon making a communication through this arrangement, with a powerful voltaic circuit, the mercury was immediately seen in violent agitation; its surface became elevated into a small cone above each of the wires; waves flowed off in all directions from these cones, and the only point of rest was apparently where they met in the centre of the mercury, between the two wires. On holding the pole of a powerful magnet at a considerable distance above one of the cones, its apex was diminished and its base extended. Ata smaller dis- tance, the surface of the mercury became plane, and rotation slowly began round the wire. As the magnet approached, the rotation became more rapid; and when it was about half an inch above the mercury, a great depression of it was observed above the wire, and a vortex which reached almost to the surface of the wire. The President thinks that these phenomena are not produced by any changes of temperature, or by common electrical repulsion, and concludes that they are of 2 novel kind. Philosophical Transactions. 123 2. On Fluid Chlorine. By M. Faraday, Chemical Assistant in the Royal Institution. [Communicated by Sir H. Davy, Bart., Pres. R.S.] This paper describes Mr. Faraday’s first step in the important series of experiments, which led to the condensation of the gases. He prepared some dry hydrate of chlorine, at a low temperature, and introduced it into a glass tube, which was hermetically closed. Being placed in water at 100, the substance fused, the tube be- came filled with a bright yellow atmosphere, and on examination was found to contain two fluid substances: the one was of a faint yellow colour, and the other a heavy bright yellow fiuid, lying at the bottom of the former, without any apparant tendency to mix with it. This fluid was easily distilled in a bent tube, and sepa- rated from the former. When the whole was allowed to cool, neither of the fluids solidified at a temperature above 34°, and the tal portion not even at 0°. When the two were mixed together, ey gradually combined at temperatures below 60°, and formed the same substance as that at first introduced. If, when the fluids were separated, the tube was cut in the middle, the parts flew asunder with an explosion, the whole of the yellow portion dis- appeared, and there was a powerful atmosphere of chlorine pro- duced. The pale portion remained, and proved to be a weak solution of chlorine in water. * The result of this experiment was confirmed by condensing per- fectly dry chlorine by a syringe, and then exposing it to a low temperature; it was thus readily made to assume the liquid form. ~ Fluid chlorine appears very limpid and fluid, and is excessively volatile at common pressure. Upon cooling a portion to 0° and then opening the tube, a part immediately fiew off, leaving the rest so cooled by evaporation as to remain a fluid under the atmosphe- rie pressure. Mr. Faraday thinks that the temperature could not have been above — 40° in this case. He calculates the specific gravity of fluid chlorine at 1:33. | In a note to this paper, the President of the Royal Society shews that these results will evidently lead to other researches of the same kind, and mentions, that by sealing muriate of ammonia and sulphuric acid in a glass tube, and causing them to act upon each other, he had procured liquid muriatic acid. 3, On the Motions of the Eye, in Illustration of the Uses of the Muscles and Nerves of the Orbit. By Charles Bell, Esq. {Communicated by Sir H. Davy, Bart., P.R.S.] This is a highly interesting paper, and, together with the second part, inserted in another part of the volume, is calculated to ex- 124 Analysis of Scientific Books. plain many ill-understood points of the mechanism and functions’ of the eye, and to renew our wonder at the properties of the organ itself, and the frame-work and apparatus by which it is suspended, moved, and protected. Mr. Bell concludes from his researches, that the high endowments which belong to this wonderful struc- ture depend not exclusively, as is generally conceived, upon the ball and optic nerve, but upon its exterior apparatus also. It is to the muscles, and to the conclusions, we are enabled to draw from the consciousness of muscular effort, that we owe that geo- metrical sense by which we become acquainted with the form and magnitude and distance of objects. It is impossible to do justice to Mr. Bell’s views in the short space to which we are obliged to confine ourselves in these abstracts: a careful perusal of the whole paper is absolutely necessary to those who would wish thoroughly to understand the investigation, and will amply repay even the more general reader. The author has shewn, by the most satis- factory illustrations, that we must distinguish the motions of the eye according to their objects or uses, whether for the direct purpose of vision, or for the preservation of the organ; that the eye undergoes a revolving motion not hitherto noticed; that it is subject to a state of rest and activity; and that the different con- ditions of the retina are accompanied by appropriate conditions of the surrounding muscles; that these muscles are to be distin- guished into two natural classes; and that in sleep, faintness, and insensibility the eye-ball is given up to the one, and in watchful- ness and the full exercise of the organ, it is given up to the in- fluence of the other class of muscles; and, finally, that the con- sideration of these natural conditions of the eye explains its changes as symptomatic of disease, or as expressive of passion. 4, An Account of an Apparatus on a peculiar Construction for per- Jjorming Electro-Mugnetic Experiments. By W.H. Pepys, Esq., F.R.S. 5. On the Condensation of several Gases into Liquids. By M. Faraday, Chemical Assistant in the Royal Institution, [Communicated by Sir H. Davy, Bart., P.R.S.] In this paper, Mr. Faraday follows up the train of investigation which the condensation of chlorine, by its own elastic power, so obviously opened.. Mercury and sulphuric acid were sealed up in a bent tube, and being brought to one end, heat was applied, whilst the other end was preserved cool by wet paper. The sul- phurous acid, which was generated, passed to the cold end, and was condensed i into a liquid. The properties of liquid sulphurous acid are as follow:—It is limpid’ and colourless; its refractive Philosophical Transactions. 125 power about equal to that of water; it does not congeal at a tem- perature of 0°; its specific gravity is nearly 1-42, and it exerts a pressure of about two atmospheres at 45°. Sulphuretted hydrogen was generated and condensed in.an ana- logous way, from muriatic acid and sulphuret of iron. It was colourless, limpid, and excessively fluid. It was not rendered more adhesive by a temperature of 0°; its refractive power ap- peared to be rather greater than that of water, and the pressure of its atmosphere at 50, was equal to about’ 17 atmospheres. Its specific gravity about 0:9. Carbonic acid was also condensed, but it required great pre- cautions to effect the condensation with safety. It is a limpid, colourless body, extremely fluid, and floated, as did all the pre- ceeding liquids, upon the contents of the tube, without mixing. It distils readily at the difference of temperature between 32° and 0°; its refractive power much less than that of water, and its va- pour exerts a pressure of 36 atmospheres at a temperature of 32°. In endeavouring to open the tubes which contained it at one end, Mr. Faraday states, that they uniformly burst with powerful explosions. Fluid enchlorine was also obtained, and proved to be a transpa~= rent substance, of a deep yellow colour, and highly elastic powers. Liquid nitrous oxide 1s limpid and colourless. It boils rapidly by the difference of temperature between 50 and 0°, and does not solidify at—10. Its refractive power is less than that of any known fluid, and the pressure of its vapour is equal to above fifty atmo- spheres at 45°. Liquid cyanogen is limpid, colourless, and very fluid, and does not alter its state at the temperature of 0°. Its refractive powers rather less than that of water; its specific gravity nearly 0-9, and the pressure of its vapour about 3°7 atmospheres. Mr. Faraday obtained dry ammonia from chloride of silver satu- rated with this gas*, and, by the usual process, succeeded in con- densing it. It was colourless, transparent, and very fluid. Its refractive power surpassed that of water, and all the other liquids hitherto described. The pressure of its vapour is equal to about 6°5 atmospheres at 50°, and its specific gravity is 0°76. Attempts were made to obtain hydrogen, oxygen, fluoboracic, fluosilicic, and phosphuretted hydrogen gases in the liquid state; but though all of them have been subjected to great pressure, they have as yet resisted condensation, 6. On the Application of Liquids formed by the Condensation of Gases as Mechanical Agents. By Sir Humphry Davy, Bt. Pres. R.S. In this paper Sir H. Davy anticipates the probability of the ap- * See Quarterly Journal, yol, y. p. 74. 126 Analysis of Scientific Books. plication of the elastic force of compressed gases to the movement of machines. He founds this anticipation upon the immense dif- ferences between the increase of elastic force in gases under high and low temperatures, by similar increments of temperature. The force of caaboni¢ acid was fouud to be equal to that of air com- pressed to 3/5 at 12°, and of air compressed, to z/; at 32°, making an increase equal to the weight of thirteen atmospheres, by an in- crease of 20° of temperature. 7. On the Temperature at considerable depths of the Caribbean Seu. By Captain Edward Sabine, F.R.S. [In a Letter addressed to Sir H. Davy, Bart., P.R.S.] Captain Sabine found the temperature of the water, at a depth of 6000 feet, in latitude 204 N. and long. 83} W. near the junction of the Mexico and Caribbean Seas, to be 45° .5, that of the sur- face being 83°. He infers, that one or two hundred fathoms more line, would have caused the thermometer to descend into water at its maximum of density as depends on heat; this inference being on the presumption that the greatest density of salt water occurs, as is the case in fresh water, ‘at several degrees above its pein] point. 8. Letter from Captain Basil Hall, R.N., ¢o Captain Kater, commu- nicating the details of Experiments made by him and Mr. Henry Foster, with an Invariable Pendulum; in London; at the Gala~ pagos [slands in the Pacific Ocean, near the Equator ; 3 at San Blas de California on the N.W. Coast of Mexico; and at Rio de Janeiro in Brazil. With an Appendix, containing the Second Series of Experiments in London, on the Return. The title is an abstract of the paper, and the follewing are the most exact results obtained by Captain Hall at each station. Diminution uf Gravity ee From Poleto Equatos,| Ellipticity, Length of Equat. Stations, Pend. Galapagos, 632 " NI .0051412 39.017196 San Blas, 21 30 . 0054611 39. 00904 Rio;.... 3 22°55 0053431 3901206 Philosophical Transactions. 127 9. Second Part of the Paper on the Nerves of the Orbit. By Chas. Bell, Esq. [Communicated hy Sir H. Davy, Bart., P.R.S.] This is a continuation of the subject upon which Mr. Bell had entered in his last paper. His object is to explain the reason of there being six nerves distributed to the eye, and crowded into the narrow space of the orbit. In this investigation he demonstrates, that there is a correspondence between the compound functions of an organ and the nerves transmitted to it. It is impossible to do more, than here sum up the distinct functions of the nerves, as unravelled by the skill of the author. “ The first nerve is provided with a sensibility to effluvia, and is properly called the olfactory nerve. ** The second is the optic nerve, and all impressions upon it ex- cite only sensations of light. “ The third nerve goes to the muscles of the eye solely, and is a voluntary nerve by which the eye is directed to objects. _ “ The fourth nerve performs the insensible traversing motions of the eyeball. It combines the motions of the eyeball and eyelids, and connects the eye with the respiratory system. _“ The fifth is the universal nerve of sensation to the head and face, to the skin, to the surfaces of the eye, the cavities of the nose, the mouth and tongue. ‘« The sixth nerve is a muscular and voluntary nerve of the eye. ‘* The seventh is the auditory nerve, and the division of it, called portio dura, is the motor nerve of the face and eyelids, and the respi- ratory nerve, and that on which the expression of the face depends. “ The eighth, and the accessory nerve, are respiratory nerves. “ The ninth nerve is the motor of the tongue. “ The tenth is the first of the spinal nerves; it hes a double root and a double office; it is both a muscular and a sensitive nerve.” Mr. Bell concludes his paper with a few very appropriate words in favour of anatomy, as a means better adapted for discovery than experiment, ‘“* Anatomy,” he observes, “ is already looked upon with pre- judice by the thoughtless and ignorant: let not its professors un- necessarily incur the censures of the humane. Experiments have never been the means of discovery; and a survey of what has been attempted of late years in physiology will prove, that the opening of living animals has done more to perpetuate error, than to confirm the just views taken from the study of anatomy and natural motion.” With another opinion of Mr. Bell’s we cannot also but coincide, and that is, that ‘* Medical histories do not often lead to the im- provement of strict science.” It is an opivion worthy the consideration of the Committee of Papers of the Royal Society, 128 Analysis of Scientific Books. 10. An Account of Experiments made with an Invariable Pendu- lum at New South Wales. By Major-General Sir Thomas Bris bane, K.C.B. F.R.S. [Communicated by Captain Henry Kater, F.RS., in a Letter addressed to Sir H. Davy, Bart., P.R.S.] The results of Sir Thomas Brisbane’s experiments are as follow: 39-07696 inches the length of the pendulum, vibrating seconds at Paramatta; .0052704 the diminution of gravity from the pole to the equator, and -->+,— the resulting compression. 11. Observations and Experiments on the daily Variation of the Horizontal and Dipping Needles under a reduced directive Power. By Peter Barlow, Esq., F.R.S., of the Royal Military Academy. {Communicated by Davies GiLvert, Esq., V.P.R.S.] The daily change of the horizontal needle is so small, that it has only hitherto been detected with the most careful observations, and with the most delicate instruments; and in the dipping needle, that change is so extremely minute, as to have escaped observation al- together. It occurred to Mr. Barlow, that it would be possible to increase this deviation in both needles, so as to render it distinctly observable, by reducing the directive power of the needle, by means of one or two magnets properly disposed, to mask, at least in part, the terrestrial influence. This idea was realized, and in this way it is easy to produce a daily variation, to almost an amount. From his experiments, Mr. Barlow draws the following conclusions :— 1st. That while the north end of the needle is directed to any point from the south to N.N.W. its motion during the forenoon is towards the left hand, advancing to some point between the N.N.W. and north; and while it is directed towards any point between the north and S.S.E., it passes to the right hand, that is, still to some point between the north and N.N.W. 2dly. That the daily change is not produced by a general de- flection of the directive power of the earth, but by an increase and decrease of attraction, of some point situated between the north and N.N.W., or between the south and S.S.E. 3dly. That the dipping needle is subject to a daily variation, which cannot, at present, be reduced to any fixed principles. 12. On the Diurnal Deviations of the Horizontal Needle when un- der the influence of Magnets. By Samuel Hunter Christie, Esq., M.A., Fellow of the Cambridge Philosophical Society: of the Royal Military Academy. [Communicated by Sir H. Davy, Bart., P.R.S.] Mr. Barlow communicated to Mr. Christie his method of ren- Philosophical Transactions. 129 dering the variations of the magnetic needles more sensible, and he commenced a series of observations in consequence of the commu- nication. — : He ascertained, that there was an easterly deviation before eight o’clock in the morning, and that the greatest westerly deviation took place about one o’clock in the afternoon. He also found, that the state of the weather had a considerable influence upon the nature and extent of the changes. But the most striking effects seemed to him to arise from changes of temperature, and he adopts the opinion that temperature, if not the only cause of the daily variation, is the principal. He expresses his intention of entering fully into the general question, when he shall have ascertained the precise effects of changes in the temperature of magnets. 13. On Fossil Shells. By Lewis Weston Dillwyn, Esq., F.R.S. [In a Letter addressed to Sir H. Davy, Bart., P.R.S.] Mr. Dillwyn remarks, that every turbinated univalve of the older beds, from transition lime to the lias, of which he can find any re- cord, belongs to the herbivorous genera, and that the family has been handed down through all the successive strata, and still in- habits our land and waters. On the other hand, all the carnivo- ruos genera abound in the strata above the chalk, but are compa- ratively extremely rare in the secondary strata, and not a single shell has been detected in any lower bed than the lower oolite. ‘He thinks, that a further examination will prove, that neither the aporrhaides or any of those few undoubtedly carnivorous species, which have been found in the secondary formations, were furnished. with predaceous powers, but that they belong to a subdivision of the trachelipoda zoophaga, which feed only on dead animals. 14. On the apparent Magnetism of Metallic Titanium. By William : Hyde Wollaston, M.D., V.P.R.S. In this paper Dr. Wollaston corrects an oversight in his former communication upon metallic titanium. He therein stated, that _ when the crystals from the slag had been freed from all particles of iron adherent to them, they appeared to be no longer acted upon ‘by the magnet. He has since found, that although they are not ‘sufficiently attractive to be wholly supported by the magnet, yet, ‘when a crystal is supported by a thread, the force of attraction is sufficient to draw it twenty degrees from the perpendicular. From ‘an ingenious comparison of different magnetic forces, he calculates “that 51, part of iron, as an alloy in the metallic titanium, would ‘be sufficient to account for this power; and he shews, that it is ‘extremely difficult chemically to detect so minute a portion of iron, on account of the high colour of the precipitates of titanium, Vor. - XVII, K 130 Analysis of Scientific Books. 15. An Account of the Effect of Mercurial Vapours on the Crew of His Majesty’s Ship Triumph, in the year 1810. By William Burnett, M.D., one of the Medical Commissioners of the Navy, formerly Physician and Inspector of Hospitals to the Mediter- ranean Fleet. Communicated by Matthew Baillie, M.D., F.R.S. The particulars of this curious case have been already published by Dr. Baird, in Nicholson’s Journal, for the month of Oct. 1810. 16. On the Astronomical Refractions. By J. Ivory, A.M., F.R.S. This is a very long and laborious investigation of the problem of astronomical refraction; its result is a new table of refractions with which the paper concludes, and which is compared with other tables that have been long in the hands of astronomers, and the characters of which are well established. Mr. Ivory shews that it is fruitless to expect a near agreement in every single instance be- tween observation and any table of refractions whatever, and that there is no test of their accuracy except the smallness of the mean error in a series of observations made at different times. 17. Observations on Air found in the Pleura, in a case of Pneumato- thorax ; with Experiments on the Absorption of different kinds of air introduced into the pleura, By John Davy, M.D., F.R.S. This is a medical history which Dr. Davy has endeavoured to illustrate by some experiments upon dogs. | He observes that the ‘circumstances which he has ventured to bring forward are some= what favourable to the idea of the secretion or exhalation of azote, but are still far from conclusive. 18. On Bitumen in Stones. By the Right Honourable George Knox, F.R.S. This is a second paper upon the same subject. Mr. Knox finds bitumen in every thing except rock crystal and pearl-white adularia. 19. On certain Changes which appear to have taken place tn the Positions of some of the principal fixed Stars, By John Pond, Astronomer Royal, F.R.S. The Astronomer Royal thinks that his observations lead to the conclusion that some variation, either continued or periodical, takes place in the sidereal system, which producing but very small deviations in a finite portion of time, has hitherto escaped notice. The nature of this motion appears to be such that the stars are now mostly found a considerable quantity to the southward of their computed planes. With respect to the laws by which these motions are governed, the observations in question, he admits, are not sufficiently exact to throw any light upon them. , 131 (lo the Editor of the QuarTerty Journat or Science, §¢.] Manchester, March 1, 1824, Sir, Tur review of the 9th editionof my Elements of Chemistry, in the last number of your Journal, contains some animadversions, to which I trust you will dome the justice to insert a brief reply. It is not, indeed, my intention to follow the reviewer through the variety of topics which he has introduced, but to confine myself to a few of those, on which I am most desirous to be set right with your readers, and which involve questions of some importance . to chemical philosophy. It has happened unfortunately that a passage, expressing doubts of the correctness of the theory of volumes, which certainly ought to have been expunged from the present edition of my work, was overlooked, owing to one or two of the early sheets having been revised under circumstances dis- advantageous to correctness. For this oversight, I am content to take upon myself whatever blame it may justly deserve ; and I should have had no reason to complain, had the reviewer pointed out the striking inconsis- tency’of the passage, which he has quoted, with other parts of my volumes. At page 299, vol.i., for example, I state, “analogy is certainly in favour of this opinion, for the instances are numerous in which gaseous bodies observe the law respecting volumes deduced by Gay-Lussac, and we have not at pre- sent any well-ascertained exception to it.” The tenor of the whole work, also, is inconsistent with the rejection of the theory of volumes imputed to me ewe reviewer ; for almost every chapter affords examples of com- pounds constituted in conformity to the law ; and at the close of the second volume I have inserted, for the first time, a table exhibiting a general view of such compounds. _ The reviewer complains (p. 338,) that I have not given a more elaborate and consistent account of the atomic theory, though he represents it (p. 339) as requiring “ mystifications,” and particularly marks the distinction between the atomic hypothesis and the theory of volumes. To a certain extent, the law of volumes is, I admit, the expression of a general fact, of which we have the indubitable testimony of our senses. But with regard to certain elementary substances, which are not known to us separately in a gaseous state, it is entirely matter of inference that their vapow’s unite in olumes, which are either equal, or multiples or sub-multiples of each other. We have, for example, no argument but from analogy, that this holds with respect to carbon; nor, if we admit the probability of such combinations, have we any decisive proof that the volumes, which have been assigned, are actually the true ones. In all such cases, where we have not access to the faets by direct experiment, the law of volumes rests on the ground of ana logy only ; and is so far purely theoretical. ‘The law, also, however, well established with respect to gaseous bodies, is limited to them only ; and we must seek for some other principle, to explain the far greater number of chemical combinations which take place between bodies existing under other forms. _ In the investigations which have led Mr. Dalton to the atomic system, it appears to me that he has pursued no other method of reasoning than that which has been followed by the most successful cultivators of natural science, siuce the introduction of K 2 inductive logic, The theory of « 132 Letter to the Editor, by Dr. Henry. gravitation itself, however firmly it may now be established, took its rise in an hypothesis founded on analogy, and could be considered as nothing more than an hypothesis, till that period of the life of its great author, when the coincidence was ascertained between the law which regulates the fall of heavy bodies, and that power which preserves the moon in her orbit.‘ A principle,” it has been remarked by the late Professor Playfair, “is often admitted in physics, merely because it explains a great number of appear- ances, and the theory of gravitation itself rests on no other foundation*.” The term hypothesis, then, is far from being one of just reproach, since it may be applied in a variety of cases to those first steps which it has been found necessary to take in philosophical inquiries, and which have led eventually to well-established laws. The views of Mr. Dalton respecting the atomic constitution of bodies appear to me to be founded mainly on the general fact, that bodies unite in definite proportions. Of this general truth, Richter certainly furnished the best and fullest evidences. Far from wishing to ‘‘ suppress” the share of credit to whicli he is entitled, I have alluded to the table, calculated by Fischer from his experiments ; but it is omitted in the appendix to the pre- sent edition, merely because it has been superseded by the more extensive tables of equivalents, which have since been constructed. ‘The law of com- bination ia multiple proportions, the first experimental proofs of which are due to Mr. Dalton, comes strongly in aid of the atomic theory, and fur- nishes its most striking proofs and illustrations. Nothing can be more evident than that if we set out from a binary compound, whose gaseous elements exist in equal volumes, and proceed to compounds of the same elements, in which either is found as a multiple in volume of the other, there must, as the reviewer observes, ‘‘ be a perfect accordance between the ato- mic hypothesis and the theory of volumes.” But the atomic theory is, [ contend, a wider and more comprehensive generalization, and includes the Jaw of volumes as well as that of combination by multiples of weights. In this ease, as in many others, when we advance from discovery to discovery, ave do nothing more than resolve our former. conclusions into others still gore general. There can surely be nothing inconsistent with sound philosophy in in- quiring why bodies unite in definite proportions, and why they unite in pro- portions which are multiples or sub-multiples of weights or oF volumes ; and the only satisfactory explanation, that has yet been given of these facts is, that in those combining weights, which are represented by equivalent numbers, are contained determinate numbers of ultimate particles or atoms, and that from the relative weights of aggregates that combine, we may deduce the proportions as to weight which the ultimate single atoms bear to each other. As there-seems every reason to believe that chemical attrac- tion is exerted, not between masses, but between ultimate particles or atoms only, combination will then take place either between single atoms or when either is in excess, the excess will be represented by some simple multiple of the number of atoms. In this reasoning it is of course taken for granted that matter is not infinitely divisible, a position rendered extremely probable by ‘a philosopher, to whose opinions the reviewer will agree with me in paying the greatest deference. ‘‘ Now though we have not the means,” that writer observes, ‘of ascertaining the extent of our own atmosphere, those of other planetary bodies are nevertheless objects for astronomical investi- * Playfair’s Works, vol. iy, p, 62, note. Letter to the Editor, by Dr. Henry. 133. gation ; and it may be deserving of consideration, whether, in any instance, a deficiency of such matter can be proved, and whether, from this source, — any conclusive argument can be drawn in favour of ultimate atoms of matter in general. For since the law of definite proportions, discovered by che-’ mists, is the same for all kinds of matter, whether solid, fluid, or elastic, if it can be ascertained that any one body consists of particles no longer divi- sible, we can then scarcely doubt that all other bodies are similarly consti- tuted ; and we may, without hesitation, conclude that those equivalent quan- tities, which we have learned to appreciate by proportionate numbers, do really express the relative weights of elementary atoms, the ultimate objects of chemical research*.” A body so constituted (it is the scope of the — which has been just quoted to shew) is found in the earth's atmosphere, all the phenomema according with the supposition that it is ‘‘of finite extent, ’ limited by the weight of ultimate atoms of definite magnitude, no longer di- visible by repulsion of their parts.” But though the atomic theory, in its general outline, seems to me to rest sufficiently on the evidence of facts, and on legitimate reasoning, yet there are some positions which have arisen out of it, that may or may not be true, » without, in the latter case, impeaching its general correctness. Of this na- ture are the two cited by the reviewer, (p. 340) especially the first, viz., ‘that an increase of the density of a gas indicates an incteased number of simple atoms associated in the compound atom.” ‘This principle, I am» ready to admit, may have been too hastily deduced ; for besides that it is at variance with the view which J have adopted of the nitrous compounds, it is inconsistent also with that which I have taken of the compounds of carbon and hydrogen; olefiant gas, the binary compound, being denser than light carburetted hydrogen, the ternary one. The other position, that ‘‘ of che- mical compounds the most simple, is the most difficult to be decompesed,’’, stands unimpeached, and is exemplified, as the reviewer himself remarks, in the greater difficulty of decomposing nitrous oxide than nitrous gas. To Mr. Dalton’s opinion of nitrous gas, which makes it the binary compound, its greater facility of decomposition might present a reasonable objection. But it is quite inconsistent with sound reasoning to frame a preposition out of Mr. Dalton’s views and mine, which are completely at variance as to the compounds of nitrogen, and to apply to that proposition the syllogistic me- thod of reasoning as a test of its truth. No syllogism can be so constructed as to involve in the same dilemma two persons, who disagree with each other as to the conditional proposition on which that syllogism is founded. Though I have adopted, as most probable, that view of the nitrous com- pounds which makes the elements of nitrous oxide to exist in binary and those of nitrous gas in ternary, atomic proportion, yetl consider the truth of this opinion as far from being demonstrated That the volumes of the elements of those two compounds are what they nave oeen represented by Gay-Lussac, I entertain very little doubt, not only from the evidence of other persons, but from methods of analysis which I have myself devised, and which, though not otherwise important, than as they bring out the re- sults by easy and summary processes, [ shall probably ere long lay before the public. But it must still remain a subject of inquiry, whether equal volumes of nitrogen and oxygen gases contain, as Mr. Dalton supposes, equal numbers of atoms ; or whether, as [ take to be more probable, the same number of atoms exists in one volume of oxygen as in two of nitrogen gas. . * Dr. Wollaston on the Finite Extent of the Atmosphere»—Phil, Trans, 1822. 134 Letter to the Editor, by Dr. Henry. The illustrious author of the Elements of Chemical Philosophy will not, T trust, require any assurance from me, that nothing could be farther from my design, or more repugnant to my feelings, than to misunderstand “intentionally” his ideas respecting chemical combination. I have, it is true, rendered the word proportion by that of atom, but I have enclosed the latter word in parentheses, purposely to shew that it was not the ex- pression of the author, but my own interpretation of his meaning. The fact is, that great ambiguity has arisen out of the use which has been made of the word proportion. Strictly, the only numerical expressions of pro- portion, that can be considered as “‘ the results of experiment,” must be de- rived from a comparison either of the weights, or of the volumes, in which bodies unite ; and it appears to me that a system of numbers, derived from the consideration of weights, should be kept distinct from one derived from aw comparison of volumes. But the numbers (1 and 15) representing hydro- gen and oxygen, were gained from the joint consideration of the weight and volume of the elements of water ; while those representing oxygen and nitrogen (15 and 26) were derived from a comparison of the weights only of the elements of nitrous oxide. Since, then, the word proportion could not, in both cases, apply to a comparison of weights only, nor yet of vo- lumes only, it was natural for me to conclude that it must bear a reference to ultimate particles or atoms, the only other objects, which I could con- ceive as, in this case, admitting of being compared. These, Sir, are the only points respecting which I deem it necessary to trespass on the attention of your readers, though there are others on which 1 am not disposed to concede the justice of the reviewer's strictures. In some instances, I allow, he has pointed out mistakes that may call for cor- rection on a future occasion, should any occur to me. Having invited the communication of errors or omissions, with a view to the improvement of my volumes, it would ill become me to feel “ offended” when that invitation is complied with ; and all that I claim is to be animadyerted upon with a reasonable share of courtesy and of candour. Tam, Sir, Your obedient and faithful servant, WILLIAM HENRY. 135 Arr. XIII. PROGRESS OF FOREIGN SCIENCE. In Volume XIII. p. 144, we briefly animadverted on some re- searches of Professor Gmelin, of Tubingen, published in Dr. Brewster’s Journal, about two years ago, where the terms refute, and refutation were applied with more freedom, than propriety or decorum, to Sir. H. Davy’s fundamental experiments relative to the connexion of chemical affinity with electrical attractions, con- tained in his Bakerian Lecture of 1806. M. Becquerel read to the Academy of Sciences on the 7th June, 1823, an interesting paper on the electrical effects which are developed during different che mical actions, which perfectly accord with, and seem fully to con- firm, the conclusions of the English philosopher. After a candid retrospect of preceding inquiries on the subject, M. Becquerel thus states Sir H. Davy’s theory: “ Supposing two bodies, whose mo= lecules are in different states of electricity, and that these states are sufficiently exalted to give them an attractive force, superior to the power of aggregation, a combination will be formed. This is the key of the electro-chemical theory.” ‘ Although Sir H. Davy has advanced the opinion, that the substances which com+ bine are those which manifest on mutual contact, opposite elec- trical states, yet we perceive from his own experiments that it is by induction he extended this property to all the bodies which exert chemical actions on one another; for instance, he was not able to verify it on alkaline and acid substances, unless they were per fectly dry. In other cases, the results were null. He adduces, among others, pure potash, and sulphuric acid, which afford no appearance of electricity at the moment of their combination. In fact, this celebrated chemist could not recognise electricity in the contact of two substances which are just combining ; for, adopting the electro-chemical theory, as soon as the combination takes place, the two electricities that were developed, recombine, and probably form, by their union, caloric: whence, in making use of a condenser to collect one of the electricities which is disengaged, traces of this fluid ought to be found with difficulty, since the con- denser requires a certain time to charge itself, during which the two electricities may re-combine. But if a galvanometrical mul- tiplier be employed, such as that of M. Schweigger, which renders the electricities sensible at the very instant of their disengagement, and consequently at the instant when the combination takes place, currents will be obtained of greater or less force, according to the degree of conductibility of the substances put in action, and that of their reciprocal affinities; I say according to the degree of con- ductibility, because when one of these substances conducts the 136 Progress of Foreign Scvence. electricity ill, there is no current, although the chemical action be very strong. The conductibility then is here an indispensable con- dition. ‘ef We shall examine in succession the electrical effects that we have observed in different chemical actions by the aid of the multi-. plier ; 72z.—1, At the moment of the combination of acids with metals and alkalis.’ 2. In the dissolutions. 3. In the contact of metallic oxides with the alkalis which combine with them. 4. In the precipitates. As to double decompositions, it has been im- possible for me to recognise the slightest trace of electricity at the moment of their formation. Electrical Effects produced at ihe moment of the Combination of the Metals and Alkalis with the Acids. We have seen above that Sir H. Davy observed electrical effects on the contact of acids and alkalis, only when these bodies had been perfectly dried. M. Cérsted asserts that he has perceived them at the instant when the acid combines with the metal. ‘The following is the means which I employ to shew the elec- trical effects in these species of actions. I make use of a galva- nometer, whose wire is of platinum. (See p. 124 of this volume.) At one of the extremities of this wire I placed a little platinum spoon destined to receive the acid, which is selected of such a nature as not to act on the platinum. To the other end of the wire is adapted a piece of the same metal, between the branches of. which (as pincers) the body is placed, which is to act on the acid. In case the platinum could exert an electro-motive action on this body, there is placed between them a bit of moistened paper. Let us begin by shewing what electrical effects result at different tem- peratures from the contact of a liquid with the platinum. At the ordinary temperature, whatever be the liquid, provided it is not nitro-muriatic acid, the electrical current is null, but when the temperature is raised, phenomena occur which we shall endeavour to explain. Let us put into the spoon distilled water, and let us raise the temperature to ebullition, there will be no current in con- sequence; if the water of the Seine be used, the current will be extremely feeble, and it will increase in intensity by the addition of a little nitric acid, or alkali. Now, since we know that boiling nitric acid has no more action on platinum than cold nitric acid, it is hence probable that the current is owing to the difference of temperature of the two ends of the wire. It has been already shewn in a former memoir that two pieces of the same metal, in a sufficiently unequal state of temperature, pass, on their mutual contact, into two different electrical states. This change of tem- perature must therefore be avoided, which is done by using small Progress of Foreign Science. 137 fragments of the bodies to be acted on, and a large platinum spoon. : Let us now fix in the platinum forceps a little bit of caustic, soda, or potash, slightly moistened with water. At the moment when the alkali touches the acid, an energetic electrical current will take place, which will proceed from the acid to the alkali fol- lowing the curcuit. ‘Thus at the instant of contact of these two bodies the acid becomes enveloped with an atmosphere of positive electricity, and the alkali with one of negative. The electrical current is so strong that it may be observed without a galvanometer. It is sufficient for this purpose to present the conjunctive wire to a needle suspended at the filament of a silk-worm. In order to observe the electrical currents which result from the action of an acid on a metal, the same process is employed ; care only is taken to prevent the metal touching the platinum directly, by interposing a small slip of paper. The experiment is made in the same way, and the result is the same, whatever be the acid and the base. M. Becquerel next shews that during the solution of a body in water, or alcohol, no electricity is produced. But the smallest acid or alkaline particles are sufficient to modify the results. He then details some experiments on the solution in caustic potash of metallic oxides, such as oxide of zinc, and of lead newly precipitated. In these, electrical phenomena were exhibited. Whenever the oxide (generally contained in the thin ceecum of an animal,) touches the alkaline solution, the needle deviates from its magnetic direction, and the current goes from the oxide to the alkali, passing along the wire. Hence in these kinds of combi- nations, the oxides comport themselves like acids, and the alkalis are always surrounded with an atmosphere of negative electricity, as in their actions on the acids. Tn slow precipitations, as when an infusion of nut galls acts on sulphate of iron, a current is developed which goes from the infu- sion to the sulphate. Let us puta solution of sulphate of mag- nesia in contact with the caustic potash contained in the mem- branous bag. The needle will deviate slightly from its direction, and the current will be from the sulphate tothe alkali. In making nitrate of barytes act on sulphuric acid, the current goes from the acid to the nitrate. When two perfectly neutral salts were em- ployed, as sulphate of soda, and nitrate of barytes, he has not been able to discern the least appearance of a current. In a subjoined notice, M. Becquerel describes the following experiment. Take a plate of platinum, and placing it horizontally, fix by cement, two glass tubes vertically upon it. Liquids poured into these tubes will communicate through the medium of the pla- tinum plate. Let us pour in any liquids whatever; if they are susceptible of exerting chemical actions on the two ends of the wire of the galyanometer which are immersed, there will be na- 138 Progress of Foreign Science. turally established an electrical current, since the plate of platinum permits the electricity to circulate from one liquid to the other. Suppose one of these liquids to be concentrated, and the other dilute nitric acid. On plunging into each tube an end of the cop- per wire of the galyanometer, the experiment will shew that the electrical current goes from the stronger acid to the other. Let us now substitute, in the place of one of these acids, ammonia, which dissolves the oxide of copper. At the instant of immersion of the two wires the current will go from the acid to the alkali, and will continue to move in the same direction, even when the acid shall be diluted with water.——Ann. de Chem. et de Phys. xxiii. p. 244. Heat. On the Property which some Metals possess of facilitating the Combination of Elastic Fluids. By MM. Dulong and Thenard. After exhibiting to the Academy of Sciences Dobereiner’s in- teresting experiment described in our last number, this gentleman proceeded to detail some modifications of it which they had de- vised. On immersing some spongy platinum into a mixture of two parts of hydrogen and one of oxygen, explosion takes place. If much azote be present, the water is slowly and actually formed. The sponge of platinum, when strongly calcined, loses the property of becoming incandescent; but in this state it produces slowly, and without any very sensible elevation of temperature, the com- bination of the gases. Platinum reduced into a very fine powder by a well known chemical process, has no action whatever at the ordinary temperature. The same is the result with wires or la- mine. It might thence be supposed that the porosity of the metal was an essential condition of the phenomenon, but the following facts destroy this conjecture. Platinum was reduced into leaves, as thin as the malleability of this metal allows. In this state the platinum acts at the ordinary temperature, on the mixture of oxy- gen and hydrogen, with the greater rapidity the thiner its leaf is, They procured some which caused detonation after some instants. But what renders this action still more extraordinary is the phy- sical condition indispensable for its development. A very thin leaf of platinum, rolled round a cylinder of glass, or suspended freely in an explosive mixture, produced no sensible effect at the end of several days. The same leaf crushed together like the wadding of a musket, acts instantaneously, making the mixture explode. Rolled leaves and wires at temperatures of from 200° to 500° cent. act slowly, but without explosion. Thin leaves of gold and silver act only at elevated temperatures ; but always below that of boiling mercury. Silver is less effica- cious than gold. In accordance with Sir H. Davy’s results with palladium and platinum in the safety-lamp these gentlemen found, Progress of Forevgn Science. 139 that these two metals, when of the same thickness, acted equally well. The oxide of carbon and oxygen combine, and nitrous gas is decomposed by hydrogen at the ordinary temperature, when they are in contact of the sponge of platinum. Olefiant gas mixed with a proper quantity of oxygen, is completely transformed into water and carbonie acid by the sponge of platinum, but only at a tem- perature above 300° cent. M. Thenard long ago shewed that iron, copper, gold, silver, and platinum, had the property of decomposing ammonia at a certain temperature, without absolving any of the principles of this alkali; and that this property seemed to be inexhaustible. Iron possesses it ina higher degree than copper, and copper more than silver ; gold and platinum under equal surfaces. Ten grammes of iron wire are sufficient to decompose, within a few hundred parts, a current of ammoniacal gas pretty rapid, and kept up for eight or ten hours, without the temperature exceeding the point at which ammonia completely resists decomposition. A tripple quantity of platinum wire, of the same size, does not produce a nearly similar effect, even at a higher temperature. Palladium, in a spongy mass, inflames a stream of hydrogen, as well as platinum. Iridium under this form becomes very hot, with the production of water; nickel and cobalt, in mass, determine at about 300° cent. the union of hydrogen and oxygen ; lastly, the sponge of platinum forms, in the cold, water and ammonia, with nitrous gas and hydrogen, and acts also on a mixture of hydrogen and protoxide of azote. M. Gay-Lussac’s hydrogen lamp answers well for the experiment of ascension, as the hydrogen would issue in a very small stream. By holding a very light bit of platinum sponge, about three quarters of an inch, before the orifice, the efflu- ent gas is instantly kindled. This is more convenient than the trophorus plate.—Ann. de Chim. et de Phys. xxiii. 440, On the Preparation of Oxide of Uranium. By MM. Lecanu and Serbat. The authors of this process, after having fused the pulverized mineral (pech-blende,) with one half of its weight of nitre, washed the mass which results from the operation, treated the residiuum with nitric acid, evaporated the solution to dryness, and re-dis~ solved in water acidulated with the same acid, add to the solution an excess of carbonate of ammonia, which, while it is sufficient to re-dissolye the whole oxide of uranium, has no action on the car- bonates of lead and lime. M. Laugier, in commenting on the above process, recommends the use of one part and a half of nitre, instead of half a part. ‘The solution containing the nitrate of am- monia, and the carbonate of uranium is to be evaporated to dryness 140 Progress of Foreign Science. and calcined, in order to get the pure oxide. M. Laugier advises in preference to wash away with hot water the nitrate of ammonia, . and to calcine the remaining carbonate of uranium which has in the filter, a fine lemon yellow colour.—Journal de Pharmacie, March, 1823, On the Oxides of Nickel. By M. J. P. Lassaigne. The metal was purified by Laugier’s process. The protoxide is. obtained from solutions in acids, it is of an ash-grey colour, gives green solutions with acids, from which caustic alkalis precipitate it of apple-green colour. Its constituents are 1 ATS 1) ete ee ae - 100 eye CR ie Se) oe 20 Whence the atomic weight of nickel appears to be 5. The deut- oxide is of a brilliant black colour, having some analogy with the peroxide of manganese. Ata red heat it gives up a portion of its oxygen, and passes to the state of protoxide, It is prepared by treating the hydrated protoxide with chlorine. M. Lassaigne’s experiments on its composition, give — Bead! ® gy FS) 5 pvelvat « +4100 Oxygen ...... at oe 39°44, approaching sufficiently near to 40. The sulphuret artificially made is of a brilliant yellow colour, like iron pyrites, and is very brittle. It consists of DHGRCL ~ 4 laste eta ghey DA + ant 100 MOREY ate pe. “we cose s “ay eee or one atom of each. He describes a chloride and bichloride, and an iodide, whose constitution may be inferred from the above numbers. On the Gaqnet y of Saturation of Delphia. By M. Feneulle, of Cambray. ' Neutral Sulphate—Acid . . , 3:031 5-0 Delphia . . 96°969 16:0 Subsulphate—not distinctly characterized. It seems to have a double dose of base. The muriate of delphia is amorphous like the preceding. It is formed of Muriatic Acid . . . 100 2°136 Delphia. . . . . 4675 100-000 There is also a submuriate. It consists of ARI A jie, gl deOe Delphia . « ~ 100-000 Progress of Foreign Science. 