oxides, in which the oxygen of the acid to the oxygen of the base is as 4 to 1. M. Peligot has endeavoured, without success, to form an analogous acid by means of chlorine; the action is very violent, and inflammation and complete destruction of the salt ensues. This happens with bromine if placed in contact with the salt in a fluid state; it must be acted on by passing the vapour of bromine slowly into it, which will be absorbed. The action of iodine differs from that of bromine, for it forms both iodide and iodate of silver; but the acid has not yet been sufficiently examined to determine its nature. The action of bromine on benzoate of silver is moreover not a particular action caused by the nature of benzoic acid, for it acts in a similar manner on salts formed by acids which appear to be less disposed to superoxygenation, as the oxalic and acetic acids, and everything tends to the belief that the mode of action of this body will become general.-L'Institut, 15 Fev. 1836. OBSERVATIONS ON THE SOLAR ECLIPSE OF MAY 15, 1836. Photometrical Observations during the Eclipse, by Thos. Galloway, Esq. To R. Taylor, Esq. DEAR SIR, The following observations, made during the solar eclipse on the 15th instant with two of Leslie's photometers, may be interesting to some of your readers. The observations were made at Mr. Bishop's observatory in the Regent's Park, and the photometers were placed on a table on the lawn, fully exposed to the sun's influence. With the exception of a few passing clouds the sky remained clear till towards the end of the eclipse, when the atmosphere became hazy. Mean Time. Phot. A. Phot. B. Mean Time. Phot. A. Phot. B. Extract of a Letter from R. V. Yates, Esq.. of Toxteth Park, Liverpool, dated Edinburgh, May 15, 1836. "We have just enjoyed a most glorious sight, an annular eclipse. The morning arose cloudy, and gave little promise; but about 10 the clouds cleared off, and during the whole period of the eclipse nothing interfered with our seeing it perfectly. It was curious to watch it when it was just going to become annular, the light broke in so rapidly. It remained annular only a very short time, perhaps between 5 and 10 minutes." In a garden near Birmingham the Gentians partially closed their flowers during the eclipse, and then opened again. The Rev. James Yates, by whom the above was communicated to us, has obligingly directed our attention to the description of an Annular Eclipse in the Norwegian Account of Haco's Expedition against Scotland, which we transcribe from p. 44 of that work. Þá er Hacon konongr lá í Rögnvalzvagi dró myrkr mikit á sólina, sva at lítill hringr var biartur um sólina utan*, ok hellt þrí nockora stund dags. While King Haco lay in Ronaldsvo a great darkness drew over the sun, so that only a little ring was bright round about the sun, and it continued so for some time. *Though relating to inquiries of a different class, I am tempted to note the Islandic expression "um solina utan," as a remarkable illustration of the real origin of our compound preposition ABOUT, jmbutan,-the noun being here interposed between the two prepositions. See my Note on the complicated mistakes in which the history of this word had been involved by Spelman, Skinner, and Tooke, subjoined to the 8vo. edition of the Diversions of Purley, 1829, vol. i. p. viii.-R. TAYLOR. HYDRAULIC LIME. M. Vicat communicated a paper to the Royal Academy of Sciences at Paris on the sole efficacy of magnesia in rendering certain limestones hydraulic. This paper has for its object the correction of an opinion given by M. Berthier in the Journal des Mines of 1822, that magnesia alone has no more efficacy than alumina to render lime hydraulic; from which it would follow that silex was the only essential principle in all cases. M. Vicat was for a long time of the same opinion, which he now declares is incorrect; and says that magnesia alone, when in sufficient quantity, will render pure lime hydraulic. He does not explain the degree of energy of these new species of lime, but only affirms that they will solidify from the 6th to the 8th day, and continue to harden in the same manner as ordinary hydraulic lime. Until his experiments are further advanced, he states that the proportions of magnesia taken and weighed after calcination should be from 30 to 40 of every 40 of pure anhydrous lime. The native limestones examined and cited by M. Berthier contained only from 20 to 26 of magnesia for every 78 to 60 of lime: it is probable that this want of proper proportions was the cause of his negative results. M. Vicat, in conclusion, points out the importance of these observations, hydraulic lime never having been found in the calcareous formation below the lias is because the dolomites have never been examined, but it is now probable it may be found in this lower formation.