GAS CHEMISTS HANDBOOK COMPILED BY TECHNICAL COMMITTEE SUB-COMMITTEE ON CHEMICAL TESTS 1916 C. C. TUTW1LER, Chairman A. P. BEARDSLEY S. R. CHURCH W. H. FULWEILER R. G. GRISWOLD C. E. LEWARS J. M. MOREHEAD C. J. RAMSBURG E. C. UHLIG A. B. WAY ALFRED H. WHITE A. F. KUNBERGER, Editor PUBLISHED BY THE AMERICAN GAS INSTITUTE NEW'YORK CITY \ ft^ CONTENTS CHAPTER I. RAW MATERIALS Coal Coke Gas Oil Purification Material CHAPTER II. PRODUCTS -OF GAS MANUFACTURE Illuminating Gas Ammonia Tar Cyanogen CHAPTER III. IMPURITIES IN GAS Hydrogen Sulphide Carbon Bisulphide Ammonia Tar Naphthalene Cyanogen CHAPTER IV. TAR PRODUCTS " JHbtler<0$ (Drip Oil) " Tar Oils Road Tars Naphthalene Salts CHAPTER V. MISCELLANEOUS Construction Materials Alloys Lubricating Oils TABLES * (The Institute is not responsible for statements of facts or opinions expressed in advance papers. This paper is subject to revision by the Board of Directors.) (Copyright, 1916, by American Gas Institute.) REPORT OF COMMITTEE ON CHEMICAL TESTS. WRITTEN FOR THE ELEVENTH ANNUAL, MEETING OF THE AMER- ICAN GAS INSTITUTE, OCTOBER, 1916, BY C. C. TUTWILER, CHAIRMAN. Since the last meeting of the Institute, the Committee on Chemical Tests has directed its activities chiefly toward the revision of the Gas Chemists' Handbook, compiled in 1914 by Mr. W. H. Fulweiler. Mr. Fulweiler, in presenting his report at the Ninth Annual Meeting of the Institute, stated as follows : The magnitude and delicacy of this work is fully realized and this is presented primarily as a progress report. In time, the Institute would be well repaid for the expense incurred in the publication of such a handbook by the uniformity of practice that would result from the adoption of these methods and by the convenience to the gas chemist of having recognized standard methods pertaining to the industry collected in one convenient publication. While this first issue of the Handbook was a very decided step in the right direction, it was recognized that much was still to be accomplished and the continuance of the work de- volved upon the 1915 Committee on Chemical Tests. This Committee was unable to do more than report satisfactory progress at the 1915 meeting of the Institute and the same Committee was re-appointed to continue the revision over 1916. It was felt from the start that it was of first importance that the work should be carried out by a committee whose activi- ties covered as wide a field as possible, not only in the gas industry but in collaterial lines as well, especially in the coke oven and coal tar by-product industries which are becoming 452052 yearly more closely identified with the gas business. For this reason, special effort was made to enlist the co-operation of chemists skilled in these various lines and I have felt myself and the Institute most fortunate in having secured the assist- ance of the gentlemen who served with me on the Committee in 1915 and 1916. Mr. Fulweiler, in concluding his report, states : It is urged that special attention be given to the question of standard methods and to the peculiar conditions under which samples must be taken in the gas industry. The Committee has felt with Mr. Fulweiler that the stand- ardization of methods of testing and sampling was the chief consideration to which it should devote its attention, and in the Handbook which we now offer for your consideration, we have endeavored to round out as far as possible the work of the first committee and to standardize and bring up-to-date methods which have been developed or improved since the work was inaugurated in 1914. It is hoped that owing to the wide connections of the members of the Committee and the various sources from which these methods have been drawn that progress has been made toward the accomplish- ment of this much desired result. The Committee has devoted a considerable amount of time to the consideration of proper methods of sampling, recog- nizing the fact that unless the sample is properly taken, the analysis might not only be worthless, but absolutely mislead- ing. We have endeavored to have the directions for sampling as well as for testing so clear that little difficulty will be en- countered even by chemists of limited experience. The Committee, recognizing the great progress being made in the application of chemistry to the gas industry and feeling that even companies of moderate size can well afford to have on their staff chemists or men of some chemical training, has kept in mind primarily the assistance of these men rather than the engineer, although it has endeavored to present the subject matter in a manner which may be easily understood by all. It will be noted that no attempts have been made to interpret the results of the analyses, nor have theoretical considerations been touched upon to any great extent, it being felt that this phase of the subject might better be left to succeeding com- mittees, possibly to be covered in a separate publication. We have included in the Handbook such of the most useful tables of constants and data as are most frequently required. But in view of the fact that there are now so many reference books readily available, matter of this kind has been kept to a minimum. While the Committee feels that distinct progress has been made in the Handbook, it is not prepared to recommend that all of the methods contained therein be stamped with the official approval of the Institute without further revision by succeeding chemical test committees or by a special com- mittee appointed for the purpose, except possibly the methods covering the analyses of coal and coke, cement, and iron and steel. All of these may safely be adopted, it is thought, since the method for analyses of coal and coke is based on the work of the Bureau of Mines and those for cement, iron and steel are the official methods of the American Society for Testing Materials. The desirability, however, of having the whole work officially approved by the Institute seems apparent and since its value would be so much increased by such action of the Institute, the Committee feels that no unnecessary time should be lost in taking the necessary steps to further stand- ardize and enlarge the work. In conclusion, I wish to express to the various members of the Committee, my appreciation of their efforts in behalf of the success of the Handbook and especially of the efforts of those gentlemen not directly engaged in the gas business, who have given their assistance. It seems proper in this connection to make special mention of the work of Mr. S. R. Church, Manager, Research Department, The Barrett Company. I also wish to express my appreciation of the efforts of Mr. A. F. Kunberger, who was appointed editor of the Hand- book since the last meeting of the Institute and upon whose shoulders has devolved most of the work in connection with 2d getting into suitable form for publication the. data secured by the Committee. C. C. TUTWILER, Chairman, A. P. BEARDSI,EY, 1 S. R. CHURCH, W. H. FUIAVEH,KR, R. G. GRISWOLD, J. M. MOREHEAD, E. C. UHWG, C. R. RAMSBURG, A. B. WAY, A. H. WHITS. (The Institute is not responsible for statements of facts or opinions expressed in advance papers. This paper is subject to revision by the Board of Directors.) (Copyright, 1916, by American Gas Institute.)' GAS CHEMISTS' HANDBOOK. CHAPTER I. COAL AND COKE. The following determinations are covered in the analysis of coal and coke : Air-Drying Loss. Moisture. Volatile Matter. Fixed Carbon. Ash. Sulphur. Phosphorus. Calorific Value. Carbon. Hydrogen. Nitrogen. Oxygen. Shatter Test for Coke. Apparent and Real Specific Gravity. These determinations are based on reports of Committee "E~4" of the American Society for Testing Materials, on Tech- nical Papers No. 8 and No. 76 of the Bureau of Mines. COAI, SAMPLING The coal should be sampled at the time it is being unloaded from railroad cars or other means of transportation. To collect samples, a shovel or specially designed tool or mechanical means should be used for taking increments of 10 to 30 pounds of coal. The size of the increments must depend on the size and weight of the largest pieces of coal and im- purities. The increments must be regularly and systematically col- lected, so that the entire delivery will be represented propor- tionately in the gross sample. The frequency of collecting the increments should be regulated so that a gross sample of not less than 1,000 pounds will be collected. If the coal contains an unusual amount of impurities, such as slate, and if the pieces of such impurities are very large, a gross sample of more than 1,000 pounds should be collected. A gross sample of the above specified quantity should be taken for delivery of 500 tons or less. When deliveries are made in large quantities as in cargoes of from 2,000 to 12,000 tons, the size of the gross sample must be governed by the size and amount of the free impurities. A gross sample of from 2,000 to 4,000 pounds is sufficient for reasonable accuracy un- less the size and amount of the free impurities are unusually large. After the gross sample has been collected it must be system- atically crushed, mixed and reduced in quantity to convenient size for transmittal to the laboratory. The crushing should be done by a mechanical crusher or by hand with a tamper or hammer on a smooth and solid floor. In the absence of a smooth, tight floor, the crushing may be done on a heavy canvas, to prevent the accidental admixture of any foreign matter. The mixing and reduction should be done by hand, with a shovel, or mechanically, by means of riffles or sampling machines. The sizes to which the coal and impurities should be crushed are approximately as here given. Size to which pieces Weight of sample should be broken to be divided before each division 1,000 pounds or more I inch 500 pounds y inch 250 pounds y-2 inch 125 pounds y% inch 60 pounds y^ inch If the sample is prepared by hand, the mixing and reducing should be done by the "long pile and alternate shovel" method on amounts of 125 pounds or more, the procedure being as follows : The crushed coal is shoveled into a conical pile. A long pile is formed by taking a shovelful at a time and spreading it out in a straight line (8 to 10 feet long for a shovel holding about 15 pounds). Each new shovelful is spread over the top of the preceding one, beginning at opposite ends, the pile being occasionally flattened with the flat side of the shovel and so on until all the coal has been formed into one long pile. By walking around the long pile, advancing a distance equal to the width of the shovel, and systematically taking shovel- fuls, and shoveling the coal to one side, alternate shovelfuls being discarded, the sample will be halved in quantity. Whenever the different increments of sample are collected throughout some considerable period of time, each increment or an accumulation of a number of increments, may be crushed as soon as taken and the pieces of coal and impurities broken sufficiently small to permit two or more reductions of total accumulated sample before further crushing is necessary. If the sampling should extend over any considerable period, w r hat would otherwise be a gross sample may be w r orked down in successive stages to samples of a size suitable for transmittal to the laboratory, and these samples which should be approxi- mately equal in quantity and as representing the several equal parts of a delivery may be analyzed and the several analyses averaged. Preparation of Laboratory Samples. ''The quantity of sample sent to the chemist will be governed by the relative proportion of free impurities and the practical limits of fineness to which these impurities can be crushed at the point of sampling. Ordinarily 5 pounds crushed to pass a 4-mesh screen is a convenient sample to send to the labora- tory." In cases where it is not feasible to crush to 4 mesh at the point of sampling, the weight of the sample sent to the laboratory must conform to the following table : Size of largest Minimum weight impurities of sample In. i,b. V 2 75 3 /8 30 V* 9 3 / 16 or smaller 5 Samples of 125 pounds and less may be reduced to the 5- pound quantity by a riffle sampler or on a canvas as follows : The sample is placed on a canvas about 8 feet square and mixed by raising first one end of the canvas and then the other, thereby rolling the sample back and forth. After thoroughly mixing in this manner, by gathering up the four corners of the canvas, the sample will be formed into a conical pile and is to be reduced in quantity by quartering. The cone is flat- tened, its apex being pressed down with the flat side of the shovel, or with a board, so that each quarter contains the ma- terial originally in it. The flattened mass which should be of uniform thickness and diameter is then marked off into quar- ters with the board held edgewise or with a piece of sheet iron, along two lines that intersect at right angles directly under the apex of the original cone. The diagonally opposite quarters are shoveled away and discarded and the space which they occupied brushed clean. The coal remaining is successively mixed, coned and quartered on the canvas until two opposite quarters are equal to the quantity required to fill two contain- ers holding about 5 pounds each. The coal should be well packed in the containers so as to exclude air as much as possi- ble. Special Moisture Sample. In the reduction of the gross sample to the sample for trans- mittal to the laboratory, there will be an unavoidable loss of moisture. To determine the moisture content in the coal, a separate special moisture sample must be taken. This special moisture sample should contain approximately 100 pounds and should be accumulated by placing in a water- proof receptacle, with a tight fitting and waterproof cover, small parts of the freshly taken increments of the gross sample. These parts should be broken to about ^2 inch in size as accumulated. The accumulated moisture sample must be reduced mechan- ically or by hand as quickly as possible and immediately placed in a container and sealed air-tight. Sampling from Loaded Cars. If it becomes necessary to sample coal from a loaded car, the sample should be accumulated by digging ten or fifteen holes, two or three feet deep, at systematically located points over the car. Sampling from a Storage Pile. In sampling from a pile, first estimate the approximate sur- face of the pile and then determine the relative distance be- tween points for taking increments, sufficient in number to insure the accumulation of the requisite amount of gross sample. Starting at three or four feet from the bottom of the pile, take shovelfuls at the predetermined distance apart around or along the pile on the same level. Then begin at a certain distance up the pile and circle it again so on to the top. Systematically alternate the depth of the holes, taking one shovelful at the surface, the next one deeper, the next still deeper, the fourth at the surface again and so on. Sampling at the Mines. The sample should be systematically accumulated through- out at least one entire day's loading. The total weight of 8 sample taken should be governed by the size and amount of impurities contained in the coal. Samples should not be taken from the tops of loaded mine cars as they are likely to be trimmed with lumps and also because pieces of roof or draw slate may have fallen onto the car. Samples of the coal being shipped should be taken while the railroad cars are being loaded. If any attempt is being made to throw out impurities w T hile loading, shovelfuls should be taken from the slanting surface just before a new mine car is dumped and after the pickers have finished cleaning the one previously dumped. The shovel should be pushed well into the coal to avoid getting only that on the surface from which impurities have been picked, and the shovelfuls should be taken systematically from various parts of the surface. SAMPLING COKE. The amount of gross sample of coke that should be accumu- lated depends on the size of the coal and the size and amount of impurities in the coal from which the coke is made. In general coke is made from slack or crushed coal and in the crushing and handling of the coal preparatory to charging it into the ovens, it becomes so well mixed that errors due to variations in its quality are minimized. A ioo-pound sample of coke is usually sufficient, to obtain accuracy for a single car, but where larger lots are to be sampled especially when the entire output of a plant is to be sampled, four or five separate samples of 50 pounds or more should be taken and the results averaged. Physical appearance as regards color and porosity is no in- dication of the chemical analysis. In general, the moisture content increases as the size of the pieces of coke diminishes and to some extent this graduation is true in the ash content as well. It is necessary, therefore, especially in sampling run of oven coke that due care should be exercised to obtain the proper proportions of lump and fines. A great many small pieces from many different parts of the lot should be taken by breaking off long slender fingers from the lumps, and there should also be included pieces of all sizes and shapes. A special moisture sample should be taken as in the case of coal, except that the time should not be spent in crushing finer than i inch for the reason that in the crushing and mixing of coke, the moisture loss is much more rapid than with coal. Preparation of Laboratory Sample. APPARATUS. Air-Drying Oven. The oven is to be used for air-drying wet samples. It is not necessary but is economical where many wet samples are received. 1 - Galvanised Iron Pans 18 x 18 x 1^2 Inches Deep. For air- drying wet samples. Balance on Solution Scale. For weighing the galvanized pans with samples. It should have a capacity of 5 kilograms and be sensitive to 0.5 kilogram. Chipmunk Jaw Crusher. For crushing coarse samples to pass a 4-mesh sieve. Roll Crusher or Coffee Mill Type of Grinder. For reducing the 4-mesh product to 2o-mesh. The coffee-mill type of grinder should be entirely enclosed and have an enclosed hopper and a receptacle capable of holding 5 pounds of coal. This is to reduce the moisture losses while crushing. Abbe Ball Mill, Planetary Disk Crusher, Chrome Steel Buck- ing Board, or any Satisfactory Form of Pulverizer. For re- ducing the 2O-mesh product to 6o-mesh. The porcelain jars for the ball mill should be approximately 9 inches in diameter and 10 inches high. The flint pebbles should be smooth, hard and well rounded. "The reduction in size of coke for the laboratory should not be done by grinding in an apparatus which will give up fine particles of iron to the sample. A 1 For details of air-drying oven, see Bownocker, lyord and Somermeier, "Coal" Bulletin No. 9, 4th series, Ohio Geological Survey, P. 312 (1908); or F. M. Stanton and A. C. Fieldner, "Methods of Analyzing Coal and Coke," Technical Paper No. 8, Bureau of Mines, P. 4 (1912); or E. E). Somermeier, "Coal, Its Composition, Analysis, Utilization and Valuation," P. 71, McGraw-Hill Book Co., (1912). 10 jaw crusher which will reduce to 8-mesh and an Abbe Ball Mill for further reduction is recommended." A Large Riffle Sampler with y* or y% inch Divisions. For reducing the 4-mesh sample to 5 pounds. 2 A Small Riffle Sampler with y^. or y% inch Divisions. For dividing down the 20 and 6o-mesh material to a laboratory sample. An 8 inch 6o-mesh Sieve with Cover and Receiver. Containers for Shipment to Laboratory. A galvanized iron or tin can with a screw top, which is sealed with a rubber gas- ket and adhesive tape is best adapted to this purpose. Glass fruit jars, sealed with rubber gaskets may be used if packed carefully to avoid breakage in transit. Upon receipt of the sample at the laboratory, it is to be pre- pared for analysis by one of two methods, as follows : (A) WHEN COAI, APPEARS DRY. If the sample is coarser than 4-mesh (0.20 inch) and larger in amount than 10 pounds, quickly crush it with the jaw crusher to pass a 4-mesh sieve and reduce it on the larger riffle sampler to 10 pounds, or to 5 pounds if it is crushed to pass a 6-mesh sieve; then crush it at once to 2O-mesh by passing through rolls or an enclosed grinder, and take, without sieving, a 60 gram total moisture sample, immediately after the ma- terial has passed through the crushing apparatus. This sample should be taken with a spoon from various parts of the 20- mesh product, and should be placed directly in a rubber- stoppered bottle. Thoroughly mix the main portion of the sample, reduce on the small riffle sampler to about 120 grams and pulverize to 6o-mesh by any suitable apparatus without regard to loss of moisture. After all the material has been passed through the 6o-mesh sieve, mix and divide it on the small riffle sampler to 60 grams. Transfer the final sample to a 4-ounce rubber-stoppered bottle. - For details of riffle sampler see Bulletin No. 9, 4th Series, Ohio Geological Survey, P. 313 (1908), or 15. K. Somermeier, "Coal, Its Composition, Analysis, Utiliza- tion and Valuation," P. 73, McGraw-Hill Book Co., (1912). II Determine moisture in both the 60 and the 2O-mesh samples by the method given under moisture. Computation. Compute the analysis of the 6o-mesh coal, which has become partly air-dried during sampling, to the dry coal basis, by dividing each result by I minus its content of moisture. Compute the analysis of coal "as received" from the dry coal analyses by multiplying by I minus the total moisture found in the 2O-mesh sample. (B) WHEN COAI, APPEARS WET. Spread the sample on tared pans, weigh, and air-dry at room temperature, or in a special drying oven, at 10 to 15 C. above room temperature, and weigh again. The drying should be continued until the loss in weight is not more than o.i per cent, per hour. Complete the sampling as under dry coal. Computation. Correct the moisture in the 2o-mesh, air- dried sample to total moisture "as received" as follows : TOO percentage of air-drying loss r X percentage of moist- 100 ure in 2o-mesh coal -f- percentage of air-drying loss = total moisture "as received." Compute the analysis to "dry coal" and "as received" bases as under dry coal, using for the "as received" computation the total moisture as found by the formula in place of the moisture found in the 2O-mesh coal. Notes. Freshly mined or wet coal loses moisture rapidly on exposure to the air of the laboratory, hence the sampling oper- ations between opening the container and taking the 2O-mesh total moisture sample must be conducted with the utmost dis- patch and with minimum exposure to air. The accuracy of the method of preparing laboratory samples should be checked frequently by resampling the rejected por- tions and preparing a duplicate sample. The ash in the two samples should not differ more than the following limits : No carbonates present 0.4 per cent. Considerable carbonate and pyrite present. . . 0.7 per cent. Coals with more than 12 per cent, ash, con- taining considerable carbonate and pyrite i.o per cent. 12 Determination of Moisture. 3 APPARATUS. Moisture Oven. This must be so constructed as to have a uniform temperature in all parts and a minimum of air space. It may be of the form shown here. Technical Paper No. j6, Bureau of Mines. FIG. i. Provision must be made for renewing the air in the oven at the rate of two to four times a minute, with the air dried by passing it through concentrated sulphuric acid. 3 This method can not be applied to lignites which have to be dried at a much higher temperature. 13 Capsules with Covers. A convenient form, which allows the ash determination to be made on the same sample, is the Royal Meissen Porcelain capsule No. 2, % inch deep and i% inches in diameter ; or a fused silica capsule of similar shape. Ihis is to be used with a well-fitting flat aluminum cover. Glass capsules with ground glass caps may also be used. They should be as shallow as possible, consistent with convenient handling. METHOD. (A) SIXTY-MESH SAMPLE. Heat the empty capsules under the conditions at which the coal is to be dried. Stopper and cover, cool over concentrated sulphuric acid, specific gravity 184, for 30 minutes and weigh. Dip out with a spoon or spatula from the sample bottle ap- proximately I gram of coal; put this quickly into the capsule, close and weigh at once. An alternate procedure (more open to error) after trans- ferring an amount slightly in excess of I gram is to bring to exactly I gram in weight (0.5 milligram) by quickly removing the excess weight of coal with a spatula. The utmost dispatch must be used in order to minimize the exposure of the coal until the weight is found. After removing the covers, quickly place the capsules in a pre-heated oven (at 104 to 110 C.) through which passes a current of air dried by concentrated sulphuric acid. Close the oven at once and heat for I hour. Then open the oven, cover the capsules quickly and place them in a desiccator over concentrated sulphuric acid. When cool, weigh. (B) TWENTY-MESH SAMPLE. Use 5 gram samples, weigh with an accuracy of 2 milli- grams, and heat for i l /> hours; the procedure is otherwise as with the 6o-mesh sample. Methods of greater accuracy may be found in the "Proceedings of the American Society for Testing Materials," Vol. XIV, 1914, p. 421. The allowable variations are as follows : 14 Same analyst Different analyst per cent. per cent. Moisture under 5 per cent. 0.2 0.3 Moisture over 5 per cent. 0.3 0.5 Determination of Volatile Matter. APPARATUS. Platinum Crucible with Tightly Pitting Cover. The crucible should be of not less than 10 nor more than 20 cubic centi- meters capacity: of not less than 25 nor more than 35 milli- meters in diameter ; of not less than 30 nor more than 35 milli- meters in height. Vertical Electric Tube Furnace; or a Gas or Electrically Heated Muffle Furnace. The furnace may be of the form as shown here (p. 21, Technical Paper No. 76, Bureau of Mines). It is to be regulated to maintain a temperature of 950 C. (-J-2O C.) in the crucible, as shown by a thermo-couple in the furnace. METHOD. Weigh I gram of the coal in a weighed 10 to 20 cubic centi- meter platinum crucible, close with a capsule cover, and place on platinum or nichrome-wire supports in the furnace chamber, which must be at a temperature of 950 C. (+ 20 C.). After the more rapid discharge of volatile matter has subsided, as shown by the disappearance of the luminous flame, tap the cover lightly to more perfectly seal the crucible and thus guard against the admission of air. After heating exactly 7 minutes, remove the crucible from the furnace and, without disturbing the cover, allow to cool. Weigh as soon as cold. The loss of weight minus moisture equals volatile matter. ALTERNATE METHOD. One gram of coal is placed in a platinum crucible of 20 cubic centimeters capacity. The crucible should have a tightly fitting cover as above. The crucible is placed in the flame of a Meker burner, size No. 4, having approximately an outside diameter at the top of 25 millimeters and giving a flame not less than 15 centimeters high. The temperature should be FIG. 2. i6 from 900 to 950 C., determined by placing a thermo-couple through the perforated cover, which for this purpose may be of nickel. The junction of the couple should be placed in contact with the center of the bottom of the crucible; or the temperature may be indicated by the fusion of pure potassium chromate in the covered crucible (fusion of K 2 CrO 4 , 940 C.). FIG. 3. The crucible is placed in the flame about i centimeter above the top of the burner and the heating is continued for 7 min- utes. After the main part of the gases have been discharged the cover should be tapped into place as above described. 17 When the gas pressure is variable it is well to use a U-tube attachment to the burner to show the pressure. Mechanical losses are incurred on suddenly heating peat, sub-bituminous coal, and lignite; therefore they must be sub- jected to a preliminary gradual heating for 5 minutes; this is best done by playing the flame of a burner upon the bottom of the crucible in such a manner as to bring about the discharge of volatile matter at a rate not sufficient to cause sparking. After the preliminary heating, transfer the crucible to the vol- atile matter furnace or place in the full flame of the Meker burner and heat for 6 minutes at 950 C., as in the regular method. The allowable variations are as follows : Same analyst Different analyst per cent. per cent. Bituminous coals 0.5 i.o Lignites I .o 2.0 Notes. The cover should fit closely enough so that the car- bon deposit from bituminous and lignite coals does not burn away from the under side. Regulation of temperature to within prescribed limits is im- portant. Determination of Fixed Carbon and Ash. APPARATUS. Gas or Electric Muffle Furnace. The muffle should have a good air circulation and be capable of having its temperature regulated between 700 and 750 C. Porcelain Capsules. Royal Meissen Porcelain Capsules No. 2, y% inch de.ep and ify inches in diameter, or similar shallow dishes. METHOD. Place the porcelain capsules containing the dried coal from the moisture determination in a cold muffle furnace, or on the hearth at a low temperature, and gradually heat to redness at such a rate as to avoid mechanical loss from too rapid ex- pulsion of volatile matter. i8 Finish the ignition to constant weight ( o.ooi gram) at a temperature between 700 and 750 C. Cool in air and weigh as soon as cold. Coals containing carbonate are best cooled in a desiccator. The results as determined by this method represent the ignited mineral matter in the coal. The actual mineral matters in the original coal are usually very different in weight and composition. The application of corrections for sulphur pres- ent in the iron pyrites and for the volatile ash constituent due to hydration of clayey material, may be omitted for technical purposes. For "corrected" ash see Jour. Ind. and Eng. Chem., Vol. 5, June, 1913, p. 523, and Technical Paper No. f6, Bureau of Mines. The allowable variations are as follows : Same analyst Different analyst per cent. per cent. No carbonates present 0.2 0.3 Carbonates present 0.3 0.5 Coals with more than 12% of ash containing carbonates and py- rite 0.5 i .o FIXED CARBON. Compute as follows : 100 := (moisture + ash + volatile matter) percentage of fixed carbon. SULPHUR. ESCHKA METHOD. Apparatus. Gas or Electric Muffle Furnace, or Burners. For igniting coal with Eschka mixture and for igniting the barium sulphate. Porcelain, Silica, or Platinum Crucibles or Capsules. For igniting coal with the Eschka mixture. No. i. Royal Meissen porcelain capsule, I inch deep and 2 inches in diameter. This capsule because of its shallow form, presents more surface for oxidation and is more convenient to handle than the ordinary form of crucible. 