CHEMICAL NEWS, Nov. 10, 1876. Development of the Chemical Arts. 197 Iodine. The rapid extension in the demand of the THE CHEMICAL NEWS. splendid violet, blue, and green coal-tar colours, which VOL. XXXIV. No. 885. REPORT ON THE DEVELOPMENT OF THE CHEMICAL ARTS Chlorine, Bromine, Iodine, and Fluorine. By Dr. E. MYLIUS, of Ludwigshafen. THE arrangements for the ventilation of the bromine works are peculiarly interesting. The critical moment is when the manganese liquid is run out of the stone tanks, since it throws off vapours of chlorine and bromine in abundance. Yet the operation is performed without the least inconvenience to the workman. Along the series of stills there runs a channel of brickwork, through which a powerful current of air is drawn by the great chimney of the works in a direction opposite to that in which the liquid runs off. The channel is situated so that the vent holes of the stills open into it. In front of every still there is introduced in the roof of the channel a damper which is opened when the plug of the vent hole is about to be knocked out. The draught is so powerful that the workmen are not in the slightest degree incommoded by the vapours evolved from the stream of solution of manganese. The workshops smell distinctly of bromine, but the odour is far fainter than that which is experienced in our scientific laboratories during the bromation of organic substances. As has been already remarked, crude bromine always contains a little chlorine, even when, according to the Stassfurt practice, the Woolf bottle is allowed to become slightly warm towards the end of the operation, so as to drive the volatile chloride of bromine over into the ironturnings. A rectification is therefore requisite. This takes place in glass retorts containing about 15 litres, the necks being cemented into receivers bedded in cold water. Each retort is set in a separate sand-bath, so that if one happens to burst-and such misfortunes cannot be avoided the injury may be limited as much as possible, Only a slight aqueous fraction contains chlorine; it is withdrawn and returned to the stone stills. The rectification lasts about twenty-four hours. The atmosphere in the rectifying-house is more offensive than that in the still-houses, since all currents of air must be carefully avoided. The workmen, however, require to enter this room from time to time. Moreover there are especial arrangements which render it possible to decant the bromine both out of the Woolf's bottles into the retorts, and from the receivers into the vessels used for transport without any annoyance from the vapours abundantly evolved during these operations. The decantation is performed in wooden chests, through which a violent current of air is drawn by the great chimney. The workmen soon acquire such dexterity and accuracy in these manipulations that they are content to cover the respiratory organs with a wet cloth, and disdain to make use of the ventilating arrangements placed at their disposal. (At Stassfurt bromine is sent off in strong glass bottles holding 25 kilos. The well-ground stoppers are sealed with shellac, luted with clay, and tied up with parchment paper. Four or twelve such bottles are packed in a chest. -A. W. H.) "Berichte über die Entwickelung der Chemischen Industrie Während des Letzten Jahrzehends." are prepared by means of the iodides of the hydrocarbons has in the last few years occasioned a notable increase in the consumption of iodine. The production, from very simple reasons, could not keep pace with the growing consumption, which of course led to a considerable increase in the commercial value of a body relatively of such rare occurrence in nature. Its price has been further increased by the circumstance that the seaweed ashes of England and France (Kelp, Varec) have become less remunerative to the producers. Formerly these weed ashes served to supply a considerable part of the demand for the salts of potash, but since the utilisation of the well-known "Abraum salts" of Stassfurt the extraction of potash salts from seaweed ashes has become so unremunerative that the loss in the returns of the kelp trade has to be balanced by a rise in the price of the iodine.* The hope of a fall in the commercial value of iodine in nitrate of soda has not been fulfilled. The production of consequence of its extraction from the mother-liquors of iodine from this source has increased but little, and some nitre refineries, which had commenced the utilisation of the iodiferous mother-liquors, have again abandoned the attempt. On the other hand, in tinctorial industry attempts have been made to dispense with the use of iodine. Although the attempt to employ bromine in place of iodine (see "Bromine ") has failed, other methods have recently been discovered for producing the most magnificent violet, blue, and green tar colours without the aid of iodine. Nevertheless the price has not been essentially reduced since the methods for preparing the dyes without iodine have not by any means been adopted in all establishments. In addition to the tinctorial arts iodine is employed in scientific chemistry, where its importance is incalculable and also in photography and in medicine. (To be continued). ON SOME EFFECTS PRODUCED BY THE ADDITION OF SULPHATE OF ALUMINA IN THE TREATMENT OF SEWAGE. By A. McDONALD GRAHAM, F.C.S. IN your review of a recent publication, "Causeries Scientifique" (CHEM. NEWS, vol. xxxiv., p. 69), the reader's attention is directed to the following paragraph :-" Sulphate of alumina, on which so much dependence