141 Facts subservient to the History of the Succinic and Benzoic Acids. By MM. Lecanu and Serbat. Subjected to the action of heat these acids comport themselves in nearly the same way. They melt, then are volatilized, leaving always a slight carbonaceous residuum. The difference of solu- bility of these acids in water, as well as in the essential oil of turpentine, establishes a remarkable difference between them. While, in fact, at the temperature of 16° cent., water dissolves scarcely an appreciable quantity of benzoic acid, and, at 100°, only one-twelfth part of its own weight; 100 parts of water, at 16°, dissolve 20 parts. and at 100°, about 46 parts of succinic acid. On the other hand, at the temperature of 16° cent. a gramme of benzoic acid requires for solution only 249 parts of essential oil of turpentine, and at 100° much less than its weight. Hence the liquor, on cooling, concretes into a mass. Succinic acid, even above 100°, dissolves in it very sparingly, although the essence thereby acquires the property of reddening litmus pretty strongly. Hitherto the property of separating iron from manga- nese, forming with the first an insoluble salt, and with the second a soluble one, seemed to belong only to the benzoic and succinic acids. It is, however, met with in the camphoric and pyrolar- taric acids. The last even, would appear even to be capable of separating these metals more completely than succinic acid does. Perhaps it would be advantageous, in regard to economy, to sub- stitute it for this acid. Succinic acid is not altered by being distilled into nitric acid, diluted with its own weight of water. It is, therefore, not con- vertible, like some of the other vegetable acids, into the oxalic. Nitric acid becomes thus the most convenient agent for purifying the succinic. The action of nitric acid on the benzoic has not been. well investigated, even by these gentlemen; but it is not transformed into the oxalic acid. Succinic acid affords with pot- ash a very deliquescent salt; with soda, a salt unchangeable in the air, or rather somewhat efllorescent, and crystallizing in plates like nitrate of silver; with ammonia, a slightly deliquescent salt, very soluble in water, and crystallizing in long prisms with four faces, transparent and colourless. It occurs frequently in plates; with barytes, a salt hardly soluble, which is obtained in the form of a white powder, by evaporating its solution. They were prevented by an accident from examining the salt that they had obtained with benzoic acid. These two acids precipitate copper, tin, silver; these precipi- tates, insoluble in water, are re-dissolved with facility by acetate of potash, and nitrate of soda, without the nitrate of potash, the sulphate and muriate of soda appearing to possess the same pro- perty.—Journal de Pharmacie, for February, 1823, 142 Progress of Foreign Science. Memoir on the Milk of the Cow Tree (Palo de Vaca). By J.B. Boussingault and Mariano de Rivero. Among the astonishing vegetable productions that are met with at every step in the equinoctial regions, a tree is found which yields in abundance a milky juice comparable in its properties to the milk of animals, and which is employed for the same purposes, as M. de Humboldt witnessed at the farm of Barbula (Cordillere lit- torale de Venezuela), where he drank some of the milky juice. The tree grows in considerable numbers on the mountains which command Periquito, situated to the north-west of Maracay, a village to the west of the Caraccas. The vegetable milk pos- sesses the same physical properties as that of the cow, with the single difference, that it is a little viscid. It has the same taste. In its chemical properties, it differs sensibly from animal milk. It mixes with water in all proportions, and when thus diluted, it does not coagulate by ebullition, The acids do not convert it into clots, as happens to cow’s milk. Ammonia, instead of causing a precipitate, renders it more liquid. This character indicates the absence of caoutchouc. Alcohol occasions a feeble coagulation, or rather renders the juice more easy of filtration, The recent juice slightly reddens litmus. Its boiling temperature is the same as thatof water. Exposed to heat, it exhibits at first the same phenomena as cow’s milk. A pellicle is formed at its surface, which prevents the disengagement of aqueous vapours. On re- moving the successive pellicles, and evaporating it at a gentle heat, an extract is obtained resembling frangipane; when the action of heat is longer continued, oily drops are formed, which increase according as the water is carried off, and finally afford an oily liquid, in which a fibrous matter floats which becomes dry and horny, as the temperature of the oil is raised. Then is dif- fused the best characteristic odour of meat frying in grease. By the action of heat, therefore, the vegetable milk is separable into two parts, the one fusible and of a fat nature, the other fibrous and of an animal nature. If the evaporation of the vegetable milk is not pushed too far, and if the fusible matter be not raised to ebul- lition, it may be obtained without alteration. It then possesses the following properties :— It is of a white slightly yellowish colour, translucid, solid, and resists the impression of the finger. It begins to melt at 40° centig., and when the fusion is completed, the thermometer indi- cates 60°.. Alcohol of 40° (sp. gr. 0°817) dissolves it totally by ebullition, and it precipitates on cooling. It saponifies with eaus- tic potash, and with ammonia forms a soapy emulsion. Nitric acid heated on it, dissolves and converts it into oxalic acid. It resembles refined bees’ wax, and serves for making candles. The fibrous substance is procured by decanting the melted waxy Progress of Foreign Science. 143 matter, washing off the last portions of it with an essential oil, squeezing the residuum, and boiling it a long time in water, to volatilize the oil, the odour of which cannot, however, be thereby completely discharged. Thus obtained, the fibrous matter is brown, having been somewhat altered by the temperature of the melted wax. It is tasteless. Placed on a hot iron, it twists itself and swells up, melts and is carbonized, diffusing the smell of broiled meat. Alcohol does not dissolve it; and hence by treating the extract of the vegetable milk repeatedly with hot alcohol, the fibrous matter is obtained white and flexible. In this state, it dis- solves readily in diluted muriatic acid. It possesses the same properties, therefore, as animal fibrine. Fibrine had already been found in the milky juice of the Carica papaya, by Vauquelin. Be= sides these two main constituents, the vegetable milk contains a little sugar, a magnesian salt (not an (acetate), and water. It contains neither caseum nor caoutchouc. By incineration, some silica, lime, phosphate of lime, and magnesia were obtained. The _ wax forms about one-half the weight of the milk.—Ann. de Chim. et de Phys. xxiii. 219. On the Hot Mineral Waters of the Cordilleras of Venezuela. By the same. The springs of Onoto issue copiously from gneiss. Their tem- perature is 44°5 centig. Their height above the level of the sea, is 702 metres. From the bottom of each reservoir, bubbles of azote rise from time to time in great abundance. The springs of Mariano have a temperature of 44° c., but in particular spots it is from 56° to 64°. They contain a very little sulphuretted hydro-~ gen. They also rise from gneiss, and evolve azote. Silica is the edominating ingredient in solution. Their height above the sea as 476 metres.—Ann. de Chim. et de Phys, xxiii. 272. Puysiotocgy.—On some recent Discoveries relative to the Nervous System. By M. Magendie. M. Magendie offers some proofs and illustrations of Mr. Charles Bell’s beautiful investigations, on the distinction between the nerves subservient to sensation and motion. An individual had lost the use of his two arms for several years, but he had retained a lively sensibility in these parts. He died, and on examining his body, the posterior roots of the brachial nerves (as they issue from the spine) were perfectly sound, while the anterior roots were evi- dently altered, had lost their medullary substance, and were re- duced to their membranous sheath. ‘The nerves give sensibility or mobility to our organs, only because they are connected with the spinal marrow; wheneyer they are insulated by a wound, or 144 Progress of Foreign Scvence. any other cause, the part to which they go becomes motionless and insensible, It was, therefore, of consequence to know if the spinal marrow was not itself divided into two halves, the one de- stended to motion, the other to feeling. M. Magendie has dis- covered that the spinal marrow is formed, as it were, of two cords juxta-posited, one of which is endowed with an exquisite sensi- bility, while the other is, so to speak, a stranger to the property, and appears to be reserved for motion. Since it is shewn by the fine experinients of Legallois, that all the other organs, without exception, derive from the spinal marrow their sensibility and mobility, we are led to the remarkable conclusion, that we must cease to seek for any one point in the whole body where the sen- sibility and mobility are compounded together. Hence it seemed very probable that, in persons who lose the power of moving, while they retain their sensibility, and that reciprocally in those who lose sensibility retaining mobility, there is a disease in the one case of the motive cord of the spinal marrow, and in the other of the sensitive. A lunatic of the hospital of Charenton, _ had lost, for seven years, the faculty of motion in the whole body, although he retained its sensibility. He died last month. M. Royer Collard, physician to the establishment, made the ‘spinal marrow be examined with the greatest care, and found, in fact, a very marked alteration in the whole motive portion of the spinal marrow, while the portion where sensibility resides was perfectly sound. ‘The centre of the spinal marrow is devoid of sensibility; on touching it, no movements are excited in the body. It is on the surface of this organ, that its properties are developed under the double relation of movement and feeling. ‘Those who think that the electric fluid circulates habitually in our nervous system, may derive from this fact a new argument in favour of their opinion; for electricity diffuses itself, as is known, on the surface of the bodies which it pervades. It is unnecessary to remark, that the facts above related, should have a great influence in the treatment of different palsies. When the cerebral hemispheres of any ani- mal are put out of condition for acting, the animal runs straight forward, with singular rapidity, as if it were pursued. We might say, that an irresistible force presses and precipitates it. If, on the other hand, the action of the cerebellum be stopped, the moyements take an entirely opposite direction. The animal draws back; and it is a remarkable phenomenon to see a bird, for ex- ample, whose cerebellum has been slightly touched, for whole days make no attempt to walk, swim, or fly, unless it be back- wards. It would seem, therefore, to result from these experiments, that an animal in the ordinary state of health, is placed between two forces, which make an equilibrium, of which one would push it in advance, while the other would push it backwards. Volition would have the power of disposing at its option of these two forces. \ Se Progress of Foreign Science. 145 A disease of the horse, little known, was proper to verify the precision of these results. Veterinary surgeons call this disease wmmobility; and, in fact, when it is wished to make the animal seized with it, fall back, whatever effort be employed, and what- ever means be taken, it stands motionless. ‘The forward move- ments are, on the contrary, easy, and seem sometimes to occur even without the participation of the will. If the inference whick I have drawn be exact, the disease ought to consist in a physical alteration of the cerebrum, or in some obstruction of the action of this organ. I caused to be examined, last month, two horses at- tacked with immobility, and the conjecture has been completely verified. In both the cerebrum was visibly altered; the cerebel- lum, on the contrary, was unaffected. It appears, then, to be de- monstrated, that the two opposite motive forces of the cerebrum and cerebellum exist in animals, and that, in certain cases, they may be withdrawn from the influence of the will. M. Magendie relates a case of a man somewhat similarly affected, who was cured by some grains of sulphate of quinina.—Ann. de Chim. et de Phys. xxiii. 429. Prussiate of Iron as a Cure of Intermittents. Doctor Zollickoffer, of Baltimore, has employed this substance, and his success has been as remarkable as with cinchona.—Journ. de Pharm. July, 1823. Injection of a Solution of Opium into the Veins of an Hysterical Patient. By Charles W. Coindet. This experiment was made at Edinburgh, and the result was such as to deter any young physiologist from repeating it in hys- teria. The patient was seized with violent spasms, constituting a case of idiopathic tetanus. They commenced very regularly by attacks of emprosthotonos, the head frequently striking the knees with force, Opisthotonos succeeded; the body took the form of a bow, and rested only on the heels and occiput. All the muscles of the body participated in this state of painful tension, which, one time, lasted twenty-seven minutes. The respiration was performed with difficulty, the pulsations of the heart became feeble and ir- regular, and the young girl (fourteen years of age), was threatened with suffocation. This horrible agony was succeeded by some convulsions of pleurosthotonos, which terminated the paroxysm. Dr. Coindet dissolved a scruple of common opium in an ounce of distilled water, heated to the temperature of 80° cent. At half- past seven in the evening he began the injection, assisted by his friends MM. Hercy and Lucius O’Brien. He made an opening in the right basilical vein, with an ordinary lancet as for blood let- Vor, XVII. L 146 Progress of Foreign Science. ting. He removed the bandage from the arm; he then introduced. the pipe of a syringe, and threw a drachm and a half of the solu- tion into the vein, taking care to exclude every portion of air, though the experiments of Nysten had shewn that a few air bub- bles would occasion no mischief. The breathing was immediately affected, becoming more regular, less rapid, and less convulsive. The pulse and other symptoms remained as before. The successive in- jections were repeated at intervals of five minutes. At the second, the breathing became quite natural; the pulse rose to 100, and was fuller. The skin became slightly coloured, and was soon covered with a faint perspiration. The spasms lost their violence; she heaved one or two sighs, like a person coming out of a pro- found sleep. After the fourth injection she recovered her hearing, but not her sense of sight. At the fifth, she began to see, and articulated some phrases distinctly. The operation was not fol- lowed with any disagreeble symptoms. On the following day, the girl described her sensations with much clearness. At every in- jection, it appearedvas if a torrent of fire had been poured into her veins, which rising up her arm, and following the course of the vessels, which she pointed out very exactly, passed under the clavical of the same side, and concentrated its operation for some instants on the chest, whence it proceeded to the head and along the back, from which it diffused itself through the whole system, and produced lively prickings and an intense heat in the skin. She spoke of her sensations as having been very painful. After six weeks of convalescence, she relapsed into a similar state of disease to that for which the injections were used. She finally re- covered from the convulsive affections by sea bathing; but was afterwards seized with swelling of the mesenteric glands. Dr. Coindet says, we must not expect from opium injections any thing more than the temporary cessation of the spasms, whereby the stomach may be brought back to its natural functions, which interval must be taken advantage of, for administering the suita- ble remedies, by the customary passages.— Bibliotheque Univer- selle, May 1823. Economics.—M. Viney one of the editors of the Journal de Pharmacie, has given, in the number for February last, the fol- lowing recipe for making a fetid and bitter solution, capable of destroying all kinds of insects: — Take of wood mushrooms, or large brown fetid boletuses 6 pounds Black soap ‘ : : Grated nux yomica_ . 2 ounces Water. : . + 200 pounds The mushrooms bruised and beginning to putrefy, are to be put into the water holding the soap in solution. The mixture is to be left to putrefy in a cask for some days, care being taken to agi- Progress of Foreign Science. 14? tate the liquid from time to time. When it has become very fetid, the decoction of the nux vomica in water is to be poured in. This liquor is employedto sprinkle the objects from which insects are to be repelled, whether in gardens or elsewhere, taking care not ‘to use it on gildings or polished metals, which it would blacken. The insect cannot stand this fetid poison. Art. XIV.—MISCELLANEOUS INTELLIGENCE. I, Mecuantcat Science. ' 1. Remarks on Iron Wire Suspension Bridges.—The following remarks on this subject are from a memoire by M. Dufour, the En- gineer of the Geneva bridge, briefly mentioned at page 369 of the Jast volume of this Journal: they are naturally connected with the account of that bridge. Speaking of the comparative strength of iron in wires and in bars, (see p. 367 last vol.,) M. Dufour says, ‘“‘ The immense ad- vantage of employing iron in wire rather than in bars, is thus rendered evident: it is more manageable, its strength is double, the strength may be better proportioned by putting the number of wires necessary to the resistance required, and a certainty is ob- tained of the state of the interior parts of the suspending lines, which nothing can give when large bars are used.” “It appears at first that the minimum of the force of the wire should be calculated upon, and not the mean; but as each bundle contains many wires, although there may be some of a smaller strength, there will be others that will surpass in strength, and thus the mean should be used in estimating the strength of the whole, although in employing a single wire the minimum only ought to be taken.” _ With regard to the Geneva bridge, M. Dufour says that after a period of four months in which the bridge had been in full use, it ad not suffered. the slightest alteration in its primitive form, ‘The path has retained the degree of curvature given it at first, and no sensible lengthening of the wires has occurred. The bridge, however, has been well tried, curiosity has taken great numbers of persons on to it at once, and all the large stones re~ quired in the latter part of the work, were taken over it on car tiages without the slightest damage. The elasticity of the bridge is also what it was at first, a man walking with a moderate step does not at all disturb the steadiness of the path; on walking quickly there are slight vibrations produced, but no oscillations, and the vibrations are such as never to be communicated from the one bridge to the other, or in any Hp to affect the masonry. 2 148 Miscellaneous Intelligence. © The expense of the bridges was as follows :— Masonry of the abutments, $c. . . . 4100 francs. lodges, stations, §c.. . 3800 Forged iron, §c., for the gates. . . - 2800 Iron wire and workmen . . . » . - 1940 Wood-work required, workmen, Jc. . 2250 Lead, copper, tin, varnish, Jc. . . - 800 Terraces for the parapets, foundation, §c. 160 Various expenses . . . . . + ~ + 4500 oe 16,350 Bib. Univ. xxiv. 297. 2. Test for the action of Frost on Building Materials, by M. P. Brard.—MM. Lepeyre and Vicat knowing that I had been long occupied in the study of mineralogy as applicable to the arts, en- gaged me in an investigation of the means best adapted to distin- guish such stones, as, being otherwise fit for building materials, gave way to the action of frost. I found it impossible in this respect to ascertain any thing from their mineralogical characters, and was obliged to follow another course. During the winter of 1819, I carefully examined with a lens the chalky limestone of the neighbourhood of Perigueux, and the sandstone of the coal basin of la Vezére, both equally liable to this action, I soon found that each scale of the limestone, and each grain of the sandstone was raised by the re-union of small needles of ice, which when they melted suffered the particles to fall and collect about the stone, and that where particles had fallen off in this way, a fresh succession was raised in the same manner, and ultimately se- parated from the mass. I was struck by the resemblance of. the ice in silky crystals to the saline efflorescences which appear between the plates of cer- tain shists and on the surface of old walls. I remembered the ef- fect of common salt on bad pottery, and on the saline rocks of the Tyrol, and conceived the idea of substituting the action ofa saline solution to that of common water. After various experi- ments, I gave the preference to sulphate of soda, its effects being the most constant and most comformable to the action of frost. The experiment that it may lead to satisfactory results should be conducted as follows. Suppose an excavation newly made into limestone or other rocks, and it be desired to ascertain the liability of the rock to disintegration by the action of frost. lst. A cube of two inches in the side is to be cut from each part to be tried; the various cubes numbered with thick China ink, and their original sites also marked. Mechanical Science. 149 2nd. About four pints of common cold water is to be saturated with sulphate of soda, so that a few grains of the salt shall remain undissolved. 8rd. This solution is to heated to ebullition, and then all the cubes to be entirely immersed in it. When the boiling has recom- mencéd it is to be continued for half an hour. 4th. The cubes are to be withdrawn from the solution and placed each one in a saucer, numbered as the cube is; a small quantity of the solution is to be poured on to each cube, and the whole left until covered with white efflorescences perfectly analo- gous in appearance to the rime or hoar frost, which causes the dis= integration of the stones. These efflorescences will appear in about twenty-four hours if the air is dry or hot, but in a humid atmosphere are sometimes five or six days. 5th. When the efflorescences appear on the angles and sides of the cubes, they are to be dissolved again by means of a few drops of water, or better still with a little of the solution in which the cubes were boiled. If well managed the efflorescences will soon re-appear, and when well formed, are again to be removed ina similar way, and this is to be repeated for three or four days toge- ther *; after which each cube may be washed with abundance of common water, but without removing it from the saucer. 6th. The specimens to be tried having been washed on all their faces, the detached matter is to be examined, and a judg- ment formed from it, of the relative qualities of each kind of stone submitted to the proof: for the greater the number of the de- tached particles collected in the saucer, the more liable is the stone to be attacked by frost; the smaller the number the more capable is it of resisting the action. As yet, all the results of this test have accorded perfectly with the effect of time and frost. Such stones as have been found to disintegrate by frost have given way to the salt, such as time has sanctioned have resisted the new agent, so that the mechanical effects of the two are perfectly analogous, Crystallization takes | place with both, augmentation of volume, efforts on the surfaces of the small cavities containing the water or solution, and if the aggregation be not sufficiently powerful to resist the action, dis- ruption, and a gradual decay of the rocks either in their natural sites, or if they have been applied to use in their new situations. The action of the sulphate of soda being quite mechanical, is ex- erted indifferently on all kinds of rocks deficient in aggregation, on limestones, sandstones, large grained granite, granites of too micaceous a structure, shists, lavas, &c. It may be employed as a proof or test also even upon slates, bricks, tufas, mortars, and cements, as is proved by a table of various results of this kind. * If the proof be continued for a longer ames good building stones may be rejected, for the prolonged action of the salt is more powerful than that of ice, 150 Miscellaneous Intelligence. The above is freely translated from a paper inserted by M. Brard, in the Bib. Univ. xxiv. 224. 3. On the Strength of Cast Iron and other Metals.—It was our intention to have noticed a new edition of Mr. Tredgold’s valuable essay on the above subject, in a former part of our Journal, but this has been prevented by the pressure of other matter. We must, therefore, rest satisfied with laying before our readers the contents of the eleven sections into which the work is divided, reserving to a future occasion a more explicit account of its contents. The First Section consists of introductory remarks on the use and the qualites of cast iron; and of cautions to be observed in employing it. This section is followed by three extensive tables, which will often save the practical man a considerable share of trouble in calculation. The Second Section explains the arrangement and use of the tables, which precede it ; and in this edition, the number of popu- lar examples is much increased. It is a common and a well understood fact, that an uniform beam is not equally strained in every part, and therefore may be reduced in size, so as to lessen both the strain and the expense of material. The Third Section points out the value of cast iron, in this par- ticular, and the forms to be adopted for different cases, The Fourth Section contains a popular explanation of the strongest forms for the sections of beams; the construction of open beams ; and the best forms for shafts. A due consideration of these two sections will enable the young mechanic to guard against some common errors in attempting to apply these things to practice. They are much augmented, and a new principle of con- structing bridges is explained in the fourth section, _ The Fifth Section is wholly devoted to experiments on cast iron; it will be found to contain, in addition to the author’s expe- riments, almost all of the experiments that have been described by preceding writers. To this section a great many new experiments have also been added, to show the relative strength of iron of different qualities ; and also seven new experiments on torsion, made by Messrs. Bramah. The section concludes with the result of the author’s observations on the relation between the appearance of the fracture and the strength of cast iron as determined by expe- riment. The Stath Section contains experiments on malleable iron and other metals, and is entirely new. The effect of hammering and the decrease of force by heat, are experimentally examined ; and Mechanical Science. 151 the cause of English iron being inferior to Swedish, for particular purposes, is pointed out. In the Seventh Section we are shown how to obtain some of the. most useful practical rules from the first principles that are fur- nished by experience. The Eighth Section treats of the stiffness to resist lateral strains, with its application to some interesting practical cases. The Ninth Section is on the strength and stiffness to resist tor- sion or twisting, with its application to machinery. The Tenth Section treats of the strength of columns, pillars, and ties, with some new examples. It may be useful to remark, that the most refined methods of analysis have been applied to the same subjects by Euler, Lagrange, and other continental mathemati- cians, without arriving at results more accurate, more simple, or more convenient in practice. In the Eleventh Section the author considers the resistance of beams to impulsive force. In this section will be found many im- portant rules, with examples of their application to the moving parts of engines, bridges, &c., wherein the advantage gained by employing beams of the figures of equal resistance is shown. The Eleventh Section is followed by an extensive Table of the Properties of Materials, and other Data, often used in Calculations, arfanged alphabetically, and in this Edition much enlarged. By means of this table the various rules for the strength of cast iron, contained in this work, may be applied to several other kinds of materials. A Note, added at the end of the table, on the chemical action of some bodies on cast iron, will be read with interest by those who employ cast iron where it is exposed to the action of sea water. 4, On the Capillary Action of Fissures, ye.—M. Dobereiner has remarked a singular effect produced apparently by fissures. Hav- ing filled a large glass flask with hydrogen, and left it standing over water, it was observed some days after, that the water had risen in it above one-third of its capacity. The only cause for this effect that could be assigned was, the existence of a very minute fissure in the glass. Filled a second time and left over water, the fluid had risen in it above an inch and a half in twelve hours, and in twenty-four had risen two inches and three quarters, during which time the barometer and thermometer had not sensibly al- tered. In other experiments, vessels of other forms were used, and the water uniformly rose in those having fissures. When one of these vessels filled with hydrogen was covered by a bell glass, or when the vessels were filled with atmospheric air, oxygen, or azote, instead of hydrogen, no change took place. — M. Dobereiner considers the effect as due probably to capillary 152 Miscellaneous Intelligence. action. He suggests that all gases may be considered as consist- ing of solid atoms of various sizes, enveloped by atmospheres of heat also very different, and that hydrogen though it has the largest atmosphere of heat, has the smallest atom, and is thus permitted to escape by fissures, which retain the other gases. “ Probably,” he says, ‘‘ fissures may be formed which will permit azote to pass, but not oxygen, and others again which will let the oxygen out, but not carbonic acid gas.” Another experiment which seems related to this subject is as fol- lows :—A thermometer-tube had been drawn out very fine in the lamp, and it being desired to have it filled with alcohol, the point was immersed in that fluid, and the bulb heated until no more bubbles of air escaped; the tube was then cooled, but no alcohol entered. When again heated abundance of bubbles of air passed out through the alcohol, though when recooled no alcohol would enter. Upon examining the tube with a lens, nothing was seen which could prevent the entrance of the alcohol ; on withdrawing the tube from the alcohol, the external air entered with a hissing noise. M. Dobereiner conceives that the diameter of the tube was so small that the alcohol could not enter, but only the air which it contained.—Ann. de Chim. xxiv. 332. 5. Sound produced by opening a Subterraneous Gallery.—In the road made by Napoleon communicating between Savoy and France, and which passes by Chamberry and les Echelles, there is, as is well known, about two miles from the latter place, a gal- lery cut in the solid rock, twenty-seven feet high and broad, and nine hundred and sixty feet in length. Mr. Bakewell states in his travels, that this gallery having been commenced at both ends, when the excavations from each end nearly met, and the thin par- tition of rock between them was first broken through by the stroke of the pick,a deep and loud explosion followed resembling thunder. The cause of this explosion Mr. Bakewell thinks is easily explained. The air on the eastern side of the mountain being sheltered both on the south and west from the sun’s rays, must be frequently many degrees colder than that on the western side. The moun- tain rises full one thousand feet above the passage, and at least fifteen hundred feet above the bottom of the valley, forming a partition between the hot air of the valley, and the cool air of the ravines on the eastern side, and a sudden opening being made for the dense air to rush into a rarer medium, must necessarily pro- duce a loud report, just as a bladder does upon bursting in the rare air of a receiver. ‘The sound of the explosion being greatly increased by reverberation through the long archway on each side.—Bakewell’s Travels. This explanation of the origin of the sound seems insufficient to us, inasmuch as it would require a much greater difference of ba- ‘ Mechanical Science. 153 rometric pressure on the opposite sides of the previously existing partition of rock than probably existed. , 6. Nautical Eye-tube.—A trial has been made on board the Clio among the Orkneys, and in the Moray Frith by Mr. Adams, of the performance of his eye-tube to the telescope of a sextant for taking altitudes when the horizon is invisible. In making the ob- servations the horizon was always screened from the instrument, and under these circumstances after rejecting a few observations the mean difference of 199 altitudes of the sun, moon, and stars, taken by the eye-tube, from those taken at the same time in the . ordinary way by the officers of the Clio, and corrected for dip, amounted to only 1’10”. The altitudes taken by the eye-tube are not affected by any dip or depression of the horizon. Consider- able care and practice is required in the use of the instrument, but that attained, the latitude, the time at the ship, and consequently the longitude may all be determined by it when the horizon is invisi- ble. By means of it also either the large or the pocket sextant may be employed on shore as a substitute for the theodolite, upon making the necessary allowance for the parallax of the instrument in the name of index, error, which oa becoming sensible, must vary inversely with the distances of the reflected terrestrial objects.— N. M. Mag. xii. 16. 7. Leghorn Straw Plait.—The Dublin Society having offered premiums for the best imitations of Leghorn plait, awarded three prizes to successful candidates. Not less than twenty-four speci- mens were exhibited from widely remote parts of Ireland. The finest specimen was made from avena flavescens, or yellow grass, by Miss Collins of Plattin, near Drogheda. The second was made of cynosurus crystatus, or crested dog’s tail, by Miss Grimley of Kiltinon, near Newton Mount Kennedy. The third of agrestis vulgaris, or common bent grass, by Miss Campbell of Lon- donderry. IJ. Cuemican Science. 1. On Fulminating Silver and Mercury.—The following results are collected from a memoire on these substances, by Dr. Just Liebeg, which has appeared in the Annales de Chim. xxiv. 294. The fulminating silver was obtained by dissolving about 60 grains of fine silver ia half an ounce of nitric acid, spec. grav. 1,52, add- ing two ounces of alcohol of spec. grav. .85, and heating slowly in a flask until ebullition commenced ; in a short time, white crys- talline flocculi appeared, the vessel was removed from the source of heat, and left to cool. The ebullition continued some time, and 154 Miscellaneous Intelligence. the deposit augmented. The vessel should not be cooled hastily in this process, as great loss of the compound is occasioned. Thus prepared, the fulminating silver appears in white silky acicular crystals, possessing the well known detonating properties, perfectly soluble in 36 parts of boiling water, and re-crystallizing as the solution cools. It has a metallic taste, stains the skin, if exposed to air becomes first red, then black, and to test papers appears as a neutral salt. Fulminating mercury was prepared according to Howard’s process: 100 grains of mercury being dissolved in half an ounce of concen- trated nitric acid, and two ounces of alcohol added. Heat is then to be applied, as in the former case. At firsta little nitrate of mercury is deposited, but is soon redissolved, and then ona sudden the liquor becomes grey from the reduction of part of the oxide of mercury, and the liberation of a dense vapour, occasioned by the volatiliza- tion of a portion of mercury with the ether that rises. After some time the liquid becomes yellow, and dendritical crystals appear, which augment on cooling until nearly a quarter of an inch in length. ‘hey are greyish-white, harsh to the touch, and heavy, but when purified by being dissolved and crystallized two or three times, appeared as perfectly white brilliant silky crystals, having a mild metallic taste, and detonating violently by a blow. ‘They are pure fulminating mercury. On adding lime-water to fulminating silver the latter dissolved, leaving a little black oxide of silver; when a few drops of nitric acid were added to the clear solution a white precipitate fell, which detonated like the original compound. It now dissolved without any residue in lime-water, and was precipitated again by acid, as before, without any indication of decomposition. Substituting potash for lime-water, and boiling, exactly the same effects took place. The fulminating silver combined also in the same manner with magnesia, baryta, strontia, soda, and ammonia, and with all of them presented the same phenomena, except that ammonia did not cause the separation of oxide of silver. The quantity of oxide separated by the alkaline bases from 100 of ful- minating silver was 31.25, Thus it appears that fulminating silver perfectly resembles a compound salt; its acid combines with the alkalies, &c., and its base, the oxide of silver, separates; and in confirmation of this view of its nature it was found that compounds of the acid, and all other bases, might be obtained perfectly definite and crystallized, and possessing strong detonating properties. A quantity of fulminating silver was decomposed by lime, the liquid filtered, concentratel, and carefully precipitated by nitric acid, excess of the latter being avoided. The new acid, when well washed, appeared as a white powder, very soluble in boiling water, reddening litmus paper, and crystallizing on cooling. Chemical Science. 155 Researches were then made into the nature of this acid: the term fulminate, has been applied to the salts containing it. Mu- -Tiate of potash added to fulminate of potash produced no precipi- tate of chloride of silver; but muriatic acid decomposed the salt, and chloride of silver, muriate of ammonia, hydrocyanie acid and earbonie acid, resulted. Fulminate of potash does not preci- pitate persulphate of iron, nor does the addition of muriatic acid form a prussiate of iron, , Metallic copper precipitates all the silver from fulminate of potash, and a plate of zine indicates the copper present; but excess of potash does not separate the copper, nor ‘does the fluid become blue by adding ammonia, though when the solution is decomposed by npuriatie acid, the copper is easily found by those tests. Chromates, prussiates, and carbonates, do not precipitate the silver from alkaline fulminates; these properties point out a strong analogy between this acid and the metalliferous cyanic acids. The fulminating acid boiled with oxide ofsilver, gave fulminating silver; boiled with oxide of mercury, it produced a compound in small brilliant plates. Conceiving from analogy that the acid of fulminating mercury differed from that of fulminating silver in the substitution of the former metal for the latter, experiments were made to ascertain this point; crystals of fulminating mercury boiled with potash, deposited oxide of mercury, and the fluid, when precipitated by nitric acid, gave.a white precipitate, which, when dry, detonated strongly by percussion; with baryta, strontia, and lime, similar compounds to those formed by fulminating silver, were produced. The separation of the acid from fulminating mercury does not al- ways succeed. In only two operations out of eight was the acid obtained in yellow detonating crystals. A quantity of fulminating silver was put with metallic mercury into water and boiled ; after some time the liquid became turbid, it was filtered, and furnished crystals exactly the same as those pro- duced by the acid of fulminating silver and the oxide of mercury. Boiling another portion for a much longer time, the precipitate deepened in colour, and when no more was formed, the whole was filtered and crystallized. The crystals were very fine, and pure fulminating mercury; and an amalgam of mercury and silver re- mained. ‘Ihe reverse operation was performed of preparing ful- minating silver from fulminating mereury; the latter was boiled with silver which had been precipitated from the nitrate by copper, and to which a quantity of platina filings had been added; by the galvanic action of the two metals the mercury was precipitated, ‘and the silver dissolved. The experiment requires rapid manipu- Jation and simple decantation, otherwise the crystals will always ‘contain mercury. Fulminating silver was boiled with copper; the silver precipitated, 156 Miscellaneous Intelligence. and the liquid, which was found to contain copper, after some time deposited a bluish-green powder, which behaved like a true com- bination of oxide of copper with the acid of the fulminating silver, containing copper in place of silver. The compound detonated more feebly than that of silver, and was difficultly soluble in boil- ing water ; on evaporating the mother liquor, a large quantity of fulminating copper was obtained. Zine gave similar results, but mrretrerterdn Iron also produced a crystallized fulminating com- ound, ! When fulminating mercury was acted on by the metals, similar phenomena were produced; and fulminating copper and fulmina- ting mercury were thus obtained. When fulminating silver was boiled with magnesia, the liquid was found to contain but very little of the acid, but a reddish pre- cipitate had formed, which, though it contained the greater part of the fulminating mercury, merely decrepitated feebly when thrown upon ahotcoal. Half an ounce of it heated in a retort, decomposed quietly, yielding a portion of carbonate of ammonia and water, and carbonic acid gas, no other gas being liberated. In order, there- fore, to obtain a knowledge of the constituents of fulminating sil- ver, 100 parts were well mixed with 400 parts of calcined mag- nesia, and heated in a luted retort, the products being carefully received and estimated. They were, With fulminating silver With fulminating mercury Carbonic acid . . 35°5 Ammonia ty ss era Zips ay eed OF Welter uy hiy erro! Valet apes Silver . . . . 41°0 . Mercury 56:9 Deas bs are eee ai wines ee 100° 100- These being the mean of four experiments on each compound. The only substance which varied was the carbonic acid, and the proportions of the other substances remained constant. These gave as the ultimate elements, Fulminating silver Fulminating mercury Oxygen . . -» 32°22... . ~ 23°39 Hydrogen. | s . BH2D wa VY BeBe Witrogen’ 145.) 4, SVE 2B A 4 Paes Gees Carbon.) 3 0a SRG8 isis ee Be A Silver . . . 41:00 . Mercury 56°90 The following are some of the compounds of the acid of fulmi- nating silver with bases. —Magnesia combines in two proportions with the acid: one is a rose-coloured powder, not soluble or deto- nating, but merely decrepitating by heat; the other is in beautiful white filamentous crystals, resembling capillary silyer, and Chemical Science. 157 strongly detonating.—Baryta combines with the acid apparently in two proportions ; the first crystallizes in dull white grains, which detonate powerfully, and are difficultly soluble in water.—Strontia resembles baryta in its compounds.—Zinc forms a salt in small yellow granular crystals, very soluble, and very heavy.—Potash produces a salt which crystallizes in long white brilliant plates, having a disagreeable metallic taste, not affecting test-paper, dis- solving completely in eight parts of boiling water, and detonating powerfully when heated or struck. It contains 85:08 of acid, and 14-92 of base.—Soda has always produced a salt in small rounded plates, brown and brilliant ; they are lighter and more soluble than the preceding, but otherwise resemble it. ‘They contain 88-66 of acid, and 11-34 of base.—Ammonia with fulminating silver leaves no residuum. Berthollet’s compound being formed at the same time with the other. On cooling, a large quantity of granular crystals are obtained, which are difficultly soluble, and have a strong me- tallic taste. They detonate even in the liquid when touched by a glass rod, but fortunately if excess of alkali be present the deto- nation does not extend to the neighbouring portions. 2. On the unequal Dilatation of a Crystal in different directions, by heat.—On measuring the mutual inclinations of the planes of a crystal of carbonate of lime at different temperatures, M. Mits- cherlich observed that they varied sensibly with the temperature, the variation sometimes amounting to 8'.5 from 32° to 212. Fahr. When the temperature rose, the obtuse diedral angles diminished, or in other words the short axis of the rhomboid expanded more than the other diagonals, so that its form approached to that of the cube. M. Mitscherlich concluded, therefore, that the double re- fraction of the crystal would at the same time diminish; a result confirmed by an experiment which he afterwards made with M. Fresnel in the manner adopted by that philosopher in 1817, to render more sensible the changes in the tints of plates of sulphate of lime. M. Fresnel had then observed, that elevation of tempe- rature sensibly diminished the double refraction of sulphate of lime ; and according to the recent experiments of the two philoso- phers the same effect is produced, though in a much less degree, on rock crystal. This experiment, however, requires repetition. It appears, therefore, that generally an uniform elevation of tem- perature in acrystal diminishes its double refraction. M. Mits- cherlich thinks that heat ought always to separate the molucules of a crystal farthest apart in that direction in which they are most contiguous.—Ann. de Chim. xxv. 109. 3. Difference of crystalline Forms of the same Substance.—M. Mitscherlich, who first observed the remarkable fact that a body may affect two different crystalline forms, has, in a memoir on this 158 Miscellaneous Intelligence. suhject, quoted sulphur as an instance. Natural crystals of sul- phur are furnished by some calcareous strata, and by volcanoes. Artificial crystals may be obtained either by evaporating a solution of it in carburet of sulphur, or by fusion of the sulphur and slow cooling. On fusing native sulphur, it gives the same crystals as common sulphur. The primitive form of the crystals of sulphur, either natural, or obtained as above by evaporation, is an octoédron, with a rhombic base; but the primitive form of the crystals ob- tained by fusion, is an oblique prism, with a rhombic base.— Anz. de Chimie, xxiv. 264. 4. Supposed Effect of Magnetism on Crystallization. — The follow- ing is an experiment first made by Professcr Maschmann, of Chris+ tiana, and confirmed by Professor Hanstein, of the same city; we should nct have noticed it but for these names. A glass tube is to be bent into a syphon, and placed with the curve downwards, and inthe bend is to be placed a small portion of mercury, not suffi- cient to close the connexion between the two legs; a solution of nitrate of silver is then to be introduced until it rises in both limbs of the tube. The precipitation of the mercury in the form of an arbor Diana will then take place, slowly only;when the syphon is placed in a plane perpendicular to the magnetic meridian; but if it be placed in a plane coinciding with the magnetic me- ridian, the action is rapid, and the crystallization particularly beautiful, taking place principally in that branch of the syphon towards the north. If the syphon be placed in a plane perpendicular to the magnetic meridian, and a strong magnet be brought near it, the precipitation will recommence in a short time, and be most copious in the branch of the syphon nearest to the south pole of the magnet. 4. On Thermo-magnetism.—The following account of results on the magnetism of a single piece of metal developed by heat, is abstracted from a paper by Dr. J. d’Yelin, or rather from an account of that paper in the Bibliotheque Universelle. The re- sults, if confirmed by further experieuce, are very highly impor- tant to the theory of magnetism. In repeating the experiment of Seebeck, M. Yelin made use of platina, gold, silver, iron, copper, brass, zinc, tin, lead, antimony, bismuth, and arsenic. The result of his observations was that ‘* the effect of Seebeck’s circuit should not be considered as a de- terminate function of power possessed by the heterogeneous metals of developing electricity by contact, and of their various conduct- ing powers as to heat; and that therefore, conclusions cannot be drawn from these properties,” as is proved by the following facts : ' 1. Silver and zine give by contact an electricity stronger than silver and antimony; but a circuit formed of the two latter metals Chemical Science. 159 has much greater power than one composed of the former, which is very feeble. The case is the same with the two sets, copper and zinc, and copper and bismuth. © 2. Brass, copper, and lead, according to Bockmann, have a conducting power as to heat of 344, 346, and 850; nevertheless, acircuit of brass and copper is sensibly stronger in its action than a circuit of lead and copper. 3. Finally, silver in contact with antimony is electrized nega- tively, in contact with zinc it is still more powerfully so; but - other circumstances being equal, a circuit of antimony and silver has seven times the power over a magnetic needle that a circle of zine and silver has. Antimony is positive when opposed to pla- tina, gold, or silver, and negative when opposed to copper, tin, lead, or zinc; but whichever of those metals be formed into a circuit with antimony, the same effect is obtained, the same pole of the needle always being urged to the same side. Bismuth and antimony are both positive when in contact with platina, gold, and silver, but all other things being equal, as the dimensions of the metal, the soldering, the temperature and arrangement, a circuit ormed of bismuth and one of the last named metals, turns the ole of the needle 14°, 51°, or 45° to the east, whilst if antimony be substituted for the bismuth, the pole is thrown 18°, 25°, or 30° to the west. Being induced to consider the rupture of the equilibrium of temperature as the principal cause of the electro-magnetic action of Seebeck’s circle, M. d’Yelin endeavoured to obtain similar effects with a single piece of metal, and having obtained very de- cided effects, he has given to this class of phenomena the name of thermo-magnetism. ‘That very feeble magnetic action might be observed, very delicate needles were used; they were of great tenuity and suspended by a single spider’s thread. If a band of any single metal be formed into a circuit of any figure, by riveting one of its ends near the other, and the projecting end be heated by a flame, whilst the circuit is plunged in cold water, this band will become electro-magnetic, and its properties may be easily ascertained. The experiment was made with zine, bismuth, brass, tin, lead, and copper, and M. d’ Yelin infers that “ all metallic bodies acquire electro-magnetic properties when their various parts are unequally heated, and that the action is stronger as the difference of temperature is greater.” This fundamental experiment being established, the following are the principal results obtained by the author:— I, The metals, in reference to their thermo-magnetic properties, may be ranged as follows, commencing with those which possess them in the highest degree, bismuth, antimony, zinc, silver, pla- tina, copper, brass, gold, tin, lead. II. A metal acts differently on the needle according as the hot or 160 Miscellaneous Intelligence. the cold part of it be placed under the needle. The following experi- ments were made with cast bars six or seven inches long, one inch in thickness, and formed either as cylinders, or as prisms with three, four, or six sides; solid and hollow balls were also employed :— 1. If one extremity of a bar of bismuth be heated, the bar be placed in the direction of the magnetic needle, with its cold end to the north, and the hot end be brought under the needle, the point of the needle will turn towards the east. 2. If the direction of the bar being preserved, it be moved towards the south until its cold end is under the needle, the needle will turn towards the west. 3. The inverse effects are obtained when the hot end of the bar is towards the north. 