19 No. i. Royal Berlin porcelain crucibles, shallow form, and platinum crucibles of similar size may be used. Somewhat more time is required to burn out the coal owing to the deeper form, than with the shallow capsules described above. No. o or oo porcelain crucibles, or platinum, alundum or silica crucibles of similar size are to be used for igniting the barium sulphate. SOLUTIONS AND REAGENTS. Barium Chloride. Dissolve 100 grams of barium chloride in 1,000 cubic centimeters of distilled water. Saturated Bromine Water. Add an excess of bromine to 1,000 cubic centimeters of distilled water. Eschka Mixture. Thoroughly mix two parts (by weight) of light calcined magnesium oxide and one part of anhydrous sodium carbonate. Both materials should be as free as possi- ble from sulphur. Methyl Orange. Dissolve 0.02 gram in 100 cubic centi- meters of hot distilled water and filter. Hydrochloric Acid. Mix 500 cubic centimeters of hydro- chloric acid, specific gravity 1.20 and 500 cubic centimeters of distilled water. Normal Hydrochloric Acid. Dilute 80 cubic centimeters of hydrochloric acid, specific gravity 1.20 to I liter with distilled water. Sodium Carbonate. A saturated solution, approximately 60 grams of crystallized or 22 grams of anhydrous sodium car- bonate in 100 cubic centimeters of distilled water. Sodium Hydroxide Solution. Dissolve 100 grams in I liter of distilled water. This solution may be used in place of the sodium carbonate solution. METHOD. Preparation of Sample and Mixture. Thoroughly mix on glazed paper I gram of coal and 3 grams of Eschka mixture. Transfer to the crucible or capsule and cover with about I gram of Eschka mixture. 20 Ignition. On account of the amount of sulphur contained in artificial gas, it is preferable to heat the crucible over an alcohol flame or in an electrically heated muffle, as in (a) fol- lowing. The use of artificial gas is permissible only when crucibles are heated in a muffle as in (b) following. (a) Heat the crucible, placed in a slanting position on a triangle, over a very low flame to avoid rapid expulsion of the volatile matter, which tends to prevent complete absorp- tion of the products of combustion of the sulphur. Heat the crucible slowly for 30 minutes, gradually increasing the tem- perature and stirring after all black particles have disappeared, which is an indication of the completeness of the procedure. (b) Place the crucible in a cold gas muffle and gradually raise the temperature to 87o-925 C. (cherry-red heat) in about i hour. Maintain the maximum temperature for about ij/2 hours and then allow the crucible to cool in the muffle. Subsequent Treatment. Remove and empty the contents into a 200 cubic centimeter beaker and digest with 100 cubic centimeters of hot water for ^< to ^4 hour, with occasional stirring. Filter and wash the insoluble matter by decantation. After several washings in this manner, transfer the insoluble matter to the filter and wash five times, keeping the mixture well agitated. Treat the filtrate amounting to about 250 cubic centimeters, with 10 to 20 cubic centimeters of saturated bromine water, make slightly acid with hydrochloric acid and boil to expel liberated bromine. Make just neutral to methyl orange with sodium hydroxide or sodium carbonate solution. Then add I cubic centimeter of normal hydrochloric acid. Boil again and add slowly from a pipette, with constant stirring, 10 cubic centimeters of a 10 per cent, solution of barium chloride. Continue boiling for 15 minutes and allow to stand for at least 2 hours, or preferably over night at a temperature just below boiling. Filter through an ashless filter paper and wash with hot distilled w^ater until a silver nitrate solution shows no precipitate w r ith a drop of the filtrate. Place the wet filter containing the precipitate of barium sulphate in 21 a weighed platinum, porcelain, silica or alundum crucible, allow a free access of air by folding the paper over the precip- itate loosely to prevent spattering. Smoke the paper off grad- ually and at no time allow it to burn with a flame. After the paper is practically consumed, raise the temperature to approx- imately 925 C., and heat to constant weight. The residue of magnesia, etc., after bleaching, should be dissolved in hydro- chloric acid and tested with great care for sulphur. When an appreciable amount is found it should be determined quanti- tatively. 4 Blanks and Corrections. In all cases a correction must be applied either (i) by running a blank exactly as described above, using the same amount of all reagents that were em- ployed in the regular determination or (2) by determining a known amount of sulphate added to a solution of the reagents after these have been put through the prescribed series of operation. If this latter procedure is adopted and carried out, say, once a week or whenever a new supply of a reagent must be used, and for a series of solutions covering the range of sulphur content likely to be met with in coals, it is only necessary to add to or subtract from the weight of barium sulphate obtained from a coal. Whatever deficiency or excess may have been found in the appropriate "check" in order to obtain a result, that is more certain to be correct than if a "blank" correction as determined by the former procedure is applied. This is due to the fact that the solubility error for barium sulphate, for the amounts of sulphur in question and the conditions of precipitation prescribed, is probably the largest one to be considered. Barium sulphate is soluble in acids 5 and even in pure water, and the solubility limit is reached almost immediately on contact with the solvent. Hence, in the event of using reagents of very superior quality or of exercis- ing more than ordinary precautions, there may be no apparent "blank" because the solubility limit of the solution for barium sulphate has not been reached or at any rate not exceeded. 4 Journal American Chemical Society, Volume 21, page 1125 (1899). 5 Jour. Am. Chern. Soc. Vol. 32, p. 588 (1910); Vol. 33, p. 829, (1911). 22 ATKINSON METHOD. Thoroughly mix on glazed paper I gram of the laboratory sample of coal with 7 grams of dry sodium carbonate and spread evenly over the bottom of a shallow platinum or por- celain dish. Place on a triangle slightly elevated above the bottom of a cold muffle. Heat the muffle gradually until a tem- perature of 650 to 700 C. (dull red heat) has been obtained in half an hour and maintain this temperature for 10 or 15 minutes. The sodium carbonate should not sinter or fuse. The mix- ture should not be stirred during the heating process. When the dish has cooled sufficiently to handle, the matter should be examined for black particles of unburned carbon and in case such indications of incompleteness of the process should ap- pear the dish should be replaced and heated for a short time. When all the carbon is burned, remove the dish and digest the contents with 100 to 125 cubic centimeters of warm water and 5 cubic centimeters of concentrated hydrochloric acid. Allow the insoluble matter to settle, decant through a filter and wash several times by decantation. Transfer to the filter adding a few drops of a solution of pure sodium chloride if the insoluble matter tends to pass through the filter. The washings should be continued until the filtrate shows no alkaline reaction. Make the filtrate just acid to methyl orange, add I cubic centimeter of normal hydrochloric acid and proceed as de- scribed under Eschka method. THE PEROXIDE FUSION METHOD. This method is most conveniently carried out in the Parr Calorimeter. The charge consists of 0.5 gram of the air-dry laboratory sample of coal, I gram of potassium chlorate pul- verized to about 2o-mesh, and 10 grams of sodium peroxide of the grade regularly prescribed for calorimetric purposes. The coal and potassium chlorate are first added to the bomb or fusion cup and thoroughly mixed, being careful to break down any lumps that may form. The sodium peroxide is then 23 added, the container closed and the ingredients thoroughly mixed by shaking. After igniting and cooling the charge, dissolve the fusion in a covered beaker, using 150 cubic centimeters of water. Add concentrated hydrochloric acid just past the neutral point (25 to 30 cubic centimeters). Add I cubic centimeter of concentrated hydrochloric acid (specific gravity 1.19) in ex- cess. Filter and wash with hot water, making the final bulk of the solution approximately 250 cubic centimeters. Heat to boil- ing and precipitate the sulphate by adding 10 cubic centi- meters of a 10 per cent, solution of barium chloride. Proceed as described under Eschka method. Particular care should be taken in washing the precipitate obtained by this method in order to remove all of the soluble salts which are formed in the fusion process. Determination of Sulphur in the Bomb Washings. Where the precise content of sulphur is not required it may be approximated from the washings from an oxygen bomb calorimeter as follows : After the combustion, the bomb is washed out thoroughly with distilled water, and the washings collected in a 250 cubic centimeter beaker. Six to eight cubic centimeters of dilute (1:1) hydrochloric acid containing some bromine water are then added and the solution is heated to boiling. The insoluble matter is filtered off and washed free from sulphates with hot water. The filtrate and washings which should have a total volume of 200 cubic centimeters are made just neutral to methyl orange with sodium hydroxide or carbonate solution, i cubic centimeter of normal hydrochloric acid is added, and the procedure completed as described under Eschka method. The allowable variations in sulphur determinations are as follows : Same analyst Different analyst per cent. per cent. For coal 0.05 o.i For coke 0.03 0.05 2 4 Determination of Phosphorus. (Recommended by Committee E-4.) To the ash from 5 grams of coal in a platinum capsule is added 10 cubic centimeters of nitric acid and 3 to 5 cubic centimeters of hydrofluoric acid. The liquid is evaporated and the residue fused with 3 grams of sodium carbonate. If un- burned carbon is present 0.2 gram of sodium nitrate is mixed with the carbonate. The melt is leached with water and the solution filtered. The residue is ignited, fused with sodium carbonate alone, the melt leached and the solution filtered. The combined filtrates, held in a flask, are just acidified with nitric acid and concentrated to a volume of 100 cubic centi- meters. To the solution, brought to a temperature of 85 C., is added 50 cubic centimeters of molybdate solution and the flask is shaken for 10 minutes. The precipitate is washed, on a filter, six times, or until free from acid, with a 2 per cent, solution of potassium nitrate, then returned to the flask and titrated with standard sodium hydroxide solution. The alkali solution may well be made equal to 0.00025 gram phosphorus per cubic centimeter or 0.005 P er cent - f r a 5 gram sample of coal, and is 0.995 of one-fifth normal, (i) Or the phosphorus in the precipitate is determined by reduction and titration of the molybdenum with permanganate. The advantage of the use of hydrofluoric acid lies in the removal of silica. Fusion with alkali carbonate is necessary for the elimination of titanium, which if present and not re- moved with contaminate the phospho-molybdate and is said to sometimes retard its precipitation. Ultimate Analysis. CARBON AND HYDROGEN. The determination of carbon and of hydrogen is made with a weighed quantity of sample in a 25-burner combustion fur- nace of the Glaser type. The products of combustion are thoroughly oxidized by being passed over red-hot copper oxide 25 and lead chromate, and are fixed by absorbing the water in a weighed Marchand tube filled with granular calcium chloride (CaCl 2 ) and by absorbing the carbon dioxide in a Liebig bulb containing a 3<>per cent, solution of potassium hydroxide (KOH). The apparatus used consists of a purifying train, in dupli- cate, a combustion tube in the furnace, and an absorption train. The purifying train consists of the following purifying re- agents arranged in order of passage of air and oxygen through them: Sulphuric acid, potassium hydroxide solution, soda lime and granular calcium chloride. One of the trains is for air and one for oxygen. In the sulphuric acid and potassium hydroxide scrubbing bottles the air and the oxygen are made to bubble through about 5 millimeters of the purifying reagent. Both purifying trains are connected to the combustion tube by a Y-tube, the joint being made tight by a rubber stopper. The combustion tube may be of hard Jena glass, quartz or fused silica. Its external diameter is about 21 millimeters, and its total length is i meter. The first 30 centimeters of the tube are empty : following this empty space is an asbestos plug (acid washed and ignited) or in its place a roll of oxi- dized copper gauze may be used; the next 40 centimeters are filled with copper oxide wire ; a second asbestos plug separates the copper oxide from 10 centimeters of fused lead chromate, which, is held in place by another asbestos plug 20 centimeters from the end of the tube. The end of the tube is contracted for rubber tubing connection with the absorbing train. The absorption train consists, first, of a Marchand tube filled with granular calcium chloride (CaCl 2 ) to absorb moist- ure. The CaCl 2 should be saturated with CO 2 before using The Marchand tube is followed by a Liebig bulb containing a 3O-per cent, potassium hydroxide solution, in which any pos- sible impurities, as ferrous iron or nitrates, have been oxidized by a little potassium permanganate (KMnO 4 ). A guard tube containing granular calcium chloride and soda lime is attached to the Liebig bulb to absorb any dioxide escaping the potassium 26 hydroxide solution and any water evaporating from that solu- tion. The train is connected to an aspirator which draws the products of combustion through the entire train. A guard tube of calcium chloride prevents moisture from running back into the absorption train. The suction is maintained constant by a Mariotte flask. The advantage of aspirating the gases through the train rather than forcing them through by pressure is that the pressure on the rubber connections is from the out- side, so that gas-tight connections are more easily maintained than if the pressure is on the inside of the tube. The connec- tions are made as tight as possible. The usual test for tightness is to start aspiration at the rate of about three bubbles of air per second through the potash bulb, and then to close the inlet for air and oxygen at the opposite end of the train ; if there is no more than one bubble per minute in the potash bulb, the apparatus is considered tight. Before starting a determination when the train has been idle some hours, or after any changes in chemicals or connections, a blank is run by aspirating about I liter of air through the train, which is heated in the same manner as if a determination on coal were being made. If the Liebig bulb and tube contain- ing calcium chloride show a change in weight of less than 0.5 milligram each the apparatus is in proper condition for use. A porcelain or platinum boat is provided with a glass weigh- ing tube of suitable size, which is fitted with an accurately ground glass stopper. The tube and empty boat are weighed. Approximately 0.2 gram of the air-dry coal (6omesh or preferably loo-mesh) are quickly placed in the boat. The boat is at once placed in the weighing tube, which is quickly stop- pered to prevent moisture change in the coal while weighing, and transferring to the furnace. The absorption tubes are connected and the boat and sample are transferred as quickly as possible from the weighing tube to the combustion tube, which should be cool for the first 30 centimeters. The copper oxide should at this time be red hot and the lead chromate at a dull red heat. As soon as the boat is in place (near the as- 27 bestos plug at the beginning of the copper oxide) the stopper connecting with the purifying train is inserted and the aspir- ation started with pure oxygen gas at the rate of three bubbles per second. One burner is turned on about 10 centimeters back from the boat, and the aspiration is continued carefully until practically all the moisture is expelled from the sample. The heat is then increased very gradually until all the volatile matter has been driven off. In driving off the volatile matter the heat must be applied gradually in order to prevent a too rapid evolution of gas and tar, which may either escape com- plete combustion or may be driven back into the purifying train. The heat should be slowly increased by turning on more burners under the open part of the tube until the sample is ignited : after which the temperature may be increased rapidly, but care should be taken not to melt the combustion tube if a glass one is being used. Any moisture collecting in the end of the combustion tube or in the rubber connection joining it to the calcium chloride tube is driven over into the calcium chlo- ride tube by carefully warming with a piece of hot tile. The aspiration with oxygen is continued for two minutes after the sample ceases to glow, the heat is then turned off and about 1,200 cubic centimeters of air are aspirated. The absorption bulbs are then disconnected, wiped with a clean cloth and allowed to cool to the balance room temperature before weigh- ing. Percentage of hydrogen = 11.19 X increase in weight of CaCl 2 tube Weight of sample. Percentage of carbon = 27.27 X increase in weight of KOHbulb Weight of sample. The ash in the boat is weighed and carefully inspected for any unburned carbon. Method with Electrically Heated Combustion Furnace. For description of furnace and method see Technical Paper No. 8, Bureau of Mines, revised edition 1913, p. 22. 28 Nitrogen. The Kjeldahl-Gunning Method. One gram of the coal sample (coke and anthracite should be ground to an inpalpable powder) is boiled with 30 cubic centimeters of concentrated sulphuric acid (H 2 SO 4 ), 7 to 10 grams of potassium sulphate (K 2 SO 4 ), and 0.6 to 0.8 gram of metallic mercury in a 500' cubic centimeter Kjeldahl flask until all particles of coal are oxidized and the solution nearly colorless. The boiling should be continued for 2 hours after the straw colored stage has been reached. The total time of digestion will be, for coal, from 3 to 4 hours and for coke and anthracite may be from 12 to 16 hours. The addition of a few crystals of potassium perman- ganate (KMnO 4 ), after the solution has been cooled enough to avoid violent reaction, tends to insure complete oxidation. After cooling, the solution is diluted to about 200 cubic centi- meters with cold water. If the dilution with water has warmed the solution, it should be again cooled and the follow- ing reagents added: 25 cubic centimeters potassium sulphide (K 2 S) solution (40 grams K, 2 S per liter) to precipitate the mercury and so prevent the formation of mercurammonium compounds Which are not completely decomposed by sodium hydroxide, I to 2 grams of granular zinc to prevent bumping, and finally enough strong sodium hydroxide (NaOH) solution (usually 80 to 100 cubic centimeters) to make the solution dis- tinctly alkaline. The danger of loss of ammonia may be mini- mized by holding the flask in an inclined position while the sodium hydroxide solution is being added. The alkaline solu- tion runs down the side of the flask and forms a layer below the lighter acid solution. After adding the alkaline solution, the flask is at once connected to the condensing apparatus and the solution mixed by gently shaking the flask. The ammonia (NH 3 ) is distilled over into a measured amount of standard sulphuric acid solution to which has been added sufficient cochineal indicator for titration. Care should be taken that the glass connecting tube on the end of the con- denser dips under the surface of the standard acid. The solu- 29 tion is slowly distilled over until 150 to 200 cubic centimeters of distillate has passed over. To avoid mechanically entrained alkali passing over into the condenser the rate of distillation should not exceed 100 cubic centimeters per hour. The dis- tillate is titrated with standard ammonia solution. Standard NaOH or KOH solution with methyl orange, methyl red or sodium alizarin sulphonate as indicator may be used instead of ammonia and cochineal. A blank determination should be made in the same manner as described above, except that i gram of pure sucrose (cane sugar) is substituted for the coal. The nitrogen found in this blank is deducted from the result obtained with the coal. Oxygen. Oxygen is computed by subtracting the sum of the per- centages of hydrogen, carbon, nitrogen, sulphur, water and ash from 100. The result so obtained is affected by all the errors incurred in the other determinations and especially by the change in weight of the ash forming constituents on ignition. A more nearly correct oxygen value may be obtained by making the corrections indicated here. Corrected oxygen = 100 (C C') + (H H') + N + H 2 O + S' + corrected ash. In which C = total carbon C' = carbon of carbonates H = total hydrogen less hydrogen of water H' = hydrogen from water of composition in clay, shale, etc. N = nitrogen H 2 O = moisture as found at 105 C. S = sulphur not present as pyrite or sulphate. This is usually small. 3 30 Corrected Ash = Mineral constituents originally present in the coal. For most purposes this can be determined with sufficient accuracy by, add- ing to the ash, as found, five- eights of the weight of pyritic sulphur, the CO 2 of carbonates , and the water of composition of clay, shale, etc. Calorimetric Determination . APPARATUS. Combustion Bombs. 6 The Atwater, Davis, Emerson, Mah- ler, Parr, Peters, Williams, or similar bombs may be used. The bomb shall have an inner surface of platinum, gold, porce- lain enamel, or other material which is not attacked by nitric and sulphuric acids, or other products of combustion. Calorimeter Jacket. The calorimeter must be provided with a water-jacket having a cover to protect the calorimeter from air currents. The jacket must be kept filled with water within 2 or 3 C. of the temperature of the room (except in calorimeters which are totally submerged, where the jacket temperature is controlled by a thermostat) and should be stirred continuously by some mechanical stirring device. Stirring of the Calorimeter Water. The water in the calo- rimeter must be stirred sufficiently well to give consistent ther- mometer readings while the temperature is rising rapidly. The speed of stirring should be kept constant. A motor-driven screw or turbine stirrer is recommended and the speed should not be excessive. This may be determined by adjusting the temperature of the calorimeter to equality with that of the jacket and allowing the stirrer to run continuously for 10 minutes. If the temperature of the calorimeter rises more than about 0.01 C. in this length of time, the rate of stirring 6 "The Committee recommends the oxygen bomb. Where no oxygen bomb calo- rimeter is available, the Parr, when carefully handled (preferably with electric igni- tion and in conjunction with a Beckman thermometer) will give satisfactory results." is excessive. Accurate results cannot be obtained when too much energy is supplied by the stirring device or when the rate of stirring is irregular. The portion of the stirring device immersed in the calorimeter should be separated from the out- side by non-conducting material, such as hard rubber, to pre- vent conduction of heat from the motor or outside air. Thermometers. Thermometers used shall have been certi- fied by a government testing bureau and shall be used with cor- rections given on the certificate. This shall also apply to elec- trical resistance or thermo-electric thermometers. Correction shall also be made for the temperature of the emergent stem of all mercurial thermometers, and for the "setting" of Beck- mann thermometers. For accurate work, either Beckmann or special calorimetric thermometers graduated to o.oi or 0.02 C. are required. Such thermometers should be tapped lightly just before each reading to avoid errors caused by the sticking of the mercury meniscus, particularly when the temperature is falling. A convenient method is to mount a small electric buzzer directly on the top of the thermometer and connect it up with a dry cell and a push button. The button should be pressed for a few seconds immediately before each reading. Oxygen. The oxygen used for combustion shall be free from combustible material. If an approximation of the sul- phur is to be made from the bomb washings, the latter when filled should contain at least 5 per cent, of nitrogen. The total amount of oxygen contained in the bomb for a combustion shall not be less than 5 grams per gram of coal. But the com- bustion must be complete as shown by the absence of any sooty deposit on opening the bomb after firing. Firing Wire. The coal in the bomb may be ignited by means of either iron or platinum wire. If iron wire is used it should be of about No. 34 B & S gauge and not more than 10 centi- meters should be used at a time. A correction of 1,600 calories per gram of wire burned is to be subtracted from the ob- served number of calories. Standardization. The water equivalent of a calorimeter can best be determined by the use of standard combustion samples 32 supplied by the Bureau of Standards. The required water equivalent is equal to the weight of the sample multiplied by its heat of combustion per gram divided by the corrected rise in temperature. The calorimeter shall be standardized by the combustion of standard samples supplied by the Bureau of Standards, and used according to the directions given in the certificates which accompany them. A standardization shall consist of a series of not less than five combustions of either the same or different standard materials. The conditions as to the amount of water, oxygen, firing wire, method of correcting for radiation, etc., under which these combustions are made shall be the same as for coal combustions. In the case of any disagreement be- tween contracting parties a check standardization may consist of two or more combustions of standardizing samples. MANIPULATION. 1. Preparation of Sample. The ground sample is to be thoroughly mixed in the bottle and an amount, approximately i gram, is to be taken out and weighed in the pan or crucible in which it is to be burned. Coals which are likely to be blown out of the crucible should be briquetted. For anthracite and coke the following procedure should be adopted: The inside of the crucible is lined completely with a thin layer of ignited asbestos, pressed well down into the angles. The sample is then sprinkled evenly over the surface of the asbestos. After weighing, the sample should preferably be immediately placed in the bomb and this closed. This procedure is necessary to avoid sublimation in the use of naphthalene for standardi- zation. 2. Preparation of the Bomb. The firing wire, if iron, should be measured and coiled in a small spiral and connected between the platinum terminals, using, if necessary, a piece of platinum wire somewhat heavier than the iron wire, to make the connection. The platinum and the iron must both be clean. About 0.5 cubic centimeters of water should be placed in the bottom of the bomb to saturate with moisture the oxygen used 33 for combustion. When the crucible is put in place in the bomb, the firing wire should touch the sample. For combus- tion of standardizing materials, or for coke, iron wire is prefer- able to platinum. 3. Filling the Bomb with Oxygen. Oxygen from the supply tank is to be admitted slowly to avoid blowing the sample from the crucible and the pressure allowed to reach 20 atmospheres for the larger bombs or about 30 atmospheres for the smaller bombs, so that the bomb shall contain an amount of oxygen sufficient for complete combustion, namely at least 5 grams per gram of coal or other combustible. For coke it will be found better to allow a pressure of 5 atmospheres more than that al- lowed for coal. 4. Calorimeter Water. The calorimeter is to be filled with the required amount of distilled water, depending upon the type of calorimeter. The amount may be determined either by measurement in a standard flask or by weighing. The amount must be kept the same as that used in standardization of the apparatus. 