has been alumina agglutinates the solid substances, but the dissolved placed, certainly clarifies the sewage. The gelatinous matters, mineral and organic, are nowise retained." The last sentence, which is a very faithful translation from the original, contains a statement which is neither new nor great Dr. Johnson's way of disposing of the swallows in true, and the language employed reminds one of the "Numbers of them," says the learned Doctor, conglobulate together, and precipitate themselves into the the sewage removes nothing but the suspended matter has water." That the application of sulphate of alumina to been asserted over and over again by persons who, from better; and perhaps it would not be amiss, now that the their position, would have been supposed to have known autumn. * According to a letter from Mr. E. Stanford, of Glasgow, to Prof. A. W. Hofmann, a ton of chloride of potassium in 1863 cost £21 138.; in the ten following years on an average £15 15s.; and is now worth only £7 10s. The price of iodine has risen in a corresponding degree; in 1863 an ounce of iodine cost 44d.; on the average of the following ten years 7d.; whilst it is now worth is. 3d. per ounce. According to private communications from M. E. Schering the production of iodine from the mother-liquors of soda saltpetre is again on the increase. A Peruvian nitre refinery, which separates the iodine as cupreus iodide by means of bisulphite of soda and sulphate of copper, produced, in 1873, 15,000 kilos. cuprous iodide, and is about to increase its production to 50,000 kilos., corresponding to 30,000 kilos. I of iodine. public attention is turned to the sewage question, to recapitulate some of the substances carried down by alumina. And, first, the phosphoric acid is removed from the sewage, and by its removal the effluent water is found to be less liable to putrefaction, while the manure derived from the sewage must be to some extent improved, although I am aware the value of phosphate of alumina as a manure has been called in question. Secondly, albuminoid substances are carried down by the alumina. I think this is proved by the general behaviour of bodies of this nature with alumina, and also by the percentage of nitrogen found in the precipitated mud, which is higher than would be produced by the suspended matter alone. The albuminoids are found to undergo rapid decomposition and to give forth offensive odours, and their removal tends to keep the effluent water sweet. {CHEMICAL NEWS, Nov. 10, 1876. 0.65 100.80 Sand Laboratory, Wallasey Ore Yard, Thirdly, the fatty acids of soap dissolved in the sewage are carried down by the alumina-a point which, I think, has been hitherto somewhat overlooked. It is true that there is some loss in the subsequent drying of the mud, bot a considerable portion of these fatty bodies is obstinately retained by the alumina, as may be proved by experiment. I am inclined to think that the beneficial effects produced by the sewage manure on the land is in a great measure due to the large quantity of fatty matters No. I. FLOWER-POT Gas Furnace, Crucible Jacket, &c. precipitated by the alumina. Farmers have assured me that they found the manure of considerable value, and I think the effect of the fatty matters on the soil has not up to this moment been sufficiently considered. An enterprising firm proposed some time ago to manufacture artificial butter from the Thames mud, and I have myself made a very fair cake of soap from the fatty acids extracted from the sewage mud. The association of ideas, however, is not agreeable, although I do not think the most fastidious person would object to burn a candle which had been derived from the sewage. In some of the Towns of Yorkshire-Leeds, for instance I have been told that a large quantity of soap is found in the sewage, not because the Yorkshire folk are more frequent in their ablutions than other people, but from the fact that soap is extensively used in the manufacturing processes, and it is possible that some portion might be recovered from the sewage. If so, the question of "How are you off for soap?" when addressed to corporations and local boards, would assume a new significance, as its recovery from the sewage would form some set-off to the expense of purification. Wellfield Villa, Turnchapel, Plymouth, October 17, 1876. THE deposit of which an analysis is given below is from the surface of the Lochar Moss, a very extensive peat moss now in part under cultivation in the south of Scotland, bordering on the Solway Firth. It is found in large quantity in the open ditches and drains; in the latter it is formed in such considerable quantity that the tiles in time become entirely choked up, so that they have to be raised and cleaned. In the ditches it forms, below the running water, a layer of thick red-brown slime, often 10 to 12 inches in depth; and as these ditches have to be cleaned out at least once in the twelve months, and sometimes even more frequently, the amount of the deposit-which, by the way, is commonly known in the district as "iron ore"-thrown up on the banks in course of time is very large. Perfectly clear water taken as it runs from the drains reacts strongly for proto-salts of iron, becomes cloudy after standing a few hours, and deposits a redbrown sediment. The sample taken for analysis was collected from an open drain, and was quite free from any foreign matter; COUNTRY LABORATORY APPARATUS. No. II. ROUGH AND READY METHOD OF ESTIMATING By EDWARD T. HARDMAN, F.C.S., No. I. THE following short description of an extremely