4. When the bar is heated in the middle, and the ends preserved cold, the same effects are obtained for each half of the bar. 5. The magnetic effects are sensible when one part of the bar is heated merely by the hand and the other cooled by snow. III. The magnetic action of metals unequally heated depends on the form given them in casting, and in this it differs from the action of Qérsted’s connecting wire. 1. If an equilateral tri- angular prism of bismuth be used as in the former experiments (1), and its faces be turned upwards successively, one of its faces will make the needle deviate to the east, the next face (that towards the east) brought into the place of the first, will make the needle deviate to the west; the third face has so uncertain an effect that it may be considered as null. 2. If a square or four-sided prism of bismuth, antimony, or zinc, be used in a similar manner, it will be found that two contiguous faces when turned upwards will make the needle move eastward, whilst the other two faces will move it westward, so that the prism may be considered as composed of two triangular prisms of which the un-magnetic faces are in contact. 3. With a regular hexagonal prism three of the faces move the “needle eastward, and three move it westward. 4. Cylinders pre- sent peculiar effects; a cylinder of bismuth had been thrown with its mould into cold water immediately after being cast, another was suffered to cool slowly ; when these cylinders were used in place of the prisms, the ends which were uppermost in the moulds being placed under the needle, one part of the curved surface urged the needle to the east, and the other part to the west; these parts were equal in the first cylinder, but unequal in the second. When the other extremities of the cylinders were placed under the needle, then the curved surface of the first cylinder presented four nearly equal portions which successively turned the needle to the east and west: the second bar presented six similar portions. The differences remarked between the extremities of the cylin- der, and also between the cylinders themselves, when cooled slow- ly or rapidly, induces M. d’ Yelin to conclude there is some rela- tion between the crystallization of metals and their magnetic pro- perties.— Bibliotheque Universelle, xxiv. 253. Chemical Science. _ 161 ’ 5. Electromagnetic Multipliers —Dr. Kaerntz has lately been oc- cupied in proving experimentally the amount of the advantage ob- tained in electromagnetic multipliers, by each additional circumvo- lution of the wire. His motor was a zinc plate about eight inches long and four inches wide, the copper opposing both sides was consequently double that'size. The fluid conductor was a solu- tion of muriate of ammonia in spring water, with the addition of one hundredth of sulphuric acid. The connecting wire was cop- per harpsichord wire, covered with silk thread, and the same length was used in every experiment. By connecting the plates with the wire before immersion, by immersing slowly and by other expedients, any important variation in the intensity or quantity of action was avoided. In this way it was found that the quantity of power of the in- strument over the needle, was exactly in proportion to the number of convolutions, six convolutions giving six times the power of one convolution; and by experiments, when the forces of the instru- ment and of the earth’s magnetism were arranged in different ways, this result was confirmed. Such an instrument is therefore wore correctly called a multiplier than a condenser.—Phil. Mag. xii, 441, 6. Plate Electrical Machines.—A variation in the construction of plate electrical machines has been devised and practised -by M. Metzger of Siblingen in Schaffhouse, which would seem to be areal improvement. Considering that the effect desired in using the machine was first highly to excite the glass, and then to col- lect the electricity from it, M. Metzger concluded that the dis- tance between the rubber and the points of the conductor in ma- chines of the common construction was injurious in its effect, not only by causing the dispersion in part of the electricity excited, but by uselessly wasting the exciting surface. Plates were - therefore mounted in a very compact and perfect manner, with three pairs of rubbers placed at equal distances from each other ; the conductor also had three arms furnished with points a little in advance of each pair of rubbers, to collect the electricity in the usual manner. ‘The rubbers were not attached to a surrounding frame, but to brass arms, which proceeding froma socket through which the axis passes, diverged at equal distances from each other towards the periphery of the plate. The machine has a very com- pact and neat appearance, and its various smaller parts are con- trived with much judgment. In some comparative experiments made with a plate twenty-two inches in diameter, the superiority of three pair of cushions over two pair was very manifest. In the following table the first column expresses the length in inches of the rubbers; the second the length of the spark when two pair of rubbers were used, and the Vor, XVII. M 162 Miscellaneous Intelligence. third the length of the spark when three pair of rubbers were on the machine. ; 6inches. . .12inches. . . 18 inches. 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OC eee ye YY hn = Z > 2 nh aq ch af a Mj as 5 q ee | 730° i 8 wees pane eed Pires x 5 nd es 1 g in ’ ’ a ~ Pas ¥ 7 a4 4 £ a 7 7 ; . , . - ‘ hike cent Pd pe aoe a, Chins Pree ~*~". nae“; 4 “ ” sys ae , ne eet >. + z . ‘ ’ ; _S yr io. 2% Beccsipge! + Ta a Le = Beh) hi I Md a. A Hedi ee LO rth ee ee me eee ry i = Bre er Sait at: Hegel: a : - -<-—- Tos st ane tee ees : buabetsssuscases Sasa UPObAAataGasee alae a Sasege oss< =o bpeptecers Ao grees } t+ -" tiene anos vo th TY onmieces =n: neato } bY Bis h eve ripuanorng unease DIVE TER) eee ee & THE QUARTERLY JOURNAL, July, 1824. Art. I. On the Horary Oscillations of the Barometer, By J. Frederic Daniell, F.R.S. Havine haa occasion, some time ago, to inquire into the facts regarding the daily periodical fluctuations of the barometer, I was greatly struck, not only with the regularity of their occurrence, but with their gradual decrease in proceeding from the equator towards the poles, as shewn by the experiments of different observers. The following table constructed from the best authorities, places this circumstance in a striking point of view. ‘ TABLE I. Mean Periodical Movement of the Barometer, at different Latitudes. North Dintiende) Mean periodical move- ‘i ier Namésiof ‘Places, ment of the Barometer St.Thomas’. ...| 0.24 | 0.074 inch Sierra Leone 8.29 0.073 Trinidad... ... . | 10.39 0.063 Jamaica ......| 17.56 | 0,058 Clermont-Ferrand . | 45°47 0.039 oS Por 48,50 0.028 i §1,.31 0.015 Vou, XVII. P 190 Mr. J. F. Daniell on the In endeavouring at the same time to account for these pheno- mena upon the known laws of aériform fluids, I was led to con- struct an hypothesis which appeared to me to explain this gradual decrease of the oscillations ; but at the same time pointed out a condition of the problem which would at once, if confirmed by ex- perience, be a test of the correctness of the solution. Let us suppose that in the atmosphere surrounding the earth a circulation is kept up between the poles and the equator; and that the cold dense air of the former regions flows in a lower current to the latter, while the elastic air of the latter is returned in an upper current to the former. There can be no difficulty in imagining further that, as long as these currents are maintained with regular velocities, a barometer, at all intermediate stations, might exhibit an equal pressure of the a€rial columns; for as much air would flow from their summits as would be returned to their bases. A general alteration of temperature, which equally pervaded both currents, would produce no alteration in the weight of a vertical section, comprising both; nor would a partial alteration equally diffused through the upper and under section of any one column. The velocities of the currents would be partially altered thereby, but the higher and lower would still compensate each other. But an alteration of temperature which affected the upper and lower currents unequally, would produce partial expansions and con- tractions, which would effect an unequal distribution of the pon- derable matter. If the lower stratum of any perpendicular section were expanded by heat, while the upper were unaffected, the out- going current of that section would be increased, while the in- coming current would be checked; and the balance of the two being disturbed, the total weight would be diminished. On the other hand, a local decrease of temperature would produce the analogous contrary effect. Now the alternations of heat and cold, produced by the changes of day and night, although they may be regarded in a general way as pervading both currents, act with suf- ficient inequality to induce us to expect a corresponding fluctuation in the weight of the atmosphere at any particular point. The heat- ing Surface being below, the warm particles quickly ascend, and EE a es = ity ey Horary Oscillations of the Barometer. 191 are immediately replaced by the cold particles from above; and by this circulation the diffusion of heat is very rapid. But the exchange of particles between the upper and lower strata must occupy some time, however small the interval, and the consequence taust be that the barometer will measure by its fall the amount of the inequality. So on the other hand, in the process of cooling, in the absence of the sun, experiment has shewn that the lower strata of the air become more rapidly affected by radiation than the upper, and the total increase of weight from this cause, will be shewn by the rise of the mercurial column. If we trace this effect along any given meridian, we shall become sensible of the manner in which this influence operates. Beginning at the equator, the only circumstance which we have to appreciate is the irregularity of the lateral expansion or contraction. As the earth acquires warmth from the sun, the barometer falls; but the check which the incoming current from the poles sustains, must be felt along the whole line of its course; and its due velocity being opposed, without any adequate compensation in the upper current, the barometer would have a tendency to rise at all latitudes be- tween the equator and the pole. Assuming an intermediate station upon the same meridian, we should have the same effect produced by the unequal expansion of the lower current of the atmosphere, but opposed now by the impulse communicated from the equator. The fall of the barometer would only then represent the balance of the two effects, and must be less than at the equator. The further we proceed towards the pole, the more must this re- yulsive action accumulate, and the less must the balance of the two become, till at some neutral point they are exactly equal. Beyond this point, again, the former action would exceed the latter, and the barometer would rise in the higher latitudes, while it was falling in the lower. The results of the preceding table obviously coincide with such a gradual progress towards a neutral point: but up to the time when I published an essay upon this subject, there were no experiments to prove the corresponding opposite effect beyond this limit. By ‘a careful examination, with this view, of the meteorological register P2 192 Mr. J. F. Daniell on the kept at Melville Island by the expedition under the command of Captain Parry, I found that there was distinct evidence of the an- ticipated result. The barometer in that high latitude periodically rose at those hours whenit is known to fall in the southern degrees. The following tables present the monthly means arranged in the proper order for exhibiting the conclusion. In the first, including the winter half of the year, it will be ob- served that the mean temperature scarcely varied from noon to midnight: the effect of the remote equatorial expansion was there- fore unopposed, and the barometer constantly rose from 6 A.M. to 6 P.M., in coincidence with the fall in the lower latitudes. From 6 P.M. to 6 A.M. it as constantly fell. In the second, comprising that portion of the year when the sun was above the horizon, the daily variations of temperature were considerable, and the effect less regular, but nevertheless the baro- meter constantly rose from noon to 8 P.M., and then descended to midnight, TABLE II. Shewing the mean heights of the Barometer and Thermometer at four different hours of the Day at Melville Island. 1819 6 A.M. Noon, 6P.M. Midnight. Bar. |Ther.|| Bar. |Ther. 29.920 |4-22.7]] 29.890 |4+21.3 29.840 |— 3.9]) 29.825 |— 5 Bar. |Ther.|} Bar. 29.884 |4-21.5]| 29.906 |4-23.7 29.777 |— 4 || 29.808 |— 2.8) 29.935 |—21 29.946 |—20.) 29.874 |—23 29.872 |-21 30.040 |—30.3)| 30.036 |—30 29.741 |—32.8)]| 29.758 |—30.8 10 days of March| 29.551 |—19.1]| 29.561 |—14.5 September .. October.... ember .. 29.946 |—20.1)| 29.937 |—21.2 December .. 29.881 |—21.1)| 29.893 |—21.6 1820 January.... 30.068 |—29.9)| 30.063 |—30.4 February ... 29.782 |—32.6)| 29.771 |—33.5 29.614 |—18.5|| 29.571 |—20.5 ——— ae ——— 29, S644 29.8500 +.0234 —.0144 Means... | 29.8288 29,8410 — .0212 | +.0122 Difference . 193 Horary Oscillations of the Barometer. LE00° + 0€00° + 6900°— L100°+ 0€00°— 6100 °— * * goudIayIg 9698 *62 8048 6% 1998 °6@ be oe SOW TE98 “6% E898 ° 6% 9998" 6z —— ey | es — | | a GOFF] GEL GU] SEF] 8EL°6S LEL' GBS GET] PEL 'GCSIL SEF] LBL 6S EEL 66 saree ata ee ysnSny T'6E+} 099 62/4" tP+] 999°6z €99'6%| SbF! 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This, as well as all other nautical registers which I have had an opportunity of examining, has been kept with the utmost pre- cision and neatness ; and it is highly gratifying to find so much attention to the interests of science amongst our naval officers, who have such opportunities of enlarging our acquaintance with the different climates of the globe. The periods of the day were almost as favourable as possible to the comparison, but the lati- tudes were not as far removed as that of Melville Island from the influence of variations of daily temperature. The following table presents the monthly means of the observations for two years, during which the Hecla was confined between the latitudes 66° and 70°: TABLE IV. Shewing the Mean Heights of the Barometer and Thermometer at four different Hours of the Day on board H, M. 8. Hecla, between the Latitudes 66 and 70. A.M. 4 A.M.8 P.M. 4 P.M.8 1821 Bar. Ther, Bar. Bar. Ther. Bar. August . .« || 29.835 33.5 || 29.846 || 29.848 39.9 |} 29.825 September . || 29.958 29.8 || 29.974 || 29.973 34.3 |} 29.977 October . . || 29.881 8.9 || 29.876 |} 29.889 17.6 |} 29.898 November. || 30.166 2.7 || 30.156 || 30.165 12.6 || 30.159 December . || 29.904 | —19.2 || 29.898 |} 29.914 | —11.5 || 29 918 1822 January . « || 29.921 | —26.9 || 29.924 |} 29.933 | —20 29.952 February . . || 29.762 | —27.5 |} 29.746 |] 29.753 | —18.5 |] 29.761 March . . . || 29.849 | —17 29,854 || 29.864 ] — 3.8 |} 29.852 April . «. . |} 29.895 | — 0.2 }| 20.993 || 29.907 | 413.9 || 29.918 May .. «|| 29.985 13.5 |} 29.957 || 29.973 | +31.5 |] 29.978 June . . «|| 29.886 26.9 || 29.877 || 29,897 38.2 || 29.868 July . . ¢|| 29.682 32.7 || 29.693 || 29.694 | 40.6 |] 29.702 August . . || 29.643 31.5 || 29.636 || 29.661 36.5 |] 29.667 September . |} 29.883 22.2 || 29.883 || 29.895 28.3 |} 29.894 October . . || 29.967 10.7 |) 29.981 || 29.981 13.1 |} 29.985 November, || 29.875 | —22.6 || 29.876 || 20.884 | —13.4 |] 29.882 December + || 29.756 | —32.5 |) 29.739 || 29741 | —25,4 || 29.726 1823 January . .« || 29.877 | —20.2 || 29.902 || 29.898 | —10.6 |} 29.893 February . , || 29.904 | —24.9 |) 29.906 |} 29.905 | —13.4 |} 29.907 March . « || 30.950 | —24.1 | 30.055. || 30.050 | —12 30. 06L April . . «|| 29.957 | — 9 |) 29.955 || 29.957 | ++ 7.5 |] 29.954 May . . «|| 29.929 | +16.9 |} 29.916 || 29.920 33.3 |] 29.921 June . . . || 29.922 | — 23.4 |} 29.910. || 29.909 41.2 || 29.909 Juky S << || 29.507 33.2 | 29.499 || 29.509 43.8 |} 29.508 29.850 29.87% -L.G0S —.001 Mean . . || 29.874 | 29.872 ; Difference || — .005 | — 602 Naepeneetenpensener ninemsn Heorary Oscillations of the Barometer. 195 It appears from this table that the rise in the mercurial column from 8 A.M. to 4 P.M. was nearly constant, and upon further examination it will be found that in the only two exceptions of any amount, namely the months of January and March 1823, some unusual influence prevailed in the atmosphere. The first was distinguished by an unusually high mean temperature, and fre~ quent storms of wind. Captain Parry remarks in his Journal, “from the morning of the 24th till midnight on the 26th, the mercury in the barometer was never below 30.32 inches, and at noon on the latter day had reached 30.52 inches, which was the highest we had yet observed it in the course of this voyage. This unusual indication of the barometer was followed by hard gales on the 27th and 28th, first from the S.W., and afterwards from the N.W., the mercury falling from 30.51 inches at 8 P.M. on the 26th, to 30.25, about 5 P.M. onthe 27th, or about 0.26 of an inch in nine hours before the breeze came on. At midnight on the 27th it had reached 29.30, and on the following night 29.05, which was its minimum indication during the gale. These high winds were accompanied by a rise in the thermometer very unusual at this season of the year, the temperature continuing above 0° for several hours, and very near this point of the scale for the whole two days.” The month of March, on the contrary, was as much below the mean in temperature, as January was above it, and the observation renders it probable that the usual course of the season was modi- fied by some extraneous cause. ; Iam aware that it may be objected, that these observations were not made with all the precision that the accurate determi- nation of such small quantities requires, and particularly that the heights of the barometer were not corrected for the variations of temperature. The objection, to some extent, is certainly valid, and it is much to be lamented that the advantages of the utmost at- tainable degree of precision in these observations have not hitherto been duly appreciated : but when it is recollected that the instru- ment made use of was placed in the cabin of the ship, where con- siderable pains were taken to maintain an equal temperature, it 196 Mr, J. F.. Daniell on the will be found that less importance attaches to the omission in this particular instance than might at first be supposed. In the last voyage, more especially, the precautions which were adopted to secure this important. end, were eminently successful. It appears, for instance, by Captain Parry’s register, that in the months of October and November, the mean temperature of the external air varied 32°, while that of the air of the lower deck only varied 5°, so that the changes in the course of the 24 hours could have been scarcely appreciable. The return of the various expeditions which are now about to depart once more for the Arctic Regions, the officers of which have most zealously under- taken to make the observations with all the requisite precautions, will, it is to be hoped, set this interesting question at rest, and not only determine the existence of the phenomenon which I have ventured to anticipate, but also the exact amount of the fluc- tuation. I would here willingly have entered into some speculations upon the mean height of the barometer as shewn by the registers of the high latitudes, and which appear, upon the first view of the subject, to be considerably below those of the more southern regions, but doubts respecting the construction of the instruments destroy the necessary confidence in the observations. These doubts are more strongly than ever impressed upon my mind by the inspection of eight barometers which were prepared for the expedition which has just sailed from the river, by one of the first opticians in London, and who undertook to bestow unusual pains in their construction. No two of them agreed in height, and the greatest difference was full 0.2 of an inch, One standard barome- ter, however, now accompanies them, and may serve to determine the errors of the others, so that little doubt exists that we shall at length be able to arrive at some precise conclusions respecting the fluctuations of the atmosphere in the most interesting and inaccessible climate of the northern hemisphere. The advantages to be derived. from a proper attention to the construction of the barometer cannot be better exemplified than by the circumstance of the same_ instrument-maker having since Horary Oscillations of the Barometer. 197 completed five barometers of very different capacities and diame- ters, whose difference from the mean and from the standard; with all corrections made, was only .006 of an inch. Arr. II. On the Alterations of Rate produced in Chrono- meters by the influence of Magnetism. By George Har- vey, Esq., F.R.S.E., &c. Tne power which a magnetic force possesses, of accelerating the rate of a time-keeper in some situations, and of retarding it in others, is a fact which has been verified by many interesting and important experiments. It is singular, however, that the same attractive power, which when applied in different directions to one ‘chronometer, tends either to accelerate or retard its rate, should in another, when allowed to operate under the same conditions, as to intensity and position, produce results precisely the reverse. It will be the object of the following paper, to refer these apparent anomalies, to the varieties of imperfect isochronism, existing among different chronometers. To illustrate this view of the subject, suppose the balance of a chronometer in its quiescent position, having its thermometer- pieces in an active, but opposite state of polarity ; and let the line joining those pieces, and which therefore passes through the centre of the balance, denote the direction in which the magnetic force acts. Now since the thermometer-pieces possess opposite polari~ ties, let that portion of the attractive influence which is destined to operate on the time-keeper, and is of an opposite kind to the polarity of the thermometer-piece on which it first acts, be allowed to exert its energy, the moment the oscillations of the balance take place. ‘The effect of such an application will be, a decrease in the are of vibration, in consequence of the effort made by the thermo- meter-piece, on which the magnetic force acts, to approach the attracting pole. This alteration in the amplitude of the are of vibration, will therefore occasion some variation of rate in the time- keeper. If instead of supposing the attractive power to pass im-~ i 198 Mr. Harvey on the influence of mediately through the thermometer-pieges, it be allowed to pro- duce its effects, on either side the point of quiescence, within cer- tain limits, the are of vibration will still be diminished, but in a less ratio than before; and changes of rate proportional to the variation of amplitude, will be the result. Suppose in the next place, the direction of the magnetic force to pass through the centre of the balance, and the limit of the semi- are of vibration; it is manifest, when motion is communicated to the balance, its effect will be to increase the arc of vibration, both from its attracting one of the thermometer-pieces, and repelling the other; and that therefore an alteration of rate, entirely the reverse of the former, will be the necessary result. It is also evident, that if the same attracting pole be applied on either side of its last- mentioned position, within certain limits, the are of vibration will still be increased, but in a less ratio than before; and alterations of rate of the same kind, but of a less remarkable degree, will be produced. If the time-screws are supposed to be magnetic, and the ther- mometer-pieces free from the attractive influence, similar results will take place. Conceive in the next place, that in addition to the magnetism of the thermometer-pieces, the entire arcs of compensation possess also a property of the same kind ; one half of each having northern polarity, and the other half southern; then will the time-screw attached to the are of compensation, whose thermometer-piece has northern polarity, become a south pole; and that attached to the arc, whose thermometer-piece has southern polarity, a north pole; the transverse arm connecting the two, if of steel, presenting all the properties of a perfect magnet. In this point of view, the entire balance may be regarded as a species of compound magnet, having two pair of opposite poles ; and different phenomena will be exhibited, according to the direc- tion in which the magnetic force acts. If, for example, the mag- netic power be allowed to develop its influence, in a direction equally remote from the opposite poles of each of the arcs of com- pensation; and that we moreover suppose each pole to possess the Magnetism on Chronometers. 199 same degree of intensity, the. acceleration or retardation produced by the action of the exciting force on one of the poles, will be en- tirely neutralized, by the opposite effects of the other. But if the attracting power be allowed to operate in a position nearer to one pole than the other, an alteration of rate will result from the change in the are of vibration, necessarily produced by the inequality of action. If on the other hand, the magnetic force be applied, in a direction between the thermometer-piece and time-screw belonging to the separate arcs of compensation, and having a polarity of a contrary kind to them, a constant effort will be made by the balance, to accommodate its arcs of vibration to the united effect produced by the maintaining power, and the intensity of the mag netic action; and a similar tendency will likewise be displayed by the balance, if the disturbing pole be placed: in the vicinity of a thermometer-piece and time-screw, having the same kind of po- larity with it. From the same considerations we may also infer, why a chrono- meter, having a balance powerfully magnetic, should present vari- ations of rate, from the influence of the earth alone, according as it is situated with respect to the magnetic meridian. If the thermo- meter-pieces alone are magnetic, and the line joining them be placed in any other direction than that of the magnetic meridian, a continual effort will be made by the balance to regain this position, thereby producing a change in the arc of vibration. Ifalso, the entire balance be considered as magnetic, some line may be found passing through its centre, in which it would repose in the direction of the magnetic meridian, if detached from the other chronometrical parts, and freely suspended. Hence it follows, that the moment the time- keeper is so placed, as to remove the balance from the Jast-men- tioned position, a tendency will be created in it, to return to that state; and which, by producing variations in the arc of vibration, must at the same time be accompanied by sensible alterations of rate. Having made these general observations, I shall finally consider the cause, why similar changes in the are of vibration, should be frequently attended, in different chronometers, with opposite alter- ations of rate, 200 Mr. Harvey on the influence of It maybe questioned, if ever a chronometer existed, in which the vibrations of the balance were perfectly isochronous; or in other words, in which the adjustments of the spiral spring were such as to admit of its elastic force, varying precisely with the arcs of vibration. Mr. Atwood has shewn in the Philoso- phical Transactions for 1794, that although the relation between the elastic force of the spring, and the magnitudes of the arcs of vibration, may appear to be in a perfect ratio of equality, there may nevertheless exist such exceedingly minute deviations from this state, as to render it impossible to be detected, by the most delicate experimenter; and yet these minute inequalities may be consider- able enough to produce in the interval of twenty-four hours, a sen- sible alteration of rate. Hence it is, that the application of a mag- netic force to a chronometer, having a balance in any degree mag- netic, in almost every case, produces a visible alteration of rate. In an example furnished by the able mathematician before quoted he demonstrates, that a variation of a thousandth part from a per- fect state of equality, in the relation between the elastic force of the spring, and the arcs of vibration, is capable of producing an acceleration of + 2”.62 in the daily rate, when the semi-are of vibration is diminished 8°; and he even states, that an increase of rate amounting to 20 or 30 seconds may exist, and yet the differences arising from the deviation of the elastic force of the spring, from the law of isochronism, be too minute to be ren- dered sensible by any statical counterpoise of the force of the spring. Assuming therefore a perfect isochronism in the vibrations of a balance, as a condition scarcely to be obtained, the deviations from it, may be contemplated under two points of view; since the elastic force of the spring may vary either in a ess ratio than the angular distances from the point of quiescence, or in a greater; and which suppositions will account for the apparent anomalies presented by different chronometers, when subject to the action of a magnetic force. This will appear evident, by referring to the function, which ac- cording to Mr. Atwood, represents the daily abberration of a time- Magnetism on Chronometers. 201] keeper, when the magnitude of the are of vibration is changed, and which is w{(5)F a where a denotes the primitive arc of vibration, a’ that produced by the action of a disturbing force; and which, according to the direction of its action, may be either greater or less than a; and x the exponent dependent on the peculiar ratio existing between the elastic force of the spring, and the angular distances from the point of quiescence. If we suppose the primitive are constant, and the other elements a’ and x of the formula variable, the entire function, as Mr. Atwood observes, will be susceptible of different modifications. Suppose, for example, we attribute to x a less value than unity *, a condition which corresponds to that of the elastic force of the spring, varying in a less ratio than the angular distances from the point of quiescence ; it is manifest, that different values will be communicated to the func- tion, according to the value assumed for a. If the supposition alluded to in an early part of the paper, of the attracting force passing through the thermometer-pieces be referred to, and in which the are of vibration would be shortened by its operation, the value of a’ must necessarily become less than a; and a positive value being thus communicated to the function, the time-keeper will gain. In the next place, if the attracting force be conceived, as in the second supposition, to pass through the centre of the balance and the limit of the semi-are of vibration, and which application will necessarily occasion a’ to become greater than a, the numerical value of the formula will be negative, and the chronometer will lose. If again we suppose n to be greater than unity, or the elastic force of the spring to vary in a greater ratio than that of the distances from the point of quiescence, the first of the preceding suppositions with respect to a’, will give to the function a negative value, indicating a retardation of rate in the time-keeper. * If wesuppose z = 1, the whole function will vanish, in indicating a per- fect isochronism ; so that whether the arcs of vibration be increased or dimi- nished by the action of a disturbing force, no alteration of rate will take place. 202 Mr. Harvey on Chronometers. In like manner, by referring to the case in which a’ is greater than a, the numerical value of the function will assume a positive charac- ter, and the chronometer will gain. Thus, with changes in the amplitude of the arc of vibration, from less to greater, or from greater to less, resulting from the applica- tion of a disturbing force in different directions, will results entirely opposite in their character be produced in different chronometers, in consequence of Varieties of Imperfect Isochronism. Plymouth, May 20, 1824. Art. Ill. On Indistinctness of Vision caused by the presence of False Light in Optical. Instruments, and on tts Reme- dies. By C. R. Goring, M. D. [Continued from p. 28] Microscorts.—These instruments though but toys compared with telescopes, nevertheless deserve to be rendered as perfect as possible, for they yield not to them in the quantity and variety of rational amusement which they are capable of introducing us to (though not of the sublime description of the wonders of the heavens). Compound microscopes though not so much to be depended upon for the purposes of discovery and philosophical investigation as single lenses, are still best adapted for recreation, but all those which I have ever seen constructed on the common principle, are so full of fog as to be quite disagreeable for exami-- ing opaque objects, which render this defect more striking than transparent ones. This false light results from the custom of making the object-glass of a very small aperture, instead of giving it a larger one, and placing a stop in its proper place (the focus of the lens employed). It is totally impossible to get rid of the fog in any other way. No doubt the larger the aperture of the lens of the common object-glass, the more indistinctness is sen- sible ; and the more it is reduced, the less;—but no practicable con- traction of the aperture will effect the desired purpose completely, Dr. Goring on Microscopes. 203 because the principle itself is intrinsically bad, and incorrect at least for low powers. Now, if we form a microscopic object-glass of a single lens of considerable aperture, haying a stop in its focus of about the same diameter as the apertures of the common lenses used for com- pound microscopes, (that is to say, about one-tenth or one-twelfth part of their focal distance,) we shall form an object-glass which gives a clear image, free from fog indeed, but very deficient in other respects; for the stop being placed where the rays cross cach other, a large portion of the aperture of the lens is called into action, in comparison to what is usually made use of, when it is at once limited by a stop of the same diameter applied close to the glass; the aberrations both chromatic and spherical are here im= mediately felt—to remedy these, another lens must be employed, the best position for which is close to or very near the farther side of the stop. The focus of it must be to that of the first as 3 to 2, oras 2 to 1—for low powers, however, it may be about 21 to 2—for the higher the best proportions seem to me to be as2 to1l*, The lenses employed should be plane convex, having their curves towards each other as represented in Figs. III, IV, V, and VI, Plate II. which are drawings of four object-glasses of this description which I have caused to be executed the lowest power is 2 inches focus, the highest 4 an inch—the foci of the lenses, and the size of the stops, Sc., are as there represented +. These object-glasses I can * The addition of this second lens has another good effect, for it enables us to regulate the compound focus so as to haye the object as near to the Object-glass as will consist with the distance which must be allowed for suf- fering the rays from a lens or mirror to fall upon it for the purpose of illumi- nation when opaque,—for the light of opaque bodies diminishes according to the square of their distance, and thus the farther the object-glass recedes from them, the less light it receives. With transparent subjects, however, the case is different, at least when they are illuminated by the converging rays of a lens orvoncave mirror ; for, by making the focus of this fall not upon the object but upon the object-glass, the maximum of light is obtained at whatever distance the object may be from the glass, so that the benefit of having them near each other is not so much felt as in the former case—the proportions I have recom- mended will answer every purpose. t It will be obvious that a microscope of my construction may be used as 204 Dr. Goring on Microscopes. confidently recommend as greatly superior to those in common use; they are bright, clear, and distinct, free from spherical aberra- tion, and will shew no sensible colour with opaque objects of any kind, not even with so trying a one as the enamelled white letters on a black ground generally used by opticians to try their telescopes with. When, however, they are made to view an object illuminated from behind, which does not suffer the light to pass through it while its edges are seen, as for example the legs of some insects, some kinds of moss, &c., which have very little trans- parency, the uncorrected colour is then decidedly seen—such objects are the best tests of achromaticity for telescopes as wel) as microscopes ; equivalent terrestrial ones for a telescope will be the bars of a window seen from the interior of the apartment to which it belongs, or the naked branches of a tree in winter, seen against the light of the sky, more especially of the sun, and nearly opposite the observer. In addition to the four object- a magnifier for a telescope, In factit is in its principle nothing but the four glass erecting achromatic eye-piece of a day telescope a little modified (there is alas nothing new under the sun). Indeed, many of Mr. Tulley’s astrono- mical telescopes are so constructed that the night eye-pieces can be applied to magnify the erected image formed by the two glasses, which do the work of my object-glass. It would, however, be much better, instead of increasing the depth of the eye-glasses in this case, to augment that of the erecting part, as a much sharper image is in this way obtained. There certainly are many objects which are seen better with this kind of eye-glass, such as Venus, and many double stars ;—the number of refractions arrest a portion of the false light or halo which so commonly surrounds these objects. However, the same or nearly the same effects seem to be produced, by diminishing the aperture of the object-glass of the telescope, except that this seems to increase the spurious disc of the fixed stars, which the other method does not. Many suppose that great advantages are to be gained by making a microscope with a long tube, and a shallow eye-glass. I have satisfied myself repeatedly by experiment, that whether the required magnifying power is obtained in this way, or by a short tube with a deep eye-glass, the effect is precisely the same. The body of my microscope is seven inches long, having an achro- matic eye-piece of about one inch negative focus, just like those applied to telescopes. I do not like the double and triple eye-glasses very commonly applied to microscopes, as they are apt to give double images, with luminous transparent objects, Dr, Goring on Microscopes. 205 glasses I have described, I have two more of 1 and + of an inch focus, which Ihave not inserted, because (though executed with the utmost care,) they are no better than the common ones. I was grievously disappointed with these, for I had fully expected that the same principle applied to deep object-glasses would form as superior an object-glass for high powers as for low ones: however the reverse is the fact;—it is one of those things which can only be learnt from experience, and could not have been predicated @ priori. There is doubtless a reason for this, but I am not able to shew what itis. Still, therefore, the common object-glass is the best for high powers, viz., for those of a quarter of an inch focus, and upwards. My object-glasses are however deep enough for all ordinary objects—certainly for all opaque ones. There are, nevertheless, many transparent objects which cannot be seen with- out object-glasses of at least 1, inch focus,—such are many kinds of animalcules and the minute lines on the dust of a butter- fly’s wing, §c. For these the common single lens of small aper- ture will perhaps ever remain the only efficient object-glass,—an equivalent power obtained with my object-glasses, or those of the common construction of similar focus, by increasing the depth of the eye-glass will never shew the objects in question, because what may be called the penetrating power of a compound microscope depends upon the depth of its object-glass, as that of a telescope upon the aperture of the metal or glass which forms the image viewed by the eye-glass. The eye-glass either of a microscope or telescope merely developes what is contained in the image it enables us to view; it cannot of course render any thing sensible to our sight which does not exist in the spectrum formed by the object-glass or metal. I may here mention that I had previously constructed my microscope with one object-glass only of one inch focus, and got my powers by increasing the depth of the eye-glass as is done in telescopes. I however, found, that a large image viewed by a shallow eye-glass made a much better instrument than a comparatively small one (formed by a shallow object-glass), viewed by a deep eye-glass; indeed the same position holds good with regard to telescopes also, for the largest and longest (ceteris Vou. XVII. Q 206 Dr. Goring on Microscopes. paribus) are sure to be the best, because the image of such needs but to be little magnified to procure a given power, and it must be evident that the more an image is magnified the more its imper- fections will become sensible, for no image can be free from im- perfection like the object from whence it is derived. I shall‘ here advert to a circumstance (though rather foreign to my subject,) relative to the proper apertures of the common mi- croscopic object-glasses, which is, perhaps, not duly attended to. It is certain that the more their apertures are reduced (within a certain point,) the more fog you exclude; and in this way you improve the instrument,—yet if this reduction is pushed too far, it will prevent you from seeing a certain class of objects, even while the vision of others seems to be ameliorated. Thus the parallel lines on the dust or feathers of a butterfly’s wing can be just seen with an object-glass of #1, inch focus, and j4 inch aper- ture as nearly as it can be measured: if, however, this aperture is very slightly contracted, they can no longer be seen with any art or management of the light,—at the same time other objects will appear fogey and indistinct with this same aperture, especially if opaque, and the vision of them will be improved by diminishing it. I am disposed, therefore, to think that the apertures should be regulated by this ratio of A, inch aperture to =, inch focus *. * The great Sir W. Herschel! has condescended to notice this subject, without however determining precisely what the aperture of a microscope ob- ject should be, in his paper in Vol. LK XVI, p. 500, of the Transactions of the Royal Society.—* Investigation of the Cause of that Indistinctness of Vision , which has been ascribed to the smallness of the Optic Pencils.’ I think, however, it will be found that Sir W. had not obtained pencils of rays of such extreme smallness as he supposed from a calculation of what the size of the pencil should have been, according to the powers he obtaitied, for the power of a compound microscope cannot be measured in the same manner ds that of a téle- scope, by comparing the size of the ultimate pencil of rays after it has passed the eye-glass with the diameter of the object-gluss or metal. Had Sir W. actually measured the pencils with a dynameter instead of calculating their dimension, he would have found them much larger than he supposed. In fact, all we obtain from comparing the size of the pencil of rays which enters the eye with the diameter of the object-glass in a microscope, is what thé power of a tele+ Dr. Goring on Miéroscopes. 207 Thave several much deeper made on this plan up to ;'5 inch—all of which shew the parallel lines in question, and other equally difficult objects,;—the deepest lenses have their apertures some~ what larger than this ratio, for the sake of the light, (for it appears that you may increase this aperture, though you must not diminish it, and yet see these objects, though the fog then becomes very great and disagreeable; the colour also grows very apparent on account of the largeness of the aperture relative to its focus. Common microscopic object-glasses as we all know are sufficiently achromatic with the small apertures, and the shallow eye-glass of one inch focus usually employed, in which respect there is an analogy between them and telescopes with object-glasses com- posed of single lenses of small aperture, and a shallow eye-glass. The achromatics only differ from them in carrying a larger aper= ture witli a deeper eye-glass, which again have their limits, beyond which the colour appears as before, _ In Figs. VII, VIII, and 1X, are representations of some silver cups for holding very deep single lenses intended to view opaque objects, which, together with the object-glasses before-mentioned, were executed for me by Mr. Tuther, optician, in High Holborn, to whose politeness and skill I am indebted for being able to carry my intentions into effect. It is generally supposed that single lenses will shew objects perfectly clear and without fog, but this is not the case unless their apertures are very small,—lenses of as ao 5, and ;!,th of an inch focus require their apertures to be so much reduced to shew opaque objects clearly, that it is scarcely possible to see at all with them from the want of light. These cups were contrived to remedy this defect as far as it is practi- scope would be, having an object-glass of the same aperture with the microscopic one with a focal length, equivalent to the distance between the object-gluss of the microscope, and the focus of its eye-glass having its image magnified by the said eye-glass. For example, I measured the power of a microscope in the legitimate way with two similar micrometers, one on the stage, the other at the field bar in the focus of the eye-glass—supposing the eye-glass of 1 inch focus to have magnified six times, the power was 386, while the size of the pencil at the eye-glass compared with the diameter of the object-glass was merely as 2 to 6—the oue being 375 of an inch, the other y¢5- Q2 208 Dr. Goring on Microscopes. cable ;—their radius is only + of [an inch, their focus consequently 4, These condense light much more than the larger cups.com- monly used, and illuminate much more powerfully. It is true that they only enlighten a small portion of an object, but then we can only see a very small portion with such deep lenses as they are intended to hold; they are not so small but that they may be made to receive and condense the whole of the light proceeding from a bull’s-eye lens placed at a proper distance from them, and in this way with no other light than that of a common candle, I have been enabled to see well an opaque object with a compound microscope, having an object-glass of only Aj inch focus set in one of them, with only a moderate aperture. A lens of ;4, inch set in this manner, used as a single lens, likewise shews opaque objects in a manner which leaves nothing to be desired. I must mention, however, that it is necessary for the stops between which the lenses are placed to be very accurately made. They should be turned out of a piece of solid brass, the external one very thin, and the holes so correct as always to coincide with each other when the stops are turned round; the apertures must be quite free from burrs ; in addition to which the stops must be so adjusted that the focus of the lens and that of the cup must precisely correspond, otherwise the benefit of the cup is in a great measure lost.- Fig. IX will carry 4 or 45 of an inch without any stop at all, which is a great convenience, for the lens is in this case close to the eye, and the field of view larger in consequence : the stops for the deeper lenses are much shorter than they would be with larger cups, (Figs. VII and VIII,) so the field is increased in the same way, and the eye much less strained in using them than it would be were the lens farther off from it. I have shewn many individuals objects with the 4, inch lens not remarkable for the strength of their eyes, who saw with perfect ease, and were not at all conscious of the extreme smallness and depth of the lens they were using. As single lenses are generally considered to be most adapted for making discoveries in natural history, as being less likely to create optical deceptions than compound magnifiers, I imagine I am doing naturalists a service in putting them into a Dr. Goring on Microscopes. 209 way of using very deep ones without destroying their eyes*. [ humbly recommend the contents of this paper to opticians, without being at all ambitious to acquire the honour of teaching them their own profession. I have the highest consideration for their practical knowledge, and conceive that one ounce of it is worth a ton weight of that of a mere theorist; at the same time I hope they will accept of my apologies for pointing out a few circum- stances to them, (certainly not of much importance,) which the value of their time and the multiplicity of avocations of higher con~ sequence will not usually permit them to attend to. If what I have written shall prove of no service to them, itis quite clear that my labours have been utterly useless. Indeed, it is too much the case that the researches of amateurs only terminate in discovering something which was perfectly well known before, and which only therefore serves to shew their own shallow acquaintance with the subject, or in bringing forward something as an improvement which has been tried and rejected long ago by those practically versed in the mysteries of optics. Art. IV.