5. Temperature Adjustments. The initial temperature in the calorimeter should be so adjusted that the final temper- ature, after the combustion, will not be more than i C., pref- erably about 0.5 C., above that of the jacket, under which conditions the total correction for heat gained from or lost to the surroundings will be small when the rise of tempera- ture is 2 or 3 C., and the effect of evaporation will also be small. 6. Firing Current. The electric current used for firing the charge should be obtained from storage or dry cells having an electromotive force of not more than 12 volts, since a higher voltage is liable to cause an arc between the firing terminals, introducing additional heat, which cannot be measured with certainty. The circuit should be closed by means of a switch, which should remain closed for not more than 2 seconds. When possible it is recommended that an ammeter be used in the firing circuit to indicate when the firing wire has burned out. 34 7. Method of Making an Observation. The bomb when ready for firing is to be placed in the calorimeter, the firing wires connected, the cover put in place and the stirrer and thermometer so placed as not to be in contact with the bomb or container. The stirrer is then started and after the ther- mometer reading has become steady, not less than 2 minutes after the stirrer is started, temperatures are read at I -minute intervals for 5 minutes and the charge is then fired, the exact time of firing being noted. Observations of temperature are then made at intervals depending upon the method to be used for computing the cooling correction. When the temperature has reached its maximum and is falling uniformly, a series of thermometer readings is taken at i-minute intervals for 5 minutes for determining the final cooling rate. 8. Titration. After the combustion, the bomb is to be opened, after allowing the gas to escape, and the inside ex- amined for traces of unburned material or sooty deposit. If these are found, the observations shall be discarded. If the combustion appears complete, the bomb is to be rinsed out thoroughly and the washings titrated with a standard alkali solution (i cubic centimeter = 0.02173 gram HNO 3 = 5 calories) using methyl orange or methyl red indicator, to de- termine the amount of acid formed. A correction of 230 calories per gram of nitric acid should be subtracted from the total heat observed. An additional correction of 1,300 calories per gram of sul- phur in the coal should be made for the excess of difference in heats of formation of SO 2 and aqueous H 2 SO 4 over the heat of formation of aqueous HNO 3 . For details of titration see Technical Paper No. 8, Bureau of Mines. Computation of Results. The following method of computation is recommended to take the place of the Pfaundler or other similar formulas for computing the cooking correction (radiation correction). Observe (i) the rate of rise (r) of the calorimeter tem- perature in degrees per minute for 5 minutes before firing; 35 (2) the time (a) at which the last temperature reading is made immediately before firing; (3) the time (b) when the rise of temperature has reached six-tenths of its total amount (this point can generally be determined by .adding to the temperature observed before firing, 60 per cent, of the expected temperature rise, and noting the time when this point is reached) ; (4) the time (c) of a thermometer reading taken when the tempera- ture change has become uniform some 5 minutes after firing; (5) the final rate of cooling (r 2 ) in degrees per minute for 5 minutes. When the temperature rise is not approximately known be- forehand, it is only necessary to take thermometer readings at 40, 50, 60 seconds (and possibly 70 seconds with some calorim- eters) after firing, and from these observations to find when the temperature rise has reached 60 per cent, of the total. Thus, if the temperature at firing was 2.135, at 4 seconds, 3.05, at 50 seconds 3.92, at 60 seconds 4.16, and the final temperature was 4.200, the total rise was 2.07 ; 60 per cent. of it was 1.24. The temperature to be observed was then 2.14 -j- 1.24 = 3.38. Referring to the observations at 40 and 50 seconds the temperatures were respectively 3.05 and 3.92. The time corresponding to the temperature of 3.38 was therefore 40 + ^ ~ 3 ' 5 X 10 = 44 seconds. 3.92 3.05 The rate r is to be multiplied by the time b a in minutes and tenths of a minute, and this product added (subtracted if the temperature was falling at the time a) to the thermom- eter reading taken at the time a. The rate r 2 is to be multi- plied by the time c b and this product added (subtracted if the temperature was rising at the time c and later) to the thermometer reading taken at the time c. The difference of the two thermometer readings thus corrected, provided the corrections from the certificate have already been applied, gives the total rise of temperature due to the combustion. This multiplied by the water equivalent of the calorimeter gives the total amount of heat liberated. 36 The result, corrected for the heats of formation of HNO 3 and H 2 SO 4 observed and for the heat of combustion of the firing wire, when that is included, is to be divided by the weight of the charge to find the heat of combustion in calories per gram. Calories per gram multiplied by 1.8 give the Brit- ish thermal units per pound. In practice, the time b a will be found so nearly constant for a given calorimeter with the usual amounts of fuel that b need be determined only occasionally. The results should be reduced to calories per gram or Brit- ish thermal units per pound of dry coal, the moisture being determined upon a sample taken from the bottle at about the same time as the combustion sample is taken. EXAMPLE. Observations : Water equivalent = 2,550 grams. Weight of charge 1.0535. Approximate rise of temperature = 3.2. 60 per cent, of approximate rise = 1.9. Time Temperature Corrected temperature 10.21 15.244 (Thermometer corrections from the certificate) .22 .250 23 -255 .24 .261 .25 .266 (a) .26 .272 15.276 Charge Fired: >o (d) 18.497 (b) 27-2 17.200* (c) 31 1 8. 500 32 .498 33 497 34 .496 35 494 36 .493 37 Computation: r i = 0.028 -f 5 = 0.0056 per minute, b a = 1.2 minutes The corrected initial temperature is 15.276 + 0.0056 X 1.2 = 15-283 r: 2 = 0.007 H" 5 = 0.0014 P er minute; c b = 3.8 minutes The corrected final temperature is 18.497 -f- (0.0014X3.8) = 18.502 Total rise 18.502 15.283 = 3.219 Total calories 2.550 X 3.219 = 8.209 Titration, etc. 0.007 Calories from 1.0535 g. coal 8.202 Calories per g 7,785 or British thermal units per pound r 4>!3 (d) The initial temperature is 15.27; 60 per cent, of the expected rise is 1.9. The reading to observe is then 17.2. The results obtained by the above method of computation and determination is the total heat of combustion at constant volume, with the water in the products of combustion con- densed to liquid at the temperature of the calorimeter, that is, about 20 to 35 C. Net heat of combustion at 20, shall refer to results cor- rected for latent heat of vaporization, as follows : Total heat of combustion in B. t. u. -- 1,040 (hydrogen x 9) = net heat of combustion in B. t. u. per pound. Also total heat of combustion in calories 580 (hydrogen x 9 = net heat of combustion in calories per gram. Allowable Variations: Per cent. Same analyst o. 3 Different analysts 0.5 Shatter Test for Coke. The apparatus consists essentially of a box capable of hold- ing at least 100 pounds of coke, supported with the bottom 6 feet above a cast-iron plate. The doors on the bottom are so hinged and latched that they will swing clearly away when open and will not impede the fall of the coke. Boards are 38 placed around the cast-iron plate to prevent pieces of coke from being lost. Each sample is approximately 50 pounds and is selected at random using a 2-inch tine fork. The sample is cool when tested but not artificially dry. The entire sample is placed in the box and dropped on the cast-iron plate. No attempt is made at distributing or arrang- ing the charge in the box before dropping. The entire material is dropped four times onto the cast-iron plate. The small material including the dust is returned to the box with the large coke each time in order to represent as nearly as possible, the practical conditions to which coke is subjected. After the fourth drop the coke is screened on a wire screen with square holes, 2 inches in the clear. The screen is held horizontally and is shaken once after the coke is placed on it, but no attempt is made to force through all the small pieces that might go through if they happened to be placed differently on the screen. The coke is weighed carefully before being placed in the box the first time and the coke on the screen is weighed on the same scales after the final screening. The coke is weighed accurately to one-eighth of a pound and the result reported in percentage of original coke that does not pass the screen after the fourth drop. Determination of the True Specific Gravity of Coal and Coke Substance. To determine the true specific gravity of coal and coke sub- stance, the procedure is as follows : A sample of the 6o-mesh coal, weighing approximately 3.5 grams is dried at 105 C., and introduced into a 50 cubic centimeter pycnometer with about 30 cubic centimeters of distilled water. In order to avoid loss of particles of the sample during boiling, a one-bulb 6-inch drying tube (a) (Fig. 4) is connected with the pycnom- eter by means of a small piece of pure gum tubing (c). The other end of the drying tube is connected \vith the aspirator. 39 Suction is applied and the contents of the flask are gently boiled on the water bath (d) under partial vacuum for 3 hours in order to expel all air from the sample. The pycnometer is FIG. 4. then detached, almost filled with boiled and cooled water, al- lowed to cool to the temperature of the balance room, stop- pered, and weighed. The temperature of the contents of the 40 pycnometer is taken immediately after weighing. Each pyc- nometer is accurately calibrated and a table is constructed giv- ing its capacity in grams of water at different temperatures. True specific gravity is determined by use of the following formula : W The specific gravity = W (W 1 P) in which W = weight of coke. W = weight of pycnometer -f- coke + water to fill. P weight of pycnometer -j- water to fill. Determination of the Apparent Specific Gravity. The apparatus used for the determination of the apparent specific gravity consists of a galvanized iron cylinder (Fig. 5) which is filled with water to the water line, as indicated in the figure. In the cylinder is immersed a hydrometer made of brass. On the top of the hydrometer are two pans. The upper one is used for weights and the lower one for the sample. Below the air buoy is a brass cage perforated with many holes to allow the air to escape when the instrument is immersed. The cage carries the sample when it is weighed under water. The method of determining the apparent specific gravity is as follows : Brass weights are placed on the upper pan until the hydrometer sinks to a mark on the stem between the cop- per pan and the buoy. The total weight required is recorded. The weights are removed, and about 500 grams of the sample in lump form (about 1^- to 2-inch cubes) are placed in the copper dish. Brass weights are then added until the hydrom- eter sinks to the mark on the stem. The difference in the weights used gives the weight of the sample in air. The sample is then carefully transferred to the brass cage below the buoy. The weights on the upper pan are now adjusted until the instrument again sinks to the mark on the stem. The weight required to sink the hydrometer to the mark with no sample on the upper pan nor in the brass cage minus the FIG. 5. 4 2 weight required to sink it to the mark with the sample im- mersed in the cage equals the weight of the coke in water. Then If the weight of the sample in air = x and the weight of the sample in water y "1C The apparent specific gravity - x y Apparent specific gravity And 100 X ^ - = percentage bv volume true specinc gravity . . of coke substance. Also 100 percentage by volume of coke substance = per- centage by volume of cell space. In making apparent specific determinations of coke the sam- ple should preferably be in lumps of nearly the same size and shape. When the sample is immersed, the hydrometer should be moved rapidly up and down in the water a number of times in order to remove air bubbles. Since coke samples are porous they take up water rapidly and should not be allowed to re- main in contact with water more than 5 minutes during a deter- mination. By observing the above-mentioned precautions satis- factory results can be obtained. All samples should be thor- oughly dry before specinc gravity determinations are made. Ash Analysis. For ash analysis follow the method outlined under refrac- tories. GAS OIL. The following determinations are covered in the analysis of gas oil : Asphalt. Index of Refraction. Bromine Number. Mean Boiling Point. Cold Test. Mean Molecular Weight. Distillation. Paraffin. Flash Point. Specinc Gravity. Fire Point. Specinc Heat. Heating Value. Sulphur. Heat of Vaporization. Water. 43 It is not recommended that all are necessary for routine analysis, but special circumstances may require more extended investigation as a means of identifying the source of an un- known sample when such determinations may be of great value. There are a number of methods in the literature .that may be used for the empirical determination of the relative propor- tion of the various classes or groups of hydrocarbons in gas oils. These methods, however, have not had the extensive use and acceptance that would seem necessary for their incor- poration in the Handbook at this time. Asphalt. The determination of asphalt is still in an unsatisfactory state as there are a number of precipitants used for the pur- pose, viz., petroleum ether, alcohol, ether, amyl alcohol, ethyl acetate, butanon. The asphalts thus obtained vary quite wide- ly both as to quantity and hardness and there does not seem to be any well denned relation existing between the results ob- tained with the different precipitants on different samples of oil. The more generally recognized precipitant is naphtha, and the method according to Engler, is as follows : QUANTITATIVE DETERMINATION. Asphalt Insoluble in Naphtha. Five grams of oil are shaken in a 500 cubic centimeter bottle with 40 times its volume (220 cubic centimeters, assuming the specific gravity to be 0.9) of normal benzene. If the oil contains only a little asphalt, as much as 20 grams of oil may be taken with the corresponding amount of naphtha. After standing at least 24 hours at a temperature between 15 and 20 and away from direct sun- light, the solution is decanted through two filters folded to- gether (white ribbon S. & S.). The residue is washed with naphtha till the filtrate gives no more oily residue. To prevent the asphalt from becoming insoluble on standing, it is at once dissolved in hot benzol, the main mass evaporated from a flask and the remainder in a tared vessel, the residue dried at 44 IO5 and weighed. Foreign substances precipitated by naph- tha and insoluble in benzol can be separately determined by using a weighed filter paper. If the suspended asphalt is to be determined, the amount of asphalt is determined in the original oil as well as in the filtered oil; the difference gives the sus- pended asphalt. In the different crude oils the amount of as- phalt runs parallel to the amount of coke obtained on distilla- tion. The German specifications for the naphtha require a gravity at 15 C. of 0.695-0.705, boiling range 65 .-95 C. with 100 cubic centimeters using a 3-bulb Le Bel Henninger Column 40 centimeters long. Not over 2 per cent, should dissolve in a mixture of 20 per cent, fuming and 80 per cent. 1.84 H 2 SO 4 , using equal volumes and shaking for 15 minutes. Bromine Number. From 0.3 to 0.5 gram of oil is weighed into a glass stoppered 8-ounce bottle. Ten cubic centimeters of bromine solution is run from the burette, the bottle is then cooled in ice water and 25 cubic centimeters of 10 per cent, potassium iodide solution is added shaking the bottle, but preventing any of the solution from getting on or near the stopper. Add I or 2 cubic centi- meters of starch solution and titrate against standard sodium thiosulphate solution. The reaction is as follows : Br 2 + 2KI = 2KBr + L, I 2 + 2Na 2 S 2 O 3 = 2NaI + Na 2 S 4 O 6 . Calculation. Cubic centimeters of bromine used x equiva- lent to thiosulphate solution = equivalent volume of thiosul- phate. Equivalent volume of thiosulphate thiosulphate added in titration = cubic centimeters of thiosulphate used. Cubic centimeters of thiosulphate used x 0.008 = grams of Grams of bromine absorbed X 100 bromine absorbed. _. - - Grams of oil used bromine number. Solutions. The thiosulphate solution is made up to contain 45 24.8 grams of C. P. sodium thiosulphate (Na 2 S 2 O 3 5H 2 O) per liter. The bromine solution is made up with dry carbon tetra- chloride and standardized with the thiosulphate. One cubic centimeter of the bromine solution should equal approximately 1.5 cubic centimeters of thiosulphate solution. Distillation. The apparatus shall consist of the following standard parts : (i) FLASK. The distillation flask shall be a standard 100 cubic centi- meter Engler distilling bulb having the following dimensions (see Stillman's "Engineering Chemistry"). Diameter of bulb 6.5 cm. Length of neck 15.0 cm. Diameter of neck 1.6 cm. Surface of oil to tubulure 9.0 cm. Length of tubulure 10.0 cm. Angle of tubulure 75 A 3 per cent, variation from the above measurements will be allowed. (2) THERMOMETER. High temperature nitrogen-filled Fahrenheit thermometer constructed according to the following specifications : (1) To be made of special German hardened glass. (2) Diameter of stem not less than 6.75 millimeters nor more than 7.25 millimeters. (3) Length of thermometer not less than 335 millimeters nor more than 350 millimeters. (4) Length of thermometer between o mark and 1,000 mark not less than 285 millimeters nor more than 300 milli- meters. (5) Length of bulb to capillary not less than 20 millimeters nor more than 22 millimeters. (6) Diameter of bulb at center of same not less than 5.25 millimeters nor more than 6.25 millimeters. 4 46 (7) Mercury column to rise from 60 to 200 in not more than 5 nor less than 3 seconds when plunged into boiling water. (8) To be correct within i at 212 and 750 after 25 suc- cessive oil tests. (3) CONDENSER. Liebig glass condenser and tube as follows : Length of body of jacket 300-350 mm. Width of body of jacket 25- 40 mm. Length of inner tube 530 mm. Width of inner tube 12- 15 mm. Width of end of inner tube 20- 25 mm. (4) STANDS. Two iron stands provided respectively with one universal clamp for holding condenser, and one light grip arm asbestos lined clamp for holding the bulb. (5) BURNER AND SHIELD. Bunsen burner with tin shield 8 inches long by 3 inches in diameter. The shield has a sight hole in the same for observ- ing the flame. (6) CYLINDERS. Ten glass cylinders, 25 cubic centimeters capacity, gradu- ated to i/io cubic centimeter. SETTING UP APPARATUS. The apparatus is set up as shown in Fig. 6, the thermometer being so placed that the top of the bulb is opposite the middle of the tubulure. All connections should be tight. Distillation Test. One hundred cubic centimeters of the oil to be tested are placed in a weighed bulb, and after adjusting the thermom- eter, shield, condenser, etc., the distillation is commenced, the rate being so regulated that I cubic centimeter passes over every minute. Cold water should be passing through the con- denser during the first half of the distillation. When the 47 thermometer reaches 600 F., the cold water should be re- moved from the condenser and hot water substituted. The receiver is changed as the mercury column just passes the fractionating point. At the end of the distillation, or when no more oil distils over, the flask is disconnected from the con- denser, inverted and two burners are used to complete the coking. FIG. 6. The fractionating points in the distillation are at every 50 F., i. e., at 300, 350, 400 F., etc. The number of cubic centimeters obtained between each cutting point will give the per cent, by volume distilling between these temperatures. 4 8 The per cent, by weight is obtained as follows : Multiply the per cent, by volume of each fraction by its specific gravity and divide by the specific gravity of the original oil. In case the oil contains more than 2 per cent, of water, it should be dried by the following method before carrying out the distillation: A definite volume of oil is placed in a copper still and heat gradually applied until all water has distilled over, returning any oil to the still that has been carried over with the water. For more accurate work the emergent stem correction should be applied to the observed temperature. This has been determined by the Bureau of Standards to be approximately as follows for a thermometer in the position as used in the distillation test : 200 C 4.50 C. 250 C 6.0 C. 300 C 10.5 C. 350 C 15.5 C. Flash and Fire Tests. DIRECTIONS FOR OPERATING TAGUABUE OPEN CUP. General Directions. 1. Test shall be made in a room partially darkened. 2. The cup shall be protected by a surrounding screen, 16 inches square, 30 inches high, open at top and front, and painted black inside. Drafts caused by the breath of the oper- ator shall be carefully avoided. 3. A fresh sample shall be used for each test. 4. The instrument must stand level. Preparation of Water Bath. Fill the metal bath with water at a temperature of 25 C. (77 F.) so that when the glass cup is in place, the water in bath will come to the rim of the metal cup. Preparation of Sample. Suspend a calibrated thermometer (see specifications) in the center of the cup with the top of the bulb of same y 2 inch below the upper level edge of the 49 glass cup. Bring sample to be tested to a temperature of 15.5 C. (60 F.). Fill the glass cup with 59 cubic centimeters of the sample. See that there is no oil on the outside of the cup or its upper edge, using a filter paper to clean the cup. Remove air bubbles, if any, from the surface of the oil. NOTE. The horizontal flashing-taper guide wire (as speci- fied by direction of the manufacturer) Is not to be used In these tests. Application of Heat to Oil Cup. Heat the bath with an alcohol, gas or other flame, so adjusted that the temperature will not be raised faster or much slower than i C. (1.8 F.) per minute, without removing the flame. Description of Test Flame. The test flame shall be spher- ical in form, and shall have a diameter equal in size to the bead furnished herewith, which may be attached to the cover of the water bath. This flame is best produced by passing gas through a straight thin metal blow-pipe tube. (See Eimer and Amend Catalogue C (1913, p. 54, Item 784) or Scientific Ma- terials Co. (1912, p. 69, Item 618) or C. J. Tagliabue special tube. Initial Test. When the sample under test reaches a temper- ature of 30 C. (86 F.) the first test shall be made, and tests shall be made thereafter at each rise of i C. (1.8 F.) until the flash point is reached. Method of Applying Test Flame. (Two Methods, both to be used and reported.) (A) Sweep Method. Holding the burner tube in a truly horizontal position the flame is passed in a straight line con- tinuously across the center of the cup, with the tube touching the edge of the cup. The time for one sweep from edge to edge of the cup to be gauged to I second. The temperature at which a flame first appears anywhere on the surface of the oil shall be considered the flash point. (B) Dip Method. Holding the burner tube in a vertical position with the flame 3 inches above the surface of the sample, the flame is quickly lowered to Y% inch from the sur- 50 face of the sample near the outer edge of the cup, and with- drawn; entire operation consuming one second. This opera- tion is quickly repeated at three equidistant points around the circumference of the cup. The temperature at which a blue flame jumps from the taper to the surface of the oil is the flash point. DIRECTION FOR OPERATING THE EUJOTT OR N. Y. STATE TESTER. General Directions. 1. Test shall be made in a room partially darkened. 2. The cup shall be protected by a surrounding screen, 16 inches square, 30 inches high, open at top and front, and painted black inside. Drafts caused by the breath of the oper- ator shall be carefully avoided. 3. A fresh sample shall be used for each test. 4. The instrument must stand level. Preparation of Water Bath. Fill the metal bath with water at a temperature of 25 C. (77 F.) so that when the metal cup is in place, the water in bath will come to the rim of the metal bath. Preparation of Sample. Bring the sample to be tested to a temperature of 15.5 C. (60 F.). Fill the metal cup with the sample to such a point that the surface of the oil will be 1/8 inch below the lower inner flange. Remove air bubbles, if any, from the surface of the sample. Place the glass cover in position and insert the calibrated thermometer (see specifica- tions) through the cork in the central opening so that the top of the bulb will be % inch below the surface of the sample. Application of Heat to Oil Cup. Heat the bath with an al- cohol, gas or other flame, so that the temperature will not be raised faster or much slower than i C. (1.8 F.) per min- ute, without removing the flame. Description of Test Flame. The test flame shall be spheric- al in form, and shall have a diameter equal in size to the bead furnished herewith, which may be attached to the cover of the water bath. This flame is best produced by passing gas through a straight thin metal blow-pipe tube. (See Eimer and Amend Catalogue C (1913, p. 54, Item 704) or Scientific Ma- terials Co. (1912, p. 69, Item 618) or C. J. Tagliabue special tube. Initial Test. When the sample under test reaches a temper- ature of 25 C. (77 F.) the first test shall be made. Tests shall be made thereafter at each rise of i C. (1.8 F.) until the flash point is reached. Method of Applying Test Flame. Holding the burner tube at an angle of 45, the flame is passed through the side open- ing in the cover to a point half way between the surface of the sample and the cover. The time consumed in entering and withdrawing the flame is to be I second. The tempera- ture at which a blue flame is seen through the glass is the flash point. Specification for Thermometer for Flash Point Tests. To be used with Tagliabue and Elliott or N. Y. State Testers. The thermometer shall be graduated from 10 to rj-iio C. in i intervals. There shall be a small reservoir above the 110 mark. The thermometer shall be finished at the top with a small glass ring. The stem shall be made of enamel backed thermometer tub- ing, but not of Jena I6 111 glass. The bulb shall be made of Jena I6 111 , Corning normal, or Jena or Corning borosilicate glass. Every fifth graduation shall be longer than the intermediate ones and the marks shall be numbered at every 10 interval. The graduation marks shall be clear cut and fine, and the num- bering clear and distinct. Each thermometer shall be provided with a suitable case. A serial number for identification shall be engraved on the stem. All material and workmanship shall be of the bes,t grade. Accuracy. The maximum error at any point shall not ex- ceed three-tenths (0.3) degree Centigrade. 52 Dimensions : Total length, not over 300 millimeters. Diameter stem, from 5.5 to 7 millimeters. Diameter bulb, same as stem. Diameter capillary, not less than o.i millimeter. L,ength of bulb, from 8 to 12 millimeters. Distance 10 to bottom of bulb, from 40 to 60 milli- meters. Distance 10 to no on scale, from 180 to 220 milli- meters. Heating Value. Refer to Heating Value of coal analysis on page 30. Heat of Vaporisation. The heat of vaporization may be calculated with sufficient accuracy for purpose of design from the mean molecular weight and the mean boiling point and specific heat from Trouton's rule. Mean boiling point (Heat of vaporization) = 20. ;! . Mean Molecular Weight The total heat of vaporization sensible heat from room temperature to boiling point + latent heat of vaporization so there must be added (mean boiling point room temperature) (specific heat). Refractive Index. The Zeiss refractometer is recommended for the refractive index at a temperature of 25 C., at which point all fractions of the usual gas oils are sufficiently liquid for observation. As detailed instructions are furnished with the instrument they are not repeated here. The use of the refractive index instead of the specific grav- ities for the fractions of gas oils is recommended as giving really more information and requiring but a fraction of the time to determine. 