CHEMICAL NEWS, Į SCIENTIFIC On the Estimation of Nitrites in the Presence of Nitrates. ANALYTICAL AND On the Estimation of Nitrites in the Presence of Nitrates, by CHARLES R. C. TICHBORNE, F.C.S., &c., &c., Chemist to the Apothecaries' Hall of Ireland. WHEN I undertook the task of working out the last process for estimating nitrites I thought that the problem would be one of extreme simplicity, and never calculated upon the numerous difficulties with which this project was attended. I have carefully gone through the modes recommended by other experimenters (of which there have not been many), and have also tried numerous original plans. From very few of these have I succeeded in getting accurate results. Of course, I now refer to direct modes of estimating nitrites, more particularly in the presence of nitrates. The difficulties are as follows: ist. All the processes of estimating nitrites directly must be essentially processes of oxidation, as we are not acquainted at present with any available precipitant.t Therefore arises the difficulty of estimating this compound by oxidation in the presence of a powerful oxidiser i.e., nitric acid. We have no available precipitant for this latter acid either by which we could dispose of it. 2nd. Another prolific source of error in the estimation of nitrites is one which seems to have been completely overlooked. It is the fact that at the slightest elevation of temperature nitrous anhydride, or nascent nitrous acid, is partially decomposed and oxidised into nitric acid when in the presence of water--that is, at the expense of that substance : 3N2O3+H2O=2HNO3+4NO. Experiments proving this will be referred to further on. The process recommended by Peligot, Lang, Jahresb., 1862, p. 581, is not applicable to the examination of nitrites containing nitrates. Also, the long digestion at an elevated temperature (twelve hours at 86° to 104° Fahr.) is inadmissible. Lang says he got results only 6 per cent. out, but I think he must have worked with pure nitrite of sodium. Feldhaus speaks against this process. In his experiments he seems to have got the results too high; the specimens of nitrite probably con. tained nitrate. This process seems, in my hands, to give results too low, after the nitrite had been correctly accounted for. The urea process has been unanimously condemned. Lang says it is bad, and Feldhaus also condemns it. As regards my own experiments, they were so unpromising that I did not carry on my exami nation of this method to any extent, for to attempt to estimate quantitatively free nitrous acid by a boiling solution is evidently radically wrong in principle.§ Read at the meeting of the Pharmaceutical Conference. Nitrite of silver, the most insoluble salt, if we except the cobalt yellows (basic potassio-cobaltic nitrite?), is readily soluble in water, unless the water is at a very low temperature. Whether the cobalt yellow is available for the estimation of nitrites is the subject of some experiments at present unfinished. 1 A known quantity of dry peroxide of lead is added to a diluted solution of the nitrite to be analysed, and the solution mixed with acetic acid. The whole is warmed for twelve hours-the weight of peroxide dissolved corresponds to the nitrous acid-1 at. peroxide i at. nitrous acid (2Pb2O2+zHNO, Pb,N2O, + Pb2H2O2). A standard solution of nitrate of urea is heated to boiling, and the solution of nitrite acidulated, is added drop by drop until the solution produces a blue colouration with starch paste and iodide of potassium. The decomposition is CH2N2O+2HNO2=CO2+N1+3H2O, carbonic anhydride and nitrogen being evolved. VOL. XII. No. 304.-SEPTEMBER 29, 1865. 147 Estimation by permanganic acid we shall dwell upon at some length, for two reasons: first, because the process has been strongly recommended by authorities; and, secondly, from the fact that, at first sight, this, of all the available oxidising substances, seems the most plausible. Permanganic acid is instantly decomposed, even at 32° Fahr., by nitrous acid; and, from the quickremedy the evils attendant upon this mode of estimation. ness of the reaction, many plans have been devised to From the gaseous nature of nitrous acid, it is not desirable to decompose the nitrites first by acids, preparatory to estimating them by a standard solution. To avoid this source of error, Pean de Saint-Gilles has recommended that the nitrite be decomposed by adding very diluted sulphuric or nitric acid. "This prevents a loss of nitrous acid;" but that this is not practically correct is evident from the fact that iodised starch paper becomes coloured on holding it in the orifice of the flask in which the nitrite is decomposed. Feldhaus says that the salt must be diluted with 2000 parts of water, and the reaction commenced in a very slightly acidulated liquid; when it is nearly completed, more acid may be added if necessary, so as to ensure the marking of the exact point. Lang condemns the process. There can be no doubt that by attention to the instructions given by Feldhaus, and by working at a very low temperature, ments was to add the nitrite under examination to a an approximation may be attained. One of my experiknown excess of permanganate of potassium, and, as nitric acid was present, to work off the excess by a volumetric solution of oxalic acid. It is, however, impossible to