Dec. 16.—The needle vibrated 15'; wind high and squally from the S.W., followed by rain. Between noon of the Ist Dec:} Nov. Rain fallen 2:207 inches. a а oft On the Conversion of Cast-Iron Pipes into a Substance bearing some resemblance to Plumbago. By William Heory, M.D. F.R.S. &c. I was lately requested by a gentleman who resides in the neighbourhood of Newcastle-upon-Tyne, to examine the nature of the change effected in a cast-iron pipe, placed in the shaft of a coal mine near that town. In sinking the shaft, it was necessary, as sometimes happens, to put down a curl, or cylinder, of cast-iron, in order to support a bed of quicksand; and into a suitable opening in this cylinder, the cast-iron pipe, three inches diameter, was bolted by means of a flanche at its extremity. Its use was to allow an exit to the water and gas, which issued from the stratum of quicksand. The fragment of the pipe, with which I was furnished, was of a dark grey colour; its inner surface was smooth and black; and its outer surface had a thin ochrey incrustation, The usual fracture of cast-iron was exchanged for an earthy one, except near the centre of the mass, where somewhat of the usual texture of cast iron was still visible. It was soft enough to be easily scraped by a knife; and was readily broken by a slight blow of a hammer. Some parts of it left a black trace on writing paper, but destitute of the lustre which the traces of plumbago exhibit. The specific gravity of the specimen was 2.008; and, after being soaked an hour or two in water, it became 2.155. Twenty grains of the powdered substance were projected upon 200 grains of melted nitre. The combustion was very feeble, compared with that which happens to plumbago under similar circumstances. - After washing off the nitre, there remained' 141, grains, which were almost entirely oxide of iron, consisting probably of 11.2 iron and 3.3 oxygen. A small piece of the pipe, weighing 61 grains, was.passed into a glass tube containing diluted sulphuric acid over mercury. The acid acted very slowly, and, in eight days, when its effect seemed to be complete, only half a cubic inch of hydrogen gas was formed. This was only about 4th of what would have been obtained from the same quantity of cast-iron.* There remained a black and a supper t to * A piece of plumbago from Borrowdale, kept eight days in dilute sulphuric acid, had evolved no gas. bulky substance, which, when dried and projected on red-hot pitre, burnt rather more vividly than the original substance, but still afforded much oxide of iron. It was clear, therefore, that a large share of the metallic part of the pipe had been removed; and that what remained was composed of iron, plumbago, and other impurities usually present in castiron. With the view of ascertaining the cause of the change, I next examined the water from the bed of quicksand, a bottle of which had been sent along with the fragment of pipe. The water had a brackish taste, and was of the specific gravity 1008. It gave no traces of iron, either with triple prussiate of potash, or succinate of ammonia. I collected the gas from a wine pint of it; but it was lost by accident before being examined. By the usual methods of analysis, a wine pint gave 64 grains of dry salt, composed of Muriate of soda... 32 magnesia. 16 10 Sulphate of lime... 4 Carbonate of lime .... 2 a lime ... 64 It is most probably to the agency of the muriates of lime and magnesia, that we are to ascribe the removal of the metallic part of the pipe. I have often remarked the effect of solutions of these salts in discharging writing ink from the labels of bottles, to which they have been accidentally applied: and I was lately baffled in several attempts to restore the legibility of some of the M.S.S. of a most accomplished scholar (the late Mr. Tweddell of Trin. Coll. Cambridge) which had lain some time under sea water, abounding, as is well known, in muriate of magnesia. The texture of the paper was entire, but the iron basis of the ink, as well as the gallic acid, was entirely removed. In that copious repository of valuable knowledge, Dr. Priestley's Experiments and Observations on Air,* some facts are stated, that bear an analogy to the one which I have described. Cast-iron nails, he found, dissolved very slowly in diluted sulphuric acid; and left a large proportion of black matter, which had the original form of the nails. This experiment, he observes, explains what happens 10 cast-iron pipes in pits, the water of which is impregnated with vitriolic acid; for, in time, they become quite soft, or, as it is called, rotten, and may be cut with a knife. In Cornwall, I am informed, cast-iron pipes are disused in many of the mines; but this is owing to the presence of sulphate of copper in the water, the corroding effects of which render it neces. Eary to substitute pipes of brass or copper. * Abridged and methodized, vol. iii. part iii, sect, 2, The following fact, which was lately observed at the printingworks of a friend of mine, belongs to a different class of phenomena; and is perhaps to be accounted for by galvanic agency. In order to confine the heat in some cast-iron steam-pipes, they were placed in a trough or gutter made of bricks, into which powdered charcoal was tightly rammed. At a place contiguous to a joint, formed by bolting two flanches together, a leak had bappened; and when the iron pipe was taken up, it was found in the neighbourhood of the leaky part, to be perfectly soft and rotten. I was not able to obtain