53 Mean Boiling Point. This figure is the arithmetical mean of the temperature at which equal volumes of the oil distil off. The oil is distilled in the usual form of apparatus and the temperatures noted when the first drop, 10 per cent., 20 per cent., 30 per cent., etc. have distilled over. The sum is divided by the number of fractions. The mean boiling point is ex- pressed in absolute temperature for use in calculating the heat of vaporization. Mean Molecular Weight. This figure is frequently quite useful for identification pur- poses and for use in calculating the heat of vaporization. The determination is made in a Beckman freezing point apparatus. Commercial stearic acid previously standardized with a sub- stance of known molecular weight or benzol may be used as solvents. The operation is as follows : The freezing tube A, with the stirrer and garnets, is care- fully washed and dried, and from 15 to 20 grams of the sol- vent accurately weighed into it. It is stoppered both at the top and side tube and placed in the jacket tube B. The jar C is then filled with a^freezing mixture (for benzol, water with a small piece of ice is suitable). The Beckman thermometer is adjusted so that the mercury at the freezing point of the solvent (benzol = 5 C.) is some- what above the middle point of the scale. The thermometer is inserted in the perforated stopper holding the platinum stirrer and after dropping in a few small garnets the ther- mometer and stirrer are rapidly inserted in place of the stop- per in the freezing tube. By this time the solvent should be from i to 2 below the freezing point. The stirrer is worked up and down to cause the formation of crystals as these be- gin to form the thermometer rises and as it reaches the freez- ing point remains practically stationary (vibrating a few thousandths under the magnifying glass however) the mean point is observed. The freezing mixture should be stirred con- 54 stantly and the solvent should be stirred at a uniform rate of from 30 to 35 strokes per minute. FIG. 7. The freezing tube is removed and from 0.5 to 0.7 gram of the substance is brought into the solvent through the side tube. For oils a weighing pipette is useful, as the quantity must be 55 i accurately weighed out. Care must be taken to allow the tem- perature to rise until all crystals have disappeared but not far enough to destroy the setting of the thermometer. The freezing tube is replaced and when the substance has gone into solution the freezing point is observed as before. The differ- ence is the depression (t). Repeated additions of the solvent may be made and the depressions noted. The depression (t) should not be less than 0.5 and not over 3.0. If M = molecular weight of substance. C = constant of solvent. P grams of substance per 100 grams of solvent. t = depression of freezing point. M CP M = t The solvent should be standardized with a pure substance of known molecular weight (naphthalene may be used with ben- zol). If 20 grams of benzol were used and 0.5 gram naph- thalene added, producing a depression of 0.986 we would have M t 128 X 0.986 Constant = -= =' - = so. 48 P 0.5 X IOQ 20 Then assuming 19 grams of benzol used, 0.7 gram of oil added and t = 1.195 we would have cp (o 7 X IPO ) M = = 50.48 X 19 = = 155 i 195 REFERENCES. Z. phys. Ch., i, pp. 577, 631; 2, pp. 307, 491, 638, 964; 5, p. 94; B., 21, pp. 711, 860; 22, pp. 1430, 2501; 23, R i; 24, pp. 1431 ; 27, R 542, R 845, R 974. Paraffine. One hundred grams of crude oil are distilled rapidly from a tubulated retort till the temperature of 300 is reached. A weighed receiver is then put into position (with- out a condenser) and all oil driven over until the residue cokes completely (without thermometer) ; the amount of heavy oil distilled is determined. Five-tenths gram of the substance is dissolved at room tern- 56 perature in a mixture of ether and absolute alcohol (i : i) to a clear solution, then cooling to 20, just enough alcohol- ether mixture added till all oily drops are dissolved and par- affine flakes are visible. With much paraffine, it is advisable to warm with ether to complete solution and then add the same volume of alcohol. The precipitated paraffine is then fil- tered on a funnel surrounded with a rock-salt and ice-freez- ing mixture, all traces of the alcohol-ether solution being re- moved, and then washed free from oil by means of cooled alcohol-ether. The residue is then washed into a weighed glass dish with hot benzol, or naphtha and the solvent evap- orated on a water bath. The paraffine is carefully washed with cooled alcohol-ether until 5 cubic centimeters of the filtrate on evaporation will give no residue, or only a trace of material solid at room tem- perature, is obtained; too prolonged washing is to be avoided because of the still quite noticeable solubility of paraffine in alcohol-ether. If on cooling, the paraffine is seen to be hard, it is heated at 105 for 15 minutes and weighed after drying in a desiccator; if the paraffine is soft (with melting point under 45), it should be dried several hours in a vacuum desiccator at 50 before weighing. Determination of Specific Gravity. For control tests on the original sample, the specific gravity may be taken with sufficient accuracy with a hydrometer. The oil should either be brought to the normal temperature 15.5 C. or 25 C., or else the temperature observed and the gravity corrected back to normal temperature. Specific gravity at T = observed gravity at temperature t + (T t x 0.009). In determining the specific gravity of the fractions the Sprengel tube type of pycnometer is recommended. The tube is completely filled and is immersed in water at the normal temperature for 15 minutes. The tube is tilted and the excess material remove^! from the capillary with filter paper until the 57 liquid reaches the calibrated mark. The tube is then dried and weighed. Platinum or nickel wire should be used in suspending the tube on the balance. For a calibration of the tube made by weighing empty and filled with water at the normal temperature the specific gravity is given by the formula : Weight filled with oil = weight empty Specific gravity . . , ^-r Weight filled with water = weight empty While the former practice has been to determine specific gravity at 15.5 C., the later standards of the American Society for Testing Materials have very generally used 25 C. as the normal temperature, and the use of this temperature is recom- mended. Specific Heat. This determination is made with a Parr or bomb calorim- eter, using the oil instead of water as a calorimeter liquid, and burning a definite quantity of a pure substance such as sugar or benzoic acid. Owing to the low specific heat of the oil, the quantity to be burned should be roughly calculated, using 0.45 as an assumed specific heat of the oil to secure a temperate rise of not over 2.5. The operation is carried on exactly as described for deter- mining the heating value : (Grams substance X heating value) = ( Water equivalent X corrected rise \ ( Weight of oil taken) X (Corrected rise) Sulphur. This determination is most conveniently carried out together with the determination of the heating value in the bomb calo- rimeter. After the combustion the gases are allowed to escape slowly through a 10 per cent, solution of sodium carbonate using about 20-25 cubic centimeters in a small beaker or test tube. The bomb is then washed out thoroughly with water, the soda solution is added to the washing and the solution boiled until the aluminum and iron are precipitated, filtered and 58 washed. The solution should have a volume of 70-100 cubic centimeters is accelerated with HC1 and precipitated in a boiling solution with BaClg. BaSO 4 x 0.1373 = S. A METHOD BY ROTHE. Three-fourths gram of oil with 1.5 grams of MgO and 30- 40 cubic centimeters of nitric acid (specific gravity 1.48) are placed in a 250 cubic centimeter round bottom Jena flask. Hood. After the first violent reaction, the flask is heated gently for iJ^-2 hours in a sand bath, the liquid being kept boiling gently. The excess nitric acid is then evaporated over a free flame and the residue heated till the nitrates begin to decompose. After cooling, 10 cubic centimeters concentrated acid are again added. After 15 minutes heating, the mass is evaporated to dryness, keeping the flask in constant motion, then heated with a triple burner until the nitrates are com- pletely decomposed. The residue is generally white ; by adding 10 cubic centimeters of hydrochloric acid (specific gravity 11.24) and heating, it is dissolved and then filtered after dilu- ting with 20-30 cubic centimeters of water. In the filtrate, the sulphuric acid is determined by precipitation with barium chloride in the customary manner. Water. Small quantities of water may be determined in the course of the distillation test. Should the water exceed 2 per cent, it should be determined separately. Water is quantitatively determined as follows : About loo grams of oil (less if much water is present) are distilled from an oil bath with toluol; this toluol should have been previously saturated with water. Pumice is added to avoid bumping. Eighty to ninety cubic centimeters are caught in a cylinder constricted to a narrow graduated tube at the bottom ( Hoffman-Mar cusson). After washing the inside of the condenser with toluol and loosening any water drops on the side of the cylinder with a stirring rod, the amount of water can be directly read on the graduations. 59 TESTING OF PURIFICATION MATERIAL. New Material. The following determinations are covered in the analysis of new oxide : Weight per Bushel. Sampling. Moisture. Metallic Iron. Iron Sesquioxide. Fouling Test. Used Purification Material. The following determinations are covered in the analysis of used oxide: Sampling. Moisture and Light Oils. Total Sulphur. Soluble Sulphur and Tarry Matter. New Purification Material. WEIGHT PER BUSHEL AND SAMPLING. These two determinations can conveniently be done in one operation. The necessary apparatus are : Bushel box, made of wood, the capacity to be 2,150.4 cubic inches, approximate dimensions inside 12 x 12 x 15 inches. Sampling tool made of brass tubing, 2 inches in diameter, 1 8 inches long, upper surface cut away to a length of about 15 inches, and rounded. A wooden handle is attached to the other end. Fig. 8. )G , 2 " ^ Section FIG. 8. Ordinary garden trowel. The operations are as f ollow r s : Samples are taken from a number of bags by thrusting the 6o sampling tool into each bag in turn. The number of bags sampled depends on the size of the lot of oxide received. It should be at least 10 per cent, of the total number of bags. For instance, if the lot contains 500 bags, a sample should be taken from every tenth bag, or from 50 of the bags. These samples are then thrown together on a clean surface, mixed, and spread out to a depth of about 3 inches. Portions are then taken over the surface at equal distances with the garden trowel, digging down to the bottom when taking each portion. These portions are thrown into the bushel box and well mixed. Sufficient material is taken in this manner to fill the box level with the upper edge. The box and contents are then weighed. The weight of the empty box deducted from this weight gives the pounds of oxide per bushel. The contents of the box are quartered down and the sample finally obtained put into a quart glass Mason jar, or a tin can with air-tight cover. CAUTION. If the oxide contains metallic iron, it must be mixed as little as possible consistent with obtaining a repre- sentative sample, because the greater density of the iron will cause it to pass to the bottom, thus interfering with the uni- formity of the sample. If the oxide is not shipped in bags, the operator must use his judgment when sampling, bearing in mind that the portions should be taken throughout the shipment in a uniform manner, so that the final sample will be representative of the entire shipment. MOISTURE. Weigh out 100 grams from the jar or can into a counter- poised tin dish, on a balance accurate to o.i gram. Dry in an oven at 100 C. for one hour. The loss of weight is reported as moisture. The dried sample is then ground in a coffee mill until it is about 3o-mesh size, and quartered down until about 30 grams are finally obtained. This final sample is kept in a tightly 6i stoppered, wide mouth bottle, and used in subsequent deter- minations. Note. The grinding is best done by first having the mill set to grind coarsely, then repeating as many times as neces- sary, adjusting the mill to grind finer each time. By this method, usually, no difficulty will be found in breaking down any iron borings that may be in the oxide. METALLIC IRON. Weigh one gram of the dried oxide from the bottle above into a 100 cubic centimeter beaker and treat with 50 cubic centimeters neutral, saturated solution of cupric ammonium chloride, allow to stand with frequent stirring for at least an hour in a warm place, when all particles of metallic iron should be dissolved. Filter off the residue and wash free of chlorides, and to the hot filtrate add ammonia in excess. The iron will be precipitated as hydroxide, while the blue cupric hydrate dissolves in excess. Filter off the precipitate, wash with water containing a little ammonia until practically free from copper salts. Dissolve the precipitate on the filter with hot, dilute hydro- chloric acid, i in 10, and wash free from HC1. To the hot filtrate, ammonia is again added in excess to precipitate. The precipitate is then filtered, washed, and ignited. Weigh as Fe 2 O 3 . This weight multiplied by 69.94 gives the percentage of metallic iron found. Note. This method must be regarded as only approximate. It is, however, the best method the Committee has been able to find. It gives low results, due to the oxidation of the iron when the residue is being filtered from the cupric ammonium chloride. The error varies with the percentage of metallic iron present, being greatest when this percentage is low. If large pieces of iron borings are present it is advisable to remove them with a magnet, brush off the adhering oxide of iron, etc., returning the latter to the sample to be analyzed. The clean pieces are weighed and the percentage calculated 5 62 and added to the metallic iron found by the method described above. IRON SESQUIOXIDE. Iron is usually present in an oxide in some form of hydrated ferric oxide. It is not practicable to determine accurately the state of hydration ; hence, it has been thought best to determine and report the oxidized iron present as sesquioxide. Dissolve 0.5 gram of the dried sample in 20 cubic centime- ters (1:1) hydrochloric acid in a 100 cubic centimeter beaker, evaporate to dryness, adding a few drops of nitric acid from time to time. Take up with 5 cubic centimeters concentrated hydrochloric acid, add 50 cubic centimeters hot water, boil and filter. Wash filter well with hot water. To the filtrate, add 25 cubic centimeters bromine, water and heat to boiling. When the excess of bromine has been driven off, remove beaker from heat and precipitate the iron as hydroxide with ammonia. Boil for five minutes; allow the precipitate to settle. Filter, wash well with hot water, dry, ignite, and weigh as Fe 2 O 3 . This gives the total iron in terms of Fe 2 O 3 . If metallic iron is pres- ent, it must be determined by the previous method, and its amount also in terms of Fe 2 O 3 deducted from the total iron as Fe 2 O 3 . The difference will be iron sesquioxide. This weight multiplied by 200 gives the per cent, of iron sesqui- oxide. Alternate Method. The residue obtained from the cupric ammonium chloride solution in the method for metallic iron is ignited in a platinum crucible until all carbonaceous matter is destroyed and there remains only a mass of red ferric oxide. Transfer as much as possible of this to a 100 cubic centi- meter beaker, dissolve in 15 cubic centimeters to 30 cubic centi- meters concentrated hydrochloric acid, at the same time dis- solving from the crucible any adhering particles of ferric oxide. When solution is complete, filter into a 250 cubic centimeter graduated flask. Wash and ignite the residue in a platinum crucible, and fuse with two grams of dry sodium carbonate. Dissolve the fusion in hydrochloric acid, add this to the con- tents of the 250 cubic centimeter flask, fill to the mark with distilled water, and mix well. With a pipette, transfer 50 cubic centimeters to a 150 cubic centimeter beaker, add am- monia to precipitate the ferric hydroxide, boil for five minutes, allow to settle, and filter. Wash with hot water, dry, ignite, and weigh as Fe 2 O 3 . The weight multiplied by 500 gives the per cent, of iron sesquioxide. FOULING TEST. The fouling test of an oxide offers the best means for de- termining its value for purification purposes. A glass tube with a bulb at one end is most suitable to hold the oxide to be tested, but a U-tube or almost any other tube compact enough so that it can be weighed on analytical balance will answer. (See C in Fig. 9.) FIG. 9. Five grams of the oxide to be tested are next mixed with about 2 grams of coarse sifted sawdust and placed in the tube, and covered with a layer of cotton to prevent any of the con- tents from falling out at the stopper end of the tube. The stopper is then inserted. The entire tube is accurately weighed and the total weight noted. For sponge ore oxide already mixed with shavings the sawdust is omitted. This tube is followed by a U-tube containing calcium chloride and weighed 64 together with the tube holding the oxide. Another large U- tube or a tower filled with calcium chloride to dry the hydrogen sulphide issuing from the generator is connected with the test tube by means of a piece of rubber tubing and the whole con- nected with the generator. A small piece of glass tubing closed at one end so as to leave only a hole the size of a small pinhole and placed between the U-tube and the generator reg- ulates the flow of gas. The hydrogen sulphide gas generated in the Kipp generator A, and dried by passing it through the calcium chloride in the U-tube or tower B, is decomposed by the iron oxide in the test-tube C, forming iron sulphide and water. The water formed is absorbed by the calcium chloride in the second test- tube D. The test is carried on for one hour, after which time the test- tubes are disconnected and weighed. The gain in weight repre- sents the amount of hydrogen sulphide absorbed, or rather decomposed, by the oxide. By dividing the amount of oxide taken into this weight, the percentage of hydrogen sulphide decomposed can be determined, and from the latter the sulphur calculated. Some oxides are very active at the first fouling (when new), but revivification is slow and incomplete, and on second fouling they give far lower results. For this reason it is sometimes desirable to carry the test far enough to determine the total absorbing capacity of an oxide. After the first fouling, the oxide tube is disconnected from the CaCl 2 tube, and air passed over it until completely revivi- fied. To prevent an oxide which has the tendency to revivify very rapidly from getting too hot and consequently burning, thus becoming more or less inert, it is advisable to pass the air used for revivification over water so as to saturate it with water vapor. For this reason it is not advisable to remove the oxide from the tube for revivification, for it being very dry, on direct exposure to air, any very active oxide is found to take fire. After complete revivification, the tubes of oxide and CaCl 2 65 are again weighed and connected with the Kipp apparatus, and fouled a second time. This second fouling as a rule is suffi- cient to show how active the material is, for if the results of the second fouling are very close to those of the first, the material is very active, but the test can be repeated the same number of times as the oxide is revivified in practice. Thus the entire capacity of the oxide can be determined before it is placed in service. \ Used Purification Material. SAMPLING. Used purification material may be required to be sampled under two conditions. I. When removed from the box for revivification. II. When revivified in the box. When the oxide has been removed from the box and spread out, portions may be taken to the entire depth of the bed with the trowel at points situated at equal distances over the sur- face. When about a bushel has been obtained, this is thor- oughly mixed, quartered down, and a quart jar or can filled and tightly closed. When the oxide is revivified in silu, samples should be taken in different parts of the box, the operator using his judgment and endeavoring to obtain a sample which represents the entire contents of the box. MOISTURE AND UGHT OILS. Weigh 100 grams of the sample from the jar or can into a counterpoised tin dish. Place the dish in a drying oven, the temperature of which is not allowed to exceed 95 C. For coal gas oxide it is advisable to air-dry the sample for 5 to 10 hours in a warm place or drying oven kept at 55 C. Examine occasionally by removing from the oven and allowing to cool. It will be found that some oxides containing much tarry matter require several days to dry. When the oxide appears hard on cooling, the dish and con- 66 tents are weighed and a loss reported as moisture and light oils. The sample is then ground in a coffee mill to 3O-mesh fine- ness, and quartered down until about 30 grams are obtained which are kept in a well corked bottle for subsequent de- terminations. TOTAL SULPHUR. Laboratory routine method, gravimetric or volumetric as desired : Oxidation of Sulphur : Mix 0.5 gram of the sample in a 100 cubic centimeter nickel crucible with 5 to 10 grams of sodium peroxide, depending on the sulphur content of the oxide. Place the crucible in a water bath containing cold water, attach a fuse by passing it through a slip in the edge of the crucible, put on the cover, which must be weighted to pre- vent it blowing off, and light the fuse. The fuse is prepared by soaking a cotton string in a strong solution of potassium nitrate and drying. Transfer the fused mass to a 500 cubic centimeter beaker and dissolve it in cold water. Next, add dilute HC1 (1:3), while stirring, until the iron precipitate co- agulates in a flocculent form, but keep the solution distinctly alkaline to avoid the solution of iron hydroxide. Heat to boiling, filter off the precipitate and wash well with hot water. Gravimetric determination of sulphur. Acidify the filtrate with dilute HC1, heat to boiling and precipitate with barium chloride. Filter, wash and ignite as usual after two hours standing. Volumetric determination of sulphur. Solutions required: Barium chromate, 40 grams dissolved in dilute HC1, (80 cubic centimeters HC1 specific gravity 1.2, 920 cubic centimeters H 2 O,) approximate value of I cubic centimeter 0.04 gram BaCrO 4 . Sodium thiosulphate, N/io, I cubic centimeter equals 0.001066 gram of sulphur. Method. Catch the filtrate and washings in a 500 cubic centimeter volumetric flask, cool, and dilute to the mark. Transfer 100 cubic centimeters of the solution to a 200. cubic centimeter volumetric flask, add 25 cubic centimeters of barium 67 chromate solution, shake for a minute and then add dilute ammonia, a few drops at a time, until the color changes to a pure yellow, indicating the complete precipitation of the ex- cess of BaCrO 4 . Dilute to i cubic centimeter above the 200 cubic centimeter mark, filter through a dry filter paper into a 100 cubic centimeter flask. Throw away the first part of the filtrate. Transfer the 100 cubic centimeters of the filtered solution to a glass stoppered bottle, acidify with 10 cubic centimeters HC1, add I gram of solid potassium iodide, shake, and titrate the liberated iodine with N/io sodium thiosulphate. Multiply the number of cubic centimeters of sodium thio- sulphate by 2.132; this gives the per cent, of sulphur in the oxide. Alternate method. Weigh 0.5 gram of the oxide into a 300 cubic centimeter Erlenmeyer flask and treat it with 30 cubic centimeters of a mixture of 3 parts HNO 3 and 2 parts HC1. Heat gently and when the action ceases add a few crys- tals of potassium chlorate, and boil. Add 20 cubic centimeters HC1 and evaporate to dryness on a water bath. Heat in an air oven to 110 C. for one hour to dehydrate silica. Next, cool the flask, moisten the mass with 5 cubic centimeters HC1, take up with 100 cubic centimeters of hot water, boil, filter, and wash well with hot water. Dilute the solution to about 600 cubic centimeters and precipitate with barium chloride. Filter after two hours standing, ignite, and weigh the barium sul- phate in the usual manner. SOLUBLE SULPHUR AND TARRY MATTER. EXTRACTION WITH CARBON TETRACHLORIDE. Weigh one gram of the dried oxide, wrap it in a 9 centimeter filter paper. Place the paper and contents in a 10 cubic centi- meter porcelain Gooch crucible, which is equipped with an aluminum wire bail. Weigh the crucible and contents and sus- pend from the hook of a Wiley- Soxhlet extraction apparatus, as shown in Fig. 10. Fifty cubic centimeters of carbon tetra- chloride are placed in the extraction flask, and the whole ap- 68 paratus is assembled and heated in a water bath. Boil the water and continue the extraction until the droppings from the Gooch crucible remain colorless for at least a half-hour. The extraction will probably be complete in three hours. Remove the crucible and contents to a drying oven and dry for one hour or until no odor of carbon tetrachloride is apparent. Weigh the crucible and contents. The loss in weight will be soluble sulphur and tarry matter. FIG. 10. Pour the contents of the extraction flask into a 100 cubic centimeter Erlenmeyer flask, and with a little fresh carbon tetrachloride, wash out the former flask into the latter. By means of a cork and bent tube, connect the Erlenmeyer flask with a Liebig condenser and distil on a water bath. When the carbon tetrachloride has been distilled off, add 30 cubic centi- meters concentrated nitric acid, warm gently on a sand bath, and add cautiously, at short intervals, potassium chlorate crys- 69 FIG. lOa. tals, (in all about 2 to 3 grams). Boil off the nitric acid, add dilute hydrochloric acid, and precipitate with barium chloride. Filter, dry, ignite, and weigh the barium sulphate. The per cent, of sulphur found is soluble sulphur, the weight of which deducted from the weight of soluble sulphur and tarry matter gives the latter. Alternate Method Using Carbon Disulphide. Proceed ex- actly as when using carbon tetrachloride as described above, taking care, however, to employ only pure, freshly distilled carbon disulphide. When the Gooch crucible is removed from the extractor, allow it to stand at room temperature until all odor of carbon disulphide has disappeared before weighing. Caution Do not dry in an oven, because of the liability of carbon disulphide to spontaneous combustion. Empty and wash the extraction flask into an Erlenmeyer flask, using pure, freshly-distilled carbon disulphide. Distil off the carbon disulphide and remove the last traces by means of a current of air applied to the gently heated flask. Oxidize the contents with nitric acid and potassium chlorate as above, and precipitate in hydrochloric acid solution with barium chloride. Note. Extraction with carbon disulphide is liable to give high sulphur results, due to the decomposition of the solvent during and subsequent to the extraction. It is therefore neces- sary to use only recently distilled carbon disulphide, and when the extraction is finished to distil off and remove the last traces as rapidly as possible. The Gooch crucible is used in- stead of the usual extraction cup on account of the convenience in weighing. CHAPTER H. GAS ANALYSIS. The following determinations are covered in the analysis of illuminating and furnace gas : Benzol. Illuminants. Carbon Monoxide. Hydrogen. Methane. Ethane. Carbon Dioxide. Oxygen. Nitrogen. Source of Method. The method of determining benzol is that due to Pfeiffer, published in Chemiker-Zeitschrift, 1904-28-76. The other methods are those due to the paper by Mr. E. H. Earnshaw, published in the JOURNAL, of the Franklin Institute, September, 1898. Sampling. The method of sampling depends upon whether it is puri- fied or unpurified under pressure or vacuum. In some in- stances, it is possible to draw the samples directly into the analyzing burette, but more often they must be transferred to the laboratory in containers specially provided for the purpose. The figures show two forms of gas sampling tubes in general use. The one shown in Fig n is provided with cocks, and is, therefore, somewhat more convenient than the one shown in the Fig. 12, which must be closed by sealing off the ends. These tubes are very useful in taking a sample sufficient for a single analysis, and in the great majority of cases, a tube of this kind will be all the equipment necessary, provided the gas is under pressure. In taking a sample with the tube as shown in Fig. n, it is first filled with water and connected to the gas supply by a short piece of hose which, together with the connections, has been thoroughly purged of air and dead gas. The water is then permitted to run out ahead of the gas, after which the outlet cock is closed ; then the inlet, which places the gas under a slight pressure and lessens the liability of air being subse- quently drawn in by a leakage at the cock. FIG. 11. Gas sampling tube with stop cock This may be further guarded against by dipping the ends of the tubes in melted sealing wax, and, as an extra precaution by placing sealing wax around the exposed portion of the barrel of the cock. This serves the double purpose of