determine the analysis, as, towards the end of the process, a reaction takes place between the permanganic acid added, the manganous oxide resulting in a copious deposit of peroxide of manganese 2HMnO4 + 3 Mn,O - H2N 5MnO2. This reaction seems to take place even more readily in the presence of nitric acid. oxide of copper, intending to wash the oxide, and, on I attempted to decompose the nitrite by ignition with dissolving it in hydrochloric acid and chloride of sodium, to estimate the amount of cuprous oxide formed volumetrically; but I found, even after prolonged ignition, the nitrite was not decomposed. The most successful methods are those which I am now about to describe. But I must premise that in all processes of estimating nitrites by oxidation one thing must be borne in mind-that it is imperatively necessary to set free the nitrous anhydride at a low temperature in the presence of an excess of the oxidising material for it must be remembered that nitrous anhydride or nitrous acid, when liberated in the presence of water, is decomposed at slightly elevated temperatures. The following experiments will illustrate this fact:If, at an ordinary temperature, a small portion of nitrite of sodium be dropped into diluted sulphuric acid in a test tube, the following reaction will be observed :—The tube will be filled with orange-coloured vapour, whilst a piece of iodised starch paper, held over the orifice, will be slowly coloured. If, on the other hand, the test tube be placed in a freezing mixture, previously to addition of the nitrite of sodium, no orange fumes will be observed, but the colouration of the starch paper is instantaneous, and very decided. In the first instance the nitrous acid oxide, the latter being evinced by the orange fumes of was decomposed, as generated, into nitric acid and nitric pernitric oxide on its coming in contact with the atmo. sphere. From the oregoing it is evident that to estimate a nitrite by an oxidising reagent, it is better that the CHEMICAL NEWS, 148 Constitution of Acids belonging to the Acetic, Lactic, & Acrylic Series. Sept. 29, 1865. two be brought together at a temperature sufficiently low, that the oxidiser used may grapple with the nitrous acid previously to a reaction being set up between it and the water. Experiments have been tried to find the reaction of two of the principal oxidisers at a temperature of 32° Fahr. Permanganic acid was instantly decolourised. Chromic acid had no action at 32° Fahr., but on its being placed on one side, so as gradually to attain the temperature of the room, decomposition took place without the evolution of any nitrous oxide. As stated in a former part of this paper, by a judicious attention to a low temperature, and by a manipulation formed upon Feldhaus's plan, an analysis by permanganate of potassium may be performed, but still inferior in accuracy to the two processes I am now about to describe. The first process is based upon the reduction of chromic acid to chromic oxide by nitrous acid. This is not so quick as with permanganic acid, but is perfected slowly at ordinary temperatures. Suppose we are analysing a specimen of commercial nitrite of sodium, the mode of procedure I adopt is as follows:If the sample contains carbonate of sodium, a weighed quantity, say two grammes, is dissolved in a rather considerable quantity of water, and the carbonate estimated by a standard solution of sulphuric acid, carefully avoiding an excess. To hit the exact point of saturation, I soak a piece of good litmus-paper in the solution after the addition of each quantity of acid from the burette, and on drying it the exact state of the solution is perceived. I may here remark that most of the litmus-paper that is bought is not delicate enough for this kind of work, as it generally contains some trace of alkali. A convenient indicator of this point of saturation in this case will be found in a solution of starch and iodide of potassium contained in a test-tube: one drop of the solution of nitrite added after each addition of acid will, when the carbonate is all decomposed, strike a blue shade on falling through the starch solution. After noting the amount of carbonate, the solution is in a fit position for the estimation of the nitrite; the remainder may practically be noted as nitrate. Three grammes of pure bichromate of potassium for every two grammes of nitrite taken are dissolved with a little water in a flask fitted with a well-ground stopper; an excess of sulphuric acid is then added, and the flask is placed in a vessel containing a mixture of sulphate of sodium and hydrochloric acid. The solution of the nitrite may be placed also in the same freezing bath for a few minutes viously to being poured on the surface of the chromic acid without mixing; the stopper is then inserted, the flask taken out of the freezing mixture, inverted, and left to regain the ordinary temperature of the room; in the course of half an hour or an hour the flask will contain a mixture of chromic acid and chromic salt, the chromic oxide representing the nitrite in the sample. But here, again, in precipitating the chromic oxide a precaution is necessary. If there is any considerable excess of chromic acid left, which is generally the case, when examining commercial samples, the ordinary method of precipitating with ammonia would not do, as a