—Hints on the possibility of changing the Residence of certain Fishes from salt water to freshu—By I. Mac Cuxttocn, M.D., F.R.8., &c. Iy the tenth volume of Tilloch’s Journal, there is a paper on the means to be employed for multiplying fish, translated from one which appeared in the Monzteur, by Monsieur Nouel, of Rouen. Although the chief speculations of this writer, which are of a very * They may, perhaps, also thank me for informing them that Mr. Cornelius Varley, of Upper Thornhaugh-street, Bedford-square, (the inventor of the graphic telescope,) worked the small lenses for me which I have described ; they were polished on wax tools, the figure is as correct as that of any shallow lenses, and their image will bear magnifying perfectly well. Mr. Varley and “Mr. William Tulley of Islington, are the only individuals I know who can make such deep lenses as they ought to be made. 210 Dr. Mac Culloch on the changing interesting nature, concern the means of transferring the inhabi- tants of fresh waters in one country, or those of certain lakes or rivers, to others where they are not found, some hints are also introduced respecting the possibility of rendering certain sea-fish in- habitants of fresh waters. The whole paper is highly worthy of attention ; but I am not aware thatit has been followed by any of the practical trials recommended by the author, on which its economical value must ultimately depend. An example in point which recently came under my notice in Shetland, has induced me to examine the subject with somewhat more care than the author of that memoir seems to have bestowed on it, and to inquire more minutely into the arguments on which the probability of success rests. The following seem to be the only results which have been obtained, or were pre- viously known with respect to that part of M. Nouel’s plan, which relates to the cultivation of sea-fish in fresh water. The plaice, Pleuronectes Platessa, as it appears, has been carried from the North sea to the ponds of East Friesland, where it has become established. The herring is said by Liancourt to frequent the Potowmack, Hudson, Elk, and Delaware rivers; but it has not appeared that the author’s project to take it from the Seine into fresh-water ponds has been put into practice. The authority of Twiss for the existence of this fish in the fresh water lakes of Ire- land, is more than questionable, and M, Nouel is assuredly misin- formed when he states that it is found in prodigious shoals in Loch ‘Lomond and Loch Eck in Scotland, both of them fresh inland lakes. I know not how this author can have thus been misled, unless he has mistaken some of the sea lochs for fresh-water lakes ; though he could scarcely have confounded those he has named with any of the western inlets. I shall hereafter, however, point out a fact which renders his assertion possible; though he could not have been acquainted with it, as it is not very long since it was known, and has not been published in any work siioiglt to have reached his hands. It is also asserted in the same paper, that the salmon, in sual has, in certain lakes, become naturalized, ‘‘ abandoning their erra- tic taste, for a calm and settled life.” Whether such an experiment the Residence of certain Fishes. 211 might not succeed, by forcibly transporting the salmon to lakes from which they could not reach the sea, is yet to be tried; but certainly there are not at present any salmon found inthe Scottish lakes, except where they have the power of making their annual migrations into salt water. That salmon are attached to the parti- cular rivers where they have been spawned and bred, is believed by all the fishermen; but this does not prove that they are naturalized to those fresh waters, as they inyariably return to the sea after haying deposited their spawn. According to Pallas, the sturgeon, the sterlet, and some species of salmon reside in the river Kama without ever descending to the Caspian sea; and the authority of such a naturalist is perhaps suf= ficient to establish this interesting fact. These, then, are the whole of the proofs“which, in M. Nouel’s paper, are adduced in support of this project ; it remains to be seen by what other facts and reasonings its plausibility may be supported, and an inducement offered to those who have it in their power, to make such experiments as alone can establish it among those facts in natural history which are capable of being applied to the uses of man; to increasing the quantity, or adding to the accessible variety of his food. In the first place, it must be remarked, that the habits of many sea-fish are, in this respect, so convertible, or so easily assimilated to the requisite change, that a large portion of their time is passed in fresh water. The common salmon, the grey salmon, and the salmon trout, Salmo Salar, Salmo Eriox, and Salmo Trutta, are fa- miliarly known to frequent rivers for the purpose of spawning; re- turning to the sea when this operation has been performed. The Salmo Migratorius leaves the lake Baikal for the same season; and, with us, the 8. Lavaretus, or Gwiniad, and the S. Eperlanus or smelt, also quit the sea; ascending rivers at the spawning season, as does the Salmo Autumnalis, an inhabitant of the frozen ocean. Now though M. Nouel is wrong in saying that the salmon is found in the Scottish lakes excluded from access to the sea, it is a fact that the salmon trout, or sea trout, as it is called in Scot- land, is now a permanent resident in a fresh-water lake in the 212 Dr. Mac Culloch on the changing island of Lismore, and without the powerof leaving it or reaching’ the sea. There, it has been known fora long course of years, perfectly reconciled to its prison, and propagating without any apparent dif- ficulty. If this fish, whose annual necessity for returning to the sea is the same as that of the common salmon, has thus easily be- come naturalized, there is little reason to doubt that the same expe- riment would succeed with the salmon itself. The fishermen ob- ject to that opinion, that this fish becomes meagre and diseased by its residence in fresh waters, and is compelled to go to the sea to re- cover itself. But we need not feel much concern respecting their philosophy; while they forget at the same time that it is the opera- tion of spawning by which the fish is injured, and that this conse- quence happens alike to sea-fish, from the same causes. It remains to be proved that the salmon would not recover itself in fresh- waters, as the sea trout does in Lismore; and this is the experi- ment which is to be tried before we are entitled to pronounce a ne-= gative. To render the salmon’a permanent resident of the fresh- water lakes of Scotland, would unquestionably be a great gain ; and that this has not been tried, often as it has been urged on those who have the means, is only an additional proof of the plodding incredu- lity and obstinacy of those who are averse to all innovation because it is innovation, and who believe that they have themselves attained the summit of all possible knowledge. With respect to the smelt, its delicacy would render it a very de- sirable acquisition in our ponds, while its size would probably cause it to find an easy supply of food, and its facility of living for a time in fresh water render its naturalizationeasy. I accordingly caused some trials to be made for this purpose: they did not how- ever succeed, but the experimenter considered that they were not fairly conducted, as the fish had been injured in the transportation. It is obvious that in every trial of this nature great attention to this part of the operation must be requisite. Since this, a perfect experiment to this effect has been made by Colonel Meynell, in Yorkshire. The fish have lived three years, and it is understood that they have propagated abundantly. They were not affected by freezing, as the whole pond, which contained the Residence of certain Fishes. 213 about three acres, was so frozen over as to admit of skating. As to their quality, it was considered by the fishermen of the Tees, by whom the pond was drawn, that they had never seen “a finer lot of Smelts ;” so that in this case there was no loss of flavour or qua ity. The common pike, Esox Lucius, which is an inhabitant of fresh lakes with us, is also found in the Caspian sea; proving that this animal among others is indifferent to the quality of the water which it inhabits, and, in this case, permanently so. It seems to be unquestionable, that in the Dee and some other Scottish rivers, the common eel, Murena Anguilla, migrates an- nually to the sea, wherever it has the power of reaching it ; return- ing again to the rivers and lakes which it has generally been sup- posed permanently to inhabit. The conger eel, Mureena Conger, which is an inhabitant of the sea, in general, also frequents rivers ; so that, of this genus, there are two at least of which the ence is occasionally convertible. The Gadus Callarias, or torsk, is also known to enter the mouths of rivers, so that it can reside at least for a time in fresh waters without injury; but it is not known to remain in them permanently. That the Gadus Morhua, or common cod, can reside permanently in fresh water, is proved in Shetland. In the mainland, as it is termed, of that group, the inlet called Stromness-voe communicates with an inland fresh-water lake by a channel so narrow as to ad- mit of a rude bridge by which the opposite shores are connected. In this fresh water, cod are frequently taken ; and that the water is perfectly fresh is certain; as the tide is never sufficient to pass the strait of communication, merely damming the fresh water till the ebb again commences. The inhabitants seem to entertain no doubt that the cod remains there for a considerable time; but the subject not having particularly interested them, it remains to be discovered whether their residence is permanent or occasional, or whether they spawn there. If they reside there, even for any length of time, it is probable that this water contains other sea-fishes, by which they are tempted, unless they feed on trout; but I could not discoyer that any others had been found. 214 Dr. Mac Culloch on the changing The Gadus Barbatus, or whiting, and the Tricirratus, or rockling, occur in abundance in those Highland sea-lochs where the water is at times perfectly fresh, from the magnitude of the riversin rainy sea~ sons; not quitting their haunts even when it is deeply tinged by the colour derived from peat. From their permanence in those situa- ations, and from being taken of all sizes, they probably spawn there; and, if so, they offer, like the common river flounder and the pike, perfect examples of the permanent convertibility of the habits of these species. The Cottus Quadricornis, a native of the Baltic, also ascends rivers, as does the GasterosteusPungitius, or stickleback, in our own country. The Pleuronectes Platessa, or plaice, as has already been observed, is naturalized to fresh water in East Friesland: and the P. Flessus, or common flounder, is. well known to be permanent in the Thames and other rivers, far within the fresh water, although equally a salt-water fish. The P. Roseus has also been taken in the Thames. Iam further informed that a sole was kept in a fresh- water pond in a garden, by a person whose name I need not quote, for a great many years ; and if the plaice and flounder can be so naturalized, it is not unlikely that this would prove true of the whole genus. Although the mackerel is rare in Scotland, it is sometimes taken in the lochs of the western highlands, where the water, from the entrance of rivers, is nearly or absolutely fresh ; a proof at least, as in many other fishes, that whatever aversion they may have to residing permanently in fresh water, whether from the want of food or for other reasons unknown to us, they experience no difficulty in respiring in it. The Mugil Cephalus, or mullet, which is a sea-fish, not only ascends rivers, but has been introduced and detained in ponds; offering another example, like the plaice, of the possibility of per- manently naturalizing a sea-fish to fresh water. This fish does not necessarily spawn in rivers; since, in England, it performs this operation on the sandy and muddy shores of the sea. Yet, in Asia minor, it appears that it always spawns in the rivers, ascending the Sturmus, the Meander, and others for this purpose, and pro- the Residence of certain Fishes. 215 dueing the Botargo so well known in the market. This is a valu- ble fact in the question under consideration; as it proves that, in the matter of spawning, fishes are not tied down to those fixed and necessary habits which has been commonly supposed. As the case of the naturalization of the grey mullet is particularly interesting, and is at the same time unknown, except to the few in- dividuals who caused the experiment to be made at random, it de- serves a more particular description; since it offers, together with the instance of the cod in Shetland, another of those facts which have come within my own knowledge. This experiment is, at the same time, perfect, as much so as that of the plaice in East Friesland ; and it holds out therefore a tempt- ing prospect of success in other cases where no trials, either from accident or design, have yet been made. _ About ten years ago a number of the grey mullet, about the size of the finger, were placed in a pond of three acres in area, in Guernsey; the water being perfectly fresh. They haye since in- creased in size, as well as in numbers; although, from the small extent of this pond, it is evident that their ultimate increase cannot be very considerable. Fish of four pounds in weight have since been taken from this pond, so that in this respect as well as in their propagation, the experiment is complete and perfectly satisfactory. It isremarked that they are much fatter than those taken in sea- water in their natural state, but that the flavour is not so good. From this pond a number of small fish were afterwards taken for the purpose of stocking a smaller one. These continued to grow and thrive for about three years; when unfortunately, the oc- currence of a severe frost, during which the water was closed up many days, destroyed them, In this case itis evident that nothing is wanting to the establish- ment of the fact in question with regard to the grey mullet: and it may safely therefore be named as one of the fish which ‘may with- ‘out difficulty be naturalized to fresh water, and made use of to in- crease the accessible variety of our food or luxury, in places where fresh waters abound, and which are far removed from the sea. ' This experiment is fully confirmed by the practice of the 216 Dr. Mac Culloch on the changing Sicilians, In the Lake Biviere, this fish is cultivated for the pur- pose of food, and because its quality is thus found to be improved. It is an important circumstance also, that the water is here such as would be supposed peculiarly offensive to fishes taken from the sea; as it lies ina marshy plain, and is such that the extent of the lake is twice as great in winter as in summer. Such water must be nearly putrid; and therefore the Mullet at least would probably live and thrive in any ditch or pond. As its quality is thus also found to be improved, it is plain that the report respecting the deterioration of the Guernsey Mul- lets is, at best, doubtful ; while it is equally probable, from this case, as well as that of Colonel Meynell’s Smelts, that the general effect would be to improve, instead of injuring, the flavour of the sea-fishes in general. Though here somewhat out of place, I may also notice, that Lobsters and Crabs are introduced into the same lake for similar purposes, where they are not only preserved but improve in flavour. It had been concluded, in England, that these animals could not be so cultivated, because an experiment made by Sir Charles Monck failed. We must probably attribute this to some accident ; as the Sicilian practice is of long standing, and has been confirmed through an unknown course of years. As to the im- provement of the flavour of the Lobsters and Crabs in this case, it is distinctly stated, and it confirms the general presumption that this would commonly be the result ; while another confirmation is found in the fact that Oysters acquire their good qualities only by residence in fresh water. Thus the Oysters of Portsmouth and elsewhere are transferred to Colchester; and if those which are called ‘“‘ Natives,” possess good qualities, it is because they are produced at the estuaries of rivers, where the water is con~ siderably fresh, as is the case with those of Milton. In’a similar way, Cockles and Muscles are perfectly worthless, except in analogous situations, as is equally the case with Periwinkles ; and it is known to every one, that the best Shrimps are those which are taken on the fresh and muddy shores of England. The Clupea Sprattus, or sprat,is well known to be taken in the fresh the Residence of certain Fishes. 217 water of the Thames; although it is not ascertained whether it re- mains for any length of time out of the salt or brackish water. The C. Alosa, however, or shad, ascends rivers to spawn in the spring, like the salmon, returning in the autumn ; and its spawn, the white- bait of London epicures, is well known to be taken in the fresh water. It is probable therefore that it spawns there, as the salmon does; and hence also, were this fish worth the experiment, it might probably be naturalized to lakes and ponds. This seems peculiarly plausible in the case of all the sea-fish which spawn in fresh waters; because this is one of the natural operations which we should conceive it 2 priori, most difficult to counteract. I already noticed that the best known fish of this genus, the herring, was found in the fresh American rivers. And though I was obliged to contradict M. Nouel respecting its existence in Loch Lomond, I may here say that it has been found at different times in Loch Dhu, a fresh water lake in Argyllshire, near Loch Fyne. In this case, it appears to have been introduced during a flood, through the small river by which this piece of water commu- nicates with the sea; being afterwards confined by the subsidence of the water, so as to have remained imprisoned for many years. It does not seem however to have been ascertained whether or not it propagated in the lake; so that this natural experiment still re- mains incomplete for want of observation. This however is a trial so easily repeated, that nothing probably has prevented it, but that ignorance or prejudice on this subject which it is the main ob- ject of this paper to remove, by holding out reasons for probable success. The Crucian, Cyprinus Carassius, the Bleak, C. Alburnus, the roach, C. Rutilus, the bream, C. Brama, the C. Idus, C. Nasus, C. Aspius, and C, Ballerus, like the pike, seem to inhabit the Caspian sea as well as the fresh waters and ponds of Europe; offering other instances of perfect and permanent indifference to the nature of the waters in which they exist. The Chaleoides, in the same genus, migrates annually from the same salt lake to the rivers that run into it; and the C, Aphya 218 Dr. Mac Culloch on the changing seems to inhabit indifferently the sea shores and the mouths of the neighbouring rivers. The Cyclopterus Liparis has also been deserve to ascend from the sea into fresh waters; and the same fact is familiar with respect to the sturgeon, the common lamprey, and the lesser lamprey, or Petromyzon Fluviatilis. Lastly, the Delphinus Leucas, or white whale, is known to ascend the fresh-water rivers of Northern America; but as this animal breathes air, it does not, in that point at least, coincide with the true fishes, which respire water. The appearance of this species of whale seems to have been the chief evidence by which Hearne and Mackenzie attempted to prove that they had reached the sea in their respective expeditions. It is known to ascend the Hudson to adistance of 100 miles and more, above the salt water, and is taken by an established fishery high up in some of the fresh rivers of Hudson’s-bay. Here then is a large body of evidence, derived not only from the occasional, but from the permanent, residence of many sea-fish in fresh waters, and, on the contrary, of some fresh- water fish in salt lakes, to prove the existence, or possibility, of these convertible habits, at least in those species. But it will be convenient to subdivide the considerations which arise out of this subject, as they affect those functions in fish which, as far as this question is concerned, must be considered as of a vital or essential nature; either as they regard the life and health of the individual, or the continuation of the species. The first of these is the act of respiration. The first doubt na- turally arising on this subject is, whether salt-water fish can with impunity breathe fresh water, and the contrary. From the great number of the sea-fish which, either systematically or occasionally, visit fresh water without inconvenience, it is fair to conclude that the latter in no way disagrees with the function of respiration in them. A much stronger confirmation of this is afforded by the facility with which the plaice, mullet, and flounder haye been per- manently naturalized to fresh water; and by the fact that so many 7 the Residence of certain Fishes. 219 others which are described in the preceding catalogue, seem by nature to inhabit both indifferently. It remains indeed to be proved that any fresh-water species now known as limited to rivers and lakes, can be permanently confined to the sea; but this is a point which can obviously never be determined. A species of argument might be derived, on this subject, from the probable state of the earth at former distant periods, and from that which has probably been the original condition of many inland lakes besides the Caspian. It is probable that many such lakes were portions of the salt ocean, and that they have been rendered fresh since their separation from it, by the effects of the rivers flow- ing into them. In this case, the fish which these contain were once sea-fish; and thus perhaps we may account for the double existénce of the pike and of those Cyprini above described, in the salt waters of the Caspian and in the fresh lakes of other inland districts. But I will not here lay much stress on this reasoning. It is evident at least, from the preceding remarks, that a change of the medium of respiration is not injurious or poisonous to all those fish which even incidentally pass into fresh waters from the Sea, as this effect, if any, ought to be immediate, or at least speedy. If so many species can bear that change in the medium of respira- tion, it is not unlikely that the whole might, as the general struc- ture of the respiratory organ is the same in all; and it is not therefore likely that this function will be the cause of any great obstruction in attempts to change permanently the residence of fishes from one variety of water to another. The next important function to be considered is that of nutrition, or the probability that food may be found or provided for those sea-fish which any projects of naturalizing them in fresh waters, may confine to inland lakes. We are so little acquainted with the food of many fishes, that it is not possible to throw much light on this subject ; but it is probable that the most important and insur- mountable obstacle will be found here. Of many species, it seems to be ascertained that they feed on marine vegetables. Others, like the mullet, are known to plough the sand in search of lum- brici; probably also, of the spawn of other fishes. Some species 220 Dr. Mac Culloch on the changing seem to be especially provided with the means and the desire of feeding on shell-fish ; others on crabs or the crustaceous insects ; while the northern whale, by an arrangement which must always appear extraordinary, is furnished only with the power of subsist- ing on animals so small as to be imperceptible, to its sense of sight at least, and which, in the scale of dimensions, lie almost at the opposite extreme to its enormous bulk. Many fish, like the cod, are known to be omnivorous ; and of others, it appears probable that they feed solely on the multitudinous tribes of vermes and in- sects which crowd the waters. It is probable that, with respect to a great number of species, they live in succession on each other, if that expression can be used with propriety ; or that, in the my- riads of animals of singular and imperfect construction, and often of microscopic minuteness, which crowd the ocean to a degree that almost surpasses credibility, provision is made for the wants, in succession, of all those which successively exceed each other in size, voracity, or activity. If we were to judge from what is within our reach with respect to many fishes, we should be tempted fo imagine that they can live for long periods, even without food, or with a very small pro- portion, Thus the cod, one of the most voracious, has been kept in perfect condition in Orkney, confined in sea-ponds for three months and more; although no visible animal was admitted with the water which the tide daily brought to its prison. During the whole residence of the salmon in fresh waters, which often extends to a considerable period, it seems to exist with little food ; since the few winged insects at which it occasionally rises, can afford no effectual nutrition to an animal of such bulk and activity. The state of the common ornamental gold-fish confined in water- glasses, is equally remarkable ; but it is unnecessary to prolong the enumeration of facts which, however difficult to explain, haye ong been familiar to those conversant with the habits of fishes. But whatever we may doubt respecting the nature or the neces- sary quantity of food for fishes, it must be evident that no perma- nent naturalization of many of them, at least, can be expected, unless the new situation is such as to provide them with a suffi- the Residence of certain Fishes. 231 cient supply of food. In many cases, perhaps, we may judge for them; and if the proprietor of a Highland lake chooses to eat cod rather than pike, at the expense of a proportion of his perch and trout, and can persuade them to live in his fresh water, it is probable that they will not have to lament. the want of food. In any case, our ignorance on this subject need not be a bar in the way of any experiment on this kind of naturalization. So many species find their food without our knowing the means or the materials, that we may safely trust to their wants and their powers. Besides, as the enormous reproduction of all these tribes is evi- dently in part destined for the general support in succession of all those of which they are the prey, it is evident that by increasing the population and the variety in any of these watery kingdoms, we increase the means of mutual support. The smaller feed on that which the larger could not find or use; and thus they maintain the existence of their superiors, who, in return, are destined per~ haps to maintain them with their own ova or offspring. If again, practically, the plaice and the flounder, natives of the sea, have found the means of permanently feeding themselves in fresh waters, it is not unlikely that many others may there. find food unknown to us, and, for want of trial, unknown at present even to them. But there is no difficulty in feeding tem, should that prove ne- cessary. This was a common practice with the Romans; and those who choose to turn to Varro or Columella, may see records of the immense sums which were expended by the Romans in feed- ing the fish in their vivaria; as they may also see, from the enor- mous prices paid by Cesar, Lucullus, and others, to what an-ex- tent the practice of keeping fish-ponds was carried, and how im- portant a branch of rural economy this was considered. The con~ sequence attached to fishes by this people is apparent everywhere ; and no one need be told of the celebrated Senatusconsultum held on aturbot, or of the fishes which, Martial tells us, came to their owner’s call and licked his hands. If, in our own rural. economy, it is found profitable to feed pigs and fowls, it would not be less so to feed fish, nor are these tribes, apparently, less omnivorous than hogs. Vor. VII. R 222 Dr. Mac Culloch on the Changing The last of the important functions of fishes likely to be an impe- diment to this attempt, is their reproduction, or the act of spawn- ing; or rather, the circumstances necessary to ensure the vivifica- tion of the ova. The instincts, as they are called, or the peculiar habits of many fish in this important affair, seem often to be as ob- stinate as they are peculiar. This is notorious in the case of the salmon; which must not only deposit the ova in a river, but ina remote part of it, and even in the very stream in which it has itself been produced. Many fishes deposit their eggs only on shallow shores, although they inhabit the deep seas, Some frequent the es- tuaries of rivers for that purpose, others select mud, a third set sand, and others again the crevices of rocks, Yet as this part of the economy of fishes is a matter of necessity, it only remains to con- sider whether, being deprived of these conveniences to which they are instinctively addicted, they would not soon find it expedient to abandon them, and to adopt those alone which were within their reach. In this respect, the habits of the land animals with which we are acquainted, have been found susceptible of temporary, and even of permanent changes. Little acquainted as we are with the intellectual powers of fishes, or with the variety of character and capacity for education which may exist among them, it is bad rea= soning to presume that they are incapable of cultivation or change of habits, and that their sole talents are to catch, and their sole oc- cupation to eat, each other, Presurning, therefore that the ova must, as a matter of necessity, be deposited somewhere, it may be observed that inland lakes pre= sent all the varieties of bottom which are found in the sea, They receive rivers, have muddy bottoms, sandy and gravelly shores, and intricate rocky creeks; and, in some or other of these places, every fish may find a situation for its ova, more or less consonant to its natural habits. Nor is there any reason to suppose that where the perent lives, its ofispring could not be vivified ; since the vitality of the ova is far less likely to be affected by a change from salt water to fresh, than the complicated functions of the living and full grown animal, In a practical view, the power of continuing the species - under such a change, is proved by the facts already cited with ree the Residence of certain Fishes. 223 spect to the plaice, mullet, and flounder; and it is only to be regret- ted that no further evidence of this satisfactory nature can be adduced in favour of this reasoning. The double residence, how= ever, of the pike, and of the various Cyprini, already more than once quoted, offers a complete argument in favour of the convertible habits of these species at least, in the business of reproduction as in that of food. Supposing now that, at least the probability of all these reason= ings is admitted, it only remains to put these speculations to the test of more extensive experiments. Nature has executed two, per- haps more; art, in the plaice, the smelt, and the mullet, has carried three more into effect. There appears no practical difficulty attending it ; as fish can be transported alive in water, for a great length oftime, and to great distances, without inconvenience. If Shetland were differ- ently constituted with respect to the distribution ofits population and the residence of its proprietors, a very satisfactory and easy experi= ment, on the cod at least, might be made in Stromness Voe. It would only be necessary to shut up the very narrow opening by which it communicates with the fresh water, by means of a grating, and time alone would soon determine the question. Should this paper meet the eyes of a body of proprietors distinguished for their intelligence and activity, it may perhaps iuduce him in whose power it lies, to make this easy experiment. Nor could there, in this place, as in some other situations in Scotland, be any difficulty in extending the same trials to other species of fish. But I need not dwell on this part of a subject which every one is competent to un= derstand, but which not many have the means of submitting to the test of experiment. On the transportation of fish, I must remark thatit is not attended with so much difficulty as is commonly imagined, and that the fault generally has lain with those who have made the attempts. Many ' fish are exceedingly tolerant of being out of water fora time. The carp is keptin nets, in cellars, and fed thus in Holland. Minnows will live for months, crowded in a quart pot, with as little water as they can barely stir in, or in absolute contact. The whole of the flat fish are similarly tenacious of life; as are the conger, the gur- R 2 224 Dr. Mac Culloch on the Changing nard tribe, the dog-fishes, and many more which I need not enu- merate. The fault of those who have attempted the transportation, has been to take fishes which had been long hooked, dragging upon Long Lines, or entangled for a night or more in a trammel net. Owing to the peculiar distribution of the arteries in fishes, their muscular power is speedily exhausted by violent exertion; and hence they are literally killed, or nearly so, before they are taken out of the water insuch cases; an effect which, in the case of salmon and trout taken by a fly, is vulgarly called drowning. This must be avoided ; and it is well known that when cod are taken by hand lines, and thence transferred to the wells of the fishing boats, they always live, unless the gills or stomach have been much injured by the hook. . As far as this may be considered a question of economy or utt- lity, it is not necessary to say much. It may perhaps, abstractedly, be deemed of little consequence whether an inhabitant of Germany is condemned to eat roach and gudgeon, or to regale on whiting and smelts ; or whether, in a Highland lake, john-dory is to be substi- tuted for pike, and turbot for par. But all the improvements in the details of human life may, if we please, {be measured by the same rule. We have naturalized and domesticated the wild animals that walk and fly, to be our fellow-labourers, our compa- nions, our servants in the chase, our amusement, and our food. Nature has given us crabs and sloes, which we have converted. by our industry and perseverance into golden pippins and green gages, It is not an illaudable pursuit to apply to the uses of man all {those bounties which nature has spread around him; but on the posses- sion and perfect enjoyment of which this law has been stamped, that without labour and industry, they shall not be attained. . Yet while on this question of economy, it may not be improper to suggest a few doubts respecting the prudence of that conduct which, in this country, neglects the sources of rural profit to be derived from cultivating the produce of its. fresh waters.. In France, it is said that the value of an acre of water is equal to that of an acre of land; and these ponds are rented by great fishermen, or fishmongers, who adapt these systems of fishing their farms in the Residence of certain Fishes. 225 such a manner as to ensure the greatest possible permanent stock of fish ; removing the superfluous produce, which would otherwise be devoured or die, without injuring the future population, and. thus procuring a constant and regular supply in the season, with= out the risk of exhaustion. In Germany, it is well known that the cultivation of carp and other fresh-water fish is a regular object of attention; and although the proximity of the sea may cause us to treat with contempt the painful efforts of our neighbours to do that for themselves which nature has so bountifully done for us, it is assuredly not unworthy, the attention of the proprietors of inland counties in Britain, to at- tempt to produce from them, either rent or profit. Under the pre~ sent system, the fresh waters of this country are of little use but to furnish amusement to the sectaries of good Isaac Walton, and occupation to those who create flies of which no entomologist ever dreamed. Amusement would not be excluded by profit. If, too, it is said, as it well may be, that, as an article of food, the fresh-water fish are inferior to those of the sea, it must also be re= membered that variety, no less than excellence, is one of the great resources, as it is one of the main pursuits, of the noble science of gastronomy. But, to be more serious, the quantity of fresh waters existing in Britain is so considerable, as, with the exception of Switzerland, to exceed those of any country in Europe. From these, no profit whatever is derived. A Scottish lake, under a regular system of fishing and care, might probably far exceed in value the miserable tract of bog and rock by which itis enclosed. The canals of this country occupy a respectable space, and might, like ponds, be stored with fish, to the probable advantage of the proprietors no less than of the community. Even the rivers are unproductive, with the solitary exception of salmon, and of eels; since the quantity of other fresh-water fish brought to market is far too in- significant to be an object of attention in a case like this where so much more might be effected. The objection to fishing on canals is the injury which may be done to the banks, That, if it really exists, would cease whenevey 226 Dr. Mac Culloch on the Changing the fishery should become a farm in the hands of a lessee. In all these cases it is merely supposed that, as in France and Germany, the object should be the cultivation of fresh-water fish. But if as the views held out in this paper attempt to prove, sea fish can be naturalized in canals, lakes, ponds, and rivers, it is not unlikely that the sources of profit might be materially imereased. Experience would in a certain time teach us to know the fish that would live together most usefully for ourselves, that would rather contribute to each other’s support and to ours, than to their own mutual extermination. As yet, this is a subject little known, because it has been too much the usage to suppose, that as man cannot live in the same element witha fish, he has no chance of acquiring a knowledge of its habits and pursuits. The lakes of Scotland, of the North of England, and of Wales, offer particular facilities for the naturalization of sea fish, on account of the small distance at which most of them lie from the sea, and of the consequent facility of transporting these creatures in a living state. Should such a project ever be carried into effect, the good consequences are obvious. The facility of commanding a supply of fish would be increased; while that would also become certain, since it would no longer depend on weather, which so often interferes with the regularity of the sea fishery and of the market. The demand and supply might then also be more ac- curately balanced, as it'is in all parallel cases when the steady price of domestic animals for food, is compared with that of those which are the produce only of chance or contingency. It is an unquestionable fact that the produce of fish for consumption may be much increased by the very act of fishing them; or that a certain proportion may be regularly taken away for use, without diminishing this subaqueous population. It is thus that a profit is made by waters which in their natural state yield no supply for man. Nor, in the sea, is the apparent supply for our uses, ever diminished by any quantity which we can consume, provided that, in some peculiar cases, care is taken not to destroy the ova, or the fish under a certain size. How little attention has been paid to this subject, in sea fishing, is proved by arecent Act of Parlia~ the Residence of certain Fishes. 227 ment regulating the use of trawl nets in Torbay, and hy other regula- tions of less value, which have occasionally been made for similar purposes. In the cultivation of fish in fresh waters., the whole management becomes so completely under our command, that there would be no difficulty in framing such regulations as increase of knowledge would soon suggest, and as private interest would follow, or that of the public enforce. In what precise manner the regularity of fishing increases the supply, or at least does not diminish the production, has not, been clearly ascertained. That the several species eat each other's ova and young, and even their own, is very well established. Many devour each other, even at full growth, and it is not unlikely that many also die of disease or want of food. _ In such cases the steady removal of the superfluous part of the population cannot check its increase. If all the Turks and Egyptians who are to die of the plague next year, were to be devoured by crocodiles, there would be a certain quantity of food gained, and every thing would go on just as before. The empire would not have been a bit less populous or prosperous if the Huns and the Ostrogoths had eaten each other instead of strewing their own bones and those of their antagonists on the banks of the Dauube, or the plains of the Campagna. _ Respecting the species which might probably succeed in fresh water, it is not possible to offer any very rational conjectures. It is probable that they might most effectually be sought among those genera of which some species are already known to be versatile in their habits, In those genera of animals at least which - are natural and not artificial, there are considerable resemblances among the habits and pursuits of the different species. Thus it is not very improbable that as the plaice, the flounder and the mullet, have been naturalized to fresh water, the whole of the fishes of analogous habits, and particularly those of the genus Pleuronectes, might be habituated to inland lakes. The turbot and the sole would be very desirable objects of cultivation, If different species of Gadus have been shown to be at least indifferent to the quality of 228 Dr. Mac Culloch-on the Changing the water into which they enter, the whiting as well-as the cod might possibly learn to inhabit our lakes or rivers, and thus become among the most accessible as it is among the most deli- cate of fishes. If the smelt could be naturalized in ponds, as I have here rendered more than probable, it would, from the esteem in which it is held, be a peculiarly desirable acqui- sition. The hints contained in this paper may possibly in- duce others, who have the means in their power, to assist in the execution of a set of trials which can succeed only in the hands of many, and which must necessarily be the work of time. It has been suggested that as the flavour of fresh-water fish is far inferior to that of the marine species, the effect of naturaliza- tion would be to diminish their value as articles of food. This does not absolutely follow, although it may be thought probable from the case of the mullet above-mentioned, and by the fact that the flavour of the salmon is constantly diminishing from the time it has quitted the sea. If such should prove to be the case, it might indeed diminish the value of the acquisition, but it would not therefore destroy it; nor is it likely that a smelt would ever sink to the scale of a gudgeon, or a whiting to that of a roach. I have already shewn, however, that this deterioration of quality, so far from being probable, is not at all likely to occur ; since with this single exception, supposed to have occurred in Guernsey, and which is probably the report of prejudice, the flavour is really im- proved in all the cases where the experiment has been fairly tried ; and since the transportation, in Sicily, is made with this very object and no other. At any rate, let the trials be made before any such condemnatory judgment is passed. I will only further remark here, that there is no very good reason why the turtle should not be naturalized. What an acquisition this would be, it may be left to the Court of Aldermen to decide. The animals of hot climates, that live in air, have been so; and and why the submarine, or amphibious ones should not equally admit of this change of habits, I know not, and nobody else does. The turtle might take its place alongside of the peacock and the pintado, and with his fellow turtles of the land; while, if he chose the Residence of certain Fishes. 229 to hybernate, he might find a dormitory in Loch Lomond or clse- where, to pass the chilling hours of a Highland winter. And the change would be less than in the case of the land animals; since there is not such a difference of temperature in the one case as in the other. While on this subject, it will not be out of place to mention a parallel object of economy, far less known than it merits, and indeed little known out of Scotland, where it has been practised, although in a very limited manner, for many years. This is the preservation of sea fish in salt-water ponds. There are three of these in Scotland ; one in Galloway, another in Fife, and the third in Orkney. In these, even cod are known to live for many months, and to increase in size, without any loss of quality, and without any other food than that, imperceptible to us, which is brought by the daily influx of the sea, In the pond in Galloway, some in- dividual cod have been living for many years, so as to have be- come tame, if such a word may be applied to a fish, feeding, like hogs, out of a trough when introduced with a supply of food. This practice is so obvious an extension, as it is an improvement, of the expedient of using well-boats, as to afford cause of surprise that it has not been adopted by those who are interested. Motives of interest in the proprietors would shortly become matter of ad- vantage to the consumers; and the unsteadiness of a fish-market, no unimportant object of municipal attention, even in London, would cease to be a subject of complaint, The Romans, who seem to haye far exceeded us in all that relates to eating, as they did in a few other matters, were well acquainted with this practice ; and the history of their Vivaria has descended to us, with much more that relates to their rural economy, of which this formed a distinguished branch. Colu- mella says, decidedly, that they transported the spawn of various sea fishes to the different fresh-water lakes round Rome, ‘ marinis seminibus implebant,” and that this was a regular trade with the early agriculturists of the rustic Republic, before the rich and lux- urious took the keeping of artificial Vivaria into their own hands, He mentions the Mugil, which is probably our mule 230 Dr. Mac Culloch on the Changing let, together with “ lupos, auratasque,” two fishes of which we are not now able with certainty to assign the names. He farther alludes to others which he has not named, as being “ dulcis aque tolerantia.” He then passes from the subject, as of too familiar a nature to require a more detailed notice; a stronger proof than even his enumeration would have been, of the facts which I have thus attempted to support from his au= thority, and of the established existence of a practice which we havelost, and appear, very strangely, to be unwilling torevive. But I must refer your readers to the original, for the whole of this curious chapter, as the translation of it would inconveniently prolong this paper. The merely temporary naturalization to our lakes and ponds in the case of sea fish, would be no light acquisition to the gastrono= mer who might desire to have turbot before the season, or to reserve it at five shillings. for consumption, when the price has risen to three guineas. If the cod chooses to live in the fresh lake of Stromness-voe, there is no reason why we should not keep them in our own gardens till the day of giving a dinner comes round, or why Mr. Groves should not render the Serpentine a park for surmullets, instead of allowing it to be consigned to frogs and tadpoles. It is tobe hoped that the Fishmongers’ Company will take these matters to heart, as in duty bound; and that, in the progress of perfectibility, even the odious canal in St. James’s Park may become a repository of turtles, instead of what it now is, a Stygian nursery of Malaria and his black host. There is a subsidiary question arising out of these speculations respecting the convertibility of the habits of marine animals, highly interesting to geology, and on which it will not be out of place to say a few words, although unfortunately not much solid informa- tioncan be procured respecting it. This relates to the power which many, perhaps all of the vermes inhabiting shells, possess of residing indifferently in fresh or in salt water. It is well known to geologists that with respect to many, if not all of those deposits supposed to have been formed, like that of Paris and of England, under fresh water, the question mainly rests the Residence of certain Fishes. 