pre- venting the cock from leaking and also from being accidentally turned. FIG. 12. -Gas sampling tube for sealing. In using the tube described in Fig. 12 the procedure is the same, except that the end is temporarily closed by means of a short piece of rubber tubing and a pinch cock, as shown in the sketch, after the water has run out. The outlet to the tube is then sealed off at the construction by means of a flame such as that furnished by a gasoline torch or a Bunsen burner. A candle flame may sometimes be used, but it is rare that the glass is soft enough to make the operation easy. Having sealed off the outlet, the inlet is closed in the same way without dis- connecting from the gas supply. When a sample is to be transported long distances or is to 73 be preserved for any great length of time before analysis, it is far better to use sealing tubes, as there is no possibility of leakage unless the end of the tube is broken, and this may be largely guarded against by fusing the end to a blunt point or turning it back upon itself. The tubes may be used repeatedly and when the end gets too short, a short piece of glass tubing may be sealed on. It is sometimes desirable to collect a sample out of contact with water. In this event, if there is an abundant supply of gas, it should be allowed to flow through the dry tube for 4 or 5 minutes in order to displace the air, and then sealed as described above. When the gas supply is small, mercury should be used to displace the air. Fig. 13. Aspirator for large gas supplies. If a large sample is required, the aspirator shown in Fig. 13 may be employed. This consists of a galvanized iron cyl- inder with conical base and top having a capacity of about 1/2, cubic foot. The top is provided with a cock (A) and the bottom with two cocks (B) and (C) as shown. The whole apparatus is mounted on a suitable tripod or stand. It is used ordinarily precisely as the tubes described above. When, as is 74 sometimes necessary, an average sample (of a run) for a definite period is described, the cock B is set so that the water will just run out in the stated time. The apparatus is then filled with water and the cock C closed. When the apparatus is connected and C is opened an average sample of the whole run will be obtained. Aspirating Tubes. In sampling gas from services and moderate size mains and connections, a fair average can usually be obtained direct without the use of the aspirating tube. If, however, the gas chamber or passage is large, as for example in a generator or large sized main, such a tube must be inserted as currents are always set up, and a sample taken simply through the shell will not give a correct average. Even when a tube is inserted to the middle of the chamber, it is difficult to get a true average of the gas passing. Glass aspirating tubes should be used when possible, as they are easily cleaned and they do not act upon, nor are they affected by, the gas passing through them. They may be used in temperatures up to 600 C. (1,112 F.). L,ead tubes may be used up to temperatures of 300 C. (527 F.) and are very convenient as they are easily handled and may be bent into any required position. For temperatures higher than 600 C. (1,112. F.) porcelain tubes, platinum tubes, fused silica pipes may be used, or water-cooled iron tubes. Fig. 14 shows a tube which may be made from the ordinary fittings procurable around a gas works. The tube shown in Fig. 14 is made as follows : A ^4-inch by ^-inch reducing socket is threaded through from the inside to receive the end of a ^-inch pipe. Into this socket is screwed a I Y^ -inch pipe threaded at both ends of a length depending upon the desired length of the complete apparatus. On the end of the I % -inch tube is placed a 1^2- inch by i^J-inch bushing threaded from the inside and through which the i^-inch pipe extends about 2 inches. A I % -inch cross is screwed on the top of the pipe. One side of the cross 75 contains a ij^j- by a ^-inch bushing which carries a }/-inch nipple 3 inches long, the other side of the cross contains a 1 1/2 -inch by ^-inch bushing which carries a ^-inch nipple 3 inches long, a ^-inch L, on the inside of the cross and a piece of y$ -inch pipe of such a length that it extends to within I inch of the bottom of the i^-inch pipe as shown in sketch. Fig. 14. Water cooled sampling tube. The pipe B, which consists of a piece of ^-inch pipe threaded at one end, is passed through the top of the T and threaded through the reducing socket. The top of the pipe is made tight with the top of the cross 'by means of a lock nut or stuffing box. When in use, the water supply is connected to pipe C and the water overflows through the nipple B. The complete apparatus, when in use, is held in place by means of 7 6 the bushing D. The sample of gas is obtained from the outlet of the pipe B. It is of very little use to provide branches to, or a slit in, the aspirating tubes, as the currents are of less velocity near the shell due to friction, and besides, with a slit pipe or one drilled with holes, more gas will be drawn in near the sides as the suction here is strongest. The best method is to set up a strong primary current and take the sample from a second- ary current at the side of the tube as shown in Fig. 15. FIG. 15. Method of supplying from large main. Fig. 15 shows a glass tube inserted through a rubber stopper into a i6-inch condenser connection. A glass or metal T is fastened close to the end of the tube by means of heavy rubber hose, and the sample is taken from the secondary current flowing from A, the large primary current all the while flow- ing from B. The foregoing directions presuppose that the gas is under pressure. If such is not the case, an aspirating apparatus must be employed. For small samples the aspirating bulb shown in Fig. 16 is recommended by analysts. FIG. 16. Aspirating bulb. 77 This consists of a small rubber bulb with valves working opposite to each other, thus enabling it to work as a suction, and as a pressure pump. In use, one end of the empty gas sampling tube is connected to the gas supply, and the bulb is connected to the other end, with the valves in such a position that the pressure and relief on the bulb will suck the air out and admit the gas. This should be continued for some time to insure thorough displacement of the air. If there is no objection to water coming into contact with the gas or if mer- cury be conveniently used, a more satisfactory method is to connect up as shown in Fig. 17 in which A is a glass or metal FIG. 17. Method of sampling from stack and breeching of boiler aspirating tube, B a rubber tube, C the sampling tube. The whole apparatus, including the hose and tube A, is filled with water or mercury, and the tube introduced into the stack or flue. Upon opening the cock on the sampling tube, the water or mercury will flow out and the tube will materially increase the pull. Where running water is at hand, a water suction pump may be used to advantage. There are many forms of these pumps in use, but for durability and general adaptability for the pur- pose, the "Chapman" pump shown in Fig. 18 is probably the most satisfactory. By its use a strong primary sample may be drawn off, and a secondary sample, taken from a side con- 6 nection as previously explained. A steam jet aspirator may also be employed in the same way where high pressure steam is available. It is shown in Fig. 19 and may be constructed as follows : FIG . 18. Chapman filter pump . The steam jet aspirator shown in Fig. 19 is made as follows : Two 24 -inch nipples H and / are threaded into a ^4 -inch by %-inch reducing tee A. H is left open for steam exhaust, while on / is threaded a ^4-inch union D, a ^-inch pipe is then threaded through a ^4 -inch by J^-inch bushing H, one end of which has been hammered down to a point leaving a i/i6-inch opening. The ^-inch bushing H is then threaded into the union B and end of piece C connected to steam supply. A l /4 -inch nipple is then threaded into the %-inch connection on tee A and connected to place where sample is to be taken from. Where it is necessary to take samples of crude gas, partic- ularly crude coal gas for the determination of tar, or naph- thalene, it is essential that the temperature of the gas be not changed after the sample is withdrawn from the main. It is, therefore, necessary that the sample tube be surrounded with a water bath maintained at the same temperature as the gas in the main. Tubes similar to Fig. 14 should be used for this 79 purpose, water at the proper temperature being supplied with a water-jacket. FIG. 19. Steam or compressed air respirator. Where crude gas is being sampled for its ammonia content, a certain amount of ammonia liquor exists as a mist in the gas, and at the same time, the walls of the main are also coated with ammonia liquor. It is, therefore, necessary to arrange the inlet of the sampling tube so that liquor collected on it from the gas will flow into the sample. This is best secured by placing an iron tube in the main approximately 83 per cent, of the diameter from one side and inserting in this a slightly smaller glass tube which will be inclined to the sample bottle so that the ammoniacal liquor condensed in the glass tube will be collected in the sample. Volumetric Determination of Benzols. The determination depends on the reaction N0 2 4- 3SnCl 12 + 6HCI = NH 2 + 3SnCl 4 + 2H 2 O. The gas is treated in a glass stoppered separatory funnel of a known content, the stopper and cork of which have been lubricated with a drop of H 2 SO 4 , the gas is allowed to blow 8o through the apparatus for 2 minutes, the stopper put in place and the cock closed. The apparatus is disconnected from the source of supply and the cock opened for a moment to insure atmospheric pressure, the barometer and the thermometer are read. Two cubic centimeters of a mixture of equal parts of concentrated H 2 SO 4 and fuming HNO a allowed to enter the funnel by means of the lower tube, the cock closed, and a half- hour allowed to complete the absorption of the benzol vapors. Thirty cubic centimeters of a concentrated NaOH solution are now added, and all the vapors set free are absorbed by shak- ing. The solution is now neutralized with very weak HC1 ; no indicator is needed, as the color of the solution as it changes from an orange red of the alkaline state to a wine yellow of an acid state, is all that is necessary. The solution is now ex- tracted twice with 50 cubic centimeters of ether shaking 5 minutes each time; it is then separated from the other nitro products and put into a flask containing I gram of potash and y 2 gram of finely powdered animal charcoal, which on shaking and standing, takes out the strong yellow red coloration. The solution is now filtered into a 200 cubic centimeter graduated flask, and washed with absolute ether, which is evaporated off on a water bath. As soon as this has taken place, 10 cubic centimeters of absolute alcohol and about 10 cubic centimeters of a stannous chloride solution (150 grams of tin dissolved in 50 cubic centimeters of HC1 and made up to I liter) are added, and the flask warmed for 10 minutes on the water bath. The flask is filled to the mark with water and 20 cubic centimeters are titrated with i/io N. iodine solution and starch paste. A blank is run with 10 cubic centimeters of SnCl 2 solution, 10 cubic centimeters of alcohol, diluted to 200 cubic centimeters and 20 cubic centimeters titrated. The difference between the two titrations gives the value of the dinitro benzol and is calculated (b -- a) 10 x 0.0014 gram. The percentage is calculated i gram dinitro benzol 0.4643 gram C 6 H 6 , I gram of benzol = 279.2 cubic centimeters of vapor of o and 760 millimeters. The combined formulae would appear as follows : J = volume of gas 8i X Vol. per cent. C 6 H 6 = 0.4643 X 279.2 3690 x weight of dinitro benzol or this can be simplified to read where b = barometer, t = temperature, g = dinitro benzol and / = flask content. Volume per cent, of benzol = (36,090 + /) x g x (273 + t + b). It is now generally admitted that the accuracy of a gas analysis made by direct absorption in a gas burette is not very great, and that the applicability of the method is also limited by the fact that only those absorbents which do not rapidly attack rubber can be used. On the other hand it is claimed that the time lost in connecting up absorption pipettes and in passing the gas backward and forward is not compensated for by the increased accuracy resulting. The following apparatus was designed for the purpose of meeting the above objection while retaining the essential feat- ures of Hempel's method. The burette as seen in Figs. 20-21 is similar to that described in Hempel's Gas Analysis on page 28, except that a four-way cock C replaces the three-way cock used by Hempel and the burette is bulbed, thereby shortening the same and allowing a finer graduation. The capacity of the burette is about 105 cubic centimeters, graduated in 1/20 cubic centimeter from 40 to 102 cubic centi- meters. It is connected through the capillary tube D coming out from the back of the cock C with manometer tube M. The manometer is connected with the Petterson correction tube R. A water jacket / surrounds the Petterson tube and burette. A potash absorption pipette K which rests on the adjustable stand S is connected permanently with the capillary tube B. This modification of Hempel's apparatus has the following advantages : 82 i. It permits of the potash absorption pipette being per- manently attached and so does away with at least five attach- ments and disengagements of a piece of apparatus disagree- able to handle, saving thereby considerable time and annoy- ance ; for after both the explosion and combustion the gas can be passed directly into the potash without stopping to connect up any other pipettes. This is also true after the absorption of illuminants by bromine and carbonic oxide by cuprous chloride when it becomes necessary to remove the fumes of bromine and hydrochloric acid. FIG. 20. 2. With the apparatus constructed in the modified form the two limbs of the manometer tube and the perpendicular por- tion of the capillary tube coming out from the back of cock C are in the same plane, so that you connect up the trouble- some "sagging" of the manometer tube common to Hempel's apparatus is overcome. 3. The bulbing of the burette make the apparatus much less top-heavy and cumbersome and also permits of a much closer reading, as the narrowed portion may be graduated to read to 1/20 cubic centimeter without trouble. FIG. 21. Besides the above important modifications, several minor changes have been introduced which greatly reduce the time necessary for an analysis, while not jeopardizing the accuracy of the results. The following pipettes and reagents are required for the analysis : A potash absorption pipette which is permanently attached to the burette, as shown in sketch. (For reagent see page 125.) A pipette filled with strong bromine water. In order that 84 this solution remain concentrated an excess of free bromine is kept in the pipette. A pipette for solids filled with stick phosphorus covered with water. A double U. G. I. absorption pipette. This combines in one piece of apparatus the two solutions of cuprous chloride which are necessary to remove the carbon monoxide. A simple pipette filled with gas-saturated water for storage purposes. A mercury explosion pipette. A U-shaped combustion tube containing about */2 gram palladium black is also required. The following is the method of procedure for an analysis of a gas containing CO 2 , C M H 8M , O 2 , CO, H 2 , CH 4 , C,H 6> and N 2 . Completely fill water jacket with distilled water. Turn cock C so that the interior of the burette Y communi- cates with A, open cock C, raise levelling bulb L, which has been filled with gas-saturated water, until water flows out A. Turn C so that interior of burette communicates with K, and draw over potash solution to just above cock C. Turn cock C so that Y communicates with D, and by raising and lowering L and allowing air to escape through A, fill M with water to N. Open C to A and by lowering L, draw in air. Close C, raise L, open C to D, and admit air in M to C, and close C. Disconnect M momentarily at P and reconnect. The air in R is now at atmospheric pressure. Connect the tube containing gas sample with A, using glass connector similar to one used on potash pipette, being careful to displace with water all air that may be in connection. Open C to A, lower L and draw in 100 cubic centimeters of gas. Close C, raise L, open C to D, and allow gas to flow into M until the water level is at O , and close Z. Take the reading on burette after allowing a minute for water to run down off the sides of the burette, add I cubic centimeter to observed reading for the I cubic centimeter gas occupying space be- tween O and cock C. Disconnect from sample tube or gas 8 5 supply as the case may be. Open C to B, raise L and allow gas to flow into K, until the water from burette reaches the bulbed portion of K, being careful to draw the I cubic centi- meter from manometer and to force that into the potash like- wise. Turn C to D and adjust water-level at N in M. Turn C to B, low r er L, and draw back gas until the potash solution just reaches its previous position above C and close C. Raise L and turn C quickly through arc of 180 so as to allow no gas to flow back to B while turning cock so that the interior of the burette communicates with manometer M. Raise L until water in M is level with O, close Z and read burette, adding i cubic centimeter to observed reading as before. The difference between this reading and the preceding gives direct- ly the percentage of CO 2 in the gas. Connect absorption pipette containing bromine to A resting it on stand S, being careful as before to exclude all air from connections. Open C to A, raise L, and force gas from the burette into the pipette until water reaches the bulbed portion of the pipette, drawing the gas from the manometer tube as before, and close C. Shake the bromine pipette slightly until gas is colored by bromine fumes, open C , lower L,, and draw gas back into burette. Close C, raise L, C to B, and force all gas immediately into potash. Close C to B, and open D, and adjust water-level. Open C to B, lower L, and draw back gas until potash assumes former position. Close C, raise L, adjust water-level and read as before; the difference between this reading and the preceding gives the percentage of C,,H 2 ,,. Disconnect the bromine pipette from A and connect the phosphorus pipette. Force the gas over the phosphorus as was done with the bromine pipette, turn C to D, raise L and adjust water-level, close C. If no white fumes are given off by the gas when in the pipette it is a sure indication that all of the C M H 2W> compounds in the gas have not been completely removed. In this event it is necessary to again pass the gas into the bromine pipette. If fumes are given off, wait a minute or two to allow them to partially condense, then open C to A, lower L, and 86 draw gas back into burette. Close C, raise L, open C to B, ad- just water-level at O, and take reading. The difference between this reading and the preceding gives per cent, oxygen present. Disconnect phosphorus pipette and connect double absorption pipette containing cuprous chloride, being careful to have all capillaries filled with the solution. Open C to A, raise L, and force all gas over one solution of cuprous chloride. Shake for two or three minutes and then draw gas back into burette until solution just passes cock on cuprous chloride, pipette, turn this cock so as to connect with other solution of cuprous chloride, raise L, and force gas over second solution to remove last of carbon monoxide, and close C. Shake for a few minutes, draw gas back into burette, and then immediately force it into the potash pipette. Adjust water-level, draw gas back from potash pipette and take reading. The difference between this reading and the preceding gives percentage of carbon monoxide. It is important to notice that even with the precaution of using two pipettes with freshly prepared cuprous chloride the absorption of the carbonic oxide is seldom complete, usually a trace remaining unabsorbed. However, this fact introduces no error in the analysis, as this residue of carbonic oxide can be determined by the combustion made to determine hydrogen. The residue of the gas mixture remaining after the absorp- tions may consist of the following : H 2 + CO + N 2 + CH 4 + C 2 H 6 , C 3 H 8 , etc. For all ordinary purposes it is sufficient to assume that the highest paraffine present is C 2 H 6 , as all others higher than this exist only in traces. There being no satisfactory known absorbent for any of these gases, recourse is had to the method of combustion. The analysis is accordingly continued as follows : The double absorption pipette is replaced by the storage pipette containing gas-saturated water. Pass approximately 15 cubic centimeters of the residue back into the potash by opening Z, raising L and opening C to B. Turn C to A, and 87 pass remainder of residue into storage pipette. Close pipette with a pinch-cock and disconnect. Adjust water-level in M at N. Turn C to A and by lowering L, draw into the burette about 85 cubic centimeters of air. Close C raise L and open C to D draw the gas stored over the potash into the burette, close C raise L, turn C quickly through arc of 180 to connect with D adjust water-level at 0, close Z and take reading. The increase over the previous reading is the amount of gas taken for the explosion. Connect mercury explosion pipette at A and pass mixture of gas and air into pipette and explode, first partly withdraw- ing glass connecting tube from rubber connection and placing clip on same. Adjust water-level in M at N, draw back gas from explosive, pipette and measure contraction resulting from the explosion. Pass the gas into potash, and the resulting contraction gives the amount of carbonic acid formed during the explosion. Dis- connect explosion pipette and connect phosphorus pipette. Pass gas residue over phosphorus to remove all oxygen in ex- cess of that which was required for explosion and measure the amount of nitrogen left. This gives nitrogen introduced with gas. By subtracting amount of air used for explosion X 79.2 from this reading, one obtains nitrogen introduced with gas for explosion. This multiplied by factor obtained by dividing the amount of gas residue taken for the explosion into the whole amount of gas left after absorbing carbon monoxide, gives the total nitrogen in the original sample of gas taken for analysis. The percentage of nitrogen thus obtained should check that obtained by subtracting the sum of the other con- stituents in the gas from 100. The equations obtained from the explosion are as follows : (1) Contraction in volume = 3/2H 2 + ^CO + 2CH 4 -f- 2/ 2 C 2 H, (2) CO 2 formed = CO + CH 4 + 2C 2 H 6 . (3) Residual nitrogen = N 2 -(- N\. Where N is the nitrogen introduced with the air. 88 An examination shows that the equations I and 2 contain 4 unknown quantities and therefore two more equations are needed for the solution. Fortunately, the method of frac- tional combustion over palladium affords the needed informa- tion. As is well known, when a mixture of hydrogen and CH 4 with oxygen or air is passed over heated palladium black, the hydrogen burns to H 2 O, but the CH 4 remains unaltered. If CO and any of the higher paraffines are also present, the CO burns, but the paraffines do not. Returning to the analysis, proceed as follows : Fill burette to A by raising L, adjust water-level at N in M. Draw in about 70 cubic centimeters air and measure it. Connect storage pipette and draw in about 30 cubic centi- meters gas residue, and measure, the increase in volume giving the amount of gas taken for combustion. Place explosion pipette with mercury level about one-half up to capillary, on stand S, connect combustion tube to A and explosion pipette, equalize pressure in combustion tube and gas burette and re-measure gas in burette. Place combustion tube in hot water by resting beaker containing water on T and pass gas mixture backward and forward over palladium until there is no, further contraction, measure gas and decrease in volume gives contraction due to combustion of hydrogen and carbon monoxide. The equations are : (4) Contraction in volume = 3/2H 2 -|- ^CO. (5) CO 2 formed = CO. From these two equations, the value of hydrogen and CO may be readily determined. For the sake of simplicity, let us now assume that the same quantity of gas residue was used in both the explosion and the combustion. We may then' subtract equation (4) from (i) and (5) from (2), whence, designation the difference between the contrac- tion due to combustion by the letter (a) and the difference in the CO 2 formed by the letter (b) we find (6) 2 CH 4 + 2-y 2 CXT = * 8 9 (7) CH 4 + 2C,H~ whence (8) C 2 H7= ^ ~ 2 o and (9) CH 4 - ~ o A very useful check on the accuracy of this determination is obtained from the following : Volume of gas taken for explosion = H 2 + N 2 + CO + CH 4 + C 2 H7 H 2 + CO are found by (4) and (5), and AT is given by (3). Therefore, we have (10) Volume taken = (H 2 + N 2 + CO) = CH 4 + C 2 H 6 and this value should be the same as the algebraic sum of (8) and (9) or (n) Volume taken + (H 2 + N 2 + CO) = 2a ~ b . \} This method if carefully pursued will give results that are extremely accurate, and what is much to be desired, the method is very rapid. Analyses have repeatedly been made in from 30 to 35 minutes. The Modified Elliott Gas Analysis Apparatus. This apparatus is shown in Fig. 22. It consists of three glass tubes marked A, B, and C, mounted on an iron stand. Tube A, called the absorption or laboratory tube, has a one- way stop-cock, i, at the top, and three-way stop-cock at the bottom, 2. The funnel, 3, is ground to fit the top of A, and has two marks 10 cubic centimeters and 20 cubic centimeters etched on the glass. The lower outlet of cock 2, drains to the sink through a piece of rubber tubing. The side outlet is connected with level bottle, 4, by another piece of rubber tubing which is long enough to allow bottle 4 to be placed on the shelf above the apparatus. There is a 100 cubic centimeter mark near the lower end of A. FIG. 22. Tube, B, is called the explosion tube. It is graduated to 100 cubic centimeters in i/io of a cubic centimeter. It has a three-way stop-cock, 5, the arms of which are connected to tubes A and C by means of short pieces, of rubber tubing, the connections being made by bringing the glass side pieces close together and fastening the rubber with fine wire. The level bottle, 6, is connected with the lower end of B by a rubber tube long enough to allow the bottle to be placed on the shelf above. The upper end of B has two platinum wires fused into the glass. The electrodes are attached to these wires when the gas is to be exploded. B is enclosed in a water-jacket which ex- tends from the platinum wires to below the 100 cubic centi- meter mark. Tube C, called the residual tube, is a plain glass tube having a one-way stop-cock, 7, and a level bottle 8. Connection is made with B as described above. REAGENTS. Sodium hydroxide 10 per cent, solution. Pyrogallic acid 10 per cent, solution, used by mixing in the funnel with equal volume of 10 per cent, sodium hydroxide. Acid cuprous chloride, made as follows : Four hundred grams chloride dissolved in 1,800 cubic centi- meters hydrochloric acid, (specific gravity 1.2) to this solution add 400 cubic centimeters water. This solution is to be kept in a bottle containing pieces of copper wire. Fill bottles 4, 6, and 8 with water and place them on the shelf above the apparatus. Open stop-cock i, turn 5 so that C is connected with A. Then open 7, allowing water from bottle 8 to fill tube C and pass into A. Close 7 and turn 5 so that B is connected with A, allowing water from 6 to fill B and pass into A, then shut off 5. Turn 2 so that water from 4 fills A and flows out at i, then close i. The apparatus is now filled with water and the next step is to transfer the gas into it from the collection tube. Before doing this, examine the apparatus to see if there are any air bubbles imprisoned in it, paying particular attention to the capillary tubes in the upper part. If 92 any bubbles are seen, drive them out with water from the level bottles. The sample of gas is transferred to the apparatus by remov- ing funnel 3, replacing it with a piece of soft rubber tubing which is filled with water, and attaching the collection tube and passing the gas into A in the usual manner. When the gas fills A to below the 100 cubic centimeter mark, cock i is closed and the collection tube detached. METHOD OF ANALYSIS. Place the funnel 3 on the tube A. Set bottle 4 on the shelf and bottle 6 on the table. Turn cock 5 to connect B with A and turn cock 2 so that the gas in A passes slowly into B. While the gas is passing into B, raise bottle 6 and hold it so that its water-level coincides with the 100 cubic centimeter mark on B, and at the same time regulate the speed of the gas by manipulating cock 2. When the meniscus in B reaches the 100 cubic centimeter mark, close cock 2, and without chang- ing the position of bottle 6, reach up and close cock 5. Place bottle 6 on the table and wait one minute to allow the water adhering to the inside of B to run down, then raise bottle 6 bringing its