-L'Institut, No. 153. NOTE RESPECTING CERTAIN CONTROVERSIAL COMMUNICATIONS LATELY SENT FOR INSERTION IN THIS JOURNAL. LIEUT. LECOUNT. We have received a letter from Lieut. Lecount, claiming the insertion, in its entire form, of his previous letter in reply to Mr. P. Barlow, from which we gave an extract in our last Number, p. 439. Lieut. Lecount makes this claim on the ground "that it is the general practice to allow any person who is attacked in a periodical publication the right of replying." We have merely to observe, in answer, that our extract includes the real matter of Lieut. Lecount's reply, and that we omitted only irrelevant matter of a personal nature, at the same time referring our readers to the pamphlet which he has published. We must therefore decline all further allusion to the subject. We may remark in reference to this, as well as to other cases of a similar kind which have lately occurred, that we cannot permit a scientific discussion to degenerate into a personal controversy. MR. HENWOOD. We take the present opportunity of noticing Mr. Henwood's letter in the Records of General Science for May, to which the remark just made is also applicable. There was a very sufficient reason for our not inserting Mr. Henwood's last reply to Mr. John Taylor on the subject of the steam-engines of Cornwall, namely, that the quotation it contains from the Records of Mining is made in so garbled a manner as to be a complete misrepresentation of Mr. Taylor's statement. To prove this we give the passage entire as we find it in the Records of Mining, including in brackets what Mr. Henwood has suppressed, and by the suppression of which he has perverted the sense of the whole. "In the early part of the year (1813) the best duty was about 26 millions, by Captain Trevithick at Wheal Prosper, [Captain John Davey at Wheal Alfred, and Messrs Jeffree and Gribble at Stray Park. Towards the close of the year Captain Davey first attained 27 millions, then Jeffree and Gribble 28, and by the end of the year the latter had nearly arrived at 30 millions.]" One half of a sentence of the foregoing paragraph is thus brought forward in contradiction of Mr. Taylor's statement that Captain Trevithick's "engine did only about 26 millions duty, and did not equal other engines then working in the common way." A reference to the work itself showed us that if the remainder of the paragraph had been given, it would at once have been seen that the imputation was groundless. Can it reasonably be required of us to lend our pages to charges thus supported? We will only add to this that the title "On a new Rotative SteamEngine," was prefixed to Mr. Taylor's first paper not by him, but by ourselves; and the only sense in which we used the term "new' was in that of "newly or lately erected." Mr. Henwood must have been aware that Mr. Taylor had himself wholly precluded the supposition that it could mean "newly invented," by mentioning an older engine of the same description erected by Mr. Godfrey. METEOROLOGICAL OBSERVATIONS FOR APRIL 1836. Chiswick-April 1. Dry haze: sleet: stormy with rain at night 2, 3. Cold and windy. 4. Clear and fine. 5. Slight haze: cloudy: rain. 6. Rain: cloudy. 7. Rain: clear. 8, 9. Rain: cloudy and fine. 10. Fine. 11. Cold haze: clear at night. 12. Overcast: rain. 13. Cloudy. 14. Overcast and cold. 15. Slight rain. 16. Foggy. 17. Rain: cloudy and cold. 18. Drizzly: fine. 19. Fine. 20. Cloudy: rain. 21. Very fine. 22. Rain: fine. 23. Rain. 24. Rain: stormy at night. 27. Cloudy and cold. 28. Overcast. 29, 30. Clear, cold and dry. 8. Rain. Boston.-April 1. Fine: rain and snow P.M. 2. Cloudy. 3. Stormy: rain and snow A.M. 4. Fine. 5. Cloudy. 6. Rain. 7. Rain. 9. Cloudy. 10. Fine. 10. Fine. 11. Cloudy. 12. Cloudy. 13. Cloudy: rain P.M. 14. Cloudy: rain P.M. 15. Cloudy. 16. Fine: rain P.M. 17. Cloudy. 18. Rain. 19. Fine: rain P.M. 20. Cloudy. 21. Finc. 22. Fine: rain 23. Fine. 24. Cloudy: rain carly A.M. 25. Cloudy. 26. Fine. 28. Cloudy. 29. Fine: ice this morning. 30. Stormy. early A.M. 27. Rain. Third Series. Vol. 8. No. 50. Supplement. June 1836. 3 M 29.792 29-826 29.361 29:35 46 33 42 Sw. SE. NW. 33.7 44.3 46 34 38 SW. W. W. ⚫591 33.8 45.0 48 30 42 WNW. var.[ N. N. ·047 32.3 46.6 51 27 39 NW. N. N. .133 34.7 50.2 54 40 43 SW. calm SW, ... 40-8 48.2 50 39 44.5 SE. var. calm SW. •111 40.3 50.3 55 35 43 S. var. SW. SW. ⚫061 38.3 49.8 53 39 40 SE. var. calm S. •355 40.2 46-7 48 39 45 E. E. calm ⚫036 40.2 53.2 56 42 47 N. NE. calm .194 42.8 48-8 53 29 43.5 N. W. calm ⚫019 38.5 53.7 53 44 45 SW. SW. 45.2 56.4 57 35 53 SW. W. W. 42.9 54.5 58 47 47 W. SW. calm 47.5 542 56 30 47.5 NNW. NE, calm 38.8 52.6 58 42 47 E. E. calm ⚫036 30-102 29.66 46.6 42.3 47.8 51 36 47 E. N. calm ⚫027 30-119 29.60 48.2 420 547 59 35 47 S. W. calm .061 29.58 | 51.2 44.3 56.2❘ 57 47 51 S. SW, 29-899 29.40 | 53.3 48.5 55.2 57 41 53 sw. var. SW. W. 29-40 49.5 43.3 56.3 58 46 50 SW'. SW. W. ⚫063 F. 22. 30-111 30 134 29-814 29.971 29.806 29-22 53.6 47.2 61.3 63 42 55 Sw. W. W. .061 29-31 | 51-6 47.4 54.6 55 44 52.5 Sw. SW. 29.25 46.9 45.3 47.9 52 35 48 E. SE. 29.65 45.8 39.7 54.7 29.51 | 50.6 57 38 46 NW. NE. calm *375 29.780 29.992 29.806 29.31 | 44.6 29.938 29.968 29.869 29-42 46:3 38.2 37.5 F. 29. 29 903 29.926 | 29·844 | 29.41 39.4 35.5 S. 30. 29-774 29.807 29.766 29-25 | 42.3 32-2 42552 44.4 53.5 55 36 50 W. NW. ... 48.7 51 33 43 NW. N. NW. 52.3 56 34 45 NNW. NW. calm ⚫036 46.7 55 27 38.5Nw. var. NW. N. ⚫027 49-451 N. N. |