231 on this, namely, whether the shells now supposed, from certain analogies and peculiarities of structure, to have been inhabitants of fresh-water lakes, may not have equally existed in salt lakes, or even in the sea. Some experiments towards the elucidation of this subject have been instituted in France; but I need not detail them, as they must be fresh in the recollection of all the readers of this Journal. It has also been recently. ascertained by M. Freminville, thet in the gulf of Livonia, the shell fish which usually inhabit the sea, and those which belong to fresh waters, are found living together in the same places. While these con- firm the general presumption which forms the basis of this come munication, their general probability is also strengthened by that analogy. A few facts of common occurrence on our own shores, seem to add additional weight to the opinion that the testaceous fishes in general are not rigidly limited to one kind of water, but are capable of living in both. On our sea coasts, the common muscle is invariably larger and fatter at the entrance of fresh-water streams into the sea, par ticularly if these bring down mud, and in these places the water is scarcely salt; yet they live also and propagate in abundance on shores which receive no fresh water. The oyster is transported from the sea to brackish water, where it also, not only lives, but improves in condition. In the same manner the common cockle inhabits indifferently the muddy sand-banks near the exstuaries of rivers, which are always soaked with fresh water, and those sandy or half muddy shores where no such water isfound. These are by no means the whole of the instances which might be enu- merated in support of an opinion, of which the determination is so important in the present state of geological science; but as this subject is too important to pass lightly over, and as the bounds of this communication are already exceeded, I shall leave it to those who may have the means and the inclination to examine it in greater detail. I will only add, that the same considerations will lead to similar doubts, where it has been attempted by geolo- gists to determine the nature of strata, as to their marine or fresh water origin, by that of the remains of fishes found in them. 232 Mr. Cooper’s Lamp Furnace, Art. V. Description of Mr. Cooper’s Lamp Furnace, for the Analysis of Organic Bodies. Havrine had occasion to use Mr. Cooper’s lamp for the analysis of organic bodies, described in the last volume of the Transactions of the Society of Arts, and having found it very effectual, we have taken the following account of it from that work, with an abstract of the method of using it; and are enabled by Mr. Cooper’s kindness to add the description of some improvements which he has since made on the original apparatus. Fig. 1. Plate iy. aa and 6 b, are two long spirit-lamps, each having ten burners and wicks, the burners of each lamp sloping towards those of the other, as seen in the end view, fig. 2. They are placed in a tin tray c c, mountedon four feet. This tray is perforated in the middle the whole length of the lamp, and as wide as ee, fig. 2. The object in sloping the burners is, that they may clear the lamps and approach each other as near as is requisite, yet leave free space for a current of air, the tray being perforated and mounted on feet for this purpose: dd are spring wires at each end.of the tray, to receive the tube ff containing the substance to be analyzed, and to hold it over the flames ; by pressing the shoulders g g, fig. 2, the wires open to receive the tube, and close on removing the pres- sure ; and should the tube be shorter than the lamps, an additional support on a leaden foot, fig. 3, is placed through the opening e ¢ of the tray to rise between the flames, and hold the end of the tube. The tubes are coated with copper foil, wrapped spirally round them ; if each succeeding fold be on half the other, there will be a double coat of copper all the way, if on two-thirds, there will be three layers of copper, by which the glass tube is prevented from bending when hot, and becomes very uniformly heated. The spi- rals are continued beyond the end of the tube to reach the support, and leave the end within the flames. The dotted line at A, fig. 4, shews the end of the tube short of the support, the foil is secured at the last coil by binding wire, as at ¢. for the Analysis of Organic Bodies. 233 Fig. 5, shews the foil in act of being wrapped on, also the pro- portion of the space occupied by the materials; first the mixture of oxide of copper with the material to be analyzed, next pure oxide of copper, or copper filings, and lastly asbestos. When the quantity of water formed is considerable, the tube is either blown into a bulb, as at &, fig. 6, or melted on to one ready pre pared. Fig. 7, is a long funnel, made by drawing out the end otf a tube of suitable thickness at m, till it is long and small enough through n n to reach to the bottom of the tube, and then cutting it off at m, by which liquids may be introduced to the bottom of the tube without soiling the sides. . . As the wicks nearest the trough are to be first lighted, and the remainder in succession as the former finish their action, there are upright supports of tin oo fixed on the lamps, one for each space between the burners, against which to rest a slip of tin pp, to pre- vent the lighted wicks from kindling those next, and it also enables the experimenter to extinguish those which have done duty. In fig. 2, the tin slip p p is shewn by dotted lines reaching from lamp tolamp. Little flat caps are put on each burner when done with, to prevent waste of spirit; fig. 8 shews one of these caps q in its place. r7,fig. 1, is a shelf fixed to the mercurial trough, to hold the lamps; ss, the graduated jar. The pipes, with corks, w w, fig. 2 are the apertures by which the spirit is poured into the lamps; their places only are marked at w w, fig. 1, The whole of this appa- raius is made of tin plate. At first Mr. Cooper operated with a tube of one piece; and the materials being put in when the tube was straight, it was afterward heated and bent at the open extremity, so as to suit the mercurial trough; but this has been improved upon by making the tube shorter and having a bent piece, attached to it by a small flex- ible tube of caoutchouc, f, fig. 1. It removes the chance of accident from stiffness in the end of the tube, and the tubes being straight, may be used many times in succession, Mr, Cooper has also used with advantage, at times, the form of 234 Mr. Cooper’s Lamp Furnace, receiver shewn at fig.9; it is about twelve inches long, and one inch in diameter, and being filled with mercury and hung over a basin is ready for use. When containing gas, its quantity is estimated by the graduated scale on the tube, care being taken previously to compensate for any difference of mercurial pressure by inserting the long funnel and cork, fig. 10, into the mouth of the receiver, and pouring mercury into the funnel until it is level with that in the re= ceiver. It is easy afterwards to admit water or solution of potash into the receiver to absorb the carbonic acid, and leave the nitrogen. The oxide of copper required in using this instrument may be procured either by burning the residuum of verdigris which has been used in the preparation of acetic acid, or by heating plates of copper with access of air, and quenching them in water. Great care should be taken that the oxide be pure, and it should be pulverised and heated ina crucible, stirring at the same time. It may then be sifted, and the different portions preserved apart. The tube used should be of crown or green-bottle glass, fourteen to fifteen inches long, (not so long if the separate bent end piece is used,) and from one to two tenths of an inch internal diameter; it should be clean and dry, one end should be sealed up by a blow-pipe, and then it may be balanced. The substance if volatile is now to be introduced, if solid it may be shaken to the bottom, if fluid it is to be poured in by the funnel, fig. 7. The quantity of substance is then to be ascertained, and a portion of cold oxide of copper introduced, suf- ficient to absorb the substance if fluid, and cover it about a quarter of an inch; after which recently heated and still warm oxide is to be added to the proper height. Then a portion of recently ignited asbestos is introduced and pressed rather lightly on to the oxide, and occupying from one to two inches. The tube, with its contents, is then to be balanced again, after which itis to be enve= loped in the copper foil, (care being taken that the foil does not cover the part containing the asbestos,) and the end piece with its caoutchouc tube is to be fastened on. : The tube is then to be arranged as in the figure, and heat applied ; the lamps are to haye but short wicks, so that the top of the flame for the Analysis of Organic Bodies. 235 shall just touch the tube, and only one set will be required, unless the tube be large, as for instance, half an inch in diameter * ; the lamps are to be lighted in succession, those nearest the gazometer first. If the substance to be analyzed be a vegetable salt, or be hy- grometric, it must be dried, which is best done in vacuo, but which Mr. Cooper effects also in the following manner. A wide-mouth stoppered bottle is selected, and alsoa smaller bottle which will easily go into it; a quantity of dry pulverized chloride of calcium is then strewed over the bottom of the larger bottle, and the smaller, containing the substance to be dried is also introduced; a small piece of bibulous paper is moistened with alcohol and put inside the larger phial; it is then lighted, and when it has burned for a second or two, the stopper is put into the bottle, and the vacuum obtained is such that the desiccation goes on very rapidly and effectually. When substances of this kind are analyzed, they must, of course, be-mixed with oxide of copper before they are introduced into the tube ; a quantity of pure oxide is then to be put into the tube, and it is as well to add afterwards a small quantity of copper filings orshavings. In heating the tube the wicks are to be lighted as be- fore, but instead of suffering the whole to burn at once, it is as well to leave only three or four in action at a time, extinguishing the others, but taking care to ignite the whole extent of tube at once at the end of the process. When nitrogen is present in the body to be analyzed it has a tendency to become oxidized at high temperatures by the oxide of copper, and in this case yields erroneous results. To obviate this as much as possible Mr. Cooper has lately used protoxide of cop- per, instead of peroxide ; and though he finds that in certain circum- stances this also will impart oxygen to the nitrogen, yet it does so with far greater difficulty than the peroxide: hence in all cases where nitrogen is concerned, the protoxide should be used. The protoxide is prepared by fusing peroxide of copper with copper filings in excess; a mass of protoxide is obtained, which, on being pulverized and sifted is fit for use, * The power of the lamps is such that a thick platinum tube, half an inch in diameter, may be rendered bright red-hot by them. Art. VI, Description of a self-acting Blowpipe. By Mr. H. B. Leeson. Ir has, I believe, before been observed that bottles of Indian Rub- ber might be expanded to a considerable size by condensing air into them: Tam not, however, aware that bottles so filled with con- densed air have been applied to the purposes of a Blowpipe. The bottles I make use of vary in weight from half to three- quarters of a pound, and may be readily procured at the Stationer’s. To prepare them they should be boiled in water till completely softened, which, if they are put into water already boiling, will generally be accomplished in ten minutes or a quarter of an hour. They must then be taken out and suffered to cool, when a brass tube may be fitted into the neck of the bottle, having a small cock screwed into it at one end, by which it may be connected with the condensing syringe, and to which the blowpipe jets may be attached. There should be a milled projection on the side of the tube, for the purpose of more firmly attaching the bottle to it, which may be effected by passing a ligature of waxed string round the neck of the bottle on each side of the above-mentioned pro- jection. The bottle must next be filled with condensed air. After a few strokes of the syringe a blister will be observed to form, which will gradually enlarge till the greatest part of the bottle (which must be selected uniform in substance, and free from defects,) has extended to asimilar substance. The condensation should not then be con- tinued farther. Bottles of the size I have mentioned will generally extend from fourteen to seventeen inches in diameter without bursting ; and Thave occasionally extended them much beyond these dimen- sions ; but in this the operator must, of course, be entirely directed by his own observations. The Indian rubber varies in its quality. There is one sort which appears of a blacker hue before extension, but becomes very thin and almost transparent on condensing air into it, whilst there is Mr. Leeson on a Self-acting Blowpipe. 237 another sort haying a browner colour, which is much less yielding in its substance, and cannot be extended to the same thinness as the former. I have found both sorts to answer my purpose, but the above observations may be useful in determining the quantity of air which may be condensed into the bottles with safety. To apply these bottles when filled with condensed air, nothing more is necessary than to remove the syringe, and in its place to- screw on a jet of such bore as may be required. On opening the cock the air will be expelled by the elasticity of the India Rubber, and its own condensation, in a strong and uniform stream, which in bottles of the size I have mentioned will continue from twenty= five minutes to an hour, according to the size of the jet. When once prepared the bottles may be constantly expanded to the same dimensions without any danger of bursting. When the air is exhausted, the bottles will be found somewhat enlarged in _ dimensions, but may again be contracted by holding them before a - fire, or a few minutes’ immersion in boiling water. This, however, is unnecessary, since no subsequent inflation will be found to in- crease the size of the bottle any further, and I have used the same repeatedly without any apparent diminution of its elastic powers. The principal advantages of this blowpipe are its great portability, and length and steadiness of action, (in which I consider it much superior to the hydraulic blowpipe,) together with the perfect liberty at which, when properly mounted, it leaves the operator’s hands. This blowpipe is applicable to any of the gases, and may, I cons ceive, be applied with advantage to contain the explosive mixture of oxygen and hydrogen, as no inconvenience can possibly accrue from its bursting, beyond the loss of the bottle. This blowpipe may be supplied with air or gas during an ex- periment, by having a separate communication for the syringe into the piece of tube before mentioned, and this will enable the ope- rator to continue his experiments for any period of time. Blowpipes on this construction may be procured, very neatly and conveniently mounted, at Mr. Newman’s, No. 8, Lisle-Street, . Leicester-Square. Vo. XVII. Ss Art. VII. ASTRONOMICAL'PHENOMENA arranged in Order of Suc- cession, for the Months of July, August, and September in the Year 1824. By James Soutnu, F.R.S. (Continued from Page 84.) JULY. Planet’s or | = #| Sidereal * Planet’s or Planet’s or | = $ | Sidereal Planet’s or é Star’s 23 Star’s P Star’s 32 Y Star’s >| Name, &c, | &2) Time. Declination. S| Name, &e, | &”|) Time. Declination. a =e a =° H. M. D. M. H. M. D. M. 1) Seaiepece 641, 23 7N 8| 44 Oph...|5.6] 17 16 24 OS Im. ¥....|7.8] 15 190r 8"39'mr. Moon.... 17.21 25.428 #s R.A. 11" 2’ Decl. 0° 26’ S. (cont.) XVII. 142] 8] 17 25 24 30S Georgian . 19° 1 23 9S Georgian . 18 59 23 10S Meréury.. 5 15 20 42N Mercury... 5 59 22 34N Venus ... 612 23 35N Venus... 6 50 23 21N 2} Sun ..... 645 23 3N Bl Sun siege 714 22 22N Moon.... 1148 5 78S Moon.... 18 17 24 478 Georgian . 19,.1;.23 98 24 Sagit..| 7] 18 23 24148 Mercury... 5 20 21 ON XVIUI.129} 6 | 18 28 23 39S Venus... 617 23 34N 141} 6} 18 31 23 59S 3] Sun ..... 6 50 22 59N Georgian . 18 59 23 10S Moon.... 1241 1057S Im. ¥....{7.8] 21 560r14"44’mrT. Georgian . 19 1 23 9S ¥s R.A, 185 24’ Decl. 24° 21’ S. (12’N.) Mercury.. 526 21 17N ELM. <5 sie 22 500r15°38(7’N.) Venus... 6 23 23 32N Mercury. . 6 7 22 47N 4) Sun ...:, 6 54 22 53N Venus... 6 56 23 16N Moon.... 13 35 16 6S 10} Sun .,... 718 22 14N Georgian. 19° b 22 8S Im. * 1..] 8 | 15 49or 8°34'mT, Mercury. . 5 81 21 35N ¥’s R.A. 19" 6! Decl. 22° 48’ S, (10’N.) Venus... 628 23 31N Em, * 1.. 16 430r 9>28'mr. 5] Sun ..... 6 58 22 48N Im. * 2 ..] 6 | 17 520r10°37’mr. Moon.... 14 30 20 20S ¥’s R.A. 19 10’ Decl. 22° 43'S. (5’N.) Georgian . igo} 23 9S oSagit...|4.5] 18 54 22 OS Mercury... 5 88 2151N = Sagit...|4.5] 18 59 2118S Venus... 6 34 23 30N Georgian . 18 59 23 108 6} Sun ..... 7 2 22 42N Em. *2.. 19 5orl1'50'sr,(1’S.) Moon.... 15 26 23 268 Moon,... 19 10 22 40S 42 Libre.|5.6} 15 30 23 148 Im. ¥ 3 ..| 8 | 19 41orl2"96’mr. KY, 192,;| 6 | 15°42 23 27S *’s R.A. 19" 12’ Decl. 22° 24’ S. (cont.) XV. 225..) 3] 15 50 22 6S Im. ¥ 4 ...|6.7| 22 Oorl4"44’mr. Georgian - 19 0 2310S *’s R.A. 19" 16’ Decl. 22° 7’ 8. (14’N.) Im. *....| 6 | 19 150r12" 15’. Em. * 4.. 22 330rl5® 177.14 *’s R.A. 15" 34’ Decl. 23° 50’ S. (3'S.) Im. *5...| 8 | 22 42o0r15"26mr. Em olay 20 160r13"16™mr. ¥’s R.A. 192 17 Decl. 21° 58 S. (cont.) ercury.. 5.45 22 6N Eclipse of , Venus ... 6 39. 23 29N eon t n988 4Gonls? $ifeey, 1) Sate on ate 7, 6 22:36 Moon sets eclipsed. Moon.... 16 24 25 148 Mercury. . 614 22 59N 25Scorpii] 6| 16 36 25 12S Venus... 7 1 28 .10N 18 Oph...} 6 | 16 89 24 19S LU in, fa « 7 22 22 GN 26 —-...| 6] 1645 24 43S Im. ¥1..] 8 | 15 llor 7°52’mr. Georgian . 19 0 2310S *’s R.A. 19" 56’ Decl. 19° 59’ S. (8/N.) Mercury... 5 om 22 22 .N Em.* 1.. 16 160r 8'57’m7.(0') Venus ... 645 23 27N Im.*2.. ue 16 590r 9"40/mr. 8) Sees. ao 710 22 29N *’s R.A. 192 59’ Decl. 19° 55'S. (1'N.) 42 Oph...|3.4) 17 11 24 49S Im.* 3. | 8 | 17 43o0r10°24’mr. Astronomical Phenomena. JULY. Planet’s or Star’s Name, &c. Sidereal itude of Stars. Planet’s or Star’s Declination. n Time. D Ma; ‘Wg H. M. OD. M. ‘ll *’s R.A.20 0’ Decl. 19° 53'S. (4’S.) Im. *4..| 8 | 17 440rl0%25'mr, © %’s R.A. 205 0’ Decl. 19° 34’ S. (12'N.) Im. ¥5 ..] 8 | 17 450r1026’mr. *’s R.A. 20" 0’ Decl. 19° 53’ S. (3'S.) Em. *4.. 18 42o0r11423’m7r.(5’N) Em. *3.. 18 45o0r11°26’m7r.(11’S) Em. ¥5.. 18 47orl1h28’m7.(11'S) Georgian . 18 59 23 11S Moon.... 20 3 19 32S XX. 80 ../7.8} 20 11 18 528 mw Capr...| 5 | 2017 18 47S XX.154..1| 6 | 20 20 19 9S Im. ¥ 6..| 8 | 21 22o0r]14" Q'mr. %’s R.A. 20" 6’ Decl. 19° 38’ S..(5’S.) Em. 6.. 22 130r14"53'mr.(13'S) Mercury. . 6 22 23 5N Venus... 7 6 23 4N 12) Sun ..... 727 21 58N Georgian . 18 59 23 11S XX. 341 ./7.8] 20 43 18 51S Moon,... 20 52 15 36S XKI.7.../7.8} 21 2 1511S 29 Capr..|5| 21 6 15 54S Mercury. . 6 30 23 12N Venus... 712 22 59N 3) Sun ,.... 731 21 50N Georgian . 18 59 231158 17 Aquar.} 6} 2114 10 4S XXI.134.|7.8} 2119 12 20S £Aqu....|5| 2128 8 388 Moon.... 21.38 11.48 Mercury.. 6 38 23 18N Venus... 7d? 22 538N 4) Sun ..... 735 21 41N | | Georgian . 18 59 23 12S | | Moon.... 2223 610S Mercury. . 647 23 18N | | Venus... 7 22.22 44N 15) Sun ..... 739 21 32N | | Georgian. 18 58 23 12S Mercury. . 6 57 23 17N Venus... 728 22 34N 16) Sun ..... 744 21 22N Georgian . 18 58 23 12S Mercury. . 7. 6 2317N Venus... 7 33 22 25N 17) Sun..... 747-21 12N Georgian , 18 58 23 12S Im. *#...+| 7 | 20 6o0rl223'mr. #’s R.A. 3 44’ Decl. 22° 41’ N. (10' N.)|}24] Sun ..... Emo's. {| | 21 12 0r13"29’m7,(4’S.) 19 20 22 23 239 Planet’s or = 2 | Sidereal Planet’s or Star’s ‘2s Star’s Name, &c. | #2] Time, Declination. = ° H. M. D. M. Mercury, . 7-5 23 ON Venus... 738 22 15N Sun ,.... 7,51 21 “1N Georgian . 18 58 23188 Mercury. . 724 23 1N Venus... 744 22 6N Sun fives who 20 Sl Georgian . 18 58 23 13 Mercury. . 7 83 22 53N Venus... 749 2156N Sun ..... 759 20 39N Georgian . 18 58 23138 Mercury. . 742 22 37N Venus... 754 21 43N Som gh 8 3 20 28N Georgian . 18 57 23 148 Im. * 1..|7.8| 22 4o0rl4" 5’ur. %’s R.A. 42 2 Decl. 23° 7’ N. (2’N.) Em. *1.. 22 55o0rl4456'm7.(6'S.) Im. ¥2..|.7 | 23 Oorl5® I’m. x#’s R.A. 41 4’ Decl, 23° 8’ N. (5'S,) Em. ¥2.. 23 450r15"46’m7.(11'S) Mercury. . 7.51 22 21N Venus... 769 21 29N Sun tfsiey,- S$ 7 20 16N Georgian . 18 57 23 148 Im.%...-| 6 | 20 550r12"52’mr, #s RA. 40 57 Decl. 24° I’ N. (4’N.) Em.s 21 Sorls® 2’mr.(2’N.) Mercury. . 8 0 22 5N Venus... 8 4 21 16N Sun ,.... 811 20 4N Georgian . 18 57 28 148 Im. ¥1..} 8 | 23 1%or15"10’mr, #’s R.A, 6" 8’ Decl. 28° 40’ N. (11 N.) Im. ¥ 2 ..|7.8| 23 240r15"17m7, #’s R.A. 6 8’ Decl. 28° 40’ N. (1I'N.) Im. ¥ 8 ...| 7 | 23 28o0r15"2I’mr, %'s R.A. 6" 9’ Decl. 23° 32’ N. (3'N.) Im. % 4...| 8 | 23 $30r15"26'mr. #’s R.A. 6! 9’ Decl, 28° 20’ N. (9’8.) Im. ¥ 5 ..| 8 | 23 450r15!38'N *'s R.A, 6" 9’ Decl. 23° 32” N. (3’/N.) Em. ¥1.. 23 5lorl5"44’mr.(11'N) Em. ¥2., 23 580r}5"5)’m7r.(11'N) Em, ¥*4. 0 l0orl6" 3’mr.(9'S) Em. *3.. 0 130r16" 6mr.(3'N) Em. * 5..« 0 8lorl62d’ur.(3'N) Mercury. , 8 9 21 44N Venus... 810 21 2N 815 19 52N Venus .., 815 20 49N 240 Astronomical Phenomena. JULY. Planet’s or = 2] Sidereal Planet’s or Planet’s or Ze Sidereal Planet’s or ‘4 Star’s aes ‘ Star’s . Star’s 2s Star’s. Bd Name, &c. ae Time. Declination. 2 Name, &e. aA! Time Declination. a tote Ss ae Hemel) De ET. H. .. D. oF. 24) Georgian . 18 57 23 14S 28] Mercury... 844 19 57N 25] Sun ..... 819 19 39N Georgian . 18 57 2315S Mercury. . 819 21 22N 29} Sun ..... 8 34 18 448 Venus... 8 20 20 35N Venus 8 35 19 45N Georgian . 18 57 23 158 Mercury. . 8 52 19 24N 26) Sun ..... 8 23 19 26N Georgian . 18 57 23 158 Venus... 825 20 18N 30) Sun ..... 8 38 18 30N Mercury. . 8 27 20 54N Venus ... 8 41 19 28N Georgian. 18 57 23 158 Mercury. . 9 0 18 5IN Bi) Sun’ asso. 8 27 19 12N Georgian . 18 57 23 15S Venus ... 8 30 20 2N ol] SUM crest 8 42 18 15N Mercury. . 8 35 20 25N Venus 846 19 12N Georgian . 18 57 23 158 Mercury. . 9 8 18 ITN 28] Sun ..... 8 31 18 58N Georgian . 18 57 23 158 AUGUST. H. M. OD. M. H. M. D. M. Sane a6 846 18 ON 6] Im. * 1.. 6 16 27o0r 726m. Venus... 8 51 18 55N *’s R.A. 18" 51’ Decl. 23° 28'S. (11’N.) Mercury. . 916 17 41N Em. *1.. 17 250r 824mr.(7'N.) Moon.... 14:12 19 28 28 Sagit..] 6 | 18 36 22 34S 2) Sumi... 8 50 17 45N 30 6 | 18 40 22 21S Venus... 8 56 18 35N 35 5 | 18 45 22 53S Mercury. . 924 17 -3N Moon.. 18 54 23 268 Moon.... 15"9 22) S2S Im, of Georgian 19 4orl0" 3’mr. 3] ‘Sun ..... 854 17 29N Im. *¥2..| *s |] 19 540r10"53’mr. Venus... 9 1 18 14N #’s R.A. 18" 55’ Decl. 23° 6 S. (cont.) Mercury. . 9 32 16 25N Em. Georgian 20 16o0rl1"15’mr, Moon.... 16 6 2450S 7 Sans fee 9 9 16 24N Im.%....| 4 | 18 32or 9°43’mT. Venus... 920 1652N *’s R.A. 16" 10’ Decl. 25° 10’ S. (14’S.) Mercury. . 10 1 13 49N Bio leis. e 5orl0"15’ (13'S.) XIX. 176.) 7] 19 26 19 14S ALT oi ctay'e 8 58 17 13N 56 Sagit..] 6 | 19 36 20 10S Venus... 9 6 #17 54N 57 .-(5.6] 19 42 19 29S Mercury. . 940 15 46N Moon.... 19 46 20 39S Moon.... LAS aSSt Sues Im. *. 22 6orl3! O'mr. @ Oph....|3.4) 17 11 24 49S x's R A. oh 50’ Decl. 20° 20’ S. (14’N) 44—....|5.6] 17 16 24 0S Ems. #023 23 Torl4” 0'mr.(0’) XVII. 142 17 25. 24 30S 8} Sun ..... 913 16.7N SL WSTTI ais, sie 9 2 16 57N Venus . 925 16 29N Venus... 910 17. 33N Mercury. . 10 8 13 ON Mercury... 947. 15-5N 13 Capr.. 20 27 15 458 63 Oph...|6.7] 17 44 2451S XX. 240.. 20 31 1645S 5 Sagit...) 7} 17 49 24-16S Moon.. 20 35 17 0S XVIL 342) 7/1754 24 248 : XX. 367.. 20 45 15 57S Moon.... 1759 25° 9S 9} Sun ..... 917 15 50N 6] Sun ..... 9 5. 16 4YN Venus . 930 16 6N Venus... 9 15 W7asN Mercury.. 10 15 12 18N Mercury. . 954 14 24N Im. x. 19 Sor 955’. Astronomical Phenomena. AUGUST. Planet's or z =| Sidereal Planet’s or Star’s aS Star’s Name, Ke. a2 Time. Declination. = ° H. M. D. M. *’s R.A, 21" 20’ Decl. 12° 50’ S.(14’N.) ime .. : 20 lorl0"47’m7.(6’N.) XXI.82../7.8] 21 12 1212S XXI. 134./7.8] 21 19 12 19S Moon.... 2123 12 41S a Capric. ./5.6} 21 37 12 10S Sun ..... 9°21" 15 °32N Venus . 935 15 43N Mercury... 10.21 ° 11 385N 30 Aquar.|5.6] 21 54 7 22S XXI.403.| 8 | 2159 7148S XXII 14.} 8 | 22 3 7208S Moon.... 22 8 7558 Tm. *1../8.9} 0 490r15"31’mr. *'s R.A. 22) 12’ Decl. 7° 8’ S. (13’N.) Im.*2..| 7 | 0 500r15"32’mr. *’s R.A. 22h 19’ Decl. 7° 8’ S. (12’N.) Im. ¥ 3 ..|8.9| 1 lorl5"43’mr. *’s R A. 22" 13’ Decl. 7° 4’ S. (12'N.) Em. *1.. 1 540r16"36'mr.(0’) Em. * 2 1 56or16438’Mr.(2’S.) Em. * 3 2 1lorl6"53’mT.(2’S.) Sun ..... 924 ».15 15N Venus . 940 15 20N Mercury. . 10 27 10 52N Im. *..../8.9] 20 370rl1"16’Mr. %’s R.A. 225 51’ Decl. 3° 23’ S. (6'S.) Em... 21 23or12" 2'wr.(15'S.) Moon.... 22 53 492 528 XXIIL68./6.7} 2315 0 40S 12 Pise....|.7 | 23 20 2.08 14 —...|6.7| 23 25 2138 SUR <.15'-%. - 928 14 57N Venus ..- 945 14 57N Mercury. . 10 34 10 8N - Im. *1..| 6 | 16 300r 7" 6MrT. %’s R.A. 235 27’ Decl. 1° 8’ N. (4'N.) Em. *1.. 17 27or 8" omur(7S.) y Piscium |4.5| 23 8 2 20N =f 6.) 28.11 4 25N 17 -/4.5| 23 $1 4 41N Daiit, % Ze. 23 360r14"10’mr, #’s R.A, 23 87’ Decl. 2° 31! N. (13'S.) Moon.... S37s8n) 2ATN Em. * 2 0 40 0r15"14’mr.(1'S.) Sun as 932 14 38N Venus... 950 14 84N Mercury... 10 40 9 25N Im.%....| 6 | 20 Sorl0"39'mr. %'s R.A. 0" 17 Decl. 6° 43’ N. (S'N.) Em. *.. 20 58orl1"24’mr(3'N.) Moon.. 022 722N Days. 14 15 1 ~o 7 0 2) 22 241 Planet’s or 3 2) Sidereal Planet’s or Star’s 28 Star’s Name, &c. a) Time Declination. ss H. M. D.°M. Suny wee 9 36 14 20N Venus 955 14 °9N Mercury. . 1046 8 42N Im. *%....|7.8] 0 360r15" 2’mrT. *’s B.A. 129’ Decl. 12° 42’ N. (5°N.) Em... 1 540r16"20’mT.(9'S.) SUM rs as 940 14 1N Venus... 1D D* 134SN Mercury. . 10 51 758N SuWijen,s es 943 13 42N Venus... 10 5 13 18N Mercury. - LOPS EFT AN Im. *2..] 7 | 22 280rl2847 mr. *’s R.A. 20 45! Decl. 19° 39’ N. (8’N.) Im.* 1..| 7 | 22 500r13" 9'urT, ¥’s R.A. 2 44 Decl. 19° 51’ N. (cont.) Em. ¥2.. 23 290r13447'(2S.) Im.*3..| 6 | O 17orl4>35’mr. x’s R.A. 2" 48! Decl. 19° 57’ N. (9S.) Em. * 3 1 2lorl5" 39’mr.(2’S) Sante 947 13 23N Venus .. 10 9 12 53N Mercury. . 11 3 6 31N Im.x....{7.8] 0 lorl4"l@mrT. x’s R.A. 3! 42’ Decl. 22° 9’ N. (cont.) Im. ¥2..| 7] 1 Q9orl5"23'mr-. xs R.A. 3" 44’ Decl. 22° 41’ N. (6'N.) Em. *2.. 2 150r16"29'mT.(1'S.) Im. *¥3. ‘lei 2 250r16"39'mr. #3 R.A. 32 47 Decl. 22° 39’ N. (4’S.) Em. *3.. 3 29o0r17843/(105S.) SUED Sore te - 951 13 4 Venus 10 14.12 27N Mercury. UB b SE mar wat at Im. * 1 ..|7.8] 20 360r10"48’mr. xs R.A. 4 31’ Decl. 23° 41’ N. (9'N.) Im.*2..| 7 | 21 4orl1"15'mr. #’s R.A. 4" 33’ Decl. 23° 45’ N. (10/N.) Em, * 1 21 16o0rl127'mr.(5'N.) Em. *%2.. 21 44orl1"55(5'N.) SUB bc wes 9 54 12 44N Venus 1019 12 2N Mercury. . 11/15. y 5S 4N Suni. saa 9 58 12 25N Venus... 10 24 11 34N Mercury. . 1120 4 22N Sun). 2% 10 2 12. 5N Venus... 10 28 11 6N Mercury. . 1126 3 40N Sint suas) 10 6 11 44N Venus... 10 338 10 89N Mexeury. . 11 31 2 57N Astronomical Phenomena. AUGUST. v 9 wc ot ae Planet’s or | 5 Z| Sidereal Planets or Planet’s or | = £| Sidereal Planet’s or Star’s aa . Star’s P. Star’s = 5 Star’s e Name, &c. og? Time. Declination. 2] Name, &e. wae Time Declination. 3 = we =) = Q Pi Sunss... 10 9 11 24N 28 - a Laoag J Venus.... 10 38 10 1IN Mercury. . lee D Lae es Mercury,.. 1] 36, ..2 15N 29| Sun ....-- 10 31 9 19N 24) Sun ..is. 10, 13, ,11) AN Venus... 11) 6 Ren Venus.... 10 42 9 44N Mercury 12 4 1458 Merecury.. 1140 1 33N Moon.... 14 48 21 128 25) Sun ..... 10 17 10 43N 30} Sun ..... 10 35 8 57N Venus... 10.47 9 17N Venus... li 9 ‘6 ba Mercury... 1145 0 52N Mercuty.. 12 9 2235 26} Sun ..... 10 20 10 22N Moon.... 15 46 23 588 Venus. « 1051 8 48N Im. *....| 7 | 19 200r 8'44’mrT. Mercury... 1150. 0 12N x’s R.A. 15" 52’ Decl. 24° 31'S. (cont.) 27) Sun sy... 10 24 10 1N 31) Suns .c. 1039 8 35N Venus.... 1056 8 19N Venus.... 11 14 624N Mercury.. 1155 0 2758 Mercury. . 12218, 8 15 28] Sun is... 10 28 9 40N Moon.... 16 45 25 198 SEPTEMBER. ~ XK. D. M. H. M. D. M. J) Sun... 10 42. 8 14N 4] x’s R.A. 204 19’ Decl, 18° 27’ S. (r's,) Venus ... 11,19. 5 55N Im. ¥ 3 ..|6.7] 19 500r 8"55’mrT. Mercury. . 12 16 3 38S x’s R.A. 208 19’ Decl. 18" 1’ S. (15’N.) Moon.... 17,41, 25 J6S Em. * 2. 20 Gor 9"10’m?.(15'S.) f B) Sun. sana. 1046 7 52N XX.45..|8|20 6 1649S Venus ... 11238. 525N Em. *1.. 20 130r 9h 17’mr(12'S,) Mercury. . 1220 4138S Em, ¥2.. 20 l5or 9"19’'mT.(10°N)F Moon.... 18 36 23 58S Moon.... 20 20 18118 v1Sagit..| 5 | 18 44 22578 XX.194..| 7 | 20 26 17 78 XVIII.255/6.7] 18 51 22 568 XX. 240../6.7] 20 31 16458 2946.7] 18 56 22 458 5) San. g.s > 10 57 645N | 3} Sun ..... 1049 7 30N Venus ... 11 37 8 54N | Venus... 1128 455N Mercury... 12 82 5 558 } Mercury... 1224 4188S Im. ¥ 1 ..] 7 | 20 40or 941’mr. Im. ¥ 1 ..|7.8] 19 llor 8"19’mr. x's R.A. 21" 8 Decl. 14° 0'S. (9'N.) #’s R.A. 190 20° Decl. 21° 42’ S. (7’8.) Im.%2..] [20 42or 9h43'ur. Of Im. ¥2..] 8 | 19 160r 8h24’mr, %’s R.A. 21" 6 Decl. 13° 55’ S (cont.) | #3 R.A. 198 30! yes 21° 39’ S. (4S.) 8 Aquar..| 6 | 20 50 13 448 ‘| | Moon.. 929 2130S y= aa 21, 0°) Teas 56 Sagit. . 6 19 36 20 10S Moon.... vi Yi oe 57 -.15.6] 19 42 19 295 18 Aguar. 2115 13 388 XIX. 377.] 8 | 19 55 2148S Em. ¥1.. 21 580rl0"59'mT.(4'S.) 7 Em. * 1.. 20 Sor 9"11/mr.(1398.) Im. ¥ 3 ..] 7 | 22 42o0r]1"42’mr. Em. * 2.. 20 180r 9h26’m7.(12'S.) ¥’s R.A. 21 10! Decl. 18° 43'S. (4N 4) Sun ..... 1053 7 SN Em. * 3.. 23 550r12455 mr.(9'S,) Venus... 1132 425N 6) Sun ..... 11 0 6 23N Mercury. . 12 28 5 23S Venus ... 1141 3 24N ; Im.%1..{| 5] 19 2or 8 7wr. Mercury. . 12 35 6 268. x's R.A. 20! 19" Decl. 18° 23’ S, (3'S.) Im.*1..|7.8 17 350r 6532'ur. | Im.*¥2. nm ql 19 130r 8) 18'mr, x's TL.A. 21" 48! Decl. 10° 24'S. (“8 Astronomical Phenomena, 243, SEPTEMBER. Planet’s or 3 Z| Sidereal Planet’s ot Planet’s or | = 2] Sidereal Planct’s or Star’s zs 4 Star’s_ . Star’s 2 Eh wa Star’s oc | Time. Declination. é Name, &c. i?) Time. Declination. =e a =? H. M. oD. M. H. M. D. M. 6] Em. * 1. 18 14or 7/11’w7r.(14’S,)}}12} Sun ..... 1122 4 TN & Aquar.. -| 542128 8 388 Venus ... 12 9 020N 46 Capr..| 6 | 21 36 9 53S Mercury. . 1253 9 7S Tm. * 2 ..|7.8] 21 38o0rl0434’mr. Im. *....|6.7] 20 17or 8"50'm7. #s R.A. 21 54’ Decl. 9° 21'S. (19/N.) ¥’s R.A. 2) 24’ Decl. 18° 6’ N. (15’N.) Moon.... 2153 9 30S Em. i. 20 550r 9528'mr.(8’N.) XXII. 44./4.5] 22 8 8 39S 13) Sun ..... 1125 3 44N Em. * 2.. 22 LL eae We Venus ... 1214 0118 {7 Sun..... iB! 6 1N Mercury. . 1255 9 308 Venus... 11 46 2 54N Im. 1 Sat.. 2 3lorl4"59'mT.(1004+ Mercury. . 12 39 6588S Im.%....|6.7 3 56 or15"24’/m Tr. 60 Aquar.|6.7| 22 25 2 28S *’s R.A. “gh 28’ Decl. 22° 5’ N. (15'N.) XXII. 183]7.8] 22 32. 4 28S Em,....3 3 320r16" 0’'mT.(12’N Moon.... 22 39 «644 348 14) Sun’..... 11 29 3-21N XXIII. 17]7.8) 23 5 3358 Venus ... 1218 0428 8] Sun ..... ll 7 5 38N Mercury. . 1257 9 478 Venus ... 1151 2-23N Im.%....] 7 | O llorl?)35’Mr. Mercury. « 12 42 7268 x's R.A. 4 20" Decl. 23° 11’ N. (9/S.) Im. * 1 ..] 6 | 19 390r 8827’mr. Em...... 0 540r13"18'mT ie %’s R.A. 235 18’ Decl. 0° 10’N. (5’N.) |/15] Sun ..... 11 33 2 58N Em. * 1.. 20 32or 920'mr.(3’N.) Venus... 1223 1428 XXIMN.15] 8] 23 5 1 15N Mercury. . 12 59 10 458 y Piscium |4.5} 23 8 2 20N Im.%1..] 6] 3 llorl5®31’/mT. % 5.6) 23 18 0 18N ¥s R.A. 5 25! Decl. 23° 55! N. (5'S.) Moon.... 23 23 «©6—0 33N Im.*%2..] 8] 3 240rl5"44MT. Im. *%2..] 9 0 41or13*28/mT. *’s R.A. 5!" 24’ Decl. 24° 10’ N. (10’S.) %’s R.A, 23" 25’ Decl. 1° 2° N. (5’N.) Em. * 1. 4 120r16"32’mT.(6'S.) Em. * 2. | 1 550r14"42/m7,(1 1S.) Em. ¥2.. 4 16o0r16"36'mT. WS.) Im.% 3 ..| 6 | 2 280r15"10’mr. 16] Sun ..... 1136 2 35N *’s R.A. 23" 27' Decl. 1° 8’ N. (11'S.) Venus ... 12 27 #1438 Em. * 3.. 2 32or15"19'mr. (13'S.) Mercury. . 138 0 10215 9} Sun ..... a 1) *6 15'N 17} Sun ..... 1140 2 11N Venus... 1] 55 (1 52.N Venus ... 12 31 2148 Mercury. . 1245 7548 Mercury. . 13 1 10308 26 Pisc...| 6 | 23 46 6 6N Im.*....|7.8] 0 120r1224’/mr. wo —=—,..|4.5| 23 50 5 44N #’s RA. ‘qh 17’ Decl. 20° 36’ N. (5'S.) Moon.... 0 8 5 52N Bim fe). 1 2orl3"14’mr.(2'S.) 45 Pisc...| 6 017 =%643N 18] Sun ..... 1143 148N 10} Sun ... 1115 4 53N Venus ... 12 36 2448 Venus... ID. Og SIM Mercury 13 1 10 38S Mercury. . 1248 82258 19} Sun ..... 1147 125N O 149...\7.8} 0 32 12 ON Venus... 1240 3158 58Pisc...|6| 038 11 IN Mercury. . 13 2 10478 O 247...| 8 049 1111N 20) Sun ..... 11 51 1 1N Moon.... 055 10 34N Venus... 1245 $3458 1}] Sun ..... 1118 4 30N Mercury. . 13 2 1047S Venus ... 12 5 0 50N Im. 1 Sat.. 4 530r16"53'm7.(100+) Mercury. . 1250 8 45N 21) Sun ..... 1154 0 38N Im.%*....6.7| 17 390r 6"16'mr, Venus... 1249 4168S %’s R.A. 1 30’ Decl. 18° 23’ N. (4’S.) Mercury. . 13 2 1046S Em...... 18 29or 7 6/wr,(16'S,))/22; Sun ..... 1158 0 15N Moon.... 144 15 8N | Venus. 1254 44658 244 2 A 26 27 28) 29 Astronomical Phenomena. SEPTEMBER. Planet’s or 3 =| Sidereal Planet’s or Planet’s or 3 é | Sidereal Planet’s or Star’s <2 Star’s E Star’s 28 Star’s Name, &e. | &”! Time. Declination. 3] Name, &e. | ¥”| Time. Declination. =¢ a Ss H. M. D. M, | H. M. D. M. Mercury... 13 2 10 45S Im. ¥ 4..] 8 | 21-360r 9" 2’. Sun tei . msuiey's 51 UME th he. o.ossai es \90 hs 58 POLY | 5) ahs use woe nies 58 11 eR A RR ea 60 ‘« Here we may observe, that the decline of the vapour from Sep- tember to December is exactly equal in both classes, but from that time it ceases about the temperature of 32° in the northerly winds, and continues in the southerly to the month of February. In March, again, the temperature of the latter has increased from the minimum 6°, but in. the former it still remains at 32°. In April, on the con- trary, the increase in the northerly winds excecds that of the southerly ; and in May, they have again attained their original relative Meteorological Essays and Observations. 345 distances and resume their parallel progression. Tt would be difficult, I think, ‘to assign any other cause for this modification of ‘the phe- nomena than the one which has just been suggested. The evolution of heat, in the process of freezing, stops the decline of the tempera- ture in the regions exposed ‘to its influence, while it proceeds in those which are not exposed to the change; and the absorption of heat in the operation of thawing, prevents the accession of temperature which is due to the returning influence of the sun. When this operation has ceased, the vapour quickly attains its former relative degree of force. Wonderful adjustments these, to mitigate the rigours of 2 northern cli- mate! They both operate from November to February, by the evo- lution of heat in the coldest season of the year; and at the same time, by an extra supply of vapour, decrease the degree of dryness, and prevent the consumption of heat which always attends the process of evaporation.” P. 273. ‘ The next essay to which we shall draw attention relates to a subject of a more practical nature, and comprises some information of con- siderable utility to the meteorologist ; it is entitled, “ Remarks upon the Barometer and Thermometer, and the Mode of using Meteorological Instruments in general.” Than Mr. Daniell no one is more compe-~ tent to furnish valuable hints on this matter, from a considerable por- tion of his attention having been given to the manufacture of baro- meters. The Committee of the Royal Society, appointed to take into consideration the state of the meteorological instruments, did the author the honour to request him to attend to the construction of a new barometer for their apartments, and in the course of this inquiry he had, of course, an opportunity of making many extremely valuable practical observations. In the course of the experiments, he was led to a new method of filling the tube, of greater facility and correctness ; for the particulars of which we must refer to the book itself. It consists in conducting the process ix vacuo, and the author has but little hesitation in con- sidering it as accurate as the method of boiling, if performed with proper care, whilst it is infinitely less troublesome and hazardous. The electric light is as strong in the tube, and its appearance, in every respect, as perfect. The following remarks on the faulty construction of meteorological instruments in general, are extremely just and important. “* The generality of observers are but little aware of the serious inaccuracies to which those instruments are liable, In the shops of the best manufacturers and opticians I have observed that no two barometers agree ; and the difference between the extremes will often amount to a quarter ofan inch; and this with ail the deceptive ap- pearance of accuracy, which a nonius, to read off to the five hundredth part of an inch can give. The common instruments are mere play- things, and are, by no means, applicable to observations in the pre- sent state of natural philosophy. ‘I'he height of the mercury is never 346 _ * Analysts of Scientific Books. actually measured in them, but they are graduated one from another, and their errors are thus unavoidably perpetuated. Few of them have any adjustment for the change of level in the mercury of the cistern, and in still fewer is the adjustment perfect: no neutral point is marked upon them, nor is the diameter of the bore of the tube ascertained ; and in some the capacity of the cisterns is perpetually changing from the stretching of a leathern bag, or from its hygrome= tric properties. Nor would I quarrel with the manufacture of such play things; they are calculated to afford much amusement and in- struction ; but all I contend for is, that a person, who is disposed to devote his time, his fortune, and oftentimes his health, to the enlarge- ment of the bounds of science, should not be liable to the disappoint- ment of finding that he has wasted all, from the imperfection of those instruments, upon the goodness of which he conceived that he had good grounds to rely. The questions now of interest to the science of meteorology require the measurement of the five hundredth part of an inch in the mercurial column; and, notwithstanding the number of meteorological journals, which monthly and weekly contribute their expletive powers to the numerous magazines, journals, and gazettes, there are few places, indeed, of which it can be said that the mean height of the barometer for the year has been ascertained to the tenth part of an inch. ‘The answer of the manufacturer to these observa- tions is, that he cannot afford the time to perfect such instruments. Nor can he, at the price which is commonly given; for few people are aware of the requisite labour and anxiety. But who would grudge the extra remuneration for such pains? Not the man who is competent to avail himself of its application, Let the manufacture of playthings continue, but let there be also another class of instruments which may rival in accuracy those of the astronomer. It will, no doubt, be a part of the plan of the Committee of the Royal Society to establish a standard barometer, and to afford every facility of com- parison with it: so that any person, for scientific purposes, may have an opportunity of verifying an instrument; and it is to be hoped that they may proceed one step further, and take measures for ascertaining the agreement of the instruments at all the principal observatories, not only in this country, but in other parts of the world. ‘‘ Nor is it in the construction of barometers only that the mete- orologist has to complain of that want of accuracy which is so essential to the progress of his science; the same carelessness attends the manu- facture of the thermometer, Few people are aware that they are all, even those which bear the first makers’ names, made by the Italian artists, who graduate them one from another, and never think of veri- fying the freezing and boiling points. The bulbs are all blown with the mouth, and very little attention is paid to the regularity of the tube. The register thermometers are particularly shamefully deti- cient. Those of Six’s construction are often filled with some saline solution instead of alcohol ; and in the best, the spirit is not exposed Meteorological Essays and Observations. 347 long enough zn vacuo, to disengage the air with which it is mixed, The consequence is, that it is liable to become liberated, and, of course, interferes with the results. ‘The original directions of the in- ventor have also been departed from, as to the proportions of the dif- ferent parts, and as to the construction of the indices. Those upon Rutherford’s plan are universally sealed with air in their upper parts, which acts as a spring against the expansion of the column: the iron index of one is liable thereby to become oxidated, and adheres to the glass when the mercury passes it, and it becomes entangled ; while the spirit of the other being unavoidably mixed with air, when the pressure is decreased by cold it is disengaged. ‘The air may be again dissolved by increasing the pressure before a fire, and passing the bubble backwards and forwards, and, in a state of solution it does not appear to interfere with the equability of the expansion. This, how= ever, is not certain; and, at all events, it is liable to re-appear, and is very troublesome. These imperfections are by no means necessary consequences of the construction of the instruments, although the makers are very willing that they should be so con- sidered; but it requires great care and attention to guard against them, The general mounting of the meteorological thermometers is exceptionable in every way; buried as they are in a thick mass of wood, and covered with a clumsy guard of brass, they can but very slowly follow the impression of atmospheric temperature. The establishment of a perfect standard thermometer, which shall be accessible to all who may wish to consult it, will also, doubtless, be another object of the Committee of the Royal Society.” P, 368. Attention to the perfection of instruments, however, as the author has very correctly observed, will be all in vain, without a proper de- gree of care and system in making and recording the observations. The proper hours of the day for observation are indicated by the barometer; the maximum height of the mercurial column is at about nine A. M., the mean at twelve, and the minimum at three P, M. Where an individual has time to make three observations in the day, these hours should be preferred ; if he can only ebserve twice, the first and last hours should be the periods; and if only once, noon should be the time. Even those who merely consult the barometer as a weather-glass, would, Mr. Daniell asserts, find it an advantage to attend to those hours; for he has remarked that much the safest prognostications from this instrument may be derived from observing when the mercury is inclined to move contrary to its periodical course. If the column rise between nine A. M. and three P. M., it indicates fine weather ; if it fall from three to nine, rain may be ex- pected. The thermometer should be inspected at the same periods, in ad- dition to which the author recommends that the maximum and mini- mum, by register thermometers, should be carefully noted ; the instru- ments should, of course, be sheltered from every kind of radiation. 348 Analysis of Scientific Books. The periods of the barometric observation are recommended also for those of the hygrometer; the mean pressure of the aqueous atmo- sphere, however, being calculated from the dew-point at three P. M., and the lowest temperature at night of the sheltered thermometer. This Essay comprises also some interesting information on the change in the freezing point which occurs in time in the best ther- _ mometers, and has been imagined to be owing to the alteration of form and capacity which the glass undergoes from the pressure of the atmosphere upon the vacuum of the tube; as well as some remarks upon the correction to be applied to barometers for the expansion of mercury and mean dilatation of glass. For information on these points the reader is referred to the Essay itself. Independently of the Essays to which we have already adverted, there are several others of very considerable interest to the philoso- pher contained in the volume before us; of these our limits will only admit of an enumeration of the titles; they will be found, however, not less scientific and important than those on which we have dwelt at some length. They are,—1. An Essay upon the radiation of heat in the atmosphere. 2. An Essay upon the horary oscillations of the barometer. 3. Meteorological observations at Madeira, Sierra Leone, Jamaica, and other stations between the Tropics, by Captain EF. Sabine, R.A. F.R.S. 4. Meteorological observations in Brazil, and in the Equator, by Alexander Caldcleugh, Esq. And 5. Mete- orological observations upon heights. The work is also concluded by an excellent meteorological journal for three years, commencing on the first of September, 1819. After the analysis and extracts which we have given in the preced- ing pages, it is almost unnecessary for us to remark on the mode in which the work is executed. The various subjects, it will have been observed, are treated of in a manner highly creditable to the talents and scientific acquirements of the author ; whilst the language is in gencral elegant and perspicuous ; the reasoning forcible ; and the pro-= positions, drawn from principles premised, are logical. To the lover of meteorological science in particular, as well as of natural philosophy in general, these Essays will be found to form a rich mine of new and important information, New London Pharmacopeta. 849 II, A Translation of the Pharmacopeia of the Royal College of Physi- cians of London, 1824. With Notes and Illustrations, By Richard Phillips, F.R.S. L. and E. &c., &c. Considering the materials he has had to work upon, Mr. Phillips has really given us a very useful book, in his translation, as he calls it, of the Pharmacopeia; and has shown something of alchemical power, in respect to the contents of the meagre original. We are ‘ well aware of the talents that exist in the College of Physicians, and are therefore utterly at a loss to account for the careless imbe~ cility of the productions which are, from time to time, sent forth under its auspices. Where is Dr. Wollaston? where Dr. Young ? What has become of Dr. Maton and Dr. Paris? have they no in- ’ terest in the public character of the body which they adorn; or are they merely careless of its reputation ; or do they leave so weighty a concern as the publication of the Pharmacopeia to the beadle and the bookseller? These are questions asked every day, and every where, and we profess our entire inability to offer to them any plausible reply. That they are not unjustly asked, we are sorry to say is but too manifest, from the present edition, which we understand to be the production of a Committee of the College; and although some tendency towards improvement is manifest in several of the processes, the general execution of the work is very unworthy of its source, The old preface of the edition of 1809 is unaccountably reprinted, and attached to the present work; had this preface contained a history of pharmacy, or a review of former pharmacopeeias, its retention might have been excusable; but it is, in fact, a poor and empty production, and particularly inappropriate to the present state of pharmaceutical science, which has lately made such rapid and important progress. ‘To illustrate and expound this progress should have been the business of the preface, if any were thought necessary. ‘Ihe researches which have led us toa tolerably accurate knowledge of the substance upon which the activity of opium depends, and those which have taught us the existence of distinct salifiable bases in the greater number of narcotic vegetables; the inquiries instituted with so much success respecting the principles upon which the active powers of the varieties of Cinchona depend ; and those which have taught us the importance of iodine, and some of its combinations, in the treatment of glandular diseases ; all these subjects should have been touched upon in the preface, if preface there needs must be ; we ought also to have been informed why the college have not in= troduced any of these new and active substances; whether they consider them ineffectual, or dangerously active; why they have altogether passed them by; why they have retained in the list of their Materia Medica, sorrel and wood-sorrel, marsh-mallow and coltsfoot, bistort and cuckoo-flowers, centaury, contrayerva and cow- Vou, XVII. 2B 350 Analysis of Scientific Books. hage, carrots, raisins and figs, bay-berries and mulberries, opoponax and sagapenum, storax, oyster-shells and toxicodendron; why, in short, so much of the old lumber is suffered to encumber this new work, while so many useful novelties, which have a place in foreign pharmacopeias, are omitted. We are fully aware of the mischief and absurdity of stuffing every new crudity into a pharmacopeeia ; the Parisian codex amply proves that; but when we know that all apothecaries are obliged to keep sulphate of quinina and hydriodate of potash, and acetate of morphia, and that several Fellows of the College, justly eminent for their skill and extensive practice, prescribe and ‘haye faith in these compounds, there are, we think, grounds for the questions we have humbly submitted. Our experience, how- ever, obliges us to admit that there must be some hidden obstacles and unseen difficulties in the way of compiling a good and rational pharmacopeeia ; for, taking it all in all, that of the London college is perhaps the best extant. Whether to the prevalence of a pugnacious diathesis, and the impossibility of deciding, when doctors disagree ; or to the want of co-operation among scientific and practical men, or to what other cause we are to attribute this fatality, we shall not now Stop to inquire; perhaps those who have access to the minute-book of the Committee of the College, are the only persons who can solve the problem. Like ancient Gaul, the Pharmacopeia is divided into three parts : one assigned to some preliminary matters respecting weights and measures ; the second to the Materia Medica; and the last to the preparations and compounds, We shall follow Mr. Phillips’ example in passing over the two former divisions without remark, The third is subdivided into sections, of which the first treats of * Acids,” alpha- betically arranged. The term ‘“ diluted acetic acid” is properly enough applied to dis- tilled vinegar, but the process of distillation might well have been rejected ; for all medical purposes a dilute acid, composed of 1 part of the concentrated acetic acid, contained in the Materia Medica, and four parts of water, is preferable. Of this mixture, or of distilled vinegar, the sp. gr. should be about 1009, and 1000 parts should saturate 145 of crystallized carbonate of soda: 50 grains of real acetic acid saturate, according to our translator, 153 grains of this salt, and upon this datum the following is the composition of the dilute acid of different specific gravities : Sp. Grav. Real Acid. Water. 1007 3.42 96.58 1009 4.73 95.27 1043 23.67 76.33 1046 28.43 ye Sy Of these acids, the two first are the average strength of distilled vinegar, and the two last that of the concentrated acetic acid, as now generally prepared by the vinegar-makers from pyroligneous acid. New London Pharmacopeia. 351 Benzoic Acid is an article which might very well be struck out of the Pharmacopeia ; the process, however, now directed is preferable to that of the last edition. A process for obtaining Citric Acid is given in this division, but it also has a place among the articles of the Materia Medica, and is so rarely prepared except by the manufacturer upon an extended scale, that the directions here given might well have been dispensed with. Mr. Phillips tells us that an ounce of water at 60° dissolves 10 drachms of crystallized citric acid ; and such solution saturates about 20 drachms of crystallized carbonate of soda. Nine drachms and a half of citric acid dissolved in a pint of distilled water, give, he says, asolution equal in strength to lemon juice. Weshall quote the article “* Muriatic acid” entire, that our readers may judge of the method which the translator pursues in his remarks and of their general usefulness to students and practitioners, Muriatic Acid. “ Take of dried muriate of soda, two pounds, Sulphuric acid by weight, twenty ounces, Distilled water, a pint and a half; *¢ First mix the acid with half a pint of the water in a glass retort, and to these, when cold, add the muriate of soda; pour the remainder of the water into a receiver; then, adapting the retort to it, let the muriatic acid distil into the water from a sand-bath, the heat being gradually raised until the retort becomes red hot. “The specific gravity of muriatic acid is to that of distilled water as 1-160 to 1°000. “One hundred and twenty-four grains of crystallized subcarbonate of soda, are saturated by 100 grains of this acid. ** Process.