water-level to that in B and verify the volume in B. Note. If the transfer of gas from A to B is done very slowly, it will be found that the water adhering to the inside of B will all have run down at the same time that the meniscus in B reaches the 100 cubic centimeter mark. After making sure that there is a volume of 100 cubic centi- meters of gas in B, place bottle 4 on the shelf, open cock i and turn cock 2 so that the water in 4 will drive out the gas left in A. Open cock 7 and allow the water from C to pass into A driving out the gas left in the capillary tubes between B and A. Close cocks 7 and i. It will be noticed that there is a little gas above the zero mark in tube B. This is less than i/ioth of a cubic centimeter and may be ignored, or it may be compensated for during the 93 analysis by allowing the water from A to come only to the cock 5 when gas is being transferred from A to B. Place bottle 4 on the table and bottle 6 on the shelf, turn cock 5 to allow the gas in B to pass into A. When the water from B has reached the capillary above the bulb of A, close 5. Do not allow any unnecessary water to flow from B into A. Now pour 10 cubic centimeters of the sodium hydroxide re- agent into the funnel 3, and slightly open i, allowing the re- agent to pass into A. At the same time, manipulate I, and give the whole apparatus a rotary motion on its base to spread the reagent over the inner surface of A. Let the reagent enter slowly and spread evenly. Use only 10 cubic centimeters of this reagent; it is unnecessary and dangerous to use more, be- cause 10 cubic centimeters will absorb about 50 cubic centi- meters of CO 2 and any excess is liable to absorb a few tenths of a cubic centimeter of illuminants for every 10 cubic centi- meters of the reagent. Close cock I when the reagent is near the bottom of the funnel, and be careful not to allow any air to enter tube A. Open cock 5 slightly, allowing water from B to wash out any reagent that may have crept into the capillary tubes be- tween A and B. Place bottle 4 on the shelf and bottle 6 on the table and drive the gas from A into B, shutting cock 5 when the water from A reaches it. When the gas is back in B and cock 5 closed, open cock i and turn cock 2 so that the water in A will pass through its lower outlet into the sink. When A is empty, fill funnel 3 with water and allow this water to flow down and spread on the inside of A in the same manner that the reagent was applied. This washes tube A clean. While doing this, open cock 7 to allow water from C to wash out the capillary tubes. Close cock 7, When A is thoroughly washed, turn cock 2 to connect its lower outlet with bottle 4 thus washing out the rubber tube connecting A and 4. Turn cock 2 so that its lower outlet connects with A, fill the funnel with water and again wash out A. Turn cock 2 so that water from 4 may enter A and when the water reaches the 10 cubic centimeter mark on the funnel, close cock i. 7 94 Now take bottle 6 from the shelf and bring its water-level to the meniscus in B, and carefully note the graduation on B where the two levels coincide. Note the reading. This read- ing subtracted from 100 will be the percentage of carbon di- oxide, CO 2 in the gas. The above method of applying reagents, manipulating the apparatus, excluding air and washing out and preparing for the next absorption refers to all subsequent operations except the following : Illuminants are absorbed by adding 3 drops of bromine to the water in the funnel and causing the bromine to enter A very slowly and spread evenly, sodium hydroxide is then used to absorb the bromine vapors. Caution. The bottle from which the bromine is taken should never be lifted to the funnel 3, as serious accidents may occur. This bottle should be on the table and the small quan- tity needed removed by a pipette dropper to the funnel. Oxygen is absorbed by a mixture of 5 cubic centimeters each of the pyrogallic acid and sodium hydroxide solutions. These are poured into the funnel from their respective bottles, and well mixed. Carbon monoxide is absorbed by 20 cubic centimeters of acid cuprous chloride solution. This reagent must be added a little at a time, waiting half a minute between each addition as its action is slow. After absorption of CO place about 10 cubic centimeters of water in the funnel and allow it to enter A, spreading evenly and washing down the white salt. The ob- ject of adding water is to absorb the acid vapors. The residual gas consisting of hydrogen, methane and nitro- gen is passed into tube C retaining 12 cubic centimeters in tube B. Tube A is filled with air to the 100 cubic centimeter mark and air is passed from A into B mixing with the 12 cubic centi- meters of gas until the volume in B is about 72 cubic centi- meters. This proportion is not absolute and must be found by experiment as it varies for different gases. The above volume is usually correct for carbureted water-gas. The excess air in A is expelled, and the contents of B passed to and fro be- 95 tween B and A to thoroughly mix. When finally mixed the volume in B is read, bottle 6 is placed on the floor and the gas exploded by an electric spark. After waiting three minutes the volume in B is read. The CO 2 formed by the explosion is absorbed by the sodium hydroxide, the gas is then passed back to B and the volume again read. The oxygen remaining in the gas is then absorbed by alkaline pyrogallol and the final volume read. The hydrogen, methane and nitrogen are calculated as fol- lows : Let R be the residual gas, T the gas taken for explosion (12 cubic centimeters), C the contraction after explosion. D the CO 2 absorbed. Then, Hydrogen in T = 2C ~4 D (H T) ; Hydrogen in R =- H Methane is T .= D; Methane in R = T D X R The sum of all the constituents subtracted from 100 will give the nitrogen. There are two methods of varifying the above results : 1. Subtract the sum of the hydrogen and methane in T from T, multiply this result by R and divide by T. This gives the per cent, of nitrogen which should come within i/io of one per cent, of the nitrogen found by difference. Expressed in formulas this would be, NT V R T (HT -f D) = Nitrogen in T. ^^~- ^Nitrogen in gas. 2. Multiply the air added by 0.791 ; this gives the nitrogen in this air volume. Subtract this from the final reading; this gives the nitrogen in T, (NT). Multiply this result by R and divide by T. This gives the nitrogen in the gas. Expressed in formulas this would be: Volume i T = air taken for explosion, (A) A X 0.791 = nitrogen in A, (NA) Final reading NA = nitrogen in T, (NT) NT X R = = nitrogen in gas. 9 6 This result should agree within one per cent, of the nitrogen found by difference. If all the calculations have been found correct and a difference exists then this is due to the presence of ethane. In this case the per cent, of nitrogen found by method 2 is added to the sum of all the other constituents, except methane, and the difference between this sum and 100 considered as methane. The Morehead Apparatus. This type of apparatus has been used for the past fifteen years in the laboratories of The Peoples Gas Light and Coke Company of Chicago, and by other large companies. The gas analyzing apparatus as shown in Fig. 23 consists of a graduated burette (4) fitted with platinum electrodes (13) and a storage bulb (6). The three aspirator bottles (7, 8 and 9) with rubber tubing (14, 15, 16 and 17), and an electric sparking outfit are also required. Both glass pieces are fitted with three-way cocks (i, 2 and 3). The measuring, explosion, washing, and the entire analysis is made in the graduated, burette; the bulb (6) is used only for storage of the reserve supply of gas after the CO absorption in case the explosion is unsatisfactory. The burette (4) is usually provided with a water-jacket (n) consisting of a large glass tube confining by large rubber stoppers at the ends clear distilled water. A bottle or beaker (10) is placed under cock (2) to form a seal and catch waste reagents and wash water. A removable fun- nel or cup (5) is attached to burette capillary tube at the top by a ground joint. A secondary funnel (12) beneath (5) serves to drain away excess reagent or wash water by means of drain tube (18). In preparing the apparatus for an analysis, first fill the as- pirator and seal bottles (8, 9 and 10) and the levelling bottle (7) with distilled water previously saturated at the tempera- ture of the water- jacketed buretted with the gas to be analyzed, and place aspirator bottles (7, 8 and 9) on shelf (21). By manipulating cock (3) displace all air from rubber tubing (15, 1 6 and 17) until water entirely free of bubbles flows up- 97 ward through ground joint into cup (5). Then open cock (2) to seal bottle (10) and purge all air out of tube (14) through FIG. 23. cock (2) into seal bottle (10). Similarly open cock (2) to burette (4) and fill same with water up to funnel. When the apparatus is quite full of water, as described, remove cup (5) 98 open cock on sampling can or pipe from which the sample is to be taken, allow gas to blow through the hose for a few seconds to insure the explosion of all air, and then attach hose to the ground joint end of the capillary tube at the top of the burette. Turn cock (2) so that the water in burette (4) communicates with the levelling bottle (7), held level with fun- nel (5). Now open cock (i) so that the gas sample enters burette only, and as the surface of water in the burette (4) is depressed, slowly lower the levelling bottle (7), keeping the surface of water in same slightly above that in the burette in order to insure no inward leaks of air through loosely attached tubing, etc. When the gas has displaced nearly all water to about a point (19) in the burette, close cock (i), remove rubber tubing at top of burette and replace cup (5). Open cock (3) for a few seconds and expel gas from capillary tubes until water flows into cup (5) and fills it about one-quarter full. If the sample is taken from the house piping, or where there is an abundant sample, it is well to allow the gas to flow entirely through the burette and out at the lower stop-cock for a few seconds, care, of course, being taken to purge out excess gas from stem of cock (2) into bottle (10) before securing the 100 cubic centimeter sample for analysis. If the gas sample be at a different temperature than the burette, allow it to remain in the burette for a few minutes before proceeding to secure the desired 100 cubic centimeters. When the gas has assumed the temperature of the burette, raise levelling bottle (7) so that the water-level is sufficiently above the 100 cubic centimeter graduation of the burette to force small bubbles of the confined sample through the water into cup (5), when the cock (i) is slightly opened. Bubble excess gas sample slowly outward in this manner until closing cock (i) and lowering bottle (7), its water-level and that in the burette are at the 100 cubic centimeter mark. If the zero mark of the burette be at the cock (i), then the 100 cubic centimeter mark is taken for a levelling point as just described, but if the zero graduation be at the point of capillary retention, where the capillary tube immediately below cock (i) widens 99 into the burette proper, then excess gas is bubbled outward, until the water-levels in the bottle (7) and burette (4) are at a mark equal to 100 cubic centimeters, minus the previously de- termined volume (usually 0.3 or 0.4 cubic centimeter) of the capillary tube between cock ( I ) and the zero graduation at the point capillary retention. In the latter case, after adjusting the burette water-level a 99.7 or 99.6, as the case may be, bottle (7) is placed on a level with (10) and the cock (i) is slightly opened until the water in cup (5) slowly enters the burette capillary tube at the top to the point of capillary re- tention, when it will be found upon raising bottle (7) that the water-level corresponds with the one in the burette, which will be at the 100 cubic centimeter graduation. When there is just 100 cubic centimeters in the burette the analysis may be started. Turn the cock (2) so as to connect the burette with the bottle (10) raise the funnel (5) until it is just off its ground joint and drain, leaving about Y^ inch of water in the bottom. L/ower the funnel onto its seat and put into it about 20 cubic centimeters of potassium hydrate solution. Be sure that cock (2) is set so that the burette is connected with (10). Now open cock (i) and let the potassium hydrate solution drain very slowly into the burette. When it has nearly all gone into the burette close cock (i) and open cock (3) and let water from bottle (8) or (9) through into the funnel (5) for about ten seconds. Rinse the funnel and fill it with about 50 cubic centimeters of distilled water previously saturated with the gas being analyzed. Pass this wash water slowly through the burette. Then turn cock (2) so that burette is connected with bottle (7), and read the contraction of the gas, at the same time holding the bottle (7) with the surface of the water in the bottle, level with the surface of the water to the burette; also note the reading on the burette graduations coinciding with the bottom of the meniscus of the water-level in the burette. The amount absorbed as indicated by the contraction in cubic centimeters, or difference in cubic centimeters, be- IOO tween the 100 and the burette reading, equals the per cent, of carbon dioxide. Turn cock (2) to connect the burette with the bottle (10), and with a I cubic centimeter pipette put about two drops of bromine into the funnel (5) which should contain about 20 cubic centimeters of distilled water. Drain this slowly into the burette, as in the previous operation, until the entire gas space in the burette is filled with reddish brown bromine fumes, then admit the rest of the bromine and most of the water in the funnel. Next pour into the funnel about 30 cubic centimeters of potassium hydrate solution and drain part of this solution in slowly until the water ceases to rise and the burette and the surface of the water are quite free from bromine fumes. Wash with about 75 cubic centimeters of aerated distilled water. Wait two minutes and measure as explained above. The amount absorbed in cubic centimeters equals the per cent, of illuminants. Now place in cup (5) about 20 cubic centimeters of pyro- gallic acid solution, and add 20 cubic centimeters of KOH solution and allow mixing to take place naturally for about ten seconds, then drain this through, wash out the burette with about 75 cubic centimeters of distilled water and measure in the way previously explained, after waiting at least two minutes for gas to resume temperature of burette jacket. The resulting contraction in cubic centimeters equals the per cent, of oxygen. Next place about 40 cc. of copper monochloride solution in the funnel and drain through very slowly until no further contraction is observed. Then if no reagent remains in cup (5) add 10 cubic centimeters of same reagent and pass it through the burette. Pass in about 50 cubic centimeters of distilled water and after this 10 cubic centimeters KOH solu- tion, drain through and wash out with about 100 cubic centi- meters of distilled water. The amount absorbed in cubic centi- meters equals the per cent, of carbon monoxide. This re- agent should be added rather slowly and several minutes al- lowed for its action on the CO. IOI The carbon monoxide is the last constituent to be deter- mined by absorption. Of the remaining three, two must be determined by an explosion and the third by difference. Make a careful note of the reading of the burette after the CO absorption, as this figure has to be used in the H 2 and CH 4 calculation. Turn cock (2) so as to give connection between bottle (7) and burette, cock (3) so as to connect (7) through burette (4) and bulb (6) with (8). Place (8) on the table level with (10) and hold (7) so that its water-level is opposite the gradu- ation indicating 10 cubic centimeters. Now open cock (i) carefully and allow gas to pass very slowly through cocks ( I ) and (3) into the storage bulb (6). When all but exactly 10 cubic centimeters has passed into the bulb (6) close cocks (i) and (3) and place bottle (7) on a level with (10). Pass a little water from (9) directly into the cup (5) so as to get all of the gas out of the passages between the bulb (6) and the cup (5). Also open cock (i) slightly and allow water to pass from cup (5) into burette to zero mark. By manipulating (7) have the amount of gas in the burette exactly 10 cubic centimeters. A small excess may be gotten rid of through cock (i) and the funnel (5). Turn cock (2) so as to connect burette (4) and bottle (10); remove funnel (5) and connect oxygen hose to top capillary tube. Then open cock (i) and let about 20 cubic centimeters of oxygen enter. Remove oxy- gen tubing and allow about 10 cubic centimeters of air to enter burette; exact proportion of oxygen and of air admitted to burette are not essential. Close cock (i), allow water to pass from (9) through (3) and (i) into cup (5), and with bottle (7) lowered, open cock (i) until water passes into burette to zero mark. Then read contents of the burette accurately. The quantity of the mixture in the burette should be in the neighborhood of 40 cubic centimeters. Attach wires to the electrodes on the sides of the burette, turn cock (2) so that the burette is connected to the bottle (7), see that tubing is straight and cause a spark to pass between the electrodes. After the explosion allow the gases to stand at least three minutes before 102 reading the burette. Measure the contraction. This contrac- tion is known as the "ist contraction." Make a note of this, then place about 20 cubic centimeters of potassium hydrate solution in the funnel (5) and drain the burette. Wash with about 100 cubic centimeters of air saturated distilled water and measure. The contraction due to absorption by the KOH solution is known as the "2nd contraction." The amount of gas left after the absorption for CO, divided by the amount taken for the explosion is called the "constant." The amount of hydrogen in the original mixture is equal to the first contraction multiplied by two, minus four times the second contraction divided by three and multiplied by the constant. FORMULA FOR H 2 Per cent, by vol. of H 2 = 2 X (ist contraction) 4 X (2nd contraction) X constant. 3 Per cent, by vol. of CH 4 = 2nd contraction X constant. The constituent which we call "methane" CH 4 often con- tains in addition ethane C 2 H 6 especially in rich gases and in natural gas from wells which are approaching exhaustion. The ethane present is burned to the explosion and is re- ported as methane increasing the per cent, of methane slightly, and lowering to the same extent the percentage of hydrogen and of nitrogen. It may, however, be readily determined separately if it is desired. The hydrogen must first be separately absorbed by means of a palladium tube. This is done by adding to 10 cubic centimeters of the residual gases oxygen and air just as directed above for explosion. The palladium tube is installed between the burette and the storage bulb. A beaker containing water, which is kept at the boiling-point by a Bunsen lamp, is so placed as to have the loop of the tube immersed in the hot water. An accurate reading of the amount of mixture is then taken and the mixture passed very slowly through the tube into the storage bulb and 103 then back. Care must be taken not to pass the gas through the tube too rapidly, or the heat generated is apt to break up some of the methane. The palladium does not really absorb the hy- drogen from the mixture, but by a catalytic action causes it to combine with the oxygen present and form water, and hence two-thirds of the contraction due to passage of the mixture over the palladium is the percentage of hydrogen. The known volume of mixture after the hydrogen absorption is then ex- ploded and the contraction noted. A second contraction due to the absorption of the carbon dioxide by KOH formed is also noted. The volume of the methane and ethane may then be cal- culated from the following formulae ; First contraction, due to condensation of water formed, and Second contraction, due to the absorption of carbon dioxide formed, Per cent, by vol. of CH 4 = 4 X (ist contraction) 5 X (2nd contraction) X constant. 3 Per cent, by vol. of C 2 H 6 = 4 X (2nd contraction) 2 X (ist contraction) - X constant. O The difference between the sum of all the percentages found by the above determinations and 100 is the percentage of nitro- gen. GENERAL NOTES FOR ANY TYPES OF APPARATUS. SOLUTIONS. i. The potassium hydrate, or hydroxide solution, is made by dissolving 5 parts by weight of chemically pure potassium hy- droxide (purified sticks) in 100 parts by weight of distilled water. This solution should be kept in well stoppered bottles using rubber stoppers to prevent sticking and deterioration of solution due to absorption of carbon dioxide from the air. The same hydrate solution is used for the absorption of CO 2 , of bromine fumes and with the pyrogallic acid for oxygen, and IO4 of CO 2 after methane. The hydroxide which comes marked "Pure by Lime" is better for this use than that marked "Pure by Alcohol." 2. The pyrogallic acid solution is made by dissolving 10 parts by weight of chemically pure pyrogallic acid in 100 parts by weight of the above hydrate solution. To every 1,000 parts by weight of this solution add 5 parts by weight of oxalic acid as a preservative. Do not mix the pyrogallic acid solution with the potassium hydrate solution except in the funnel and until quite ready for use, as the potassium pyrogallate thus formed will absorb oxygen from the air and lose its strength. At least two min- utes should be given the oxygen absorption with potassium pyrogallate when flue gases or engine exhaust is being analyzed. 3. The copper monochloride solution is made by dissolving 75 parts by weight of chemically pure copper monochloride in 720 parts by weight of concentrated hydrochloric acid, to which has been added 400 parts by weight of distilled water. Ten or twenty grains or more of clean bare copper wire or foil should be added and kept constantly in the bottle with the' mixture to prevent deterioration. When a small quantity of the solution is added to a large amount of water a cloudy white precipitate of copper monochloride appears. When no cloudiness is thus produced, and the mixture shows a blue tint, the preparation has become oxidized and is unreliable. 4. Gas-saturated distilled water may be prepared by passing gas through the water at a temperature not less than, and preferably a few degrees above, that at which it is to be used so as to avoid evolution of the dissolved gases in the burette. 5. Distilled water may be sufficiently aerated by shaking it vigorously for two or three minutes in a large bottle three- quarters full of distilled water. APPARATUS. 6. The apparatus may be cleaned from time to time by run- ning through it a solution of potassium bichromate in sul- phuric acid. This is useful, when the platinum points become coated with carbon. This cleaning solution should be used with care, as sudden mixing of the sulphuric acid solution with the water in the burette generates considerable heat which may break the burette. 7. For constant use it is well to install the water-jacketed burette by means of clamps attached to a permanent pipe stand supporting shelf over a sheet lead drain. The electrodes leading from burette are insulated from the water-jacket by rubber tubing, containing copper wires fused to the platinum leads and leading to the terminals of a %-inch spark coil, operated by at least two ordinary dry batteries. A drain fun- nel connected by rubber tubing to a glass tube of ^-inch bore extending to sink or drain pipe, will be found of great con- venience in a permanent installation for getting rid of waste from funnel or cup. A drain tube leading from bottom of the seal bottle upward and curved in a semi-circle at the top so that the outlet is level with the desired water-level in the bottle will be found advantageous in securing cleanliness. 8. Rubber tubing should be of the heavy- wall, pure gum variety, and of such internal diameter as to give tight joints over the glass tubing, etc. The joints should be wired to in- sure freedom from leaks incident to loosely attached tubing. 9. By keeping the apparatus and all of the bottles filled with water, especially when not in use, and the reagent bottles in immediate proximity, the entire outfit acquires about the temperature of the room, and the error arising from the source of temperature in the sample is eliminated. 10. The explosions take place in the explosion burette. A coil which will give a ^4 -inch spark is ample. Too strong a spark is apt to crack the glass as is a continuous play of sparks between the points, or a play of sparks when the burette is dry. If the explosion does not occur simultaneously with the first spark, the spark need not be continued. Something else is wrong. The usual trouble is that the confined mixture is not an explosive one and the proportion of air or oxygen to gas residual must be changed. 11. The reagent funnel and top ground joint of burette io6 should be washed well after the completion of each analysis to prevent sticking at the ground joint, due to any potassium hydrate solution which may be present. This rule is applicable also to other movable parts such as cocks which are likely to stick. 12. The bulb which is not graduated, or an extra pipette is used to hold the excess of gas when the explosion is being made. The analyst occasionally loses an explosion, and were it not for the gas thus held, the entire analysis would have to be made over. By putting into the bulb all of the gas that is left after the CO absorption, except the 10 cubic centimeters which is used for the explosion, several explosions may be made as checks on one another, or in case the first one is lost. 13. If the cocks stick, they can usually be loosened by a little hot water on the outside. They should be kept well lu- bricated with a mixture of equal parts of vaseline, tallow and paraffme. 14. For getting samples, it is best to get four sample cans. The sketch above will show what these are. In getting the sample the can is placed in an upright position and filled quite full of water, perfectly saturated with the gas to be sampled in order to expel all of the air. A tube connected with the upper stop-cock is then introduced into the space from which the gas sample is to be drawn, and the lower stop-cock is opened, allowing the water to run out and thus the sample is aspirated into the can. In drawing samples from places which have a suction in- stead of a pressure, such as the inlet of an exhauster, or at the base of a stack, or in the breeching of a boiler, the water should be allowed to flow through a U-shaped glass tube attached by a piece of rubber hose to the lower stop-cock. If this is not done, after the water is all out, air will enter and spoil the sample. It is essential to draw out all of the water, even if only a small sample is required, as a number of the constituents, illuminants and CO 2 , for example, are soluble in water. If the gas to be sampled is under pressure it is well enough to allow it to flow through the can for a few seconds after all of the water has run out. To get the sample out of the can, the lower stop-cock is connected by a hose with a source of water under pressure such as an aspirator bottle filled with water and placed at a level above that of the sampling can, and as the water runs into the can the gas will be displaced and may be led by means of a hose to the burette. 15. The principal precaution necessary in gas analysis is to see that the temperature of the apparatus and of the water used, and of any additional water which may be used as well as the temperature of the sample undergoing examination, does not change during the analysis. A change of 5.2 F. will cause a change of about I per cent, in the volume of any gas at an ordinary temperature of 60 F. The temperature at which an analysis is made is immaterial but that temperature MUST remain constant. 16. In reading the burette, hold levelling bottle front and just to one side of the burette, so that the eye of the analyst can sight along the under surface of the water-level and bring it in the same horizontal plane with the bottom of the meniscus in the burette. Analysis. The quantities of reagents and wash water d- scribed in the foregoing method of analysis are intended main- ly for the analysis of carbureted water-gas, henc^n the analy- sis of any other gas the quantities specified should be changed if it is found to be necessary in order to insure complete ab- sorption of the various constituents. This is also true of the oxygen and air required for explosion. 1 8. Introduce potassium hydrate solution slowly for first absorption as the tendency otherwise is to secure too high a percentage for the carbon dioxide. 