brown precipitate of a peroxide of chromium (chromate of chromium ?) not decomposable by ammonia is thrown down, although the substance is instantly decomposed, upon boiling, by a solution of potash into chromic oxide and chromic acid. It is therefore necessary to nearly neutralise with potash, and finish off with a few drops of ammonia, and boil until all trace of the latter substance is gone; but if accidentally to pre much potash is added, a few drops of chloride of ammonium and a boiling for a few minutes will rectify the mistake. If the manipulation has been correctly performed, it will be indicated by the colour. The darkbrown colour instantly disappears on boiling, the precipitate obtaining the bright green of chromic oxide, whilst the solution becomes a bright yellow. The chromic oxide is washed, but for accurate results the hydrated chromic oxide retains the chloride of potassium too tenaciously to ignite and weigh directly. It is better to re-dissolve the washed hydrated chromic oxide in diluted hydrochloric acid, and to re-precipitate with ammonia in the usual manner. This gives the most exact results; but there are quicker methods. Thus, the hydrated chromic oxide might be washed and converted into chromic acid by Chancel's method (by peroxide of lead) and estimated volumetrically. Chromic oxide found x 1'354 nitrite of sodium. •* 4Cr2O3 + 3N2O3 = 3N2O5 + 2Cr103. The second process is based upon the first, that both nitrites and nitrates of the alkalies are converted into chloride, upon ignition with chloride of ammonium. Pure nitrite of sodium gives 84.78 per cent. of chloride of sodium, whilst nitrate of sodium only gives 68.82. From these data, it is therefore easy to calculate the percentage, as anything under 84.78 indicates the presence of nitrate. It must be borne in mind that if the specimen contains carbonate, this would give the percentage of nitrite too high. As 100 parts of carbonate would give 110:37 parts of chloride of sodium after ignition, therefore it will be necessary to deduct an equivalent quantity of chloride of sodium from the results before calculating them. A weighed quantity of the nitrite is intimately mixed with powdered chloride of ammonium, and introduced into a platinum crucible; a gentle heat is applied, until the whole of the excess of sal ammoniac and other gaseous bodies are volatilised. The residue is dissolved in water, and the chloride of sodium estimated volumetrically with a silver solution. CHEMICAL NEWS, acetic, lactic, and acrylic series. They had succeeded in building up the higher members of the acetic series from acetic acid itself, by the substitution of hydrogen in that acid atom for atom, by the alcohol radicals, methyl, ethyl, &c. Numerous new members of the lactic series had been in like manner constructed from oxalic acid by the substitution of one atom of oxygen (0 = 16) by two atoms of the alcohol radicals, whilst several members of the acrylic series had been produced from the lactic series by the abstraction of an atom of water from the latter. These investigations had led to the following conclu sions:- 1. The acids of all three series are constructed upon the radical type. They are all double radicals, composed of a chlorous and a basylous constituent. 2. The chlorous constituent is the same in all, and consists of an atom of methyl, in which two atoms of hydrogen are replaced by one of oxygen, and the remaining atom by hydroxyl, that in future times the important researches performed by Drs. Frankland and Duppa on the synthesis of organic acids would be looked upon as the true foundation of what might be termed the anatomy of organic chemistry. These researches, of which an admirably lucid account had been laid before them by Dr. Frankland, had produced a profound impression upon che mists. He had lately travelled leisurely from Berlin to Birmingham, visiting all the universities and schools that lay on his way. Wherever he came the first question of his chemical friends was invariably, Have you heard of the recent experiments of Frankland and Duppa? As a remarkable feature of these experiments he must mention that there was scarcely a chemist who had not, at one time or another of his scientific career, endeavoured to produce ethylacetic acid. The formation of this compound, which hitherto had been nothing more than a pleasant chemical dream, had at last been realised by a reaction which in beauty, simplicity, and generality could not be easily surpassed. It is this chlorous constituent which determines the The Reciprocal Action of Glycerine and Oxalic Acid; basicity of these acids. Propionic Acid. Butyric Acid. Its heterologous variation, on the other hand, gives rise application to the Industrial Preparation of Concen- FORMIC acid may be obtained by the splitting up of to 5 per cent. of real formic acid. to different series of acids, of which the acetic, lactic, I. Industrial Preparation of Formic Acid at and acrylic are examples. In the acetic series the basy with dehydrated or commercial glycerine is heated in a 56 Centiemes.