—The nature of common salt, and the production of mu- riatic acid, are explained by two theories, both of which I shall state, because, from the name of muriate of soda which the college retain for common salt, it would appear that, as a body, they have not adopted the generally-received doctrines of Sir H. Davy on these subjects. «© On the supposition that muriatic acid is an undecomposed body, the explanation of its production is the following: Common salt, or muriate of soda, is a compound of muriatic acid and soda, and when it is mixed with the sulphuric acid, this, owing to its greater affinity for soda, expels the muriatic acid from it, which, being gaseous, and having considerable affinity for water, rises in the state of vapour with it, and is condensed in the receiver into liquid muriatic acid. The sulphuric acid and soda remain in the retort in the state of sul- phate of soda, ** This process will be explained by the annexed diagram: i 352 Analysis of Scientific Books. Liquid Muriatic Acid. Muriatic Acid. Water. : Diluted ees of Sulphuric Acid Soda. Sulphuric Acid. Dry Sulphate of Soda. “ According to the opinion of Sir H. Davy, now generally adopted, common salt, or chloride of sodium, is a compound of 36 chlorine and 24 of the metallic body sodium; liquid sulphuric acid consists of 40 parts of dry acid and 9 of water, the water being composed of 1 of hydrogen and 8 of oxygen; when these quantities of common salt and liquid sulphuric acid act upon each other, the water and chloride of sodium are both decomposed; the 1 of hydrogen uniting with 36 of chlorine, constitute 37 of muriatic acid gas, and the 8 of oxygen with the 24 of sodium form 32 of oxide of sodium, or soda. The 37 of muriatic acid gas combining with the water used in dilut- ing the acid, rise with it in the state of vapour, and by condensation in the receiver, liquid muriatic acid is produced; the 40 parts of dry sulphuric acid uniting with the 32 of soda, form 72 of dry sulphate of soda, which remain in the retort. 37 Muriatic Acid Gas. pe 36 Chlorine 1 Hydrogen § Oxygen 9 Water 49 Liquid 60 Chloride of Sulphuric Sodium : 24 Sodium pits 8 Oxygen — 40 Dry Sul- 32 Soda phuric Acid. eee. Fo eee 72 Dry Sulphate of Soda. “¢ In preparing this acid it is, I think, more convenient to mix the sulphuric acid and water in a separate vessel than in the retort; to introduce the salt first into the retort and to pour the acid upon it ; and to put less water into the receiver, and more into the retort. “ Qualities.—Muriatic acid, when perfectly pure, is colourless ; it emits white suffocating fumes, which turn vegetable blues red ; its taste is strongly sour and acrid ; when its sp. gr. is 1°160 as directed by the college, a fluid ounce weighs about 527 grains; it is stated New London Pharmacopoeia. 353 that 100 grains saturate 124 of crystallized subcarbonate of soda, which, from some indirect experiments, I believe to be not quite correct. _ By the French chemists it is termed hydrochloric acid, to express its nature. It acts upon and dissolves several metals with the evolution of hydrogen gas arising from the decomposition of water. Thus iron, zinc, and tin are readily dissolved by it; it acts but slowly upon copper, but dissolves its oxides with facility. Its saline compounds are termed muriates, and most of them suffer decompo- sition when heated, as I shall explain when describing the properties of muriate of lime. side “© Composition.—Muriatic acid gas is composed of equal volumes of hydrogen gas and chlorine gas; and the combination takes place without alteration of volume. By weight it consists nearly of Hydrogen 2°7 or 1 atom of hydrogen . Chlorine 97°31 do, ofchlorine .. 100°0. Number representing its atom = 37 1 36 “ Liquid muriatic acid of sp. gr. 1:160 is composed of nearly 32:4 of muriatic acid gas, and 67°6 water. «« Adulteration—This acid, as usually met with, has a yellow tinge, which is owing either to the presence of chlorine or of peroxide of iron ; if the former be present, it may sometimes be determined by the smell, or by its power of dissolving gold leaf; the latter is dee tected by the addition of solution of ammonia, which, when added slightly in excess, throws down the peroxide of iron of a reddish yellow colour. It sometimes also contains sulphuric acid; this is discoverable by adding a solution of muriate of barytes to a portion of the acid diluted with 4 or 5 parts of distilled water. This dilution is requisite, because the acid, when concentrated, attracts the water from the solution of muriate of barytes, and causing it to crystallize, gives a fallacious appearance of the presence of sulphuric acid. ** Incompatibles.—This acid is incompatible with alkalies, most earths, oxides and their carbonates, sulphuret of potash, tartrate of potash, tartarized antimony, tartarized iron, nitrate of silyer, and solution of subacetate of lead. “* Officinal Preparations. —Ferrum Ammoniatum.—Tinctura Ferri muriatis, , “ Medicinal usesx—According to Dr. Paris, it may be advanta- geously employed in malignant cases of scarlatina and typhus, and, mixed witha strong infusion of quassia, he considers it to be the most efficacious remedy for preventing the generation of worms. Dose m, v.— xx. frequently repeated.” When Mr. Phillips says, “ the nature of common salt and the production of muriatic acid are explained by two theories,” &c., and when he speaks ofthe ‘ supposition that muriatic acid is an unde= composed body,” and afterwards, without expressing any doubts 354 Analysis of Scientific Books. upon the subject, states, that it is composed of equal volumes of hydrogen and chlorine, we think that he exceedingly perplexes his subject, as far as medical readers are concerned ; it is just as if he were to say that the calcination of a metal may be explained upon two theories, and then cite the phlogistic and antiphlogistic hypothe- sis. SirH. Davy’s chloridic theory alone furnishes a consistent ex- planation of the phenomena above alluded to, and we are sorry to see the blunders of the oxymuriatic school perpetuated by such a writer as Mr. Phillips, when even Berzelius has ceded. In other respects the chemical remarks of the translator are very pertinent and useful, but we could have wished for information somewhat more extended in respect to the medicinal uses of the different articles, and think that the list of ‘‘incompatibles” had better, in most cases, have been omitted. Our author’s remarks upon the other acids are very much to the purpose, and are studded with several originalities useful to the phar= maceutical chemist. He has made much use of diagrams, and has given wood-cuts of the usual crystalline forms ; we, however, rather doubt their use, and are certain that neither the apprentice nor his master will ever refer to the relations of the several plane surfaces to each other, which are given with an elaborate minuteness incompa- tible with the general tenor of the work. The officinal acids of the present Pharmacopaia are seven, viz., the acetic, benzoic, citric, muriatic, nitric, sulphuric, and tartaric. Might not the hydro-cyanic have been properly added ? Alkalies and their salts are treated of in the second division of this part of the Pharma- copwia. Mr. Phillips has unnecessarily embarrassed his observations on the subcarbonate of ammonia, by giving the wrong as well as the right theory of its formation, but in other respects his remarks upon the carbonates of ammonia are original and important. Under its medicinal uses he says that thirty grains of carbonate of ammonia are emetic, which is far from being always the case. The College continue to apply the erroneous terms Subcarbonate and Carbonate of potass to the carbonate and bi-carbonate, but the process for obtaining the latter is materially improved by deriving the carbonic acid from carbonate of lime, instead of (as formerly) car- bonate of ammonia. But, as if some fatality attended the intro- duction of an innovation, they direct the gas to be passed into their own liquor potasse, instead of a much more dilute solution, which ought to have been employed. Mr. P. objects, we think without reason, to the use of dilute sulphuric acid for the decomposition of the powdered marble, and recommends muriatic acid as a substitute, suggesting that, for sake of economy, the muriate of lime may be decomposed by sulphuric acid, and thus dilute muriatic acid regained; but we have not found his objections to sulphuric acid hold good in practice. The remaining salts of potash require little notice ; the super- New London Pharmacopaia. 355 sulphate, perfectly useless, is still retained ; and of he hydriodate, of which many practitioners think very highly, not a word is said. In respect to the salts of soda we observe the same impropriety of nomenclature in distinguishing the carbonates which has been noticed of the carbonates of potash. The sod@ carbonas is however, as it commonly o¢curs, a compound of an atom of carbonate and one of bi-carbonate, with four of water, and therefore may be called a Sesqui-carbonate of Soda. Mr. Phillips found the native carbo- nate of soda from Africa to be an analogous compound. The fore mula for sulphate of soda is quite unnecessary, as it is always pre pared by the wholesale manufacturer. ( Among the earths we observe that lime is directed to be obtained by the calcination of marble, and of shells, the use of the latter being by no means obvious; and although marble duly heated fur- nishes very good lime, that which may be had wholesale is as fit for the preparation of lime-water. Proceeding to the metals and their salts, we have to congratulate the College upon the improvement in their formula for that most important compound tartarized antimony, which is now prepared by boiling finely-levigated glass of antimony with tartar in a due pro- portion of water. The exact composition of emetic tartar is not very easily determined, nor has our author given us any thing ori« ginal respecting it. The hydro-sulphuretted oxide of antimony is still retained under the improper title of Precipitated Sulphuret of Antimony ; and the very uncertain formula for the preparation of antimonial powder remains nearly as it was. The more we consider the antimonial remedies of the Pharma copia, the more we are convinced that emetic tartar is the only certain and definite remedy of that class; that it may be used in various mixtures as a substitute for the other preparations, and that it is the only compound of the metal which ought to be retained in a pharmacopeia compiled upon sound principles. The exceeding absurdity of calling certain solutions wines which contain no wine, occurs first under this head, where 20 grains of tartarized antimony dissolved in 8 ounces of water, and 2 ounces of rectified spirit, is foolishly termed Vinum Antimonii tartarzati. We are not generally inclined to be very sceptical upon the subject of pharmaceutical nomenclature, but this capricious innovation we cannot leave unnoticed. In the last Pharmacopaia the term liquor was learnedly applied toa real vinous solution ; and now, the term vinum is applied to that which contains no wine. But the alteration is otherwise mischievous. Antimonial wine and steel wine are do- mestic remedies, with which every body is acquainted, and no vender of medicines who wished to retain his customer would think of sending out the wines of the present Pharmacopeia under that name. ‘The apothecary therefore is obliged to hamper his shelves with both solutions, and this merely to gratify a whimsical propen~ 356 Analysis of Scientific Books. sity for something new, which exists somewhere in the College ; for after all, the present wines, which contain no wine, are as ob- jectionable as the former wines which do contain it. But the authors of the Pharmacopeia will probably tell us that it is com- piled exclusively for their own use and convenience; that they have nothing to do with the vulgar public; and hat if other people are unlearned enough to call things by their proper names, they regret their want of taste. ‘* We have thought it better,” it is said in the Preface to the Pharmacopeia, “to risk the accusation of barbarism than to admit terms of doubtful or uncertain significa- tion,” but in the cases before us certainty might have been attained without barbarism. “tn It is with unfeigned regret, that we find ArsENtc is still retained in the Pharmacopeia. We do not mean to say that it is useless as a medicine, but we do mean explicitly to assert that the mischief of retaining it is many thousand times greater than any benefit that in any possible case can be derived from its curative powers. The only plausible excuse for the sale of arsenic is its supposed use in medicine ; and as long as the College think it right to sanction its employment, so long may any person obtain it of any chemist, druggist, or apothecary—let it be struck out of the Pharmaco- peia, and its sale prohibited, and the numerous cases of accidental and intentional. poisonings with it would, at all events, be thrown off the shoulders that now alone must bear the responsibility. As to the cow-doctors and horse-leeches, (who by the way kill more cattle than they cure with their arsenical lotions,) we put them out of the question—and why then is arsenic, in every way the most dan- gerous, pernicious, portable, and certain of the poisons, the most easy of administration, and the most difficult of detection, suffered to be sold at every chandler’s shop in the kingdom? The College have given sub-nitrate of bismuth a place in their new Pharmacopeia—to this we haye no objection, though we find upon inquiry that the physicians of most practice never prescribe it: we must repeat that sulphate of quinine and hydriodate of potassa should not haye been neglected, for they, and especially the former, are in daily use. Among the preparations of iron we, in the first place, observe that Ferrum Ammoniatum and Liquor ferri Alcalini, useless, uncer- tain, and unchemical as they are, are retained; this is a pity, for all these pharmaceutical incumbrances are, in more ways than one, prejudicial ; the advantages of tartarized iron are frustrated by the directions for drying it; and our old acquaintance steel wine, the vinum ferri, has a most clumsy and inefficient substitute in a solu- tion of tartarized iron in proof spirit. Mr. Phillips is more tem- perate in his remarks upon this preposterous innovation (which has already excited infinite dismay and perplexity in many nurseries) than we feel inclined to be, and we shall therefore quote his New London Pharmacopeia. 357 most merciful criticism, observing by the way, that in compound- ing their wines the College seem to have had an inverse eye upon Mrs. Glass’s water pudding, so called, as she facetiously tells us, because made with wine only. “« This preparation,” says Mr. Phillips, “ is tartrate of potash and iror, with excess of supertartrate of potash, which is probably intended to supply the place of the acid contained in the wine for- merly employed, and to effect the perfect solution of tartarized iron in the weak spirit. “The quantity of iron directed to be used is very nearly such, that if it were all acted upon by the supertartrate of potash, and dis- solved by the spirit, the strength of the present preparation would almost exactly equal that which I found the former to possess. But three causes prevent this: first, the whole of the iron is not acted upon by the tartar; secondly, a part of that which is converted into tartarized iron, is rendered insoluble by drying; and thirdly a portion which is dissolved by the water is immediately precipitated by the spirit. I find that owing to these circumstances, a pint of the present vinum ferri contains only sixteen grains of peroxide, instead of twenty-two grains, which an equal quantity of the former pre- paration held in solution.” Among the preparations of mercury we think that the red oxide, the grey oxide, and the sulphurets, might without much inconve-= nience to any one have been omitted. The formula for calomel is most unequivocally improved ; it is, indeed, the best extant; that for corrosive sublimate would be the better for a little alteration in the proportion of the materials. The solution of corrosive sublimate is here called Ziquor and not vinum, as is the case with that of emetic tartar ; but it should not have been among the formule, for it is liable to decompose, and in remedies of such activity every thing depends upon the accuracy of the proportion held in solution. We wish the College had been prevailed upon to reject their present names for calomel and corrosive sublimate; and that Mr. Phillips had not added to the proper chloridic explanation of their composi- tion and formation, the incorrect and exterminated muriatic hypo- thesis; he seems to have done it out of compliment to the College, “« who,” he says, ‘* do not appearto have adopted the modern views of the nature of muriatic acid ;’’ but no authority can justify the perpetuation of error. The preparations of lead remain much as in the former Pharma~ copwia, excepting that the term sub-carbonate is now improperly used for what before was properly called carbonate. The formula for acetate of lead is now no longer necessary; it is prepared of great purity, and ata low price by the wholesale manufacturer, and might therefore have been transferred to the Materia Medica. _ The formula for oxide zinc is much ameliorated by substituting precipitation of the sulphate by ammonia, for the old process of com= 358 Analysis of Scientific Books, bustion; in this way it is obtained free from metallic particles. By some oversight the quantity of water directed for the solution of the sulphate is however too small. Of the preparations of sulphur, the solution of that snbstance in oil, and the * precipitated sulphur,” might be dispensed with. The general directions given in the Pharmacopeia for the collec- tion, preservation, and preparation of vegetables, are meagre and un= satisfactory ; Mr. Phillips has merely transcribed them without any remarks. Among the distilled waters, we observe that cinnamons water, peppermint-water, miut-water, and penny-royal-water, are directed to be distilled either from the herbs, or from their essential oils. The same rule should have been extended to rose=water, which is more fragrant and less apt to acidify when so prepared. With very few exceptions, we think that the infusions and decoc- tions should have been left to extemporaneous prescriptions, espe= cially the former; there are also many among them which cer= tainly might have been altogether expunged. The extracts are also much too numerous; they are generally apt to spoil by keeping, and such only, therefore, should have been retained as are really useful. Under the term eatractum stramoni we have an useless extract of the seeds of the thorn-apple. i Among the mixtures and spirits we also have several useless, or, at least, unnecessary formule; among the latter, especially, spiritus ammonie fetidus, spiritus ammoni@ succinatus, spiritus armoracie@ compositus, spiritus colchici ammoniatus, spiritus menthe viridis, spi- ritus pimente, &c. &c., are mere incumbrances; if they are medi- cally wanted, extemporaneous prescriptions with the essential oils are preferable. The “ tinctures” offer a sufficiently judicious se= lection, but many of them might be improved by digestion for a shorter time, in a moderate heat; nothing is said of the temperature at which they should be prepared. Under the “ preparations of ether” we may remark, that the formulee for sulphuric ether and rectified ether should have been given under one head; for what is rectified sether but sulphuric ether ? or, what medical use can be made of the impure ether which the College call ether sulphuricus? ‘They certainly direct it, but probably by mistake, in their spirit and compound spirit of sulphuric ether. thereal vil, aromatic spirit of ether, and com- pound spirit of sulphuric ether, as now directed by the College, are very useless supernumeraries upon this list. The Section on Athereal Preparations is followed by one including the wines containing no wine; and then follow the medicated vine- gars, honeys, syrups, and confections. Among the compound powders we observe many, and among the pills more formule, which might be dispensed with; the latier are liable to harden, and with few exceptions should never be kept ready made, New London Pharmacopeia. 359 _ Under the remaining heads of the Pharmacopeia, including plasters, ointments, &c., we observe nothing worthy of particular remark. Mr, Phillips has added to his translation a series of woodcuts, exhibiting the must commonly occurring crystalline furms of the principal salts, &c., which, as far as they go, are useful, as being more explanatory than mere descriptions, and the pupil ought, for several reasons, to be acquainted with the ordinary figures which these bodies exhibit ; but, as before observed, the measurements of angles and inclinations of surfaces which accompany the description of the salts are not, we con= ceive, very important to the utility of a work like this. We are also somewhat disappointed at the brevity of the original remarks and scan- tiness of the criticisms, where there is so much room and opportunity for both, and more especially when we advert to the diligence and acu- men, sometimes perhaps a little too highly seasoned, with which our author animadverted upon the glaring errors and abundant inconsis- tencies of the former Pharmacopeia. Something more also might have been said of the medical uses and forms of prescribing the lead- ing articles; indeed we doubt whether the present extremely concise notices culled chiefly from Dr. Paris’s Pharmacologia, had not better have been omitted. But we must not complain: these things are not in Mr, Phillips’s way, and upon the whole we are indebted to him for many useful hints and pertinent remarks. We wish,.in conclusion, to disclaim the remotest intention of dis- respect towards the College in any of the remarks which we have found it necessary to offer upon their Pharmacopeia, and which, with all its imperfections, we have already acknowledged among the best extant. There seems, therefore, to be some hidden impediment to the compilation of a rational Pharmacopeeia, and at all events it must not be assumed as a standard of the talents of its nominal edi- tors; there must be something radically wrong in the mode of mas naging the matter, and before the College give us another edition, we trust they will seriously consider the subject, and adopt some less exceptionable mode of proceeding. We apprehend that the whole business should be unconditionally delegated to three or five indi- viduals, who should alone have power, and be solely responsible: they should moreover be well paid for their trouble, and no expense should be spared in furnishing them means of information and research. The Committee which determines by vote what formule are to exist and what to be expunged, should certainly be broken up: the men of practical eminence in the College have no time to attend to it; and the mcn of science are, if we mistake not, wearied out by the perse- vering prosers and obstinate ancients with which all such Committees are pestered, 360 Art. XIV. MISCELLANEOUS INTELLIGENCE. 1. MecHANICAL AND GENERAL SCIENCE. 1. Adhesion of Nails i in Wood.—Mr. Bevan has published in the Philosophical Magazine a series of very interesting experiments on the adhesion of nals when driven into different kinds of wood, the results of which we have abstracted and condensed as below, The following table exhibits the relative adhesion of nails of various kinds, when forced into dry Christiana deal at right angles to the grain of the wood: Number to the inches _inches forced Ibs, required Ib. avoirdupois. long. into the wood. to extract. Fine sprigs . . . 4,560. .0.44. .040. . 22 Ditlois 0 ie By 9S} {OOK , 1OVES! 3" OAS 2 eae Threepenny brads . 618 . . 1.25. . 0.50. . 58 Cast-iron nails) . . 380. . 1.00. .050. . 72 Sixpenny nails . . 73. . 2.50. . 100. 187 Ditto Hee he Ss ve Penge tenets ie EOL Semaey Dittorrey teetewten eit radii wit. donee SO Ol yee Fivepenny nails . . 139. . 2.000. . 1.50. 320 The percussive. force required to drive the common sixpenny nail to the depth of 14 inch into dry Christiana deal with an iron weight of 6,275 lbs. was ipa blows falling freely the space of 12 inches, and the steady pressure required to produce the same effect was 400 lbs. A sixpenny nail driven one inch across the grain into dry elm required $27 lbs. to extract it; driven end-ways, or longitudinally, it required 257 lbs, for its extraction: driven end-ways two inches into Christiana deal it was drawn by a force of 257 lbs., but driven in one inch only in the same direction, it was extracted by 87 lbs. The relative adhesion therefore, when driven transversely or longitu- dinally, is as 100 to 78, or about 4 to 3, in dry elm; and as 100 to 46, or as 2 to 1, in foe To extract a common sixpenny nail from a depth of one inch out of dry oak required . P ‘ : . 507 lbs. dry beech ” ‘ A . P santaOZ green sycamore . : 312 a common screw of + of an inch diameter was found to have an adhesion about three times that of a sixpenny nail.—The resistance to entrance of a nail was found to be to that of extraction, in some experiments, as 6 to 5.—Phil. Mag. \xili, 168, Mechanical and General Science. 361 2. Levels in London above the highest Water-mark. eet. inches. North-end of Northumberland-street, Strand . 19 74 North of Wellington-street, Strand . 5 a 1 Shs 6 North of Essex-street, Strand : ° ZTE West of Coventry-street . ‘ : : - 52 0 South of St. James’s-street . F . . 13. 3 South of Air-street, Piccadilly . . . 49:8 North of St. James’s-street . . .« . 46 7 West of Gerrard-street . . . e 61 4 North of Drury-lane~ . : : : Pe NE South of Berner’s-street : . . - 74 3 South of Stratford-place . : : . » 59 A North of Regent-street : : = . 76 0 South of Orchard-street . ‘ ; : - 70 A North of Cleveland-street . bp wets : 80 10 Centre of Regent’s Circus " . ant 77.02 North of Gloucester-place . 5 ~ mys a ORES North-side of Aqueduct crossing Regent’s Canal 102 6 Opposite south-end of King-street, Great George-st. 5 6 The whole of Westminster, except the Abbey and part of Horse- ferry-road, is below the level of the highest tide. N. M. Mag. xii. 206. 3. On the comparative Advantage of Coke and Wood as Fuel. Some trials have been made by M. Debret on the heating power of coke and wood, when consumed in stoves, at the Royal Academy of Music. Two similar stoves were heated, one by wood and the other by coke, and the temperature of the exterior, taken at some distance from the fire. The temperature of the flues was at first 9° c., and the mean temperature, at the end of six hours, was, by the wood, 13° c., by the coke, 16° c.; so that the increase by the wood was 4°, by the coke 7°. These effects were produced by se- venty-three kilogrammes, (103 pounds) of wood, worth three and a half francs, and twenty-four kilogrammes, (53 pounds) of coke, worth one franc eighty cent. During the progress of this experiment another stove had been heated for several hours with wood, and the temperature had not risen above 13°, ‘The use of coke very quickly raised it to 15° or ‘16°. Hence it is concluded, and with reason, that coke is. much preferable for these purposes to wood; but where thie stove is small the mixture of a little wood with the coke is recommended to facilitate the combustion. —Bzb. Univ. xxv. 237. 4. Vicat on burning of Limestone or Chalk.—¥rom some experi- ments formerly made by M. Vicat, that philosopher was induced to conceive, that probably an imperfect calcination of limestone would 362 Miscellaneous Intelligence. make it yield a better hydraulic lime than a more complete burning; but having,. by the lapse of time, had occasion to make further ob- servations on the specimens of chalk mortar, which formed the sub- ject of the experiments on which that opinion was founded, he has taken the opportunity of guarding against any such conclusion being drawn from his previous statement.-—(See vol. xvi. p. 386.) On examination of the specimens of chalk cement, four months. after they were immersed in the water, they were found just in the state they were in on the twelfth day; they resisted the trial needle to a certain extent only, and not at all like a specimen of good hydraulic lime, which was put into water at the same time. M. Vicat had occasion to make further remarks on the imperfect burning of lime, in consequence of the opportunity afforded by a large block of limestone which had been used in the construction of a kiln, and which furnished from different parts various specimens burnt in different degrees. Five varieties were selected, No. 5, and also No. 4, slacked in water, and were therefore set aside as consi- derably burnt. Nos. 3, 2, and 1-were not attacked by water, they were almost as hard as before burning, and being pulverized, sifted, and made into a paste, they were immediately immersed in water and left. After a month they were scarcely hardened, and were far worse than the specimens of chalk before referred to. ‘The same stone pulverized and calcined for twenty minutes on a red hot iron, gave a cement not so good as the chalk, but better than the specimen from the furnace. ‘* These experiments,” says M. Vicat, ‘¢ are far from confirming the general results announced by M. Minard, (vol. xvi. p. 387); I can scarcely believe that we shall ever obtain, I will not say good, but even passable, cement, by the calcination, more or less com- plete, of pure calcareous stones. We must probably always have recourse to the argillaceous limestones, and when these are well studied and classed in proportion to the quantity of clay and lime which they contain, and that accounts are preserved in all cases of the results of the experiments, we shall perhaps be forced to acknow= ledge, that nothing is more advantageous than a good hydraulic lime, which yielding from 1.1 to 1.3 parts for 1, can for 100 measured parts receive 160 or 180 of sand, and thus furnish at a very moderate price a mortar equally capable of resisting the vicissi- tudes of the atmosphere, and the destructive effects of running water.—Ann. de Chim. xxv. 60. 5. On the Application of Muriate of Lime as a Manure—M. Du- buc, a druggist, and member of the Academy of Sciences at Rouen, has, during the years 1820, 21, 22, and 23, made use of chloride of calcium as a manure, or according to his own expression, as a vegetable stimulant, His experiments have been numerous, and the following short notice is given of them by M. Lemaire Lisancourt. Mechanical and General Sotence. 363 A kilogramme (2.2 Ib.) of chloride of calcium is dissolved in sixty litres (126.8 pints,) of water. The ground intended for experi- ments is watered with the solution; the seeds are then sown, or the plants set in the ground, and ultimately the watering is repeated a third or fourth time.with the solution. M. Dubuc sowed some Indian corn in a light soil, watered six or eight days before with the solution, Ata distance of six feet, but in the same soil, and with the same aspect other maize was sown and watered with common water. The first, which was watered from time to time with the solution of the chloride, attained to double the size of the second. Specimens of both were presented to the academy at Rouen. He has also hastened and favoured the developement of the great pyramidal campanula, of the lilac, and other trees, and also of fruit-trees, §c. He has also made experiments on market vege= tables ; onions, and poppies, which grow to a large size in the soil of Rouen, have doubled in volume by the action of the chloride, He has observed the great annual sunflower rise as in Spain to a height of twelve or fifteen feet, whilst in ordinary circumstances this large herb did not rise more than six or eight feet. He has seen the stems of these vegetables three or four inches in diameter above the earth, the leaves from eighteen to twenty inches long, the discs of the flowers twelve or fourteen inches in diameter, producing seeds from which haif their weight of good oil has been extracted, and ultimately ex- uding from their centres a transparent secretion analogous to turpen-~ tine, very odorous, and easily drying in the air. Finally, M. Dubuc made his experiments on potatoes, taking such as in size and weight were nearly alike. These were planted May 1, 1822, in the same soil, and with the same aspect but in two beds, separated from each other by a path six feet wide. One of these beds was watered with the vegetative liquor, the other with water from a cistern, They were all gathered the 10th Nov. 1822. The first gave tubercles six inches long, twelve inches in circumference, and weighing nearly 2lbs. each ; the others were generally about half that size. These large potatoes were equally nourishing with the ordi~ nary potatoes, and were equally well preserved until the following April. They were watered only three times with the solution during the time they were in the earth, and their leaves were developed in an equal proportion. ' It appears that in general it is sufficient to water the vegetables submitted to the action of chloride of calcium three or four times with the solution at long intervals. The electro-organic power of this substance seems very singular, for, as M. Labarraque, of Paris, has observed, when applied to the animal organization, it in a short time arrests the progress of gangrene, chancres, or ulcers, and powerfully favours the production of fleshy pimples, which cicatrize the sore, — Ann. de Chim, xxv, 214. 364 Miscellaneous Intelligence. 6. Preparation of Caoutchouc.—Mr. T. Hancock, has succeeded, by some process, the results of long investigation, but which he has not published, in working caoutchouc with great facility and readiness. It is cast, as we understand, into large ingots, or cakes, and being cut with a wet knife into leaves or sheets about 3 or +4; of an inch in thickness can then be applied to almost any purpose for which the properties of the material render it fit. The caoutchouc thus prepared is more flexible and adhesive than that which is gene- rally found in the shops, and is worked with singular facility. Re- cent sections made with a sharp knife or scissors, when brought to- gether and pressed, adhere so firmly as to resist rupture as strongly as any other part, so that iftwo sheets be laid together and cut round, the mere act of cutting joins the edges, and a little pressure on them makes a perfect bag of one piece of substance. ‘The adhesion of the substance in those parts where it is not required is entirely prevented by rubbing them with a little flour or other substance in fine powder. In this way flexible tube catheters, §c., are prepared ; the tubes being intended for experiments on gases, and where occasion might require they should sustain considerable internal pressure, are made double, and have a piece of twine twisted spirally round between the two. This therefore is imbedded in the caoutchouc, and at the same time that it allows of any extension in length of the tube, prevents its ex- panding laterally. The caoutchouc, is in this state, exceedingly elastic. Bags made of it as before described, have been expanded by having air forced into them until the caoutchouc was quite transparent, and when expanded by hydrogen they were so light as to form balloons with considerable ascending power, but the hydrogen gradually escaped, perhaps through the pores of this thin film of caoutchouc. On expanding the bags in this way the junctions yielded like the other parts, and ultimately almost disappeared. When cut thin, or when extended, this substance forms excellent washers, or collars for stop-cocks, very little pressure being sufficient to render them perfectly tight. Leather has also been coated on one surface with the caoutchouc, and without being at all adhesive, or having any particular odour, is perfectly water tight. Before caoutchouc was thus worked it was often observed how many uses it might in such a case be applied to; now that it is so worked it is surprising how few the cases are in which persons are induced to use it. Even for bougies and catheters it does not come into use, although one would suppose that the material was eminently fitted for the construction of these instruments. 7. Magnetic Intensity of a Chronometer——A remarkable example of the magnetic intensity of a chronometer has just appeared in Vol. X., PartI., of the Transactions of the Royal Society of Edin- burgh. Mr, Harvey, the author of the investigation, by employing Mechanical and General Science. 365 a very delicate apparatus, constructed on the principle of Coulomb, and capable of detecting the minutest traces of attraction, disco- vered very remarkable varieties of magnetic power in a time-keeper. By denoting the intensity of the terrestrial magnestism by 100, he found the intensity of the chronometer one inch above the centre of its crystal, to be respectively 90.79, 102.29, 90.69, and 78.89, ac- cording as XII was directed*north, east, south, and west. By deter- mining also the tntensity one inch below the bottom of the time- keeper, the intensities in the same directions were 77.17, 91.34, 101.26, and 94.94. In like manner Mr. Harvey found, by deter- mining the intensities of the sides, that they were severally 105.61, 89.61, 91.78, and 84.05. The intensity also one inch above the extremity of the steel arbour of the fusee was 109.09; and in the line of a common tangent, proceeding from between the barrel and fusee, XII being uppermost, 107.82. When, however, the chronometer was turned a quadrant, so as to bring the middle of the side of the spring-box an inch below the centre of the oscillating bar, IX being uppermost, the intensity amounted only to 92.223 and over the small interval between the balance and. the fusee, it fellto 79.51. On examining the balance Mr. Harvey found the inner rims of the arcs of compensation to be of steel, and which, together with the time-screws, were in a state of active magnetism, particularly the latter, one having strong northern polarity, and the other southern. The small wormed cylinders also, on which the ther- mometer pieces moved, presented equal proofs of polarity, one being a north pole, and the other a south. When the north pole of a small bar magnet was placed near the extremity of the wormed cylinder which possessed northern polarity, the balance immediately receded a smal] quantity ; but when the south pole was applied, the power was sufficient to cause it to advance through a minute but sensible arc; and similar effects were produced when the proper poles of the magnet were presented to the extremity of the wormed cylinder having southern polarity. On presenting a more powerful magnet, the balance was drawn more than a quadrant from its quiescent position, and motion communicated to the chronometer. The effect of the balance on a pocket compass was observed in another experiment; and a table is given in the paper, illustrating the deviations produced in it, by moving the balance through given ares. An arc of 110° produced a deviation of 544°. A compass needle of a more delicate construction was inverted, the moment the time-screws had passed through an arc of 90°. A curious effect was also remarked by Mr. Harvey, by turning the balance through a greater arc than a quadrant, and thereby causing the north pole of the compass to point west, when, by allowing the balance to oscil- late, the compass needle ranged for many seconds through the com- Vou. XVII, ; 2C 366 Miscellaneous Intelligence. plete circumference, until the directive power of the earth, by gaining the ascendancy, caused the arcs of vibration successively to diminish ; the needle ultimately obtaining a position coincident with the meridian, where it continued in a state of tremulous motion as before. Mr. Harvey remarks, that the quantity of steel contained in the chronometer was truly remarkable, and no part of it was destitute of vigorous polarity. Every screw displayed its influence, and of which there were ten large, and several small ones, in the frame alone. The chain also, the axles of the different wheels and pinions, the arbor of the fusee, the balance and its spring, exhibited the same intense and active power. Nor did this polarity partake of the transient character of that imparted by induction from the earth to soft iron, but was permanent, undergoing no sensible alteration frem change of position. ‘ 8. Influence of Magnetism on the Rates of Chronometers.—This interesting and curious subject continues to interest philosophers, and Mr. Harvey, in the XIXth and XXth Numbers of the Edinburgh Philosophical Journal, has two papers, devoted to the consideration of the changes which time-keepers undergo, altering their positions with respect to the attracting force, A pocket chronometer, having a very steady and uniform rate of +20".4, was placed with its main spring nearly in contact with the magnet, and with the magnetic power directed through its centre, when the rate altered to +65".1; but on moving the centre of the main spring 90° from the preceding position, so as to cause the mag- netic power to be transmitted through the centre of the balance, the rate immediately declined to —23'.2; and on turning the time- keeper another quadrant, so as to remove the centre of the main- spring 180° degrees from its first situation, the rate again rose to +43".4; and when through another quadrant, the attractive force being in this situation transmitted nearly through the centre of the balance, the rate became —2".6 ; and on restoring it to its first posi- tion +72".7. When the time-keeper was detached, its rate returned to +18”.2. Similar experiments with another chronometer, having a detached rate of —2’.0, produced in situations corresponding to the last, the rates +10”.0, +31; -+5”.0, and —1".1. From these experiments, Mr. Harvey deduces, that an increase of rate resulted from the direct transmission of the magnetic influence through the centre of the main spring ; and a diminution thereof, when the same power passed nearly through the middle of the balance and its spring. Mr Harvey has, however, not only determined the effect of the direct transmission of the magnetic power, through the centre of the main-spring, but also that produced by its partial operation. For this purpose, the first of the before-mentioned chronometers was so Mechanical and General Science. 367 placed, that a radial line proceeding from the centre of the time= keeper through the middle of the main-spring, might form an angle | of 27° with the longitudinal axis of the magnet. The consequence of this application was an immediate increase of +20".1, its de- tached rate, to +52".3 ; a quantity /ess than the mean of the two re- sults obtained from the direct transmission of the magnetic power through the centre of the spring, by +16".6. By pursuing this branch of the subject, the author of the experiments found, that the removal of the centre of the spring from the axis of the magnet, through equal arcs, appeared to produce proportional declensions of rate. In one experiment, the rates +68."9 and +43."4, pro- duced by the direct transmission of the attractive force through the eentre of the main-spring, and when this point was at its least and greatest distance from the pole of the magnet, are very nearly pro- portional to +50’.8, and +-33’.7, the rates obtained, when the ra- dial line proceeding from the centre of the time-keeper through the middle of the main-spring, formed respectively angles of 27° and 153°, An exception to the above conclusions was discovered by Mr. Harvey, when experimenting with ancther chronometer, the accele- rations in the rate having taken place when the’ magnetic power was transmitted through the centre of the balance; and the retardations, when it passed through the middle of the main-spring ; and the author, when alluding to this anomalous result, properly observes, in the pursuit of experimental science, every result ought to be fairly and impartially recorded. The admirable maxim of Bacon, we cannot control Nature, uniess by making her manifest, should ever be present to the mind of the inquirer. The influence also of magnetized plates is illustrated by several experiments. ‘Iwo chronometers, when placed on a circular mag- netic plate, Jost by having XII turned from N. to E.; gained by being turned from EK. to S.; dost from S.to W.; and gained from W. to N.; the changes from plus to minus being alternate. It was found also, that the difference even of one-eighth of an inch, in the position of the chronometer on the magnetized plate, was constantly accompanied by a sensible alteration of rate. The rate was always augmented by moving it nearer to the north pole; and the most con- siderable alterations were found in the east and west positions of the time-keeper, whien the line drawn from the axis of the chronometer to the centre of the balance, was at right angles to the meridian of the magnetized plate. ‘Ihe smallest changes were also produced in those situations of the chronometer corresponding to north and south, the centre of the balance being in those positions of the machine, in’ the magnetic axis of the plate. 9. On the Adaptation of a Compound Microscope, to act as a Dyna- meter for Telescopes. By C. R. Goring, M.D,.—It appears to me 2C2 368 Miscellaneous Intelligence. that at this moment asimple, cheap, and accurate dynameter, is ra- ther a desideratumm ; the best, 1 believe, now in use is that invented by the late ingenious Ramsden, whose ruling passion seems to have been not only to surmount difficulties, but to create them also in many instances. He seems to have selected one of the most com- plicated and difficult principles to carry into effect on which a dyna- meter can be formed; and however excellent it may be in itself, very few workmen of the present day will undertake to execute dyname- ters of his construction. In consequence the most common instru- ment of the kind is nothing more than a mother-of-pearl micro- meter, with divisions of an inch into 200 parts, attached to a lens. This again is too coarse an instrument, and is, moreover, very difficult to use, having no contrivance to adjust it to perfect vision on the pencil of light, in addition to which it frequently cannot be adapted to measure high powers at all, from an impossibility of getting it close enough to the eye-picce, the brass work of which will not per- mit the plate of the micrometer to arrive at the point on which a very short pencil of rays falls. ‘To obviate all these inconveniences, nothing more would be necessary than to use a compound micro- scope, having the micrometer at its field-bar, in the focus of the eye-glass. It will be very easy to shew that this sort of dynameter will be perfectly commodious, not liable to get out of order, and susceptible of any degree of accuracy which we may think it neces- sary to obtain; I am only surprised that it is not to be found in all the opticians’ shops. Let us suppose the object-glass of such a microscope to be 4 inch focus, that the eye-glass is 1 inch focus, with a negative field-glass, and that there is a micrometer of mother-of-pearl at the field-bar having divisions to the =45 of an inch, (which I know by experi- ence can be read with a lens of 1 inch focus).—According to the length of the tube of the microscope the image at the field-bar will be more or less magnified,—say it is 7 times larger than the object— then a pencil of rays of =$5 of an inch diameter will subtend 75 on the micrometer, and may be seen divided into 7 parts, therefore it may be measured to the 3555 of an inch, a degree of accuracy quite sufficient, I apprehend, for practical purposes—if not, we have only to increase the depth of the object-glass, and we may obtain a scale to any extent we please. In the same manner, if the divisions of the micrometer are not seen with sufficient ease, the depth of the eye-glass may be augmented. Were it an object to carry this prin- ciple to its utmost extent, onc of Mr, Troughton’s micrometers might be attached to the body of the microscope; but this | apprehend would be quite superfluous. One circumstance in constructing this dynameter must be strictly attended to; I mean the ascertainment of the exact value of the di- visions of the mother-of-pearl, which is done with perfect facility by viewing another similar micrometer placed in the focus of the Mechanical and General Science. 369 J object-glass ; and by shortening or lengthening the tube of the mi- croscope, the divisions may be made to coincide in any point which is selected. J think it will be found convenient to have the micro- meter in the field-bar on a narrow slip of mother-of-pearl divided into 100 parts to one inch, and then again into 5 more, and to adjust the eye- glasses and the length of the tube so that 1, of an inch in the focus of the object-glass shall be equal to 1 inch at the field-bar, and so to fill the whole of the field of view. It would perhaps facilitate the reading of the divisions if a dot were placed at every tenth of an inch on the micrometer. With respect to mechanical arrangements, the body of the dy- nameter should be made to slide up and down in another tube with or without rack work, which may be pressed firm by the hand against the eye-piece of the telescope, whose powers it is applied to measure ; while the internal microscope is adjusted to distinct vision, the external tube may be casily made applicable to any telescope, or a shoulder with a screw might be left upon every eye-piece to which the said tube may be firmly attached. It will be evident that the object-glass of such a dynameter will always be at an abundant distance from the shortest pencil of rays it is employed to measure. I should scarcely have thought it worth while to have pointed out so obvious an application of the compound microscope, but I have never seen or heard of its adaptation to any such purpose as I have recommended, Jt must be recollected that some have the faculty of perceiving things for themselves, others only when they are pointed outto them, and many hardly then ;—of this the history of Columbus and hisegg will remind us. II. Cuemicat Scrence. 1. On a Reciprocity of insulating and conducting Action which the incandescent Platina of Davy exerts on the two Electricitics.—The fol- lowing is part of an extract communicated to the Annales de Chimie, (xxy. 278.) from a memoir of M. Erman, inserted in the memoirs of the Academy of Berlin, for the years 1818 and 1819. Place on an electrometer an aphlogistic lamp, of which the upper spirals of platina wire are in full incandescence, and hold at the distance of four or five inches above the lamp the negative pole of a dry voltaic pile, or the negative coating of a small Leyden jar feebly charged, the electrometer will diverge powerfully. Present in the same manner the positive pole or coating, there will be no diver- gence or atleast a very slight one, and that due to induction, Place above an insulated aphlogistic lamp, at the distance of four or six inches, a small screen of any conducting substance, making it communicate with an electrometer, then touch the lamp with a po- sitive pole or coating, ad the electrometer of the screen will diverge 370 Miscellaneous Intelligence . powerfully; but if the lamp be touched with’a negative pole or coating, no divergence, or only a very slight one, will take place. The following table will illustrate the difference of effect when the lamp was postive and negative. ‘The first column is the number of inches between the lamp and the screen above. Lamp positive. ‘ Lamp negative. 