19. Care should be taken in handling bromine. Keep it al- ways under water, and do not allow it to come in contact with the skin. Bromine is an exceedingly energetic reagent and will cause painful chemical burns. If bromine fumes are breathed, relief from the irritation caused to the throat can be loS obtained by inhaling alcohol or steam. The slick feeling caused by getting potassium hydrate on the hands may be removed by a little dilute hydrochloric acid. 20. The absorption of illuminants by bromine is a heat pro- ducing reaction, and the increased temperature is apt to cause the sample to expand unduly and may cause the loss of a part of the sample by forcing it out through the cock and thus vitiate the analysis. If it is seen that the expansion is becom- ing excessive a little water may be added. The bulb at the lower end of the Morehead burette is provided for this con- tingency. In the analysis of acetylene, which contains over 90 per cent, of illuminants, this is especially apt to occur. If the percentage of illuminants is high, it is well to admit a little water during the absorption with bromine to restore the normal temperature of the gas. 21. Twenty cubic centimeters of potassium pyrogallate solu- tion when mixed with 20 cubic centimeters of potassium hy- drate solution produce a rise in the temperature of the mix- ture of about 5 F. over that of the original solutions. The heat gained by the gas in the burette due to this cause should, be taken into consideration and sufficient time allowed the burette gases to resume initial temperature before reading, ^his solution should be passed into the burette very slowly, as the absorption of oxygen is rather sluggish. The absorption may be cor^kiered complete when no further discoloration to purple or brown occurs upon introduction of the clear reagent. 22. The absorption of the last traces of CO is attended with difficulty, and hence the analyst should be careful to add sufficient copper monochloride solution and allow plenty of time for the complete absorption. The reagent being strongly acid, about 10 cubic centimeters of potassium hydrate solution should always be added, after passing in about 50 cubic centi- meters of wash water to insure removal of all fumes of hydro- chloric acid and followed with the customary wash water. 23. When carbureted water-gas is being analyzed, double quantities of residual gases, oxygen and air may be taken for the explosion in order to secure higher accuracy. 109 24. Prior to all explosions, sufficient time (at least two min- utes) should be allowed for the gases to thoroughly diffuse through the oxygen and air added so as to give a homogeneous explosive mixture and insure the combustion of all the oxidi- zable gases. 25. No special care need be taken in measuring the amount of air, or of oxygen added for the explosion, though the amounts taken should not be less than those stated in the "Method." Care must be taken, however, to measure accu- rately the amount of gas taken for the explosion, and the total amount of the gas, air and oxygen just before the explosion. 26. Air is added to the mixture to be exploded merely to lessen the jar. If the gas is very poor, or contains large quantities of nitro- gen, no air need be added, and on the other hand if the gas is quite rich, no oxygen need be added, air being sufficient, al- though if oxygen is available it is best added to insure combus- tion. With extremely poor gas such as blast-furnace gas and the like, no explosion will take place even when oxygen is used and no air added. Oxyhydrogen gas may be necessary, in such cases. This is made by the electrolysis of water slightly acidulated with sulphuric acid. Five to ten cubic centimeters of the oxygen and hydrogen mixture added in addition to the oxygen will always insure an explosion. As it recombines to water, no special reading or note of the volume added need be made. 27. Use only C. P. chemicals. 28. Never allow the funnel to become entirely empty; al- ways keep about j^-inch of water or other liquid in the bottom to prevent the suction of air into the burette. 29. In acetylene, flue gas, engine exhaust, air and gasoline gas, there is no hydrogen or methane, and hence the analysis need not be carried beyond the absorption with copper mono- chloride for CO, and the oxygen tank or apparatus, the elec- tric coil, batteries, etc., need not be provided. In analyses of these gases the sum of the first found contractions subtracted from 100 gives the percentage of nitrogen. 8 no 30. Where analyses are to be made, or where dispatch is an important element, it will be more satisfactory to obtain a cylinder of compressed oxygen for use in the hydrogen and methane determinations, but where the apparatus is to be moved from place to place, or is to be used only occasionally, or where the analyses are confined for the most part to gases which do not contain hydrogen or methane, such as flue gases, acetylene, air, engine exhaust, etc., a cheaper and quite satis- factory substitute can be had in a small retort by means of which oxygen can be generated on the spot as needed. To generate oxygen this retort is filled not more than half full with a pulverized thoroughly mixed charge of potassium chlorate and manganese dioxide in the proportions of 20 of the first to i of the latter by weight. This is heated gently over a Bunsen lamp. The evolution of oxygen begins at once and it may be led to the burette by means of a rubber tube. As 100 grams of potassium chlorate will produce 27,000 cubic centimeters of oxygen and only about 20 cubic centimeters of oxygen are used for one analysis, a very small spoonful of the mixture will suffice for a great many explosions. 31. The method of analysis is so laid out that each deter- mination must be made in its turn. With the exception of the absorption of CO 2 with KOH, and possibly that of CO with cuprous chloride, no isolated determination of any one constituent can be made with anything approaching accuracy without starting at the beginning and making all of the ab- sorptions down to that constituent. Careful readings of the burette should be taken before and after each determination, and especial care should be taken in making the analysis to thoroughly absorb each constituent in its turn. Partial absorption, or errors in the readings, will not only introduce an error in the percentages of the constit- uents in question, but the remaining portions of this constit- uent will effect the latter determinations in the analysis and thus have a doubly vitiating effect upon the accuracy. Any CO 2 left after the first absorption will be absorbed by the KOH following the bromine and will be reported as illu- Ill minant or if by chance it is not absorbed by the KOH follow- ing the bromine, it will be absorbed by the alkaline pyrogal- late solution used for oxygen absorption and will appear as O 2 . Any illuminant not absorbed will remain and burn to ap- proximately 3^ times its volume of CO 2 when the explosion is made and will appear as CH 4 . A very small proportion of illuminant left and burned and calculated to CH 4 will be sufficient to run the total of the analysis to more than 100 per cent. Any bromine vapors left after the absorption with bromine will be absorbed by the pyrogallate solution and will be reported as O e . Any unabsorbed CO will be burned to CO 2 in the explosion, H 2 and CH 4 , and increase the percentage of N 2 to the same extent. Any unabsorbed O 2 left would decrease the percentage of H 2 and CH 4 , and increase the percentage of N 2 to the same extent. Any unabsorbed CO 2 after the explosion will decrease the percentage of CH 4 and increase that of the H 2 and N 2 . The N 2 being determined by difference will necessarily show the net effect of any and all errors in either readings of the burette, or in the performance of the analysis. Specific Gravity of Gas. Schilling's apparatus for ascertaining the specific gravity, or density, of gases, is both simple and convenient. It consists of a glass jar with a metal top into which fits a brass column having suspended from its base a long graduated glass tube and at its top a cock and a ground joint socket, into which sets a socket holding a small glass tip closed in at the top with a very thin piece of platinum. In this platinum is a very small hole to permit the passage of gas or air at a very slow rate. All metal parts are nickeled. The mode of operation is as follows : The glass jar is filled with water to or a little above the top graduation of the tube. The tube is then withdrawn so as to fill it with air. The cock on the standard is then closed and the tube replaced in 112 the jar. The cock is then opened and with a stop watch the time is taken that elapses while the water passes from the lowest graduation to the top or the next to the top graduation. FIG. 24. The tube is then withdrawn and filled with gas and the procedure repeated the same as with air. The specific gravity, air being one, is obtained by dividing the gas time squared by the air time squared. Heating Value of Gas. (From Report of American Gas Institute.) Set up the apparatus as shown in cuts of the different sets. Screw on the inlet water pipe and see that the air vent tube is in its place in this pipe. FIG. 25. Level the calorimeter by means of the screw feet and plumb- bob. Connect the center hose nipple on the inlet weir with rubber tubing to the water supply and the side connection to the sink to carry away the overflow. Connect the tubing for water running to weighing pail to the vertical nipple on the three-way cock on the outlet weir and for the wasteyto the side nipple. FIG. 26. Handle the thermometers with the greatest of care. Screw the 32 to 100 thermometer on the inlet water pipe and the 60 to 110 thermometer on the top of the instrument for the outlet water. Screw the small thermometer in place on the exhaust flue. Place the two telescopic sights in position on the water thermometers, being very careful not to break them off by pressure against the sights. Connect the meter to the governor and the governor to the H5 burner with short pieces of rubber tubing, or with flexible metal tubing having coupled ends. The calorimeter should be set up in a quiet, light and well ventilated room or cabinet, which is free from draughts and in which the temperature can be maintained constantly at not less than 6oF. The room should be provided with a sink and with a good supply of running water. It is advisable to have a large shallow overhead covered tank, from which the water supply can be taken. Should the tank capacity be small and not hold enough water for a prolonged series of readings, a small gas water heater may be employed as already noted to bring the water to approximately the room temperature. It is desirable to use water that is clear and free from sus- pended matter in the calorimeter, therefore, a filter should be installed in the water supply line before it enters the overhead tank. If only a single test is desired, gas may be taken from the house piping, but if an average value is required, a small gas holder, or averaging tank, should be used, and the gas flowing into the holder adjusted to a rate of flow to just fill it in the time during which the sample is to be taken. Care should be taken to have a short service to this holder in order that an average sample of gas may be obtained, and if the sample be taken from a line on which there is no considerable consump- tion, see that this line is thoroughly purged before sampling. It is recommended that the gas be metered at a pressure not to exceed two inches of water; if this is not obtainable, it is advisable to insert a holder or diaphragm governor in the supply line to reduce the pressure to within this limit. Set up the calorimeter so that the overflow and outlet water can be easily led to the sink. Make water connections with rubber tubing, being careful not to cramp the tubing. To avoid air currents caused by the movement of the observer's body, set up the calorimeter so that the water supply and waste may be easily adjusted and that all temperatures may be readily observed. Lead the outlet water to a waste funnel supported a little above the top of the copper or glass container used in n6 collecting the water, so that the water can be shifted from the funnel to the container and back without spilling. Set up the gas meter facing the observer and level it care- fully. Then adjust the water-level of the meter, both inlet and outlet being open to the air. To do this, remove the plug from the dry well, open the funnel cock and disconnect the tubing on the outlet of the meter. Add or remove water (through the funnel or by the cock under the gauge glass) until the lowest edge of the meniscus just touches the scratch on the gauge glass, or is even with the fixed pointer. If the meter has been filled with fresh water the gas must be allowed to burn at least two hours before making a test. When the water in the meter is saturated with gas, 20 minutes should be sufficient. Fill pressure regulator with water, about ^ full, then con- nect it to the calorimeter burner. Metallic tubing is prefer- able, but when rubber tubing is used to connect meter, pressure regulator and burner, connections should be as short as pos- sible, and should be saturated with the gas. Turn on gas and allow it to burn for 5 to 10 minutes with the burner on the table. Shut off gas at burner and watch hand on meter for leakage. Be sure that all leaks are stopped before attempting to make a test. Start water running through the calorimeter at a rate of about 3 pounds per minute. Then regulate the gas to flow at the rate of 4 to 7 feet an hour, as may be found by experiment to give the highest result with the gas to be tested, admitting enough air through the burner so that the flame shows a faint luminous tip, then insert the burner as far up into the combustion chamber as the bracket permits, and observe again the condition of the flame to see that it is all right, using a mirror. The excess of air passing through the calorimeter is con- trolled somewhat by the position of the damper in the exhaust port, and the best results are obtained by having the excess air as low as possible and still maintaining complete combustion of the gas. To determine this position of the damper, some ex- perimentation may be necessary. Operate the calorimeter until a thermal balance is established on the inlet and outlet water thermometers. Start with the damper closed, then open slightly, observing carefully the outlet thermometer. When this thermometer reads at a maximum or in other words, when the greatest rise in temperature is given to the water, which is presumably passing through the calorimeter uni- formly the damper is in approximately the correct position for the amount of gas being burned, and the excess air neces- sary for perfect combustion is at a minimum. Water should be regulated so that there is a difference be- tween the inlet and outlet temperatures of about 15 F. The temperature of the inlet water should vary but little when an overhead tank is used and the water maintained at room tem- perature. Be sure that both overflows are running. Before making the test, the barometer, temperature of the gas at the meter, temperature of room and temperature of exhaust products should be recorded. It is desirable to have the temperature of the inlet water and temperature of exhaust products as nearly as possible at room temperature, in order to establish more nearly a thermal balance the difference in these temperatures should never, exceed 5. Next allow the gas to burn in the calorimeter until a ther- mal balance is established, or until there is the least change in the inlet and outlet waters. The test may now be started by shifting the outlet water from the funnel to the container just as the large hand on the meter passes the zero point. Readings are then made of inlet and outlet thermometers, making the readings as rapidly as the observer is able to record them during the consumption, prefer- ably of two-tenths of a cubic foot of gas. At least ten readings should be made of both inlet and outlet water temperatures. Water is again shifted from the container to the waste funnel as the hand passes the zero point the second time. Water is then weighed or measured. The uncorrected heating value per cubic foot is obtained by multiplying the difference of the averages of inlet and outlet temperatures, by the number of pounds of water and by dividing by two-tenths. This quantity is divided by the correction factor for barometer and tempera- n8 ture, obtainable from tables, to give the heating value at 30 inches pressure and 60 F. The weight or contents of con- tainer should be obtained while the inside is wet. This may be done by rilling it with water, emptying and shaking for about five seconds in an inverted position. This will do away with any correction where several consecutive tests are required with same container. A second, and perhaps a third test is advisable, and these should be made without disturbing the existing conditions, provided all readings are within the above prescribed limits. In practice the operator should get consecutive results on the same holder of gas within ten (10) B. t. u/s. Under such conditions an average of the results may safely be taken. RESULTS AS OBTAINED BY CALCULATION. The method of calculating the calorific value of the gas from the observations indicated is very simple when all read- ings are made in English units, as recommended, and entered in some form conveniently arranged. A simple record sheet is shown herewith, a convenient size for which is 5 by 8 inches. The averages of the inlet and outlet water temperatures are determined and necessary corrections for thermometer errors are made. The difference in these averages should give the rise in temperature of the water. This rise in temperature of the water is therf multiplied by the number of pounds of water passed through the calorimeter during the test. The product of these two is then divided by the quantity of gas burned 0.2 of a cubic foot. This quotient will give the heating value of one cubic foot of gas in B. t. u.'s at the in- dicated temperature and barometric pressure. To correct this to 60 F. and 30 inches pressure, divide by the "Correction Factor" for the indicated temperature, and pressure as ob- tained from some standard table. [Printed on card sent with apparatus.] The final result will be the corrected heating value of the gas tested, in B. t. u.'s. H9 Expressing the above in a formula we have : W X T B. t. u.'s per cubic foot = . W = weight, in pounds, of water passed. T = the average difference in temperature, in degrees Fahrenheit, between inlet and outlet water. G = corrected volume of gas burned, in cubic feet. The correction for atmospheric humidity is made, finally, if so desired. USE OF COMPUTER. The labor of making the calculations for determining the heating value from observations of a calorimeter may be lessened by the use of a heating value computer. The computer consists of a circular slide rule, with divisions corresponding to the readings made on the calorimeter. This computer gives the corrected heating value of a cubic foot of gas in B. t. u.'s, having the barometric pressure and temperature of the metered gas, and the difference in temperature between the inlet and outlet water, and the pounds of water passed. This computer is designed to operate within the limits of from 300 to 800 B. t. u.'s. Should a gas of a lower or higher heating value be measured, the computer can still be used by dividing or multi- plying one or the other of the factors in its computation. A cut of this computer can be found on page 373, Vol. Ill, Pro- ceedings of the American Gas Institute. Corrections for Atmospheric Humidity. (From Report of American Gas Institute.') This correction is found to be the greatest when the per- centage of humidity of the atmosphere is the lowest. The reason being that the relatively dry air entering the calorimeter causes to be carried out in the exhaust products a larger amount of the water in the form of a gas or vapor, that is formed by the combustion of the gas, and which does not condense, and, therefore does not give up its latent heat to the calorimeter. I2O The humidity correction should correct for any discrepancy in water vapor carried in by the air and gas, compared with that carried out by the products of combustion. Owing to the contraction in volume, during the combustion of ordinary illuminating gas and air, this discrepancy is prac- tically nothing when the percentage of atmospheric humidity is about 80 per cent., at normal temperatures, and the excess of air introduced for combustion is about 30 per cent. In correcting for atmospheric humidity it is assumed that the gas is saturated with water vapors having passed through a wet meter. This assumption might not be absolutely true, but the percentage of saturation has been found always to be high, and as the volume of gas is only about one-eighth of the mixture, the error involved may be neglected. TABLE I. CORRECTIONS TO OBSERVED HEAT TO GET TOTAI, HEAT VAUTE. AIR, GAS AND EXHAUST MUST BE AT THE SAME TEMPERATURE. If 7 volumes of air per volume of gas are used. Humidity Room temperatures Per cent. 65 70 75 80 85 90 10 +4.8 +5.7 +6.7 +7.9 +9.2 +10.5 20 +4.1 +4.9 +5.7 +6.8 4-7.8 4- 9.0 30 4-3.4 4-4.1 +4.7 4-5.6 4-6.5 4- 74 40 4-2.7 4-3.2 4-3.7 +4.5 4-5.2 4- 5.9 50 4-2.0 4-2.4 4-2.8 +3.4 4-3.8 4- 4.3 60 4-1.3 4-1.6 +1.8 +2.2 +2.5 + 2.8 70 +0.6 +0.8 +0.8 +1.0 -+I.2 +1.2 80 o.i +0.0 o.i o.i o.i - 0.3 oo 0.8 0.9 i.i 1.3 1.5 1.9 100 1.6 1.8 2.0 2.4 2.8 3.4 Note These corrections are expressed in B. t. u. Directions for Using Or sat Apparatus. The gas burette A (in Fig. 27) is attached to the levelling flask B, which is filled with water. By raising B, A is filled with water to the uppermost mark. In order thus to fill A with water, the air must have opportunity to escape from the uppermost portion of A. The absorption pipette D is used to absorb carbonic acid gas. 121 It contains such a quantity of caustic potash solution that when the solution is drawn entirely into the front part of the pipette (the proper position for the solution when the pipette is ready for use), the front part of the pipette is filled with the solution, FIG. 27. and the rear part is empty. The solution is drawn up into the front part of the pipette D, as follows : Communication is es- tablished with the outside air by means of the stop-cock a. Stop-cock d, e and / are closed. A is filled with water by rais- 122 ing B. Stop-cock a is closed, stop-cock d is opened, and the solution in pipette D is drawn into the front part of the pipette, by lowering B. When the solution has filled the front part of D, close stop-cock d. Rubber bags are usually attached to the capillary opening at the rear of the pipettes to prevent free access of air and to allow the escape of the confined air when the solution is per- mitted to flow back again in the pipette after having been used. Pipette B is for the absorption of oxygen gas, and pipette F for the absorption of carbon monoxide gas. Pipette B is filled similar to D, with a solution of pyrogallic acid or with thin sticks of phosphorus in water. In case the phosphorus is used, the pipette is covered with black paper to prevent the action of light on the phosphorus. Just as in the case of D, before using H and F, the solutions are drawn into the front parts of the respective pipettes, and held there by closing their respec- tive cocks. Pipette F contains a solution of cuprous chloride. The front part of each of the pipettes contains a bundle of glass tubes, in order to increase the absorption power of the pipettes. The glass tubes for pipette F contain curved copper wires to maintain the cuprous chloride solution at a constant strength. The pipettes being in readiness with stop-cocks d, e and / closed, and A open, burette (A) is filled with water by raising (B). The other end of the capillary tube or beam is now con- nected with the gas to be tested. A bent tube is provided for purifying the gas before allowing it to pass into the apparatus. This tube is fastened outside the case on the upper left side, and is connected with the capillary stop-cock tube by means of rubber tubing. Before attaching the bent tube it is filled with a sufficient quantity of calcium chloride, or glass wool. When everything is ready, with a connection made for the gas to enter the apparatus through the bent tube, (B) is lowered, by which means the gas is drawn into A to the O mark. Par- ticular care must be taken that there is exactly 100 cubic cen- timeters of the gas. Stop-cock A is now closed, stop-cock D opened, vessel (B) raised, burette (A) filled with water, and 123 the 100 cubic centimeters of gas forced into the pipette D. Here it is allowed to stay for some minutes, the pipette being shaken slightly, if practicable, in order to bring the gas fully into contact with the solution. When the absorption is complete, the flask (B) is again lowered, thus drawing the gas back again into A. One hun- dred cubic centimeters minus the amount of gas remaining shows the amount of carbonic acid gas absorbed by the caustic .potash solution. Stop-cock d is now closed, stop-cock e opened, and (B) again raised thus forcing the gas into H. Here the gas is treated as it was in D, (B) is then lowered, the gas forced back into (A) and the amount read. The gas unab- sorbed by the caustic potash minus the present remainder shows the amount of oxygen which has been absorbed by the pyrogallic acid, or by the phosphorus, as the case may be. Stop-cock e is now closed, stop-cock / opened, and (B) again raised. The gas is now forced into F. Here especial care must be taken to be sure that complete absorption takes place. When the absorption is finished, (B) is again lowered and the gas drawn back into (A). The previous remainder minus the present remainder shows the amount of carbon monoxide which has been absorbed by the cuprous chloride solution. The last remainder is usually reckoned as nitrogen, though it contains also small quantities of other gases. In case there is reason to suspect the presence of considerable quantities of hydrogen, a four-pipette apparatus, Fig. 28, is used. The gas left over from the last operation is increased by the admission of air from the outside until it is again as nearly as possible 100 cubic centimeters. The air added will allow of the burning of a quantity of hydrogen corresponding to two-fifths of its volume; that is, twice the volume of the oxy- gen contained in the air. This suffices for ordinary producers' gas; but when analyzing "Water Gas" or similar mixtures containing a rather considerable quantity of hydrogen, a smaller quantity of gas must be employed for analysis, or also oxygen is used instead of air. After reading off the total volume, the spirit lamp (h) is lighted and turned so that it 124 heats the capillary (i) very gently. Then (B) is raised, g be- ing open and all other stop-cocks closed. FIG. 28. The gas passes through the capillary i, into the pipette G, and then on lowering (B) the gas passes back again into the burette (A). One end of the palladium asbestos should be- come hot in this operation. The volume of gas is read off and the passage through i is repeated. If, which is usually not the case, a further contraction is now observed, the passage through I must be repeated once more. The residual gas is now finally measured, and two-thirds of the diminution is read as hydrogen, the other one-third being, of course, oxygen. 125 REAGENT. SOLUTIONS FOR ABSORPTION PIPETTES. (Method in use December 7, 1914.) Potassium Hydrate. Five hundred grams of potassium hy- drate (not purified by alcohol) are dissolved in 1,000 cubic centimeters of water. Capacity: I cubic centimeter absorbs 40 cubic centimeters of CO 2 . Sodium hydrate, at present, has replaced KOH, in many works. This reagent, although not quite as active, may be used ; but solutions should be changed oftener to avoid clogging of capularies by sodium bicarbonate formed. Potassium Pyrogallate. Fifty grams of pyrogallic acid are dissolved in 1,000 cubic centimeters of the solution as made above. Cuprous Chloride. Mix 35 grams cuprous chloride (CuCl) and 200 cubic centimeters HC1 (specific gravity 1.19) and to this arrange a bunch of copper wire to reach the entire length of the bottle. LIFE OF REAGENTS. If the solutions are protected from the air, their life is about as follows : One cubic centimeter of caustic potash solution will absorb 40 cubic centimeters or more of CO 2 . The absorp- tion of O by pyrogallic solution should be at temperatures not less than 15 C. ; I cubic centimeter of pyrogallol solution will absorb about 13 cubic centimeters of O. Phosphorus will last a long time, inasmuch as the oxidation products are dis- solved off by the water leaving the phosphorus free to com- bine with more O. One cubic centimeter of the cuprous chloride solution is equal to about 16 cubic centimeters of CO. The palladium renews itself constantly by contact with the air,, so that its activity is almost inexhaustible. There is also largely used, the modification of the Orsat ap- paratus known as Franklyn Flue Gas Analyzer for the deter- 9 126 mination of CO 2 , O and CO, which is explained by the follow- ing illustrations. Its chief advantages are, its compactness, FIG. 29. that is, its parts are more compact and not as easily broken as those of the Orsat Muencke apparatus. CONSTRUCTION AND OPERATION OF HYGROMETER FOR DETER- MINING THE MINIMUM TEMPERATURE OF SATURA- TION OF GAS IN DISTRIBUTION MAINS. The instrument is employed to determine the minimum tem- perature to which illuminating gas has been cooled on its way to the burner, its action being dependent upon the fact 127 that the gas will be saturated with vapor at the minimum tem- perature to which it has been cooled. The instrument reduces a small quantity of the gas back to the minimum temperature, and upon further slightly cooling, it gives evidence, in the deposition of dew, that the point has been reached. The tem- perature is then noted on a delicate thermometer placed inside the instrument. The function of the instrument is therefore to duplicate, on a small scale, what has previously taken place in the main. Construction of the Apparatus. The apparatus consists of an interior glass vessel A (Fig. 30) known as the condensing tube, the glass jacket D sur- rounding the condensing tube, the thermometer support O, and the thermometer T which is suspended in the condensing tube. The cap K covers the top of the instrument and carries the burner-head E. The whole is mounted on a base provided with a cock, which is so constructed that the gas may be made to pass straightway into the instrument or first through either one of the scrubbers ( G //). The needle valve Z, is pro- vided in order to permit of the gas being passed directly to the burner instead of through the vaporizing tube. The in- strument may be taken apart at C for the purpose of cleaning the jacket; the cap also unscrews, giving access to the con- densing tube. The two scrubbers may be unscrewed at the bottom for filling and cleaning. Setting up the Apparatus. The support for the apparatus M is screwed on to a con- venient gas bracket (no rubber connections should be used), the outside jacket D is screwed on the base of the apparatus at N, and the instrument then placed upright on the support with the handle of the cock toward the observer. The cap K is re- moved and the thermometer support C pulled out and the thermometer placed in position, as shown. The cap K is then replaced and surmounted by burner-head . The right-hand scrubber cover H should then be unscrewed from the base, 128 FIG. 30. Hygrometer. 