effective, cheap, and cleanly substitute for crucible jackets, &c., may be useful, especially to those who, like myself, have occasion to shift their quarters often, and are obliged to work with a necessarily limited laboratory accommodation. The ordinary crucible jacket being made of sheet-iron has in reality but one use-to protect the flame from currents of air. The small concentration of heat which it affords may be regarded as nearly nil, since, from the nature of the material and its thinness, radiation takes place very freely. Another drawback it has, is that it soon becomes rusty or coated with scale. It is not only dirty to handle therefore, but also presents the inconvenience of dropping some of its scale into the crucible if not carefully manipulated. Then it is an awkward thing to pack, taking up a good deal of space, rusting everything it comes in contact with, and behaving generally in a disagreeable manner; while, as it is not to be obtained in country towns, it may not be left behind. Now an ordinary earthenware flower-pot answers the purpose in every respect. It is the proper shape, and being made of a non-conducting material it in a great measure prevents loss of heat from the burner. It is extremely cleanly to use, and last but not least, it can be procured in every town or village at the small cost of one halfpenny or so; so that there is no necessity to cumber oneself with it when moving. The bottom of the flower-pot has a circular hole. This serves for the introduction of the Bunsen burner. As the supply of air would be insufficient otherwise it will be necessary to enlarge the opening. This can be easily done with a knife, and I find it best to cut the aperture nearly in the form of a cross, and not too large. One or two trials will give the happy medium. A current of air is then obtained which not only steadies the flame, but acts in some degree as a blast. The flower-pot may be supported in the ring of a retort stand in the usual way. The chimney is a second flower-pot inverted. To support it the handiest way will be to make three S hooks of stout wire, and having passed the narrow end of the pot upward through the ring, fix the rim within the hooks caught on the ring, as in fig. 1. CHEMICAL NEWS, Nov. 10, 1876. Country Laboratory Apparatus. It will be found convenient to devote a small retort stand permanently to the purpose. The whole arrangement is shown in fig. 2. This will be very handy, as the upper part can be raised to any desired height, regulating the heat and draught; or can be shifted from side to side, whenever it is desirable to inspect the progress of the operation going on. The apparatus acts admirably as a small gas furnace for crucible operations, such as the fusion of silicates with carbonate of soda-as in the analyses of rocks; while for simple ignition of precipitates it renders the flame of a common glass spirit-lamp most effective. The size of the flower-pot required will, of course, depend on that of the crucible and of the burner used. I find the smallest size, 3 inches high and about 3 inches diameter at top (internal), most generally useful. The support for the crucible may be either a triangle of wire covered with pipe shank, the end of the wire being bent upwards and formed into hooks so as to hang on the edge of the flower-pot (fig. 3), or three pipe-covered wires suspended in the position of the ribs of a crucible jacket. The former is necessary for small crucibles. The flower-pot also makes an excellent lamp screen, for steadying and concentrating the flame under evaporating basins, &c.; of course a sufficient interval must be kept between the pot and the basin, else the light will be extinguished. 199 whole is exposed to strong heat in the furnace for an hour or two, when the volatile matter is driven off. After cooling the difference of weight against that determined before ignition gives the volatile matter. Having occasion to determine the volatile matter of a coal, and not having at hand the elaborate arrangements referred to above, I bethought me of the schoolboy's method of manufacturing coal-gas. The retort he uses is a common clay tobacco pipe. A piece of coal is put in, the top is luted with clay, and the pipe is inserted in the fire-grate with the stem projecting. Presently a dense smoke issues from it, and a match being applied a veritable gas light-but not "16-candle "-results. On opening the luting a piece of coke is found in the pipe. I suppose most of us have performed this experiment. It is obvious that it is only necessary to weigh the pipe and contents before and after the operation, and we have the volatile matter and coke determined. The larger the pipe the better. Those I have used hold about 100 grains of coal broken small but not powdered. The pipe is weighed, then filled with the coal and weighed again to obtain weight of coal. Then inside the top is fitted a circular piece of writing-paper, the use of which is to prevent any of the luting getting down among the coal, where it could not be removed, and would falsify the last weighing. The top is luted with moist fireclay, or with the cement used for luting the covers of gas retorts, A small flower-pot with wire gauze tied over the top is | a very effective low temperature lamp when the gas is lighted below the gauze. If the gas is lighted above the gauze we have a capital argand lamp giving a large clear blue flame. In the latter case a common burner can be used, a consideration when Bunsen's are all temporarily occupied or not available. After a time the pots