-The mixture of ordinary oxalic acid lous constituent is always an alcohol radical derived from methyl (except in formic acid, where it is hydro-retort. At 75° the reaction will commence, and will be gen). In the lactic series it is an alcohol radical derived in full activity at 90°. Simultaneously with the disenfrom methyl, in which one of the typical atoms of hy-gagement of carbonic acid, an aqueous liquid passes, By the addition of a fresh drogen is replaced by hydroxyl (OH); whilst in the charged with formic acid. acrylic series it is a similar alcohol radical, in which two quantity of oxalic acid- added some time after the carof the typical atoms of hydrogen are replaced by a dia- bonic acid has ceased to be disengaged, the decomposition tomic member of the olefiant gas family. The relations immediately recommences; a liquid again passes still of these three series of acids to each other and to methyl oxalic acid, the richness in formic acid, of the liquid obricher in formic acid; and by successive additions of may therefore be thus simply expressed ::tained during this series of reactions, is always on the increase, until it reaches a limit which is precisely that which crystallised oxalic acid should give. The equation H C2 H H Acetic Series. Lactic Series. Acrylic Series. (H [H H H H он H Methyl. Acetic Acid. Glycolic Acid. Acrylic Acid. After the paper of which the foregoing is an abstract had been read, Dr. Hofmann, who temporarily occupied the chair, made the following observations : He sincerely regretted that in the temporary absence of their eloquent president it devolved upon him to address them on the memorable occasion of Dr. Frankland's communication. He congratulated the meeting on the privilege they had enjoyed in listening to a resume of a series of inquiries, which in his opinion would form an era in the history of organic chemistry. For many years one of the leading aspirations of philosophers, working in the field of organic chemistry, had been the elucidation of the internal constitutions of the endless variety of carbon compounds, but he thought = C1H2O8.4HO C2H2O4 + 4HO + C2O ̧ shows that 126 grammes of oxalic acid furnish 82 grammes of aqueous formic acid, which ought to contain, and, in fact, does contain, 56 per cent. of true formic acid. The existence of this limit is the result of the held back by the glycerine, with this polyatomic alcohol, repeated and successive combination of the formic acid, that the quantity of water eliminated from the glycerine -a combination rendered especially evident by the fact is equivalent to the quantity of formic acid fixed in each of the successive phases of the reaction. In one series of experiments the aqueous formic acid of 250 grammes, titrated 24, 44, 53; in a second series, from each kilogramme of oxalic acid, added in portions 17, 33, 41, 46, 50, and 515; the standard was raised more rapidly at the commencement of the operation. The excess of water, shown by these experiments to "Comptes Rendus, lxi., 382. exist in the first products, appears, then, to be the result of the formation of a compound of glycerine and formic acid, the acid being regularly produced only after this compound has ceased to be formed. The limit of saturation has been found to correspond to 70 centiemes of the quantity of formic acid which would have been necessary to saturate the glycerine, giving a monoformine. I This method of preparing formic acid of 56 per cent. is so continuous and regular that it is one of the easiest of chemical operations. No attention need be paid to the temperature, the disengagement of carbonic acid forming the initial and final phases of the operation. Starting with 1 kilogramme of glycerine, and by successively adding 250 grammes of oxalic acid, we obtain, for each kilogramme of acid added at one time, 650 grammes of formic acid at 56 per cent. It is moreover evident that under these conditions an equal weight of formic acid at 25 per cent. costs no more than the oxalic acid which has served to produce it; for by the addition of water, forming a litre of each quantity of formic acid collected in the second series of experiments, I obtained the standards 21, 26, 31, 33, 34. The glycerine being saturated, 1 kilogramme of oxalic acid furnished 15 kilog. of formic acid, at 25. The operation may be prolonged to any extent, and if after being used a long time it is found necessary to change the glycerine, it will be on account of the impossibility of avoiding the almost imperceptible losses, and of the presence of impurities in the oxalic acid. I have, however, used the same glycerine for several months, the operations continuing incessantly night and day. 11. Formic Acid at 75 Centiemes.-By making dehydrated oxalic acid act on saturated glycerine, I obtain formic acid at an average standard of 75. The heat, however, requires very careful management to avoid frothing. The decomposition of oxalic acid commences at 50°. III. Monohydrated and Crystallisable Formic Acid.