an opportunity of examining the nature of the change by any experiments on the altered iron. Manchester, Dec. 1814. ARTICLE VI. Proceedings of Philosophical Societies. posed of polarising ROYAL SOCIETY. On Wednesday the 30th of November, the day of the anni- Taylor Combe, Esq. M. A. OF THE OLD COUNCIL, gold-bea OF THE NEW COUNCIL waris wut Hatalos tout spa At the was read, lates, and Ni the d escribed, are the muscular • eve, HAN lems, and Rev. Charles Burney, LL. D. Henry Warburton, Esq. On Thursday Dec. 8, Dr. Brewster's paper on the depolarisation of light by different bodies was continued. He gave a long list of animal, vegetable, and mineral bodies, that have the property of depolarising light; together with a list of bodies that have no effect in producing this depolarisation. He then gave his theory of this depolarisation. Bodies capable of depolarising light may be divided into seven classes. 1. Those that have a neutral axis and produce a double image. With respect to these bodies the theory is evident. 2. Those that have a neutral axis but produce only a single image, as the human hair. In these bodies he supposes that two images are really produced, but that they coincide with each other, On Thursday Dec. 15, Dr. Brewster's paper was concluded. He continued his enumeration of the different classes of depolarising bodies as follows: 3. Those that have no depolarising axis but depolarise light in every direction, as gum arabic. These he conceives to be composed of layers placed one over the other, each of which has a depolarising axis ; and as these axes are placed in every direction, the body acquires the property of depolarising in every direction. 4. Those bodies that have an approximation to a neutral axis, as gold-beater's skin. 5. Those that have an approximation to a depolarising axis. 6. Those that allow the light nearly to' vanish, but not quite, at every alternate sector, as oil of mace. 7. Those that allow it to vanish entirely at every alternate sector, as calcareous spar, when the light passes through the shorter axis. At the same meeting part of a paper by Benjamin Travers, Esq. was read, On the Mechanism by which the Eye adjusts itself to different Distances. The paper was drawn up with uncommon clearness, and even elegance. It consisted of three parts: 1. A sketch of the different hypotheses to which this mechanism has been ascribed, with the author's reasons for not admitting them. These are the muscles of the eye, the ciliary processes, the supposed muscularity of the lens itself. 2. An account of the anatomy of the eye, as far as it is requisite for the purposes of the paper. 3. His reasons for believing that external pressure is applied to the lens, and that this pressure is sufficient to alter its shape. the On Thursday 22d Dec. Mr. Travers's paper was continued. He gave his reasons for considering the iris as muscular, and that by means of it the pupil is adjusted to different distances. The Society adjourned over two Thursdays, on account of the approaching holidays. LINNÆAN SOCIETY. On Tuesday, December 6th, a paper by James Johnson, Esq. was read, giving an account of some fossil bones found in the cliff near Lyme, Dorsetshire. This cliff abounds in belemnites, nautili , and the remains of other sea animals. The bones in question have been supposed to belong to the crocodile; but Mr. Johnson gave his reasons for considering that opinion as ill founded. He thinks they constitute the bones of a new and unknown species of amphibious animal. He is of opinion that the animals whose remains are found here lived and died upon the spot. A communication from Mr. Sowerby was also read, On the Spiral Tubes of some Fossil Shells belonging to the genus Anomia of Linnæus and Terrebratula of Lamark. These shells occur in limestone, and he thinks the spiral tubes will furnish characters sufficient to constitute them a new genus. M. Vieillot's paper begun at the last meeting was continued. On Tuesday December the 20th M. Vieillot’s paper was continued. Specimens of flax and hemp were exhibited to the Society, prepared by machinery invented by Mr. Lee, without water steeping or dew retting. The specimens were beautiful. The advantages of the plan are that the produce is greater and better; and the green part of the plant is preserved, which furnishes very good food for cattle, and is an excellent manure. The seed also is preserved. WERNERIAN SOCIETY. At the Meeting of this Society, on Saturday the 12th of November, there was read a paper by the Rev. Dr. Fleming of Flisk, On the Fossil Species of Orthocera found in Britain. T'he Doctor has paid much attention to petrifactions; and he here described no fewer than ten species of orthocera, all of them found in strata belonging to the independent coal formation in the county of Linlithgow. Two of these orthoceratites have already been figured by the late Rev. Mr. Ure, in his History of Rutherglen and Kilbride; the rest were now for the first time described; and the de. scriptions were illustrated by beautiful and correct drawings. The secretary presented two communications from Mr. Scoresby, junior, of Whitby, of great interest to the meteorologist; being journals kept during voyages to Davis's Straits, in the years 1813 and 1814, in which Mr. Scoresby notes the latitude and longitude; the temperature, generally giving the mean of three daily observations; the direction and strength of the winds; the aqueous and other meteors; Springs wence 1 AS At G CS Allen. dicines |