become cracked from the heat, but as they are easily replaced this does not matter, and even when cracked they will often hold out for a considerable time. Fireclay flower-pots made rather thick would, however, afford a really good cheap and portable furnace. It has just occurred to me that by placing the flowerpot inside another just large enough to encase it, loss of heat by radiation would be effectually checked. No. II. The usual method of estimating the volatile matter in coals implies a laboratory on rather an extensive scale. A furnace with a good draught is required. The coal is placed in a large porcelain crucible, which is then put into a Hessian crucible, and covered with powdered charcoal to exclude air. The cover being then put on, the Fig 3 and the pipe, being placed in a common coal fire or in a gas furnace that described above (No. I.) answers very well-from ten to twenty minutes completes the operation. When cool the luting is carefully taken off and the charred paper removed. The pipe and contents being then weighed, the loss gives the volatile matter, the same weighing, of course, determining the coke. If a very exact determination is required, a quantity of the coal may be broken small, well mixed together, and four pipes filled as above. They can all be ignited together in a fire, and weighed very quickly. The results will be found to agree very closely. The figures thus obtained do not differ from those given by the same coal assayed on the laboratory plan to a greater amount than will be found to occur between two experiments made on the same coal in the latter way. And the tobacco pipe process has the great advantage of being very expeditiously performed-the whole experiment including weighings not occupying more than thirty minutes-and with very simple apparatus. Kilkenny, October 9, 1876. 200 Action of Different Fatty Oils upon Metallic Copper. ON THE ACTION OF DIFFERENT FATTY OILS UPON By WILLIAM THOMSON, F.R.S.E., F.C.S. CHEMICAL NEWS, Nov. 10, 1876. METALLIC COPPER.* AT the Chemical Works at Aalborg, in Jutland, Denmark, where about 30 tons of alkali are made per week by the ammonia process, Mr. Thowald Schmidt, the Director of the Manufactory, proposes to work, in conjunction with this process, a method devised by himself of treating seaweed so as to obtain iodine, potash salts, and other marketable products therefrom. In Denmark a very heavy duty is levied on the importation of common salt, whilst enormous quantities of seaweed rich in iodine and potash can be obtained at small cost in the neighbourhood of the works. Mr. Schmidt's process is as follows:After the seaweed is dried and burnt a concentrated solution of the ash is made and added to the liquor containing chlorides of sodium and calcium, left after the ammonia has been recovered in the ammonia-soda process by boiling with lime. The sulphates of potash, soda, and magnesia contained in the ash of the seaweed are thereby decomposed, and hydrated sulphate of lime and hydrated magnesia are precipitated in a form which may be available for paper-making as "pearl-hardening." The last traces of sulphates are got rid of by adding a small quantity of solution of chloride of barium. To the clear solution nitrate of lead is now added until all the iodine is precipitated as iodide of lead, which is then separated by filtration and treated for the production of iodine or iodides. After filtration the liquid is boiled, nitrate of soda is added to convert the chloride of potassium present into nitrate of potash. The latter is separated by crystallisation. There remains a solution of common salt containing traces of ammonia from the previous soda operation and a trace of chloride of potassium. This solution is again treated by the ordinary ammonia-soda process for he production of bicarbonate of soda and white alkali. ON ANTHRACENE TESTING. By DR. FREDERICK VERSMANN. (Concluded from page 193). I HAVE stated at the beginning of this article that the failure with sulphuric acid induced me to look for another test and led me to the separation of the products of oxidation into crystals and powder. It was natural, therefore, that I should apply the sulphuric acid not only to the mixture but also to the two separate products, and the results thus obtained point with almost absolute certainty to the conclusion that the powder is practically useless, and is, in fact, no anthraquinone at all. I have tried the usual sulphuric acid and also fuming or Nordhausen acid, the use of which naturally suggested itself from its application in the al zarine manufacture. The results obtained do not sensibly vary, but I have adopted the last acid as the strongest and most active, and I may state that in speaking of sulphuric acid I always mean fuming or Nordhausen acid. The samples treated, a small proportion of which only are given in the first table, are so different that it is necessary to record the separate results; but I am anxious to condense the matter as much as possible, and I have therefore in the following table reduced to one-half the number of experiments of the first table. The treatment with acid was carried out in the following manner : The products of oxidation were for ten minutes heated in a small porcelain basin or in a large watch-glass with ten times their weight of acid at a temperature not exceeding 110° C.; they were then allowed to stand for. twelve hours, largely diluted with water and brought on a double filter, well washed, dried, and weighed. following table the first line of each number gives the In the |