- Monohydrated formic acid has hitherto been obtained by decomposing formiate of lead by sulphuretted hydrogen, a long and difficult operation, which in un practised hands is rarely successful. I have, in the first place, substituted formiate of copper, comparatively a very soluble salt, for formiate of lead, it being more casily crystallised, dehydrated, and decomposed by sulphuretted hydrogen, and giving the theoretical quantity of formic acid. This is probably not the only case in which salt of copper would be preferable to salt of lead for the preparation of organic acids. It occurred to me, however, that the 25 per cent. of water might be eliminated from the 75 per cent. acid by the use of anhydrous oxalic acid. On making this acid react at 70° on formic acid, the temperature rises, the mixture becomes liquid when carefully heated, and when left to stand it crystallises; by decanting and distilling to separate the dissolved oxalic acid, formic acid, at a standard of about 100 is obtained, which, by a proper lowering of the temperature, gives crystallisable formic acid. IV. Various Experiments. In the course of these researches I have observed the following facts: -1. That of all the formiates, formiate of copper alone when decomposed by heat, gives formic acid of only a certain degree of concentration-82. 2. Whatever precautions I have taken, I have rarely obtained acids at 70 by the action of sulphuric acid on formiates, and those always in relatively small quantities. With biformiate I have been not more successful. 3. The splitting up of ordinary or dehydrated oxalic acid under the influence of acetic and formic acids, may be utilised in the preparation of formic acid. 4. Dehydrated oxalic acid, submitted to the moderate action of heat, furnished in one experiment a considerable quantity of formic acid at 55. 5. From a theoretical point of view the use of sulphuric acid as an absorbent of aqueous vapour, is of some interest. I have operated on formic acid at 57'5 in the months of November and December, at the ordinary temperature of the laboratory; by once in every three days weighing and taking the standard, always at the same hour, I was enabled carefully to follow the phenomenon. Water is always absorbed more rapidly than the acid, and the standard rises to 63; the relation between the acid and water converges, and remains at about the limit 17. This relation, which differs a little from = 1704, seems to indicate, under these conditions, the existence of a hydrate of formic acid, corresponding to the formula On the Results of Agricultural Experiments in 1864, by Dr. STEVENSON MACADAM. THE experiments now referred to were undertaken at the author's suggestion by agriculturists in Roxburghshire, and they form one of the first series of field experiments undertaken in a systematic manner in Scotland. Twelve different manurial mixtures were used in the trials, and formed a set of experiments, whilst ten farmers made arrangements for carrying out the experiments in the field. The manurial mixtures employed consisted of Peruvian guano, phosphatic guano, phosphoguano, bone ash, superphosphate, guano superphosphate, sulphate of ammonia, and ground bones, taken singly or mingled together in definite proportions. The manures were analysed so as to be certain of their exact composition. In each set of experiments the various operations were conducted on the same day with the plots of ground allotted to each manure. The soils on which the experiments were made were in part of a heavy nature, and in other part of a light character-the proportion of each being equal. Each experiment was conducted on a quarter of an acre, and the twelve experiments consequently required three acres on cach farm. The crop was turnips, and the yield of produce was weighed on the field. The results obtained were various on the different farms, as the manures which gave the largest return on one farm did not yield the largest crop on another, These variations are to be expected in all field experiments, and are due to the special circumstances or conditions of each field where the trials are made. Where only one set of experiments are conducted on a single farm, the local influences may materially affect the results; but where, as in the present case, the field operations are conducted on teu farms, and the mean produce of the ten trials is obtained, then the disturbing influences of one farm are counteracted or practically neutralised by those of the other farms. Taking the mean produce from the ten trials, calculated to the same money value for each of the manures, the greatest return of crop was yielded by the dissolved phosphatic guano, followed closely by the Peruvian guano. Indeed, the difference in the produce obtained from the plots treated with these manures was so slight-only 19 lbs. to the acre-that they may be regarded as having yielded the same results. In referring to these experiments, it must be remembered that the season of 1864 was exceptionally dry, though the drought was not so great in Scotland as it was in England. The results obtained, however, are valuable as representing the produce obtainable in a dry season, and as a similar series of field experiments are being made this year in the same district, an opportunity will be obtained for contrasting the results for both years. -Abstract of Paper read at the British Association Meeting. On the Possibility of Manufacturing Neroli in the British Colonies, by Dr. J. E. DE VRIJ. WHEN on my way to Java in the month of October, 1857, I passed through the South of France, my attention was fixed by the large number of orange trees cultivated in the neighbourhood of Cannes, Grasse, &c., for the purpose of manufacturing néroli, which fragrant essence is exported from the southern parts of France, and from Italy, to England and other northern countries. The high price of this essence induced me to inquire if it would not be possible to manufacture it in the colony where I was