1 inch The leaves opened to their full The leaves opened extent (14 lines) in 1” and dis- — the 14 lines in 345” charged themselves against the side every second. ost Ditto in 14" 345” 3 5 (0:98 540” 4» as leaves diverged one line in 150° and only diverged 24 lines on the whole. 5", rset 1 line in 210” total divergence 14 lines. Gigs 39. ah! 1 line in 240” total divergeace 1 line. A similar, but inverted table would represent the progress of the electrometer attached to the lamp, the screen being similarly electrified. There exists, therefore, incontestibly a reciprocity of conducting and insulating actions ; the lamp conducts and transmits the positive effect tothe screen, but not the negative ; on the contrary, the screen transmits the negative effect to the lamp, but not the positive. This singular property is found to exist in all the combinations of this kind which can be imagined. ‘Thus, for example, if a Leyden jar is moderately charged positive by its ball, and this applied to the insulated aphlogistic lamp, a smaller Leyden jar, with its ball held about four or six inches trom the incandescent platina, will become very sensibly charged; but if the ball of the first be electrized ne- gatively, there will be no charge given to the second, on iepeating the experiment. By disposing successively a number of electro- meters, each with its aphlogistic lamp, so as to establish a communi- cation from one to the other, a very paradoxical system is obtained, representing a species of pile which is rapidly traversed by positive electricity from right to left, but not at all in the opposite direction, whilst with negative electricity the inverse directions are equally distinct: though as the author has not succeeded in increasing the effect by the successive groups, it has perhaps more analogy with the tourmaline. Electro-magnetic phenomena were not known at the time when M. Erman discovered the reciprocity of insulating and conducting action, and he has not as yet published the result of his ultimate researches on the electro-magnetic effects of incandescent platina, Chemical Science. 371 It may, perhaps, be supposed that the effect is due to the power the ascending current of vapours has to take positive electricity with it to the screen above, and probably the experiment may be considered as a proof of the truth of Franklin’s theory, and an argument against Dufay. But it is not in a vertical direction only that the aphlogistic lamp receives negative electricity from without, and not positive ; but in all directions, and from all the concavity of a sphere, of which the lamp is the centre. It is not therefore on an emanation in the direction of the ascending current of vapours that the effect depends, but it resembles rather a radiation like that of light and heat. Se- condly, the reciprocal effect essentially requires the actual incan- descence of the upper spirals of platina; without this the apparatus may be disposed so as to emit a much larger quantity of vapours, but in vain. Thus, for instance, 397 grains of platina, which arranged properly on a wick would light amadou at two lines distance, and keep 400 grains of water boiling, offered nothing like the reciprocal action because the upper spires were not ignited ; whilst a spiral only a few grains in weight, but incandescent to its extremity, acted in a most decided manner. ‘Thirdly, heated iron offers some traces of this reciprocity, but only whilst it is in full ignition. The effect cannot, therefore, depend on a heated current, which would continue long after ignition had ceased. M. Erman has also seen many cases in which the iron has had the opposite power to the platina, emitting the ~ negative and receiving the positive electricity. Finally, as an argu- ment against the efficacy of a heated current, undecomposed vapour at a high temperature possesses no power,of conducting electricity. Without insisting much upon it, M. Erman suggests the following explanation of the phenomena: There exists two electricities, between which there is a specific difler- ence of expansibility: the heat of incandescence acts by augmenting this expansibility, in the same manner as the pointed form of con- ductors augments the tension, If this augmentation of expansibility be very considerable, the specific difference of the two electricities disappears in the greatness of the whole effect: this is the case with flame ; but there exists a certain degree of heat which augments the expansibility in a less degree, and precisely to the point at which the most expansible of the two (the positive) is able to over- come the constraining force of the circumambient medium, whilst the less expansible (the negative) notwithstanding the increment of force it has received, has not yet attained to the point at which it can over- come the resistance of the medium, ‘The action of the incandescent wire is, therefore, according to this view, connected with the pheno- mena of the specifically different lights, presented by points positively or negatively electrified. Sufficient examination has not been made whether points, not incandescent, emit different quantiiies of elec- tricity according as they are positive or negative; but the marked 372 Miscellaneous Intelligence. effects of a pile ofa single metal, terminating at one side in a point, and the other in a large surface, and placed end to end in water, with merely this geometrical difference, proves evidently that something of this kind exists, and it was whilst occupied with these piles on geo- metrical principles that the author was conducted to researches on incandescent points. If the rays of the sun, by heating the soil, produce an effect ana- logous to that spoken of, 2. €., to increase the electric repulsion, but only in the proportion required to make the positive fluid overcome the resistance of the air, and not the negative, it would explain the habitually positive state of the lower strata of the atmosphere. The author has not, however, found this idea confirmed by experiments with the aphlogistic lamp. In fact, when left on a condenser for several hours it had not disturbed the electrical equilibrium, 2, e., the excess of expansibility acquired by the positive electricity was not sufficient to detach it from its combination with the negative electricity. 2. On the Magnetic Action of strong electrical Currents on different Bodies.—Coulomb, in 1802, gave the results of a well-known series of experiments on the action exerted by the opposite poles of two power- ful magnets on minute needles of any substance delicately suspended between them. It was found that, whatever the nature of the sub- stance, the needle ultimately arranged itself in the direction of the poles; but he finally concluded that this was due to the minute portions of iron which they contained. M. Biot, who repeated these experiments very carefully, is not entirely of this opinion; but suggests, that inasmuch as simple con- — tact of heterogeneous bodies is sufficient to develop electrical forces, which for a long time were quite unsuspected, perhaps other cir- cumstances may develop similar or analogous forces extremely feeble, but sufficient to affect apparatus delicate as Coulomb’s. After this M. Ampere, with M. A. Delarive, made an experiment at Geneva on the effect of electrical currents on a plate of copper, and conceived that the copperplate, by being near the currents, was capable of affecting the magnet like the neighbouring wires, through which the current was passing, but afterwards ascertained that this was not the case. Ultimately M. Becquerel has resumed the examination of these or similar phenomena, making use of Schweigger’s multiplier for the concentration of the powers of the clectrical current, and he has observed differences between the effects thus produced and those obtained in M. Coulomb’s experiments. The galvanometer used was 1.97 inches long and about 0.4 inches wide. Care was taken that the substances should not be worked with iron instruments, and the needles formed of them were made very small, especially if of a substance but feebly affected by the electrical current; they were then suspended Chemical Science. ae’ in the galvanometer just as a magnetic needle would be, and a Wollaston’s pile of 10 pair of plates connected with the wires of the instrument. A needle of soft iron instantly placed itself parallel to the axis of the spirals, the arrangement of magnetism in it being similar to that of a common bar magnet. Deutoxide of iron enclosed in asmall paper cartridge 0.157 of inch in diameter, and properly suspended, was rapidly drawn into the plane of the apparatus, and took a position perpendicular to the axis of the spirals; but soft iron filings similarly circumstanced acted just like the iron needle. The difference exhibited in this way between these two sub- stances does not exist in Coulomb’s manner.of making the experi- ment, and hence a difference of action would seem to be indicated between the electro-magnetic wire and magnetic poles. Needles of copper, wood, or gum Jac, were affected like the deutoxide of iron, but in a smaller degree; but great caution is re- quisite in making these experiments to avoid currents of air; this is best done by closing the extremities of the galyanometer in glass. Needles thus affected by the electric current were then examined as to their action on a feeble magnet. The iron needle was found to act like a regular magnet, and it is to be presumed that the car- tridge of iron filings did so also ; but the parcel of deutoxide of iron, when examined, was found to act with one pole of the bar in the same manner at every point situated towards one side of the galvano- meter, and inversely when the pole was changed, so that the north Magnelism was on one side of the needle, and the south on the other. It is, however, possible to distribute the magnetism as in the common needle, which is done by retaining the cartridge for some time parallel to the axis of the instrument; but when left to itself, it returns gradually to the state described. ‘The action of the magnet on the other needles, when in the galvanometer, gave no certain results. A needle of wood about 1 inch in length, and .04 of an inch in diameter, had fixed at each extremity a square plate of steel or soft iron .08 of an inch in the side, and .008 of an inch in thickness, when placed in the spiral it was rapidly drawn into a position pa- rallel to the plane of the spirals, the distribution being as in the car- tridge of deutoxide. Two pieces of iron wire 0.04 of an inch in length were then put in place of the plates, and now the needle stood in the instrument at an angle of 45° with the plane of the spirals, or with its axis; as the length of the ends of iron wire was increased the needle tended more to parallelism with the axis, and when these extremities were 0,4 of an inch long, the needle stood parallel to the axis of the instrument.—Ann. de Chim. xxv. 269. 3. On Electro-motive Actions produced by the contact of Metals and 374 Miscellaneous Intelligence. Liquids, &c., by M. Becquerel.—The apparatus used by M. Beequerel to collect and indicate the electricity developed by the contact of a solid with a liquid is a condensing clectroscope of extreme sen- sibility, invented some time since by M. Bohnenberger*, but varied and rendered more delicate for the present purpose by M. Becquerel. The instrument of the latter philosopher consisted of a single dry voltaic column fixed horizontally on a wooden support, and having attached to each of its poles, in a vertical position, a plate of metal about 3 inches long: these plates are placed near together, and a slip of gold leaf hung between them, connected with a condensing plate 9 inches in diameter. The sensibility of this apparatus is such that a tube of glass rubbed on cloth acts in dry weather at a distance of 8 or 10 feet, and the electric state of the hand or hair has an influence at the distance of several fect. Hence the utmost precau- tion is requisite in experimenting with the instrument. The following are some of the experiments made with this appa- ° ratus, the gold leaf being in communication in all of them with the lower plate of the condenser. A brass capsule containing an alkaline solution, or ammonia, was placed on the upper plate of the condenser: a communication was then made with the solution by touching it with the finger, or a moistened band of cloth, and the lower plate was also connected with the earth; a few moments after the upper plate was raised, and the gold leaf moved towards the positive pole; thus the alkaline solution, or ammonia, by con- tact with the copper, had taken positive electricity, and the metal negative electricity. When sulphuric acid was used in place of alkali, opposite elec- trical effects were produced, the acid became negative, and the metal positive. A platina capsule filled with an alkaline solution was placed on the upper condensing plate ; the under plate was then touched on the one hand by a plate of platina, and on the other the liquid was touched by the finger, and in this manner the electro-motive actions of the platina on the copper was neutralized, being the same on both sides, and therefore the upper plate would only retain the electricity due to the contact of the platina with the solution. Sometimes it is ne- cessary to put a small piece of paper between the platina and the copper, for the apparatus is so sensible, that a very small difference in the state of the surfaces is sufficient to influence the results. Ope- rating thus the same results were obtained as before with alkali; the platina became negative, and with acid it became positive. A zinc capsule filled with solution of soda became negative, and with con- centrated sulphuric acid positive; when the acid was diluted no elec- tricity was developed. Silver became very feebly electrical in con- tact either with acid or alkali. * See vol. xi. p. 208, of this Journal. ee Chemical Science. 375 - In general metal in contact with acid becomes positive, making the acid negative, and with alkalies the reverse effects are obtained ; but there are many cases, as with silver, in which the electro- motive action can scarcely be observed. “ Sir H. Davy had found that those acid and alkaline substances which can exist in a dry and solid form become electrical by their contact with metals; thus perfectly dry oxalic or succinic acid, either in powder or mass, when placed on a copperplate, takes negative electricity, and communicates positive electricity to the metal. The celebrated English chemist found also, that in consequence of the difficulty of depriving potash and soda of water, they did not in general produce any electricity by their contact, but that after being strongly calcined they possessed for a moment the power of be- coming electric by contact with a metal, He endeavoured also to determine, by means of very delicate instruments, the electric state of an insulated acid or alkaline solution after their contact with the metal, but there were no results of that nature.” ; “« We have proved, therefore, that the electric effects observed by Sir H. Davy as produced by the contact of a solid dry acid or alkali with a metal, and where consequently there is no chemical action extends to the contact of all the metals with acid or alkaline solu- tions, even though sometimes chemical action may have com- menced.” Haying determined the electric state of an acid or alkaline solu- tion in contact with a metal, the next object was to ascertain the effect when the solution was placed between two different metals, The copper capsule was placed on the upper condensing plate, and filled with an alkaline solution or very dilute sulphuric acid; the solution was then touched by a plate of zinc, taking care that the two metals did not come in contact, and the lower condensing plate was touched with the finger; twenty seconds after, on raising the upper plate the gold leaf moved towards the positive pole, so that the copper capsule had become positively electrified. On putting a zinc capsule on the upper plate with one of the two solutions, touch- ing the lower plate with a piece of zinc so as to neutralize the electro- motive action of that metal on the copper, and touching the liquid with a piece of copper held in the hand, an electrical state was pro- duced, which, on raising the upper condensing plate, made the gold leaf move towards the negative pole, consequently the zinc capsule had become negative. Hence it is seen, that when zinc and copper are separated by an acid or alkaline solution, the zinc becomes negative, and the copper positive, which is the inverse of that which takes place when the two metals are in contact. Another result obtained experimentally by M. Becquerel is, that copper in a solution of muriate of soda becomes negative, and the solution positive. —Ann. de Chim. xxv. 405. 376 Miscellaneous Intelligence. A. Measurement of the conductibility of Bodies for Electricity —M. Rousseau has, for several years past, been occupied in the construc- tion and observation of dry voltaic piles, and has lately applied them to the determination of the conducting power of bodies, in regard to electricity. MM. Ampere and Dulong were directed by the French Academy to report on a memoire by M. Rousseau on this subject, and the following statement is drawn up from that report. The dry pile is formed of discs of zinc-leaf, and tinsel, separated by discs of parchment, previously imbibed with a mixture of equal parts of oil of poppies and oil of turpentine ; the whole pile is covered with resin to prevent the contact of the air. The pole is fixed vertically com-. municating below with the earth, the upper end is made to communi- cate at pleasure by awire to a pivot, on which is placed a weakly- magnetized steel needle, and alsoto a metallic ball placed at the same height as the needle, and not quite half its length from the pivot ; hence, when the communication is made the needle and ball are similarly electrified and the needle is repelled ; and when the needle and ball are previously placed in the magnetic meridian, the position to which the needle is repelled is proportionate to the magnetic and electric forces, and is constant for a very considerable time for the same apparatus. The magnetic needle might be replaced by a simple electric needle suspended by a wire of proper length and diameter, forming a balance of torsion; but the arrangement of M. Rousseau is more convenient, and sufficiently sensible. On using the instrument, the substance of which the conductibility is to be measured, is made part of the connexion between the top of, the pile and the needle and ball, care being taken that the portion: traversed by the electricity is always of the same dimensions. If the time occupied in producing the greatest deviation is not instantaneous, then the period which passes before the needle takes a permanent position is a measure of the conductibility of the substance employed. Liquids, when tried, are put into small metallic vessels communi- cating with the ball and needle, then a wire partly covered with gum lac, except for a certain length at the extremity, has that uncovered portion entirely immersed in the fluid, so that the same surface is always in contact; then, on connecting the other end of the wire with the end of the pile, the time which passes before the needle is at its maximum deviation is observed, and is inversely as the conducting power of the liquid. Observing in this manner, a remarkable fact was noticed with olive oil, for, notwithstanding its similarity to other oils, it was found to be exceedingly inferior in conducting power. ‘Thus all other things being equal, olive-oil required 40’ to produce a deviation produced in 27’ by poppy and other oils, and on adding to olive-oil only +45 of another kind of oil, the time was reduced to 10’. Hence any adulteration of olive-oil is easily discoverable by the instrument. Solid fat conducts with less facility than animal oils, from the ex= SS ere Chemical Science. 377 cess of stearine in it, for it was ascertained that elaine conducted electricity much better than stearine. ‘The fat of an animal dimi- nishes in conducting power with the age of the animal. ‘The same apparatus also marks a nectable difference between resin, gum lac, and sulphur, the most insulating of all bodies known, and also be- tween silk, flint-glass, and common glass. As to alcoholic or aqueous fluids, acids, alkalies, §c., the time required was too short to be adopted as a measure, but a modification of the apparatus would enable it to measure the conducting power of allof them. It is remarked also in the report, that ‘* it would be equally possible and very curious to make trial of the two electricities on various substances, for it would be suflicient for that purpose to put the poles of the pile alternately in communication with the earth, Itis probable, according to the results formerly obtained by Erman, that differences would be found with certain substances.—Ann. de Chim. xxv. 373. 5. Distinction of Positive and Negative Electricity.—Positive and negative electricity may be readily distinguished by the taste, on mak= ing the electric current pass by means of a point on to the tongue. The taste of the positive electricity is acid, that of the negative elec- tricity is more caustic and, as it were, alkaline —Berzelius. 6. Electricity produced by Congelation of Water.—When water is frozen rapidly in a Leyden jar, the outside coating not being insulated the jar receives a feeble electrical charge, the inside being positive, the outside negative. If thisice be rapidly thawed, an inverse result is obtained, the interior becomes negative, and the outside positive.— Grothus. 7. Hare’s Single Gold-leaf Electrometer.—This instrument consists of a glass vessel, fixed by a foot on to a wooden stand, and haying an aperture at the top and also another at one side. ‘The top is closed by a metal cap, finished externally by a horizontal zinc disc, six inches in diameter, and connected internally with a single leaf of gold cut into an acute triangular form, and hanging in the centre of the instru- ment with the point downward. Opposite to the lower end of this leaf of gold is a ball attached to a horizontal wire, and which passing through a screw cap fixed in the lateral opening of the glass vessel, can be made to approach to, or recede from, the leaf at pleasure, the distance being estimated by a graduation on the screw into +4oth parts of aninch. A plate of copper six inches in dia- meter, and furnished witha glass handle, generally accompanies the instrument. *« The electricity produced by the contact of copper and zinc is ren- dered sensible in the following manner: Place the disc of copper on the disc of zinc, take the micrometerescrew in one hand, touch 378 Miscellaneous Intelligence. the copper disc with the other, and then lift this disc from the zinc. As soon as the separation is effected the gold leaf will strike the ball, usually if the one be not more than +3, of an inch apart from the other.” “That the phenomenon arises from the dissimilarity of the metals is easily shewn by repeating the experiment with a zine disc, in lieu of a disc of copper. ‘The separation of the homogeneous discs. will not be found to produce any contact betweenthe leaf and the ball.” ** Itis probable that the sensibility of this instrument is dependant on that property of electricity which causes any surcharge of it which may be created in a conducting surface, to seek an exit at the most projecting termination or point connected with the surface,” this disposition being increased of course by the proximity of the ball. These effects are not to be expected in weather unfavourable to elec- tricity, but in favourable circumstances they have been produced by a smaller instrument, the discs being only two inches and a half in diameter. 8. Hare’s V oltate Trough.—Dr. Hare states that, having had occasion to remark the surprising increase in the deflagrating power of a series of galvanic pairs, when, after due repose, they were simultaneously exposed to the acid, he was induced to devise means of accomplishing this object in various, ways, and that ultimately the following method occurred to him as the best: Two troughs are joined lengthwise edge to edge, so that when the sides of the one are vertical, those of the other are horizontal. Then by a partial revolution of the two troughs, thus united upon pivots which support them at the ends, any fluid which may be in one trough must flow into the other, and on revers- ing the motion, must flow back again. The galvanic series being placed in one of the troughs, the acid in the other, by a movement such as above described, the plates may all be instantaneously subjected to the acid, or relieved from it. The pivots are made of iron, coated with brass or copper, as less liable to oxidizement ; they are connected within with the galvanic. series, and move on pieces of shcet-copper, which are easily made the extremities of connecting pieces, and thus the whole can be ar- ranged in any way found convenient. 9. Dobereiner’s Instantaneous Light Apparatus.—Since the very curious observation made by M. Doberciner of the power possessed by spongy platina of determining the combination of oxygen and hy- drogen at common temperature, that substance has been applied, among other uses, to the construction of an instantaneous light ap-= paratus; a jet of hydrogen is thrown on to a portion of the spongy platinum, and is by it inflamed. Various modes of presenting the plantinum to the hydrogen have been devised, but none surpass or even equal that originally adopted by M. Dobereiner. The extre- mity of a fine platina wire is to be rolled into a spiral form, and then Chemical Science. 379 dipped into ammonio-muriate, or muriate of platina, until about two grains are taken up, after which it is to be heated red-hot in a spirit lamp. In this way a quantity of spongy platina is formed on the wire so minute, that if put into contact with a mixture of oxygen and hydrogen it becomes heated, and inflames the gas as rapidly almost as if an electrical spark had passed. Such a wire as this fixed on the jet-pipe, so that the spongy metal shall be exposed to the current of hydrogen, immediately inflames it. It happens that if an instrument of this kind has been exposed for some hours to a humid atmosphere, the inflammation does not take place readily, but in this case if the top of the platina be touched by the finger or palm of the hand, either before or during the time that the current of hy-= drogen is passing out, the inflammation immediately takes place. Contact, indeed, is not necessary, for the mere approach of the hand is sufficient to elevate the temperature so much as to cause instant inflammation. In using spongy platina for eudiometrical purposes *, M. Dobe- reiner attaches his balls to the end of a platina wire, so as to be able to withdraw them when the experiment is completed, or even during the experiment if requisite, so that they may be dried and again introduced.—Bib. Univ. xxv. 117. 10. Test of the Alteration of Soiutions by contact with Air.— M. Becquerel remarks, that if iron be dissolved in nitric acid, and the solution filtered, and two plates of platina connected with the two extremities of the wire of a galvanoscope, be immersed into the solution, and if one plate be withdrawn, and then re-introduced into the solution, it will produce an electric current passing from this plate to the other; and generally the plate withdrawn from the solution and re-introduced becomes positively electrical. The nitrates of copper and lead give similar results, but they do not retain this power, and in the course of a few hours no effects of this kind are observable. Nitrate of zinc does not operate in this manner. Suspecting that the effect was due to the action of air on the film of solution which adheres to the withdrawn plate, the expe- riment was made in an atmosphere of hydrogen, and then no such results were obtained. M. Becquerel, therefore, attributes the effec t to the alteration induced by the air on the portion of solution with- drawn with the plate, and which, when the plate is re-immersed, being dissimilar to the fluid that has not been exposed, determines the current of electricity, The effect of the air he considers is pro= bably to convert such portion of deutoxide of azote and proto-nitrate as may have been formed by the action of nitric acid on the metal into nitrous acid and deuto-nitrate, and that when this has taken place * See Vol xvi. page 874. 380 Miscellaneous Intelligence. with all the portions of the solution the power of producing electrical currents ceases.—Ann de Chim. xxv. 413. 11. Odour of Hydrogen Gas extraneous, Inodorous Hydrogen Gas. —When hydrogen gas, obtained from a mixture of iron filings and diluted sulphuric acid, is passed through pure alcohol, the hydrogen loses its odour in a great measure; and if water be added to the alcohol it becomes milky; if enclosed in a flask and left for some days, an odorous volatile oil is deposited, which was contained in the gas, and which contributed to its well known odour. Perfectly inodorous hydrogen gas may be obtained by putting an amalgam of potassium and mercury into pure distilled water, but if an acid or muriate of ammonia be added to the water, which accele- rates the development of gas, it gives it the same odour as that re- marked in the solution of zinc by weak sulphuric acid. ‘This odour, therefore, does not belong to the hydrogen gas, but is given to it by impurities. — Berzelius. 12. Inflammation of Sulphuretted Hydrogen by Nitric Acid.— When a few drops of fuming nitric acid are put into a flask filled with sulphuretted hydrogen, the hydrogen is oxidized by the nitric acid, and the sulphur is disengaged in a solid form. If the flask be closed with the finger, so that the gas which becomes heated cannot escape, its temperature is raised so much as to produce combustion with a beautiful flame, and a slight detonation which forces the finger from the mouth of the flask. ‘This experiment may be made with- out the least danger, with a flask containing four or five cubical inches of gas.—Berzelius. 13. Artificial Chalybeate Water.—If a few pieces of silver coin, (says Dr. Hare,) be alternated with pieces of sheet iron, on placing the pile in water it soon acquires a chalybeate taste and a yellowish hue, and in twenty-four hours flocks of oxide of iron appear. Hence by replenishing with water a vessel, in which such a pile is placed, after each draught we may obtain a competent substitute for a chalybeate spring. 14, Mercurial Vapour in the Barometer.—M. Billiet observes, that “ for a long time past it has been known that during hot seasons mer- curial vapour has formed spontaneously in the upper part of the baro- meter tube, which condenses in minute drops on its inner surface. It is sufficient for the observation of this phenomenon at pleasure to apply a small tin vessel, filled with ice, to this part of the tube for an hour or two, On removing the cooling vessel there may be perceived on the internal surface of the tube a dimness about six lines in diameter, and by means of a lens it will be found that this is nothing but a Chemical Science. — 381 mass of minute globules of mercury attached to the glass, those in the centre being largest. Hence arises the question, whether this vapour may not have some influence on the oscillations of the barometer ?— Bib. Univ. xxv. 93. _ 15. Combustion of Iron by Sulphur.—Dr. Hare makes this experi- ment in the following manner :—A gun-barrel is heated red at the butt end, and a piece of sulphur thrown into it ; then either blowing through the barrel, or closing the mouth with a cork, will produce a jet of sulphurous vapour at the touch-hole, to which if iron wire be exposed it will burn as if ignited in oxygen gas, and fall in fused globules of proto-sulphuret of iron. 16. Ammonia in Oxides of Iron.—M. Chevalier has stated to the Royal Academy, that he has ascertained the presence of ammonia in various oxides of iron, and promises further accounts.—Ann. de Chim. xxv. 429. 17. Iodous Acid.—Il Sig. Sementini, of Naples, has published an account of a combination of iodine and oxygen, containing less of the latter principle than iodic acid. Itis obtained in the following man- ner :—equal parts of chlorate of potassa and iodine are to be triturated together, in a glass or porcelane mortar, until they form a very fine pulverulent yellow mass, in which the metallic aspect of the iodine has entirely disappeared. If there be excess of iodine the mixture will have a lead colour. ‘This mixture is to be put into a retort the neck being preserved clean, and a receiver is to be attached with a tube passing to the pneumatic trough. Heat is then to be applied, and for this purpose a spirit lamp will be found sufficient; at first a few violet vapours rise, but as soon as the chlorate begins to lose oxygen dense yellow fumes will appear, which will be condensed in the neck of the retort into a yellow liquid, and run in drops into the receiver ; oxygen gas will at the same time come over. When the va- pour ceases to rise, the process is finished, and the iodous acid ob- tained will have the following properties :— Its colour is yellow ; its taste acid and astringent, and leaving a burn- ing sensation on the tongue. It is of an oily consistency, and flows with difficulty. It is heavier than water, sinking in it. It has a par- ticular odour, disagreeable, and something resembling that of eu- chlorine. It permanently reddens vegetable blues, but does not de- stroy them as chloric acid does. It is very soluble in water and al- cohol, producing amber-coloured solutions. It evaporates slowly, and entirely in the air. At 112° F. it volatilizes rapidly, forming the dense vapour before mentioned. It is decomposed by sulphur, disengaging a little heat, and liberating violet vapours. Carbon has no action on itat any temperature. Solution of sulphurous acid de- composes it as well as iodic acid, i the iodine as a brown 2 VoL, XVII. 382. Miscellaneous Intelligence. powder. It is characterized by the manner in which potassium and phosphorus act on it: the instant they touch it they inflame; the po- tassium producing a white flame and dense vapours, but little or no liberation of iodine ; and the phosphorus, with a noise as of ebullition, violent vapours appearing at the same time. The odorous nature of this acid, its volatility, colour, and its power of inflaming phosphorus by mere contact, shew that some of the principal characters of iodine are retained, and that it is oxyge- nated, therefore, in a minor degree, and deserves the name of iodous acid. Its composition has not been experimentally ascertained. M. Se- mentini endeavoured to analyze it by putting 100 grains into the end of a long sealed tube, and then dropping a small piece of phospho- rus in, iodine was disengaged, and condensed in the upper part of the tube, and this was found to amount to 45 grains: but this can furnish only very uncertain results. Iodous acid dissolves iodine, becoming of a deep colour, more dense aud tenacious, and having more strongly the odour of iodine : when heated the iodine partially rises from the iodous acid, but they can- not be separated in this way. M. Sementini believes also in an oxide of iodine, and has given the name to the black powder, which is produced by the action of sulphurous acid on iodous acid, and which still contains oxygen ; but he mentions that this and some other points still require investi- gation. The following are the properties of the iodic and iodous acids, by which a judgment may be formed of their specific difference. Jodzc acid is solid, white, without odour, reddening blue colours, and then destroying them. Volatile at 456° F., with decomposition: heated with charcoal or sulphur it is decomposed with detonation. Jodous acid is liquid, yellow, odorous, reddening blue colours, but not de- stroying pau volatilizing at 112° F., and even at common tempe- ratures without decomposition ; heated with sulphur it is decomposed without detonation, and inflames potassium and phosphorus by mere contact,— Bib. Univ. xxv. 119. 18. Preparation of pure Oxide of Uranium.—The following is M. Arfwedson’s mode of procuring oxide of uranium pure, Finely pulverized pechblende is to be dissolved by a gentle heat in nitro- muriatic acid, after which a good deal of water is to be added, anda little muriatic acid,if necessary, The undissolved matters, consisting of sulphur, silica, and a portion of the gangue, are to be removed, and a current of sulphuretted hydrogen passed through the solution as long as it affects it. The first precipitate is dark coloured, but the latter portions being sulphuret of arsenic is yellow. On filtration, the liquor is free from copper, lead, and arsenic, but contains iron, cobalt, and zinc. It is now to be digested with a little nitric acid to ae en Chemical Science. 383 peroxydize the iron, and then decomposed by carbonate of ammonia, in excess, which leaves the iron and earths ; the filtered solution is to be hoiled as long as carbonate of ammonia is disengaged, the oxides of uranium, zinc, and part of the oxide of cobalt falls down, and is to be collected on a filter, washed and dried. It is then to be heated to redness, by which it becomes of a dark green colour, and afterwards by maceration in dilute muriatic acid has the oxides of cobalt and zinc, with a small portion of oxide of uranium, dissolved out, and after washing and drying, pure oxide of uranium remains. About 65 per cent. of the pechblende used was obtained in this way. 19. Uranium Pyrophori.—When solutions of per-nitrate of ura= nium and nitrate of lead are mixed together, and precipitated by caustic ammonia, a precipitate falls, which M. Asfwedson considers as an uraniate of lead ; after being washed, heated, and pulverized, it was of a cinnamon brown colour. This substance being placed in a tube was heated, and hydrogen gas passed over it, much water was formed, and it is to be presumed that the lead and the uranium were both reduced to the metallic state. The product was a dark brown powder, which when exposed to the air on paper, took fire and ignited, leaving uraniate of lead asa residue. This singular phenomenon, which was quite unexpected, may have been occasioned (M. Arfwedson suggests) by an electro-chemical action between the two metals, which caused their combustion. When uraniate of barytes is reduced by hydrogen in a similar manner it also produced a body presenting the same phenomenon in the air; and the pyrophorus thus obtained from the uraniate of iron is still more powerful than either of the former. 20. Atomic ox proportional Weights.—Dr. Thomson gives the fol- lowing as the most correct expression of the atomic weights of the substances mentioned according to his last experiments ; Boracic acid. .. - . 3.00 Tartaricacid , . « . $8.25 Pie ACI Me aw (dno Fluoboricacid . « . « 4.25 Tartaric acid crystallized. 9.375 Oxygenbeing . . . . 1.00 The crystals of tartaric acid contain 1 proportional of water.— Ann, Phil. N.S. VII. 245. 21. On the Acetates of Copper. By M. Vauquelin,—The follows ing results are abstracted from a paper by M. Vauquelin, read to the Academy of Sciences, Nov. 6, 1823, and published in the Mé- moires du Museum, x. 295. ; Analysis of the Crystallized Acetate of Copper.—A given weight was 2D2 384 Miscellaneous Intelligence. pulverized, mixed with nitric acid in a porcelain crucible, aud heated ultimately to redness, it yielded 40 per cent. of black oxide of cop- per. Other portions were heated to a temperature sufficient to dis- sipate the water, but not to decompose the salt. In these cases the loss was never more than 10 per cent., and was very constant. In respect to the acid, two grammes of the salt were dissolved in four grammes of sub-carbonate of potash; the mixture filtered, all the soluble portions collected, and after being carefully neutralised by sulphuric acid, evaporated to dryness, and digested in alcohol. This solution again evaporated gave 1.8 grammes of acetate of potash, which containing 0.93 of a gramme of acetic acid, gives a propor- tion of 46.5 per cent. on the acetate of copper employed. The atomic composition of this salt is therefore given as nearly the fol- lowing :— Acetic acid 2 atoms = 12.7 5or percent 51 Oxide of copper 1 _,, =heLo bt 40 Water Si hes aa = 22:25 re 9 When solution of crystallized acetate of copper is boiled for some time it is decomposed, a little acetic acid escapes, much black oxide of copper falls down, and when the decomposition ceases, which it always ultimately does, another acetate of copper is found in the so- lution. This decomposition takes place in close vessels, where no acetic acid is allowed to escape. One hundred parts of the crystal- line acetate deposit about 14.65 of oxide, leaving in solution 25.35 parts in combination, with twice its weight of acetic acid. On continuing to boil the solution, no further deposition of oxide took place ; as concentration proceeded acetic acid escaped, but suf- ficient remained to keep all the oxide in solution. Ultimately the usual crystallized acetate was obtained, which when dissolved in water and boiled, precipitated oxide as before, so that by several operations the whole might be decomposed in this manner. Verdigris is known to be a mixture of the crystallized acetate of copper, and a sub-acetate. A portion of the latter was extracted by washing pulverized verdigris rapidly, with successive small portions of cold water, to avoid a decomposition afterwards to be noticed ; this, when dried, was analyzed in a manner somewhat like the pre- ceding, and found to consist of nearly 66.5 oxide, and 33.5 acid. Hence there are three combinations of acetic acid, and oxide of copper, containing, the first, 66.5, the second, 44.44, and the third 33.34 of oxide, supposing them all dry. M. Vauquelin remarked also a singular decomposition of verdigris which takes place spontaneously, and without the assistance of heat. If 1 of verdigris be mixed with 500 of distilled water, and left at a temperature of 60° or 70° F. it gradually becomes yellow, then brown, and in seven or eight days no green portions are observed. When filtered, per-oxide is obtained, and a blue solution, which ee Chemical Science. 385 when boiled becomes turbid, and deposits more oxide. Although the quantity of water is mentioned above, yet the decomposition takes place with other proportions, but most rapidly when the proportion is greatest ; 100 parts. of verdigris were found to leave about 23 parts of oxide of copper. In order to ascertain the correctness of an Opinion, that it was the sub-acetate only in the verdigris which underwent this change, some of that salt was prepared, and one part mixed with 500 of water, and agitated from time to time. At first the salt swelled and became flocculent, then it became yellow, and at Jast brown, diminishing rapidly in volume. These effects were more rapid in the sun’s rays, without doubt from the heat produced. The per-oxide, when collected gave 46 per cent. of the sub-acetate em- ployed, just double that afforded when verdigris was used, and the soluble crystallized acetate of copper formed remained in the solution, as.was proved by boiling the solution ; it underwent a further de- composition, just as the crystalline acetate had done before. “ Thus,” says M. Vauquelin, “ there are three combinations of the oxide of copper and acetic acid: Ist, a sub-acetate insoluble in water, but decomposing in that fluid, at common temperatures be- coming per-oxide, and an acetate ; 2nd, a neutral acetate, the solution of which is not altered at common temperatures, but is decomposed by ebullition, changing into per-oxide, and a super-acetate ; 3rd, a super-acetate, which, when in solution is not decomposed, cither at common temperatures, or at the point of ebullition, and which cannot be obtained crystallized, except by slaw spontaneous evaporation, or evaporation in a vacuum.” . 22. Duhline or Inuline in the Jerusalem Artichoke.-—M. Braconnot, whilst engaged lately in an examination of the tubercles of the Heli- antk.as Tuberosus, or Jerusalem Artichoke, ascertained the presence of a substance in them, in all respects resembling the Dahline of M. Payen. The recent tubercles were rasped, pressed, and the juice collected; left to itself it deposited a substance like starch, which, when collected and boiled in water, was almost entirely dis- solved; but on evaporation a substance was deposited like the Dahline. (See vo}. xvi. p. 387.) M. Braconnot, however, does not think that this, or M. Payen’s substance should be considered as a new proximate principle, but considers them both as specimens of Inuline.—Ann. de Chim. xxv. 361. 23. New Vegeto-alkalies.—Violine.—At a sitting of the Académie Royale de Médicine, M. Boullay read a memoir on the analysis of the violet, viola odorata, from which it appears that the violet contains an active alkaline, bitter and acrid principle, similar to the Emetine of Ipecacuanha, and which is called by the author, Emetine of the violet, indigenous emetine, or violine, According to M. Ortfila it 386 Miscellaneous Intelligence. possesses powerful poisonous qualities. It was found to reside equally in the root, leaves, flowers, and seeds of the plant; but associated with different proximate principles, so as to have its action on the animal system modified.—Jour. de Pharmacie, Jan. 1824, 24. Jalapine or Jalapia—Mr. Hume, jun. of Long Acre, is said to have discovered a vegeto-alkaline principle in Jalap, and pro- poses to call it Jalapine. It is procured in the following manner. Coarsely powdered jalap is macerated for 12 or 14 days, in strong acetic acid; a highly coloured tincture is thus obtained, which, when filtered, is to be supersaturated with ammonia, and thmie violently shaken: a sabulous deposit will fall rapidly, and a few crystals will form on the sides of the vessel. The deposit and crys= tals are to be collected and washed with distilled water, again dis- solved in a small quantity of concentrated acetic acid, and re-pre= cipitated by ammonia added in excess, which throws down the jala- pine in small white acicular crystals. Jalapine is without any perceptible taste or smell, and seems to be heavier than Morphia, Quinia, or other substances of this class; it is scarcely soluble in cold water, and only to a small extent in hot water; ether has no effect upon it; alcohol is its proper solvent. Very little trouble is requisite to purify jalapine from extractive or colouring matter, for which it appears to have but a slight affinity. Mr. Hume has not made many experiments upon this substance, but thinks that one ounce of jalap will, on careful treatment, afford about five grains of the substance.—Med. Jour, li. 346. 25. MM. Liebeg and Gay Lussac on Fulminic Acid and Fulminates. An abstract was given in the last number of this journal, (p. 153..0f a paper by Dr. Liebeg on fulminating silver, mercury, &c., in w.rich the author proved that they were saline compounds containing a peculiar acid, which he called the fulminic acid, and the compounds of this acid with bases he called fulminates ; shewing at the same time that they all possessed similar properties to the compounds of silver and mercury. Since the researches referred to, Dr, Liebeg has been joined by M. Gay Lussac in further investigations on this subject, and the remarkable result has been obtained that cyanic acid is the true acid existing in these compounds. The paper containing these ulti- mate investigations is published in the Annales de Chimie, xxv. 285. and contains admirable examples of chemical reasoning and mani- pulation ; but we cannot do more at present than give a very brief account of if. ‘ The compound principally experimented on was that of silver ; the fulminate of silver from its insolubility being more readily obtained perfectly pure than any other. It was prepared by putting 6.5 Chemical Science. 387 grains of nitric acid,” s.g. 1.56 or 1.38 into a pint matrass, and a piece of coin, containing nearly 35 grains of pure silver. The re- sulting solution was poured into about 927 grains of strong alcohol, and heated until it boiled; on the appearance of turbidness it was removed from the fire, and an equal quantity of alcohol added by degrees to cool the solution and moderate the ebullition. When cold, the whole was filtered, and the precipitate washed with pure water until no longer acid. It is then perfectly pure, and white as snow. The filter was put on a plate which was placed on a saucepan half filled with water, and heated to 212°, for two or three hours, that it might be perfectly dry ; its weight was generally equal to that of the silver employed, Tulminate of silver will not detonate alone at 212° F, or even at 266° F. but a slight blow between two hard bodies, even under water, will explode it : hence wooden stirrers and paper spoons should be used in experiments made with it. When mixed with 40 times its weight of per-oxide of copper it may be rubbed in a porcelain capsule with the finger, or a cork, and does not then detonate by heat. This mode of analysis was therefore adopted to ascertain the proportion of carbon and nitrogen in the salt, or rather in the acid. ‘The gaseous mixture obtained by heat con- tained exactly 2 volumes of carbonic acid, and 1 volume of nitrogen: hence, these elements are in the same proportion as in cyanogen. Fulminate of silver contains two proportions of oxide, one belong- ing apparently to the acid, and the other, serving as base: Muriatic acid ; entirely decomposes the fulminate, giving a chloride equivalent to the oxide contained in the metal; operating in this way, 100 of the compound gave as a mean result, 77.528 of oxide of silver, or Silver . . 72.187 Oxygen . 5,341 It is assumed that the silver is all in the state of oxide, a supposition supported by alithe results. Muriate of potash precipitates only the silyer serving as base, and does not affect that of the fulminic acid ; and operating with it instead of muriatic acid, 100 of the compound gave a quantity of chloride equivalent to 38.105 of oxide of silver; and the solution remaining, which contained the fulminic acid united to potash, when decomposed by muriatic acid yielded chloride equivalent to 38.359 oxide of silver. Oe it may be concluded that the fulminate of silver contains twice as much oxide of silver as will saturate fulminic acid. When the compound was decomposed by oxide of copper and heat, a process which was conducted with the utmost attention and accu- racy, 100 of fulminate of silver gave a mean of carbon and nitrogen, equivalent to 17.16 of cyanogen; small quantities of water were obtained, but they were irregular, and never amounted to any thing like a proportional of hydrogen in the compound. Other proofs 388 Miscellaneous Intelligence. were also obtained during the investigation of the absence of hy- drogen, Thus far, then, the elements obtained from the fulminate of silver were: Silver het sive) \TREST Oxygen. . 