going to reside for some years. A few months after my arrival in Java I fortunately had the opportunity of putting my idea into practice. In Bandoug, the town where I lived, which is situate at an elevation of about 2300 feet above the level of the sea, I was struck in the months of October and November by the fragrant smell of orange flowers, which perfumed the whole neighbourhood. Upon inquiring the cause I found there existed in that part many thousand shaddock trees (Citrus decumana) whose flowers were the cause of the fragrance. This fact appeared very curious to me, for although the fruit of the good kind of shaddock is one of the most delicious fruits in the tropics, this is only true when the tree is grown in very warm localities, as in the neighbourhood of Batavia, situate almost at the level of the sea in about 6° South latitude. In higher localities like that of Bandoug, where the average temperature is much lower than in Batavia, the fruit of the shaddock has only the size of an ordinary orange, and is not eatable. As the many thousand shaddock trees growing in the neighbourhood of Bandoug were therefore almost useless, I thought it interesting to make some experiments on the preparation of the essence of shaddock flowers. This seemed the more interesting to me as I found the shaddock tree growing at an elevation of about 4000 feet, producing an abundance of flowers. The fact that I once collected from one tree in my garden not less than 300 lbs. weight of flowers proves the abundance of flowers that may be obtained under happy circumstances. I must mention that the wood of the tree is very hard, and acquires a beautiful yellow colour; it may also prove to be of some value. After a great many distillations of several hundredweights of fresh flowers, the result was that the average quantity of essence yielded by 1000 lbs. weight of fresh flowers was 1 lb. Having ascertained the amount of product, the following question arises: Is the essence obtained by me from the petala of the shaddock trees identical with the *Read before the British Association Birmingham meeting. essence of orange flowers called néroli? The result of my experiments in this direction was, that the two essences are really identical, which conclusion was afterwards confirmed upon my return to Europe, by the principal manufacturers of perfumes, whom I consulted on this subject, and who declared the essence of shaddock flowers prepared by me to be identical with firstrate quality of néroli. Another question of importance also arises:-Would the manufacture of néroli in the tropical countries pay? This can only be answered by practical experience. In Java, where I made my experiments, the local circumstances are such that the manufacture would certainly pay. But besides the néroli obtained by distillation of the flowers, there remains in the still after the distillation a substance which deserves attention if ever my plan of preparing néroli in the tropical colonies should be carried out. If the residue in the still is thrown, yet boiling, upon a cloth, the clear yellowish liquid which passes through the cloth deposits after a few days a large amount of yellow crystals. My experiments with these crystals have proved that they are identical with the substance discovered in 1828 by Lebreton in unripe bitter oranges, and called by him "hesperidine." This hesperidine, which I find very widely spread in the genus Citrus, is the pure, bitter substance contained also in orange peels. As this hesperidine is a pure and quite innocent bitter substance, which can be obtained easily, and in tolerably large quantities, from shaddock flowers, it deserves, perhaps, attention as a substitute for hops. The Composition of Esparto Fibre, or Spanish_Grass, and its Employment in the Manufacture of Paper,† by Dr. STEVENSON MACADAM. DURING the last three years large quantities of a grass have been obtained from Spain, and been employed in from lands which are, comparatively speaking, waste, this country in the manufacture of paper. It is collected and, when delivered in Great Britain, costs about 57. 10s. to 67. per ton. The recent high price of rags necessarily caused a demand for esparto fibre as a substitute for rags in the manufacture of paper; and, should the demand continue, other countries than Spain-such as Barbary, which are known to yield the same grass—will no doubt contribute largely to the supply of the raw material. The chemical composition of an average supply of • esparto fibre is as follows:— Moisture Oil Albuminous compounds Ligneous fibre Starch, gum, and sugar Ash 9'62 In the manufacture of esparto fibre into paper, the material is first carefully examined and cleaned, and is then subjected to the action of a solution of caustic soda. The proportion of soda employed is oneeighth of the weight of the grass, being 14 lbs. of caustic soda to the cwt. of fibre, or 2 cwt. to the ton. The general size of boilers contains 12 cwt. of fibre, to which are added between 800 and 900 gallons of water, and 1 cwt. or 154 lbs. of caustic soda. The boilers are either close or open, and the boiling process is carried on for six or eight hours, during which time the soda dissolves away from the fibre the albuminous compounds, oil, resin, and silica; whilst the starch and gum are also abstracted, Read before the British ssociation. |