5,341 Cyanogen . . 17.160 Feossv 3.) h sly ithe 2942 100.000 The loss is very nearly equal to the quantity of oxygen combined with the silver, it could not be hydrogen or water, neither of which could have escaped the search made by the experimentalists, it could only therefore be oxygen contained in the fulminic acid, a supposi- tion ultimately confirmed. Fulminate of silver, therefore, contains 2 atoms of silver, 2 atoms of oxygen combined with the silver, 2 atoms of oxygen combined with the elements of fulminic acid, 2 atoms nitrogen, 2 atoms of cyanogen, = j el cde eacialanen It was desirable, if possible, to ascertain the products of the de- tonation of this substance, but after some trials the danger made it necessary to desist. Endeavours were then made to decompose it by heat, when previously mixed with substances that could not furnish oxygen. Glass in impalpable powder always exploded it, but chloride of potassium and sulphate of potash fused and finely pul- verized could be mixed with it by the finger or 2 cork without pro- ducing explosion. The chloride of potassium gave inconvenient and uncertain results, in consequence of its partial decomposition by the silver, and the production of carbonate of potash, as well also as of carbonate of ammonia. When the sulphate of potash was used, the gaseous and other results furnished by heating the fulminate were first collected, examined, and ascertained, and then the residue in the tube was mixed with oxide of copper, and heated for the decom- position of the substance operated en. A quantity of nitric acid was produced in the latter part of the operation, and at times also car= bonate of ammonia in minute quantity; in the latter case no water could be perceived, and it appeared that the formation of one of these compounds excluded that of the other; for it was found by direct experiment that when the fulminate was first slightly moistened much carbonate of ammonia was formed: thus then a new proof was obtained of the absence of hydrogen from the compound, for the quantity of carbonate of ammonia was so small, it could not have resulted from any proportional quantity of hydrogen in union Chemical Science. 389 with the other elements, but only from a minute trace of water in- troduced with the materials operated upon. From further experiments of this kind it was concluded, that when fulminate of silver mixed with sulphate of potash was decom- posed by heat, only half its carbon became carbonic acid, and only that proportion of nitrogen was set free which with the carbon would form cyanogen, so that the silver was left in a state of asubcyanuret. If the elements thus analytically obtained are correct, the follow- ing will be the equivalent number of fulminic acid: 1 atom oxide of silver . » 145.161 2 — cyanogen ‘ ‘ 65.584 2 — oxygen. : . . 20.000 230.745 and on experiment it was found that 3.833 of fulminate of baryta decomposed by muriatic acid gave 1.585 of chloride of barium, which by calculation would give 228.873 as the number of fulminic acid, a result sufficiently in accordance with the former to justify the calculated number. The authors then consider the probable nature of fulminic acid. That the metal should be an essential principle can hardly be ima- gined, inasmuch as one metal may be replaced by another; thus a fulminate may be obtained with zinc only, analogous to that of silver : are not therefore the various fulminic acids formed by the different metals super salts, of which the acid really contains no metal but only cyanogen and oxygen ? As fulminates may be obtained with oxides which lose their oxygen with difficulty, oxide of zinc for instance, as well as with silver or mercury, it is evident they must all include one common principle of fulmination independent of the bases, and which can only be acompound of oxygen and cyanogen, or of oxygen, car- bon, and nitrogen. Again, if the fulminates be compared to neu- tral tartrates, and the various fulminic acids to bitartrate, a perfect avalogy will be found; thus neutral tartrates of zinc, copper, silver, or mercury, are only half decomposed by potash, just like the fulminates of the same bases: all the fuliminic acids form double salts with bases like the bitartrates: fulminic acid with a base of silver is, in consequence of its insolubility, precipitated by acids like cream of tartar : and there are many fulminates, as well as neu- tral tartrates, in which acids produce no precipitates, because the corresponding acid fulminates, or tartrates, are soluble; such are the fulminates and tartrates of zinc and copper. Hence it appears to the authors extremely probable, if not certain, that the various fulminates form a particular class of salts, all containing the same acid composed of an atom of cyanogen and an atom of oxygen only, and which is without doubt the cyani¢ acid, The neutral fulminates 390 Miscellaneous Intelligence. are cyanates, and the various fulminic acids bi-cyanates, and the equivalent number of cyanic acid will be 42.792, oxygen being 10. All attempts to separate the acid from the fulminates failed. Mu- riatic acid, hydriodic acid, and sulphuretted hydrogen, decompose the fulminate of silver even at common temperatures, giving rise to some particular results, which are described at considerable length in the Memoire. For the preparation of alkaline fulminates, it is recommended that the chlorides should be used: thus, to obtain the double fulminate of silver and potash decompose the fulminate of silver by solution of chloride of potassium, being careful to add no more of the chlo- ride than is sufficient to precipitate half the silver, or even a smaller quantity; for the undecomposed fulminate of silver being scarcely soluble, will remain with the chloride of silver, and the solution will contain the pure double fulminate of silver and potash. Cau- tions are again enforced at the end of this paper on the care required in working with these substances. 26. Supposed new Metal, Taschium.—A description of a new metal, with an accompanying specimen, has been sent to the Presi- dent of the Royal Society. The metal has received the name of Taschium, from the mine of Taschio, in which it was found. The specimen sent was said to be silver containing the new metal, the two metals having been separated by amalgamation, and the mer- cury afterwards driven off. On dissolving the button in pure nitric acid, it was stated that the Taschium would remain as a black powder. The Taschium was described as being combustible, with a bluish flame, a peculiar smell, and dissipation of the products. Amal- gamating with mercury, and in that way being separated from its ores. Not soluble in any single acid, but soluble in nitro-muriatic acid. If previously boiled with potash, then soluble in muriatic acid, the solution being precipitated by water. Its solution giving, with prussiate of potash, a blue precipitate brighter even than that with solution of iron, but not precipitating with tincture of galls. The button was therefore dissolved in nitric acid, which left a blackish powder in small quantity, and also some grains of siliceous sand. The powder was well washed, and then being heated on pla- tina foil in the flame of a spirit lamp, did not burn or volatilize, but became of a deep redcolour. Muriatic acid being added to another portion of the washed powder, and a gentle heat applied, dissolved by far the greater part of it, forming a red solution, which being evaporated till the excess of acid was driven off, and then tested, gave blue precipitate with prussiate of potash; black with tincture of galls; and reddish-brown with ammonia. On evapo- rating to dryness, it left muriate of iron. Nitro-muriatic acid being made to act on the minute portion of powder yet remaining, dis- Chemical Science. 391 solved very nearly the whole of it, leaving a small trace of silica, and producing a solution similar to the former. Hence the Taschium in this button of silver was nothing else than iron; and from the ‘presence of silicious sand it may be supposed to have been intro- duced into the button through the inaccuracy of the preparatory manipulations.—M. F. 27. Liquefaction of Sulphurous Acid.—In the Annales de Chimie et Physique for May last, M. Bussy is stated to have obtained the above acid liquid, and free from water, by causing it to pass in its gaseous state through a tube containing fused chloride of calcium, and after- wards into a flask surrounded by a mixture of ice and salt, where it completely liquifies, and remains in a liquid state under atmospheric pressure at the temperature of 0°. Itis a colourless, transparent, and very volatile liquid, of a specific gravity ='1.45. It boils at about 10° centigrade below 0 = 14° Fahrenheit, but in consequence of the cold produced by the evaporation of the portion which is volatilized the residue remains liquid, being reduced to a temperature much below its boiling point. It occasions intense cold, and rapidly eva~ porates when dropped upon the hand, Poured into water at com=- mon temperatures one portion is dissolved and another volatilized ; but as the solution approaches to saturation, the acid collects in drops at the bottom of the vessel, like an oil heavier than water. If in this state it be touched by the extremity of a glass tube, it passes into vapour, occasioning ebullition, and ice forms upon the surface of the water. The bulb of a thermometer enveloped in cotton, and dipped into the liquid acid, falls spontaneously, when exposed to the air, to — 57°. (= — 70° Fahr.) The atmosphere being at 50° F. In the vacuum ofthe air-pump a cold of —68° (=—90° F.) is thus easily obtained*. Mercury therefore is easily frozen by the aid of this acid, simply by dipping the bulb of a mercurial thermometer sur- rounded with cotton into it, and agitating the air with it. The ex- periment succeeds better when a little mercury is put into a cup with a small quantity of sulphurous acid upon it, and the whole put under the exhausted receiver. By the evaporation of the acid in vacuo, M. Bussy has frozen alcohol of a strength below 33° (of a specific gravity below .852 at 55°). By passing chlorine and am~- monia through tubes cooled by the evaporation of sulphurous acid, M. B. liquefied those gases; and by a similar method cyanogen was obtained in the form of a crystallized solid. * M. Bussy says these low temperatures can only be accurately measured by an air thermometer. 392 © III. Narurat History. 1. On the different Manners in which Bodies act on the Organs of Taste, by M. Chevreul.—Persuaded as I am that many phenomena appear complicated to us only because they are the results of many causes acting simultaneously, I have adopted as a principle, when I examine phenomena of this kind, to endeavour to separate the dif- ferent causes which may operate so as to refer to each the effects de- pendant on it. Viewing from this point the varied sensations which we perceive when substances are introduced into the mouth, I have arrived at a satisfactory analysis of these sensations in recognising those which are perceived ; Ist. By the touch of the tongue; 2d, by the taste; 3d, by the smell. It is generally known that we can perceive these three orders of modifications by the introduction of substances into the mouth; but since no physiologist that I have consulted has indicated the means of recognising the special modi- fications belonging to the senses of touch, taste, and smell, I have determined to publish the following results, which make part of my general considerations on immediate organic analysis, and on the application of this branch of chemistry to the history of orgunized beings. It is not possible to separate the action which a substance intro- duced into the mouth exerts on the touch from that exerted by it on the taste, but it is easy to distinguish the effects produced on each of these senses; for that purpose one must first appreciate the effect produced by the substance on the organ of touch by applying it to some other part of the body than the tongue, and then this effect may mentally be abstracted from that produced when the substance is put into the mouth, and by this means the effect produced on the taste will be obtained, except that as the tongue is more sensible than the skin, the sensation of touch on the tongue will be stronger than that on the skin elsewhere. For instance, if a little powdered chloride of lime be pressed upon the skin the water of transpiration will be solidified by the compound, and a sensation of heat expe- rienced, | If, on the contrary, crystallized muriate of lime in pow- der be used, it will liquefy, and a cold sensation be felt. It is evi- dent therefore that chloride of lime put into the mouth will produce heat, whilst the muriate of lime will produce cold, and that these effects will be more marked than on the surface of the body, since the tongue is more sensible and more humid than the skin. The substances which fusing or evaporating on the surface of the body produce cold, will also produce the same effects in the mouth if they fuse or evaporate there. But how are the sensations of smell to be separated from those of the touch and taste? Very simply; pressing the two nostrils one against the other is sufficient to prevent all sensation of smell, because Natural History. 393 then the air, which becomes more or less charged with the odorous particles which a sapid and odoriferous substance in the mouth has emitted not being able to pass by the nose, cannot any longer carry those particles to the membrane which occasion the sensation of smell. When therefore the nostrils are pressed together, no other sensations are perceived than the taste and the touch of the tongue. One can hardly form an idea of the extreme difference which exists between the sensations produced by a sapid and odorous substance in the mouth according as the passage of the air expired by the nose is open or interrupted. I have ultimately established four classes of bodies relative to the sensations which they excite when put into the mouth, amongst which I do not include those caustic substances which attack and alter the organs. Ist Class. Bodies which act on the tongue only by touch.—Rock- crystal, sapphire, and ice. 2d Class. Bodies which act by »y touch on the tongue and by smell.— The odorous.metals: when tin is put into the mouth the odour of that metal is perceived; but on pressing the nostrils all sensation, ex- cept that of touch only, entirely disappears, 3d Class. Bodies which act by touch on the tongue and by tasteom— Such bodies as these are sugar, salt, &c. When these substances are put into the mouth the sensations they cause are not modified by pressing the nostrils together. Ath Class. Bodies which act by touch on the tongue, and by taste and smell, Examples 1. Volatile Oils.—They are generally acrid, but with a particular odour for each sort of oil. When put into the mouth, and the nostrils are pressed, the acrid gemsation: is always sensible, whilst that of smell vanishes entirely. 2. Lozenges of Pep- permint, Chocolate, &c.—When the nostrils are saa “after these have been introduced into the mouth, nothing is perceived but the savour of the sugar ; but if the nostrils be relieved, the odour of the peppermint or the chocolate becomes evident. It will not be useless to remark that the urinous taste attributed to fixed alkaline bases, does not belong to these substances, but to the ammonia, which is set at liberty by their action on the ammoniacal salts contained in the saliva. ‘The proofs of this are the disappear- ance of the sensation referred to, when the nostrils are pressed, and the perception of the same sensation when one smells to a mixture of recent saliva and alkali, made in a small glass or porcelain capsule. | It appears that the sense of smell weakens by age, before that of taste.—Mem. du Mus. x. 439, 2. Action of Meconic Acid on the Animal Economy.—Doubts hav- ing arisen with regard to the effects produced by pure meconic acid and the meconiates on the animal system, i Signori Fenoglio, Cesare, 394 Miscellaneous Intelligence. and Blengini, of Turin, prepared some of these substances very care= fully, and administered them in cases where the results could be accurately observed. It was found that eight grains of any of these substances produced no deleterious effects on dogs, crows, or frogs ; nor on a horse even when the dose was repeated. ‘The meconiates were also administered to two persons in cases of teenia, in doses of four grains, but without producing any effect either on the persons or the worms. These results agree with those obtained by MM. Suertuerner and Semmering : and in those cases where death was produced by doses of a grain of meconic acid, Dr. Fenoglio attributes the results to the defective preparation of the substance, and the pre- sence of morphia in it; and the symptoms observed seem to accord with this opinion. 3. On the different masses of Iron which have been found on the Eastern Cordbiliera of the Andes. By MM. de Rivero and Boussin- gault.—On arriving at Santa Rosa, a village situated on the road from Pamplona to Bogota, we learnt that a mine of iron had been discovered in the neighbourhood, and that a fragment of the mineral served for an anvil to a farrier (or blacksmith) ; but we were agree- ably surprised when we saw that this supposed mineral was a mass of iron full of cavities, of an irregular form, and presenting all the characters of meteoric iron. This mass was found on the hill of Tocavita, about a quarter of a league to the east of the village in 1810. We went to the place, and saw the hole from whence the mass had been removed, for it was almost entirely under-ground, a point of a few inches only appearing at the surface. The hill of Tocavita, like that of Santa Rosa, belongs to the secondary sandstone formation, and which we have observed for a considerable extent. Santa Rosa is about twenty leagues N.E. of Bogota, lat. 5° 40’, long. 75° 40’ west of Paris, and 2744 metres (9003 feet) above the sea. The people of the village collected together to remove the mass of iron: it remained eight years at the town-hall, and afterwards for seven years did service in the blacksmith’s shop. The iron was cellular, but no vitreous coat could be perceived on ite It was malleable, of a granular structure, easily gave way to the file, was ofa silvery aspect, and its specific gravity 7.3. The volume of the mass was 102 cubic decimetres (3.6 cubical feet), its weight therefore must be nearly 750 kilogrammes (1655 Ibs.) It is worthy of observation, that at the same time that this mass was discovered, a number of smaller fragments were found on dif ferent parts of the same hill. During the short time which we re= mained in the place, we collected several specimens. To demonstrate the identity of these masses with those which various travellers have described, some chemical examinations were undertaken, The usual Natural History. 395 process of analyses is'then described. A portion of the large mass yielded ‘ Oxide ofiron . 1.17 1 ee 91.41 Oxide of nickel 0.15 ” Nickel . 8.59 100.00 Some of the other fragments were then examined. ‘* We com- menced with a mass weighing 681 grammes (10,517 gr.) discovered in 1810, near Santa Rosa. It was malleable, but difficult to file. Its’ lustre was silvery ; its grain fine like that of steel; it forged very well but was red short ; its specific gravity 7.6 ; it gave, Oxide of iron , 9.46 Tron 91.23 Oxide of nickel 0.75 or Nickel 8.21 Insoluble in nitric acid 0.02 Residuum 0.28 99.72 The insoluble portion was difficultly acted upon by hot nitro-muri- atic acid ; it appeared to be a compound of nickel, iron, and perhaps a little chromium. Another fragment of 561 gram. (8664 gr.) found at the same time near Santa Rosa, was cellular, very hard to the file, but malleable, of a silvery aspect, and a fracture resembling that of tilted cast-steel ; it gave, Oxide ofiron . 2.62 Tron 91.76 Oxide of nickel . 0.16 “ Nickel 6.36 98. 12 We have also ascertained the presence of nickel in a Bred num- ber of other fragments, collected at the same time near Santa Rosa, the weight of the largest being 145 grammes (2229 grs.) But itis not there only that metallic iron has been found ; it has also been discovered at a village called Rasgata, i in the neighbourhood of the salt-works of Zipaguira, lat, 4° 57’, long. 76° 33° west of Paris, and 2650 metres (8694 feet) above the need of the sea. We saw one mass in the hands of M. Geronimo Torres weighing 41 kilogrammes ( Ibs.) We could perceive no cavity in it ; its texture exhibited small facets; it was very hard to the file, was malleable, of a silvery lustre, and a specific gravity of 7.6 ; it gave, Oxideofiron . 5,23 «ss Iron. 90.76 Oxide of nickel . 0.40 Nickel . 7.87 98.63 Another mass weighing 22 kilogrammes (90.5 lbs.), which was, shewn us at the same place, was nearly spherical, and contained many cavities. It was very malleable, and its fracture had a silvery lustre. We found from seven to eight per cent. of nickel in itx—dnn. de Chim, xxv. 438, 4, Natural Ice Caves.—1n a memoir on some natural ice caves, read 396 Miscellaneous Intelligence. by Professor Pictet, to the Helvetic Society, in 1822, the author had- advanced the singular fact, attested by the neighbouring inhabitants, that the ice forms more in summer than in winter, and conceived that this effect might be due to two concomitant causes ; descending cur- rents of air, and the cold produced by evaporation. {It was desirable that this fact should be confirmed by observation made in the winter ; a season, however, when the fall of snow pre-~ vented ascents to any great height. One of these natural ice caves visited by Professor Pictet, is situated near the crest of the Mont Vergy, in Faucigny ; itis called from the name of the neighbouring chalet, Montarguis. ‘Two countrymen of the village of Sionzier, near the road to this ice-cave, had the curiosity and perseverance to make three visits to this place during the last autumn and winter, and have drawn up a short notice, which has been read to the Geneva Society. It is as follows : “© The 22d Oct. we ascended to the ice-cave of Montarguis with some little trouble, because of the first snow, and we found very little ice in columns ; it had begun to melt. ‘* The 26th November we re-ascended to the before-mentioned ice-cave. There we found very little ice at the bottom of the cave, out of which came a sort of warmth. ** The 25th Dec. we re-ascended to the above-mentioned cave with much difficulty and trouble, and were almost carried away by an avalanche. This circumstance discouraged us, but recovering from our fear we ascended. There we found a moderate warmth in the cave, and noice; instead of which where there is ice in summer, there was actually water: therefore in winter it is warm in this ca- vern, and in summer it is cold. The roof appears cavernous ; it appears as if there were chimneys.”’ The fact, therefore, seems well ascertained, and the editor of the Bibliothéque Universelle observes, that the concluding remark comes in support of the explanation given by Professor Pictet, depending on descending currents of air, cooled by evaporation, whilst traversing considerable strata of stones constantly moist. ‘This effect can only take place in summer, for in winter the current of air would be ascending from the superior warmth of the interior to the exterior. The descending current of cold air was observed during the last summer by M. Gampert, who visited this cave, and penetrated to its extremity ; there he discovered a crevice, or aperture, by which water descended and flowed over the ice, and also a very rapid cur- rent of very cold air.—Bzb,. Univ. xxv. 243. 5. Glacier of Getros, Valley of Bagne.—The glacier of Getros, in the valley of Bagne, has‘been noticed at different times in this journal*, and the ingenious and successful means adopted by M. Venetz for its * See Vols. v. p. 372. vi. 166. xv. 396. Natural History.. 397 destruction described. This means had, at the end of the summer of 1822, reduced the glacier, which originally covered the river for a length of 1350 feet, to an extent of 498 feet only. The cold-winter of 1822-3 and the following spring, increased the glacier to 924 feet, and this new part was excessively rugged and dangerous to work upon, and continually exposed to masses falling from the upper glacier. It was requisite, however, that this should be first destroyed, which was done atthe risk of many serious accidents by currents of water as before, during the summer of 1823, and such advantage taken of the rest of that cold short summer as to diminish the whole glacier to 252 feet only. Thus, notwithstanding the accessions which it must have teceived during the last winter, there is little doubt but that it will be entirely removed during the present sum mer, and then the course of the river being open, it will generally remove all the avalanches that may fall at any future period ; or if a disastrous year like that of 1816 gives rise to the formation of a new glacier, the means for its removal are known, and may be practised before the formation of another lake can again destroy the country. Vor. 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L j---+ Aupung CO - - Aepsany, S16 19 ‘ps son J, g - + kvpanes fox - SS, |S ~~ Sepuopy ~ + = ACPA 5 a os |e | --- Avpung & |-- Avpsanys, oD - 6z | & | -- Avpanaeg £ |~ Aepyeapoyy - Se |e |+-- -Avpry t j-- + sepsany, s GSz |r |-- Avpsanyy 1 j-- Aepuojy “uso ysipy | MOT *aary | cusory | roarg | suaoyy| UStET | A077 saa | Uso | UAH | MOT *pulAat saajyamloswg 5 Ss “putas ssoja uLoaugy Be a “PULA s1aj}am0AEg A id . ‘ — Y . ‘ FZst Any 107 FESL udy 10,7 FEST “Yo? Loo [pear oy WO Joo] B pur ‘punozds oY) woy yoo} oay ynoge “oodsy wo;sva-YWON & Ul SSuLy o}EWOULOY, UL ‘arrysuojduiey}io yy ut ‘diowpy ye yeeg SWHONTaG TUVY ev Woy “pegy ‘Aeyy pue pudy ‘yore INDEX. Acetate of lime, phosphorescence of, 163. Of morphia, how detected in cases of poisoning, 168—170. Of copper, 383—383 Acids, succinic and benzoic, facts relative to the history of, 141. Preparation of sulphurous acid gas, 163, 164. Acid tartaro- ‘sulphate of potash, 171. Conversion of Gallic acid into ulmin, 174. Analysis of sodous acid, 381, 382. Liquefaction of sulphureous acid, 391. Action of the meconic acid on the animal economy, 393, 394 Algol, table of the recurrence of the smallest light of, 184, 185 Analyses of scientific books, 105—130, 335—359. Of cafeine, 174. Of sodous acid, 381, 382 Arfwedson, (M.) his mode of procuring the pure oxide of uranium, 382. And uranium pyrophori, 383 Arsenic, detection of, in cases of poisoning, 165 Astronomical and Nautical Collections, 85—104, 295—334 ; Astronomical Phenomena, for April, May, and June, 1824, 77—84 ‘And for July, August, and September, 238—244, Atmosphere, a finite and exact expression for the refraction of one, nearly resembling that of the earth, 255, 2.56 Atomic Weights, table of, 383 Badnall, (Mr.) improvement of, in dyeing with Prussian blue, 167 Bakewell, (Mr.) theory of, to account for the production of sound by opening a subterraneous gallery, 152. Table of vegetation at different heights, 176 Barlow, (Peter, Esq.) experiments and observations by, on the daily variation of the horizontal and dipping necdles, under a reduced directive power, 128 ' Barometer, horary oscillations of, 189—197, Remarks on the ba- tometer, 345—347. On the formation of mercurial vapourin, 380 Becquerel, (M.) account of the electrical effects produced at the moment of the combination of the metals and alkalis, with the acids, 136—138. Observations of, on the electro-motive actions produced by the contact of metals with liquids, 374, 375. His test of the alteration of solutions by contact with air, 379 Bell (Charles, sq.) on the motions of the eye, in illustration of the uses of the muscles and nerves of the orbit, 123, 124, 127 Berthier, (M.) on the preparation of sulphuretted hydrogen, 164. Of the saturated hydro-sulphuret of potash or soda, 165. And of the pure oxide of nickel, 166. Berzelius (Professor) letter ae 274 400 INDEX. Bevan, (Mr.) experiments by, on the adhesion of nails, in different kinds of wood, 360 Blainville (M.) sur les Ichthyolites, analysis of, with strictures on his errors and the imperfections of his work, 105—121 Blowpipe, self-acting, described, 236, 237 Boussingault and Rivero, (MM.) Memoir of, on the milk of the Cow tree, 142. On the hot springs of the Cordilleras, 143 Brande, (W. T., Esq.) prospectus of his course of lectures on elec- tricity, 282—284. And on vegetable chemistry, 288—289 Brard, (M.) on the action of frost on building materials, 148, 149 Brinkley (Dr.) remarks on the parallax of a Lyree, 264, 265 Brisbane, (Sir Thomas) account of experiments made by, with an invariable pendulum, at New South Wales, 128 British Channel, observations on the soundings in, 245—247 Cafeine, composition of, 173, 174 Caoutchouc, observations on the preparation of, 364 Capillary Action of fissures, §c., remarks on, 151, 152 Carrara Marble, natural changes in, 178 Chalk, observations on the burning of, 361—363 Chalybeate Water, artificial, notice of, 386 Cheltenham Water, existence of nitrate, and a salt of potash, dis=- covered in, 178, 179 Chemical Science, intelligence in, 153—175, 369—386 Chevreul, (M.) observations of, on the action of bodies on the organs of taste, 392, 393 Chili, account of the earthquake in, in Noy., 1822, 38—46 Chiswick, account of an overflowing well at, 70—74 Christie, (Samuel Hunter, Esq.) observations on the diurnal varia- tions of the horizontal needle, when under the influence of magnets, 128, 129. And on the effects of temperature on the intensity of magnetic forces, 279 Chronometers, influence of magnetism on, 197—202, 365—367 Climate of London, meteorological remarks on, 340—345 Coal Strata, products of the combustion of certain, 180 Coindet, (C. W.) account by, of the injection of a solution of opium into the veins of an hysterical patient, 145, 146 Collyer, (Charles, Esq.) observations by, on univalves, 272, 273 Comets, remarks on the catalogue of the orbits of, that have hitherto been computed, 85—96. Remarks on the periodical comet (86 Olb.) 96—99. Elements of the comet of 1823,4, by various computers, 104 Conchology, observations on the present state of, 29, 30 Condensation of Gases, experiments on, 123, 124, 125. Conductors (fluid), on the motions produced in, when transmitting the electric current, 256—259 Cooper (Mr.) analysis by, of the ancient ruby-glass, 165. Descrip- tion of his lamp-furnace for the analysis of organic bodies, 232 INDEX. 401 Copper, experiments on the acetates of, 383—385 _ _Copper-sheathing of ships, how prevented from corrosion, 253 9 Cordilleras, on the hot-springs of, 143. Account of the different masses of iron which have been found n the eastern Cordillera of the Andes, 394, 395 ; Cow-Tree, memoir on the milk of, 142, 143 Crotch (Dr.) syllabus of his course of lectures on music, 287 Croup, sulphate of copper an excellent remedy in, 181 Crystal, unequal dilation of, in different directions, 157. Differ- ence of crystalline forms of the same substance, zhid., 158 Crystallization, supposed effect of magnetism on, 158. Of the sub-carbonate of potash, 167 Dahline, discovery of, in the Jerusalem artichoke, 385 Daniell (J. F., Esq.) observations and experiments on evapora- tion, 46—61. On the horary oscillations of the barometer, 189. Review of his Metereological Essays and Observations, 335 Davy (Sir Humphrey) on a new phenomenon of electro-magnetism, 122, On the application of liquids, formed by the condensa~- tion of gases, as mechanical agents, 125, 126.. On the mode of preventing the corrosion of copper-sheeting by sea-water, in ships, 253—279—280 Davy (Dr. John) on air found in the pleura, in a case of pneu- mato-thorax, 130, 263 Debret (M.) experiments of, on the comparative advantage of cok and wood, as fuel, 361 Dew, observations on some phenomena relating to the formation of, on metallic surfaces, 1—12 Dillwyn (L. W.) observation of, on fossil shells, 129, 267 Dipping-needle, general results of, 104, Experiments and ob- servations on the daily variation of the horizontal and dipping- needles, under a reduced directive power, 128, 129. Dobereiner (M.) on the capillary action of fissures, 151, 152. No- tice of his instantaneous light apparatus, 378, 379 Dulong and Thenard (MM.) Experiments on the property which some metals possess, of facilitating the combination of elastic fluids, 132, 133 Earthquake in Chili, account of, 383—46 Electrical Machines, variation in the construction of, 161. Account of an electrical arrangement, produced with different charcoals and one conducting fluid, 174, 175. Electricity, connexion of phosphorescence with, 163. Electricity, on the separation of parts, 162. Electric light, 162. Observa- tions on a reciprocity of insulating and conducting action, which the incandescent platina of Davy exerts on the two electricities, 369—372. Measurement of the conductibility of bodies for electricity, 376. Destruction of positive and negative electricity, 377. Electricity produced by congelation of water, ibid, On 402 INDEX. the magnetic action of strong electrical currents on different bodies, 372, 373. . Electro-Magnetism, on a new phenomenon of, 122. Electrical effects produced at the moment of the combination of the metals and alkalis, with the acids, 136—138. On electro-magnetic multipliers, 161. On electro-motive actions produced by the contact of metals and liquids, 374. Electrometer of Dr. Hare, notice of, 377. Encke (Professor) on the periodical comet (86 Olb.) 96 Erman (M.) experiments and observations of, on a reciprocity of in- » sulating and conducting action, which the incandescent platina of Davy exerts on the two electricities, 369—372, Evans (Col.) experiments of, on the action of sulphur on iron, 165 Evaporation, observations and experiments on, 46—61 Lye, on the motions of, in illustration of the uses of the muscles and nerves of the orbit, 123, 124, 127. Observations on the appa- rent direction of the eyes in a portrait, 264—276 “a Fallows (Rev. F.) an easy method by, of comparing the time indi- cated by any number of chronometers with the given time at a certain station, 315, 316 Faraday (M.) experiments on fluid chlorine, 123. And on the condensation of several gases into liquids, 124, 125. On the ex- istence of a nitrate and a salt of potash in Cheltenham waters, 178 Ferrari (M.) process of, for obtaining strychnia, 170, On the volatility of salts of strychnia, abed., 171 Fiedler and Hagen (MM.) observations of, on sand-drigs or fulgo- rites, 181—183 Fish, Chinese mode of hatching, 176 Fishes, observations on the possibility of changing the residence of certain, from salt water to fresh, 209—-231]. On the generation of fishes, 277 Fissures, on the capillary action of, 151, 152 Fossil Shells, observation on, 129, 267 Frost, test for the action of, on building materials, 148, 149 Frost (Mr.) syllabus of his course of lectures on botany, 284, 285 Fuel, comparative advantage of coke and wood for, 361 Fulminating silver and mercury, results of experiments on, 153— 157 Fulminic Acid and fulminates, experiments on and analysis of, 386 Gases, experiments on the condensation of, 123, 124, 125. On the application of liquids, formed by such condensation, as mecha- nical agents, 125. The odour of hydrogen gas extraneous, 380 Geneva, expense of the iron-wire suspension bridge at, 148. . Its durability, 147 Getres, notice of the remoyal of the glacier of, 396, 397 Goring (Dr.) On indistinctness of vision, caused by the presence of false lights in optical instruments, and remedies for it, 1728, INDEX. 403. * 202—209. On the adaptation of a compound microscope, to act . as a dyrameter for telescopes, 367—369 Griffiths (Mr. T.) account of an electrical arrangement produced _ with the different charcoals and one conducting fluid, 174, 175 — Groombridge (Mr.) comparison by, of the new tables of refraction with observation, 100—103 Guiana, the common, observations on, 255 Hall (Capt. Basil) results of experiments made by, with an invari- able pendulum, 126 Hancock (Mr.) process of, for preparing caoutchouc, 364 Hare (Dr.) account of his single gold leaf electrometer, 378. And of his voltaic trough, 2bid. On the preparation of artificial cha- lybeate water, 380. On the combustion of iron by sulphur, 381 Harvey (George, Esq.) observations on some phenomena, relating to the formation of dew on metallic surfaces, 1\—12. On the influ- ence of magnetism on chronometers, 179—202, 365—367. Ex- _ perimental inquiries by, relative to the distribution and changes of the magnetic intensity in ships of war, 261, 262. Harwood (Dr.) syllabus of his lectures on zoology, 286 Hatching of fish, Chinese method of, 178 Hayotte, advancement of the ground in the village of, 180, 181 Henry (Dr.) remarks on the review of his Elements of Chemistry, in this journal, 131—134. On the action of finely-divided platinum on gaseous mixtures, and its application to, 277, 278 Herschel (J. F.) analysis of the Bakerian lecture by, 256—259 Herschel (J. F.) and South (James) observations by, on the apparent distances and positions of certain double stars, 250—253 ; Hill (Mr. P.) particulars by, relating to the ornithorhynchus paras doxus, 247—250 Home (Sir Everard,) facts by, relative to the natural history of the walrus and seal, 262, 263. Account of the organs of gene+ ration of the Mexican Proteus in a developed state, 278, 279 Hume (Mr.,) notice of his discovery of anew vegeto-ralkaline base, in Jalap, 386 Hydrogen Gas, odour of, extraneous, 380 Hydrogen, (sulphuretted,) preparation of, 164. Inflammation of, by nitrie acid, 379 Hydro-sulphuret of potash, preparation of, 165 Hysterical Patient, eflect of the injection of a solution of opium into the veins of, 145, 146 Ice-caves, natural, account of, 396 Immobility, a disease of horses, cause of, 145 Insects, solution for destroying, 146 Intermittents, prussiate of iron a remedy for, 145 Todine discovered in mineral waters, 180 Tron; action of sulphur on, 165. Experiments and observations on the developement of magnetical propertics in, by percussion, 404 INDEX. 254, 255. Combustion of, by sulphur, 381. Ammonia found in the oxides of iron, ibid. On the different masses of iron found in the eastern Cordillera of the Andes, 394, 395 Tron-wire suspension bridges, remarks on, 147, Expense of the bridge at Geneva, 148 Irritability of plants, 176 Jalap, a new vegetable principle discovered in, 38600 Just (Dr.) results of the experiments of, on fulminating silver and mercury, 153—157 Kermes mineral, preparation of, 165 Lamp-furnace for the analysis of organic bodies, 232—235 Lampyrides, inquiry into the nature of the luminous power of some, 269, 270 Larva, account of an undescribed species of, 176—178 Lassigne (M.) experiments of, on the oxides of nickel, 140. On the detection of the acetate of morphia, in poisoning, 168—170 Latitude, easy approximation to the difference of, on a spheroid, 316, 317 Lecanu and Serbal, (MM.), on the preparation of oxide of uranium, 139. Collection of facts by, on the history of the succiniic and benzoic acids, 14] v Leeson (Mr. H. B.), description of a self-acting blow-pipe, 236 Leghorn straw-plat, premiums for, 153 Leyden Jar, improvement in the construction of, 162 Liebeg (Dr.) experiments of, on fulminating silver and mercury, 153—157 ; and on fulminic acid and fulminates, 386—390 Limestone, experiments on the burning of, 361—363 London, observations on the climate of, 340—345. Table of the level in, above the highest water mark, 361 Longitude of Madeira and Falmouth determined, 270, 271 Mac Culloch (Dr.,) hints by, on the possibility of changing the re- sidence of certain fishes from salt-water to fresh, 209—231 Magendie (M.) on some recent discoveries relative to the nervous system, 143, 144, Magnetism, on the apparent, of metallic titanium, 129. Supposed effect of magnetism on crystallization, 158. On thermo-mag- netism, 158—160. Influence of magnetism on chronometers, 197 —202, and 365—367. Experimental inquiries relative to the distribution and changes of the magnetic intensity in ships of war, 261, 262. New phenomena caused by the effects of mag- netic influence, 276. Memoir on the theory of magnetism, 317—334. Mechanical Science, Miscellaneous Intelligence in, 147—153, 360—369 Meconic Acid, action of, on the animal economy, 393, 394 Melania Setosa, a new species of fresh-water shell, description of, 13—15 ; CONTENTS. 405. Mercury (fulminating) results of experiments on, 153—157 Metallic Surfaces, observations on some phenomena relating to the formation of dew on, 1—12 Metals, experiments on the property which some metals possess of facilitating the comination of elastic fluids, 138, 139 Meteorological Diary for December 1823, and January and Feb- ruary 1824, 187. For March, April, and May, 398 Metzger (M.) improvements by, in the construction of electrical machines, 161, 162 Microscopes, observations on the indistinctness of vision caused in, by false lights ; and on the remedies for it, 202—209. On the adaptation of a compound microscope, to act as a dynameter for telescopes, 367—369 Milzinsky (Count,) account of an undescribed lava, which preys on snails, 176—178. Mineral Waters, presence of iodine discovered in, 180 Minerals (new,) found in Mount Vesuvius, 180 Mitra, description of several pieces of, 34—38 Mole and Van Beck(Drs.) experiments by, on the velocity of sand, 266 Morphia, detection of, in cases of poisoning, 118 Morphium, test for, 170 Muriatic Acid, existence of free, in the stomach, 181 Nails,experiments on the adhesion of, when driven into different kinds of wood, 360 Natural History, Miscellaneous Intelligence in, 175—183, 392— 397 Nautical Eye-tube, notice of, 153 Needle (horizontal and dipping,) observations on the daily varia- tion of, 128, 129 Nervous System, recent discoveries relative to, 143, 144 Nickel, experiments on the oxides of, 140 Olbers (Dr.) remarks on the catalogue of the orbits of the comets, that have hitherto been computed, 85—96. Opium, effects of the solutions of, when injected into an hysterical patient, 145—146. ’ Optic Nerves, observations on semi-decussation of, 259—261. Optical Instruments, on the indistinctness of vision caused on, by false lights, and remedies for it, 17—28, 202—209 Ornithorhynchus Paradoxus, some particulars respecting, 247—250 Oxide of uranium, preparation of, 136, 382. Of nickel, experi- ments on, 140 Parallax of « Lyre, remarks on, 264, 265 Phenomena, relating to the formation of dew on metallic surfaces, observations on, 1—12 Phillips(Mr.) on the detection of arsenic in various cases of poison- ing, 167. Analysis of his translation of the London Pharmaco- peia, with remarks, 349—359 406. INDEX. Phosphorescence, connexion of, with electricity, 163. _Phosphores« cence of acetate of lime, 163 Platinum, action of, when finely divided, on gaseous mixtures, and its application to their analysis, 277, 278. ee Pneumatic- Thorax, remarks ,on a case of, 130, 263 Poisoning by arsenic, tests for detecting, 167. Poisoning by the acetate of morphia, how detected, 168—170 Poisson, (M.) extract of his memoir on the theory of magnetism, 317—334 Pond, (John, Esq.) on certain changes in the principal fixed stars, 130 Potash, preparation of the saturated hydro-sulphuret of, 165. Crys- tallization of the sub-carbonate of, 167. Acid tartaro-sulphate of, 171 Prevost (Dr.) observations by, on the generation of fishes, 277 Prout (Dr.) on the existence of free muriatic acid in the stomach, 181 Prussiate of Iron, a cure for intermittents, 145 Pyro-ligneous ether, or pyrocilic spirit, preparation and analysis of, 171—173 . : " Refraction, comparison of the new tables of, with observation on astronomical refractions, 130 Revero and Boussingoull (MM.) account by, of the different masses of irpn, found on the eastern Cordillera of the Andes, 394, 395 Royal Society, analysis of the translations of, 122—130. Account of its proceedings, 250—280 Royal Institution, proceedings of, in 1824, 281. Syllabus of the various courses delivered there, 282—289, List of its officers, 282,290. Terms of admission, 291, 292. Report of the visi- ters, 292—294. Ruby-glass (ancient) composition of, 167 Sabine (Captain), on the temperature at considerable depths of the Caribbean Sea, 126. Comparison of barometrical measurement with the trigonometrical determination of a height at Spitzber- gen, 268, 269 Sand-drigs, observations on, 181—183 Scientific Books, analysis of, 105—130, 335—359 ‘ Scoresby (William, Esq.) general results of observations by, on the dipping needle, 104. Experiments and observations on the de- velopement of magnetical properties in steel and iron by per- cussion, 254, 255 Scott, (H. Esq.) particulars by, respecting the ornithorhynchus paradoxus, 247—250 Sea, (Caribbean), temperature of, at considerable depth, 126 Seal, fact in the natural history of, 263. 3 Shells, two new species of fresh-water, described, 13—17. The INDEX. 407 _ characters of several new shells belonging to the Linnzean volute, 28—38 Ships, the copper sheeting of, how prevented from becoming cor- roded by the action of sea-water, 253, 279, 280. Experimental inquiries relative to the distribution and changes of the magnetic _ intensity in ships of war, 261, 262 Silver, (fulminating), results of experiments on, 153—157 Snails, account of an undescribed larva, which preys on, 176—178 Soda, preparation of the saturated hydro-sulphuret of, 165 Sodous Acid, analysis of, 381, 382 Sound, produced by opening a subterraneous gallery, 152. Ex- periments on the velocity of, 266 South (James, Esq.) tables of astronomical phenomena computed _ by, from April to June 1824, 77—84. See Herschel Stars, observations on the apparent distances. and portions of cer- . tain double and triple, 250—253 Steel, observations and experiments on the developement of mag- netical properties in, by percussion, 254, 255. Experiments on the elasticity and strength of hard and soft steel, 267, 268. Stomach, existence of free muriatic acid in, 181 Straw-plat, premiums for, 153 ; Strychnia, process for obtaining salts of, 170. Volatility of the _ salts of, zbed., 171 Sulphate of copper, an excellent remedy in croup, 181 Sulphur, action of, on iron, 165 Sulphurous Acid, liquefaction of, 391 ‘ Sulphuretted hydrogen, preparation of, 165. Inflammation of, by nitric acid, 380 Swainson (Wm., Esq.) description by, of two new fresh-water shells, 13—-17. On the characters of several new shells be- longing to the Linnean Volute, 31—38. Remarks on the pre- seut state of conchology, 29, 30 Tartaro-sulphate of potash, 171 Taschium, a supposed new metal, notice of, 390 Taste, organs of, how affected by different bodies, 392, 393 Taylorian Theorem, demonstration of, 74—76 Telescopes, on the indistinctness of vision caused in, by the pre- sence of false lights ; and remedies for it, 17—28 Temperature of the sea, at various depths, 126. Effects of tem- perature on the intensity of magnetic forces, 279 Thames, design by Mr. Ware, for making a public road under, 62—65. Notice of other tunnels, attempted or proposed, 66—69. Thomson (Dr.) table of atomic weights by, 383 Tiark’s (Dr.) longitude of Madeira and Falmouth determined by, 270, 271 Tides, extracts relating to the theory of, 295—315 408 ENDER. Time, indicated by any number of chronometers, an easy method of comparing, with the given time at a certain station, 316, 316. Titanium (Metallic), on the appa ent magnetism of, 129 Todd (Dr.) inquiry into the nature of the luminous power of some of the lampyrides, 269, 270 Tredgold (Mr.) analysis of his work on the strength of cast iron and other metals, 150, 151. Account of his experiments on the elasticity of hard and soft steel, 267, 268 Unio Gigas, a new species of fresh-water-shell, description of, 15—17 . Univalves, remarks on, 272, 273 Uranium, preparation of the oxide of, 139, 140—382. Notice of uranium pyrophori, 383 Variation, daily, of the horizontal and dipping-needle, under a reduced directive power, 128 Vauquelin (M.) experiments of, on the acetates of copper, 383 Vegetation, table of, at different heights, 176 Velocity of sound, experiments on, 266 Verdigris, observations on, 384 © Vesuvius, notice of new minerals found in, 180 Vicat (M.) experiments of, on the burning of limestone, 361—363 Violine, notice of a new vegeto-alkaline, 385, 386 Vision, on the indistinctness of, in optical instruments, and re- medies‘for it, 17—28, 202—209 Voltaic Troughs of Dr. Hare, notice of, 378 Volute, characters of several new shells belonging to the order of, 31—38 Walker (Mr.) syllabus of his lectures on plane geometry, 285 Walrus, new fact in the natural history of, 262 Ware (Samuel, Esq.) design by, for making a public road under the Thames, with observations, 62—69 — Weill, overflowing, at Chiswick, account of, 70—74 — Wollaston (Dr. W. H.) observation of, on the apparent magnetism of metallic titanium, 129. On semi-decussation of the optic nerves, 259—261. On the apparent direction of the eyes in a portrait, 274—276 Young (Dr. Thomas) a finite and exact expression by, for the refraction of an atmosphere nearly resembling the earth, 255. Printed by WILLIAM CLOWES Northumberland-court. Plate 1. Vol.XVI. Fi wg Z aes as Bs Ae 4 ie re 22 23 Jt Basire se ¢.Harvey delin Published by John Mur) Abenwale Strect Londen 1824 si ‘ : : ate ead . Slate I Vel. XVI. o D0 Bagh of the Body jf the Mlcrovegpie 7 inches. a ot Stop 1 - h 5 %) Stop 75 In = Focus Bn Focus 2In. Published by John Murray. Albemurle Street Londen Big J? Basire se, Llate IM. VOL. XVIH. 7) Llete IN VOL AVI. DESIGN jr makig)2 ROADWAY under th THAMES, fiom the east side of the Tower nex Irongate Stairs, w the opposite stde near Horstvdown Stairs South To the Lower Depttord Road bc Prem the Minories and Teaver Z porn t eres and Tower Hill dhdeng et & =. Lon Water LONGITUDINAL | SECTION , ARCHWAY HORSERXDOWN STARS WE — HORSELYDOWN LANE ving &: the Docks Buildings not disturbed To Hayy Frame. the 7 - rm. the Mines, 2 “Ores and Tower Hyp Tl teoncare stains FREEMANS LANE Grout for Butldings 22UDLLUT RMER THAME suey wnopApos al a { North Grou for Puildings Ground tor Buildings South Bupunse — pooy Koad ascending to Fro" Building s Greund for Buildings Slope Lehi Warehouses not dishabedl Tom, to ok PLAN of © ARCHWAY and tr APPROACHES. Scale NB. Sn the dav time the Archway will be sullictenily lighted from the ends. The yround required tor this approach Pre verte wip frome the belongs wholly to the Tower High water _ Low water Bed of the River: ELEVATION Of the ENTRANCE atA TRANSVERSE SECTION of the ARCHWAY. TF Bane om. 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