129 uncovering the calcium chloride scrubber. This tube should be filled with small pieces of calcium chloride. Replace the scrubber cover, screwing firmly into place with the fingers. Likewise unscrew the left-hand scrubber cover C and see that the glass tube is filled with rubber bands; then replace cover. The gas should now be turned on and lighted, the cock at the base of the instrument being turned so that the gas passes straight into the jacket. By turning the cock to the right or the left, the gas can be made to pass through the scrubbers (G H) at will, or cut off entirely. A good flow of gas (from 2 to 3 feet per hour) should be obtained either straight- way or through the scrubbers. The instrument is now ready for observation. Making the Test. Shut off the gas at the cock on the base of the instrument and lift off the burner-head. Place the stem of the small funnel sent with the instrument through the cap and pour pentane or ether into the condensing tube until it contains about i inch of the liquid. Replace the burner-head and open needle valve L. The gas is now turned on with the cock set so that it passes straight into the jacket and out through the burner-head, the condensing tube being by-passed. By throttling the needle- valve L, a portion or all of the gas may be made to bubble through the pentane, the rate of its pas- sage through the pentane being regulated entirely by the needle-valve. The vaporization of the pentane causes a re- duction in temperature of the tube and finally dew will be de- posited on its outer surface. The temperature at which the dew commences to deposit opposite the bulb of the thermometer is noted and recorded as the "dew point" or minimum temperature of the gas. When this point is reached the needle-valve should be opened, by- passing the condenser tube. Soon the thermometer will rise and the dew will disappear. The observance of the point of disappearance furnishes a check upon the first reading. The gas before passing into the instrument may be first passed 130 through the scrubbers (G H) to remove a portion of the unfixed hydrocarbon vapors or water vapor. The functions of these scrubbers are described in a paper by C. C. Tutwiler, published in the Journal of the American Chemical Society, April, 1908, and republished in the American Gas Light Jour- nal, of April 20, 1908. TAR. For tar shipments it is, as a rule, sufficient to determine the specific gravity and the water in the tar. The following two methods are recommended for these determinations. For a more complete analysis, refer to chapter on Tar Products. SAMPLING. Tar is best sampled while being unloaded from or loaded in the tank car or barge. A pet cock with a nipple projecting about one-third of the diameter, should be placed in the pipe line and a continuous stream of tar drawn off into a barrel during the time of unloading. The pet cock should be so regu- lated that the sample will represent approximately o.i per cent, of the shipment. The tar may then be stirred up and a sample taken from the barrel. Samples of tar should be placed in heavy clear bottles or screw top tin cans. When necessary to sample from storage tanks, or wells, it should be done by means of a "thief." This is particularly necessary when differ- ent shipments of tar of widely different gravities have been run into the same tank. A simple and efficient apparatus may be made from a piece of 2-inch pipe provided with a lever handle cock. This may be closed by means of a small iron rod as shown in Fig. 31. By cutting away part of the cock and one-half of the plug, an opening nearly as large as the interior of the pipe is pro- duced. In taking the sample, the cock is opened and the "thief" slowly lowered to the bottom of the tank, well, or car, the "thief" having previously been rinsed with the liquid to be sampled, the cock is closed, the "thief" is withdrawn, and the sample run into a bottle. This operation is repeated until a sample of about I gallon is obtained, after which the con- tents should be thoroughly mixed, and a portion taken to serve as a smaller sample for analysis. It should be noted that this method cannot be used with horizontal cylindrical tanks. u FIG. 31. -Thief sampling tube. In the case of tar where there is always a certain amount of water or ammoniacal liquor floating on the surface, it seems best to attempt to locate the level of the water or liquor, taking a sample at this point, and then sample a lower portion of the tar which is reasonably free from water, and by calcula- tion, estimate the total quantity of water present. DETERMINATION OF SPECIFIC GRAVITY. When there is no free water the gravity may be determined with a hydrometer after bringing the sample to normal tem- perature or by observing the temperature and correcting as follows : Specific gravity at 70 C. = specific gravity observed at jo c. + (T t) X 0.0008. It is recommended that the specific gravity be taken at 25 C. Where more accurate results are required the pycnometer bottle is recommended. These are straight sided thin glass bottles with a ground stopper the full size of the bottle and provided with a capillary hole in the center of the stopper. The bottle is dried and weighed empty and filled with water at normal temperature. It is nearly filled with tar and weighed again, it is then completely filled with water, and brought to 132 the normal temperature, the excess water removed and the bottle dried and weighed. Specific eravity - (Wt. bottle X tar) - (Wt. bottle) ~ Wt. water full Wt. water added" DETERMINATION OF WATER. The sample should be very thoroughly agitated to insure that the portion taken for analysis is representative. FIG. 32. 133 The apparatus is set up as shown in Fig. 31. Put 25 or 30 cubic centimeters of benzol in a 250 cubic centimeter cylinder, add 200 cubic centimeters of the well mixed sample, pour into the copper still and wash out three times with benzol using 25 to 30 cubic centimeters adding washings to still. Fasten on Ud with the clamp using a gasket of manila "de- tail" paper, connect apparatus as shown in Fig. 27. Start ring burner at top of still and lower after the water has been driven off until the thermometer reaches 200 C. The distillate is collected in two 100 cubic centimeter grad- uated cylinders. Where an excessive amount of water is suspected the dis- tilling head is replaced with the expansion chamber shown in Fig. 32, the side outlet and receiver is connected with a filter pump and the distillation carried out in a partial vacuum. The contents of the receiver is then transferred to a measuring cylinder. AMMONIA. Ammoniacal Liqiior. SAMPLING. When the liquor is contained in a tank with straight sides, sampling is done with a "thief," which may be a bottle thief or a pipe thief, A very satisfactory bottle thief for ammonia- cal liquor may be made as follows from a one-quart milk bottle. Enough shot are put into the bottle to overcome its buoy- ancy and cause it to sink easily when immersed in water. The shot are held in place by pouring over them a thin paste of Plaster of Paris. The bottle is provided with a two-hole cork or rubber stopper through which pass two glass tubes pro- jecting about one inch above the stopper. One tube extends just below the stopper; the other to about % inch above the bottom. In use the thief is lowered at even speed through 134 the liquor to be sampled till it strikes bottom, and then immedi- ately raised at even speed. The speed must be such that the bottle is not completely filled when it is drawn out from the liquor. The thief is emptied, and the operation repeated till a sufficient quantity for the sample is obtained. It will be noticed that the thief does not take a portion from the liquor lying be- low about 8 inches from the bottom. When there seems reason for thinking that this bottom layer may be considerably differ- ent from the rest, the pipe thief should be used. The pipe thief consists of an iron pipe of 1^4 inches to 2 inches size, as desired, long enough to reach to the bottom of the tank. Its lower end is provided with a plug-cock hav- ing a lever handle which points across the pipe when the cock is open. A rod or chain is attached to the end of the handle. The thief is slowly lowered, with the cock open to the bottom of the tank. The cock is then closed by pulling on the rod or chain, and the thief withdrawn and emptied. The operation is repeated till a sufficient sample is collected. When liquor can be sampled during pumping, this should be done in preference to taking a sample from the tank. This is especially true with tank cars or other horizontal cylindri- cal tanks. A pet cock should be attached to the pipe line on the outlet of the pump by a nipple projecting into the line about one-third of the diameter of the latter. A small stream of liquor should be drawn at steady speed from the pet cock through a tube into a covered receiver of not much larger size than the sample desired. Where the question of sale is involved, an amount equal to o.i per cent, of the total quan- tity should be collected in the receiver. After shaking, a sample is taken from the latter for the laboratory. In collecting a running sample, as described above, it is necessary that the rate of flow and the pressure in the line where the pet cock is inserted be uniform throughout the un- loading of the tank. When a tank is unloaded by gravity, these conditions are not fulfilled and therefore a pet cock in the line does not give the true average sample. In such a case, however, an approximately correct sample can be ob- 135 tained if several running samples are taken, each represen- tative of a definite fraction of the whole quantity, such as one- sixth or one-eighth. Equal portions are taken from each sep- arate sample, and mixed to form the composite sample. In sampling from a horizontal cylindrical tank, the thief cannot be used, because equal depths of liquor at different elevations represent quite different volumes. A good approxi- mation to a true average, however, can be made by taking several samples at varying depths, which latter are chosen to represent a division of the tank into equal parts by volume. Equal amounts are taken from the various samples, and mixed. The greater number of the samples, the more representative is the mixture. The following table shows the depths, ex- pressed in per cent, of the diameter at which samples should be taken, when six, eight, ten and twelve samples are desired : For 6 samples For 8 samples For 10 samples For 12 sample Percentage 13.7 11.3 9.8 8.6 30.0 24.4 20.7 18.3 of 43-6 35-3 3-o 26.2 56.4 45-2 38.3 33-3 diameter 70.0 54.8 46.1 40.1 86.3 64.7 53.9 46.7 75-6 61.7 53.3 88.7 70.0 59-9 79.3 66.7 90.2 73-8 81.7 91.4 These depths represent the centers of gravity of zones of equal volume. For collecting these samples, the bottle thief is suitable. The ends of a short piece of rubber tubing with a string tied around its middle are pushed lightly over the tubes of the thief, thus sealing them. The bottle is then lowered gently to avoid disturbance of the strata, till the tops of the tubes are at the right depth for taking the first or top sample. The rubber tube is then drawn off and the thief allowed to fill. The second sample from the top is then taken, etc. i 3 6 The foregoing table is intended for use on completely filled tanks. It may, however, be used for sampling partially filled tanks, without much error, if several samples are taken, and special calculation is made as follows for the top sample : The boundary between zones is assumed for this purpose to be half-way between the centers of adjoining zones. The top zone will then consist of the liquor from the surface to the first zone boundary below, and the top sample should be taken half-way between these points. The amount of this top zone sample taken for the mixed sample, should be in the ratio of the actual depth of the top zone to its full depth according to the table. Tanks and tank cars of ammoniacal liquor, often contain tar, which may either float or sink depending on its nature. To estimate the depth of the floating tar, use a glass tube of */% inch or more diameter whose lower end is fitted with a rubber stopper, which may be drawn up into the tube by a string fastened into the stopper and passed up through the tube. Lower the tube slowly through the tar layer, with the stopper suspended well below the tube end. When the tube end is well into the liquor, draw up the stopper, closing the tube. Measure the depth of the tar layer. To measure the depth of tar in the bottom of the tank, attach a piece of cotton wicking to a rod. Wet the wicking with benzol or other light colored tar solvent, and put the rod into the tank. The tar will color the moist wicking. SPECIFIC GRAVITY. The determination of specific gravity is made by hydrom- eter. A regular specific gravity hydrometer, graduated to read to the third decimal place is used. However, in cases of doubt or dispute, a pycnometer (Sprengel tube) should be used. The standard temperature for taking the gravity is 60 F. The gravity is referred to water at 60 F. A hydrometer jar of the liquor to be tested should be brought to that tem- perature by immersion in water, and the reading taken. 137 When it is desired to know accurately the weight of liquor present in a tank or tank car, the gravity must naturally be taken at the temperature at which the volume of the liquor is also measured. This may be done by taking the gravity of a freshly drawn sample at the tank; or the temperature may be noted and the regular sample brought to that temperature in the laboratory for a determination of the gravity. The Committee recommends the general use of the specific gravity scale in reporting the gravity of ammoniacal liquor. It recognized, however, that the use of the Twaddle hydrom- eter is common in several of the older companies. Readings in the Twaddle scale may be changed into readings on the specific gravity scale by the use of the following formula : Specific gravity = i.o divided by 0.005 Tw. The objection to the use of the Twaddle scale, is that it is often assumed that the value of the liquor in terms of "ounce strength" may be found by multiplying the Twaddle reading by two. There is, however, no general numerical connection between the hydrometer reading of a liquor and its content of ammonia. (In any one plant, operating regularly under the same con- ditions and using the same coal, it is true that an increase in the strength of the liquor will generally be accompanied by an increase in its gravity, and in such case the hydrometer read- ing offers a simple means of following the daily operation of condensers, scrubbers, etc.) Since considerable changes in the reading occur when the temperature is much different from 60, and since it is incon- venient to adjust the temperature of the liquor in works test- ing, the following table has been prepared to find the equiv- alent reading at 60 from a reading taken at a different tem- perature. The numbers are degrees on the Twaddle hydrom- eter. The table is not perfectly correct for all ammoniacal liquors but is sufficiently so for the routine testing for which it is intended. 138 w rt 88888888 S^ffS,^^!?^ BU p j^ oo r^\o 10 T co PI M r^vo 10 - 04 IH I !|| - w 00 g^s-crs^s 5 ?? 00 J?^^C0^5^-K^ fl fi "S H ^ H OO l^^O IO <* CO PI M a ft W ,4 g p 55 smm^ " OO COO lO^vO M IO^\ M w rCcO^Ti-ioiOcO t^.\O IO ^f CO W M I* I!} -< 5 s *""" 10 OOCOOOCO^CO^M^ ?- ? g 06 l"**vC IO ^ ro CS M t^^O iO ^ to W t-< | *li Q g <* t^COPIOSOOvOCOM^ ^; cooo Pir. covo O^M - <1 1 d CM oo r^\o 10 ^" co PI *H t^O >O >O PI ^|8 S o ,4 oo r>vo 10 4 co pi M t^-vO IO T CO PI w 1 g t> W ^3 >vo 10 ^ co w M j fcl ^ fc O i M 33Rgeg> M .oPi^as^oco^ * 8 in 00 t^VO IO TT CO PI IH t^vO >O * CO PI w S . B (U J3 < OO^VO^^-COWM C-vO^^tOPl'- ' |' _. 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A 500 cubic centimeter round-bottomed long-necked flask (a Kjeldahl flask) into whose neck is set by a rubber stopper a bulb tube with the bulb portion bent to 45 off the vertical, or some other form of Kjeldahl connecting bulb, to prevent the mechanical carrying of spray into the condenser. Inside an ordinary glass Liebig condenser jacket is slipped a block tin tube about ^ inch outside diameter, in place of the usual glass condenser tube. The tin tube can be obtained from a plumbing house. There is, however, no objection to the use of a glass condenser as shown in Fig. 28 if preferred by the chemist. About 7 inches of tin tube projects beyond the jacket and this portion is bent back on itself to an angle of 135 from the vertical and joined by rubber tubing to the connecting bulb previously mentioned. To the lower end of the tin condenser tube is attached a plain bulb tube of about 150 cubic centimeters capacity. The lower end of this will dip into the beaker of, standard acid. The object of the bulb is to prevent the accidental sucking back of the contents of the beaker. The equipment of flask and condenser should be carried on a single stand. There will also be needed one 25 cubic centimeter pipette for sampling weak liquors ; and one 100 cubic centimeter pip- ette and one 1,000 cubic centimeter graduated flask for use with concentrated liquors. On account of the inaccuracy of some of the volumetric apparatus on sale, the pipettes should be checked by filling them with boiled distilled water at room temperature, discharging into tared small stoppered bottles and weighing the water. The weight should not vary by more than 2 parts in 1,000 from the weight given in the tables (See circular No. 19 of the Bureau of Standards for complete tables). The water from a 25 cubic centimeter pipette cali- brated for 20 C., should weigh 24.948 grams at 15 C. ; 24.929 grams at 20 C.; 24.904 grams at 25 C. Water discharged 140 FIG. 33. from a 100 cubic centimeter pipette, calibrated for 20 C. should weigh 99.793 grams at 15 C. ; 99718 grams at 20 C.; 99.617 grams at 25 C. New marks should be made on the pipettes if they are in error by more than the allowed amount. It should be determined also that the 1,000 cubic centimeter flask holds ten fillings from the 100 cubic centimeter pipette. Operation A. For liquor under 3 per cent, ammonia (ordi- nary weak liquor). Put 150 cubic centimeters distilled water into the 500 cubic centimeter flask and run in 25 cubic centi- meters of liquor from the pipette. Add 25 cubic centimeters of 30 per cent, sodium hydroxide solution (300 grams NaOH in 700 cubic centimeters water) and a small piece of gran- ulated zinc to prevent bumping. The addition of a small bit of parafnne will hinder troublesome foaming. Put 50 cubic centimeters of normal sulphuric acid and 50 cubic centimeters of water in a 400 cubic centimeter beaker and support the beaker so that the bulb tube on the condenser end dips about y 2 inch below the surface of the acid. Con- nect up the apparatus and heat up gently till the air is expelled and the boiling is steady. All the ammonia will be driven off with the first 100 cubic centimeters of distillate. From time to time lower the beaker so that the seal of the bulb tube is not much over ]/ 2 inch. When about 100 cubic centimeters has distilled over, lower the beaker clear of the tube and allow the distillate to rinse the inside of the latter. Wash the out- side with a w r ash bottle. Titrate the solution in the beaker with half-normal am- monium hydroxide or normal sodium hydroxide, using coch- ineal or methyl orange as indicator. Calculate the number of cubic centimeters of normal acid which have been neutralized by the ammonia from the liquor. The percentage of ammonia is found by multiplying this num- ber of cubic centimeters by the factor 0.06813 and dividing by the specific gravity of the liquor. In calculating the percen- tage strength, the gravity used should properly be that of the liquor at temperature of pipetting. The difference, however, 10 142 may be disregarded unless the temperature varies from 60 F. by more than 10 or 12. B. For Concentrated Liquors. One hundred cubic centi- meters of the concentrated liquor are made up to 1,000 cubic centimeters and an aliquot of 100 cubic centimeters taken for the distillation. This is put in the distilling flask with 75 cubic centimeters of water and 25 cubic centimeters of 30 per cent, caustic soda solution. Zinc and paraffine are added as before. The ammonia is received in 100 cubic centimeters of normal sulphuric acid in a 400 cubic centimeter beaker, or in 125 cubic centimeters for very strong liquor. Calculate the number of cubic centimeters of normal acid neutralized by the ammonia. For percentage of ammonia mul- tiply this number of cubic centimeters by 0.17033 and divide by the specific gravity of liquor. C. For Waste Liquors From Ammonia Stills. Two hun- dred cubic centimeters of the waste liquors are put in the dis- tilling flask, with 25 cubic centimeters of 30 per cent, caustic soda solution together with zinc and paraffine. One hundred cubic centimeters is distilled off and received in 20 cubic centi- meters of normal acid diluted with 80 cubic centimeters of water. Calculate the number of cubic centimeters of acid neutral- ized by the ammonia. For percentage of ammonia, multiply this number of cubic centimeters by 0.00852. The Committee strongly recommends reporting the amount of ammonia in liquor as a percentage, as described above. Several of the older companies, however, are in the habit of reporting in so-called "ounce-strength." Two different mean- ings appear to be given to this latter term. It is sometimes defined to mean the number of ounces of 100 per cent, sul- phuric acid which will be neutralized on direct titration by i Imperial gallon (277.27 cubic inches) of this liquor. Only the free ammonia is taken into account in this test. For the determination, see the determination of free ammonia by titra- tion, as described below. Again "ounce-strength" is defined to mean the number of 143 ounces of 100 per cent, sulphuric acid which will be neutral- ized by the total ammonia contained in I U. S. gallon (231 cubic inches). If figures in "ounce-strength" of this definition are sought they may be obtained from the results of the dis- tillation analysis above described by the following calculation : A. For Weak Liquors. Multiply the number of cubic cen- timeters of acid which have been neutralized by the ammonia from the liquor, by the factor 0.26196. B. For Concentrated Liquors. Multiply the number of cubic centimeters by the factor 0.6549. C. For Waste Liquors. Multiply the number of cubic centimeters by the factor 0.03275. It should be noted that the ounce strength as thus found is really the ounce strength of the liquor at the temperature of sampling with the pipette. The ounce strength will increase proportionately as the gravity increases with lower tempera- tures and vice versa. The difference in value for 10 F. will amount to about 1.5 parts of 1,000. The liquor, as sampled, should not therefore vary by more than 10 from 60 F. In the method described for the determination of ammonia in ammoniacal liquor, it is usually assumed that ammonia is the only substance distilling off, which will neutralize the sul- phuric acid. This is not strictly correct, for the pyridine present in the liquor will distil and will neutralize some of the acid, thereby causing the apparent ammonia found to be larger than the true value. The amount of pyridine is usually small but where high accuracy is desired, a correction should be made for it, in the following manner: In the determination of pyridine, as described below, there is found the number of cubic centimeters of normal acid which are neutralized by the pyridine contained in a given amount of liquor. From this calculate the number of cubic centimeters of acid corresponding to the pyridine contained in the amount of liquor taken for the ammonia test. Subtract this from the number of cubic centimeters of acid neutralized in the ammonia test, and the result is the number of cubic centimeters neutralized by the ammonia alone. 144 To detect possible errors in the distillation test for am- monia, it is well to make a test on a pure ammonium salt. For this purpose pure ammonium sulphate or chloride should be dissolved in hot water, filtered and recrystallized. After drying at 50 C., 4.5 to 5.0 grams are put in the distillation flask with 175 cubic centimeters of water and 25 cubic centi- meters of 30 per cent, caustic soda. The ammonia is received in 100 cubic centimeters of normal acid. If the equivalent of sulphate of ammonia found differs by more than 0.3 of I per cent, from the 100 per cent, expected, the error should be cor- rected. It will very likely be found in the standard solutions used. Free Ammonia. Free ammonia is, by definition, that which can be distilled off from liquor by boiling alone, without the use of alkali. Its determination is made exactly as the determination of total ammonia, described above, except that no caustic soda solu- tion is used. The results are calculated in the same way and by the same factors. For greater convenience, when the utmost accuracy is not desired, the determination of free ammonia may be made by direct titration, as described below. For weak liquors, 25 cubic centimeters of the liquor is diluted with 100 cubic centimeters of water, and the solution titrated with normal sulphuric acid, using methyl orange as indicator. The indicator is gradually destroyed by something in the solution. If the amount of acid needed is approximately known, it is better to run in almost that amount, without adding indicator, agitate the solution till most of the gas has gone, add a few drops of indicator and bring to the end point. In any case, if there is delay in reaching the end point, a couple of drops of additional indicator must be added from time to time. For concentrated liquors 100 cubic centimeters are diluted to 1,000 cubic centimeters, an aliquot of 100 cubic centimeters 145 taken and mixed with 100 cubic centimeters of water. Titra- tion is performed as for weak liquors. When results are desired in "ounce-strength," meaning the ounces of sulphuric acid neutralized by the free ammonia in i Imperial gallon, as previously denned, the calculation is per- formed thus. For weak liquors, multiply the number of cubic centimeters of acid used by the factor 0.31443. For concentrated liquors, multiply the number of cubic cen- timeters of acid used by the factor 0.78608. The results by direct titration check fairly well with those by distillation, being usually a trifle higher. Where speed is of more importance than high accuracy, the direct titration is preferable. Fixed Ammonia, To the residue left in the distillation flask, after boiling off, the free ammonia are added 100 cubic centimeters of water and 25 cubic centimeters of 30 per cent, sodium hydroxide solution. The ammonia is distilled off and received in 20 cubic centimeters of normal acid, diluted to 100 cubic centi- meters. Calculation of results is the same as described under "total ammonia." Other Constituents of Liquor. A. Pyridine: 200 cubic centimeters of weak liquor, or 25 cubic centimeters of concentrated liquor diluted to 200 cubic centimeters are neutralized with sulphuric acid of about 1 : 5 strength. The directions given for the direct titration of free ammonia should be followed in reaching the neutral point. Pyridine will now be combined as pyridine sulphate. Add about 10 cubic centimeters of normal ammonium hydroxide, or its equivalent, put in an ammonia distillation flask and distil off as for total ammonia, into about 25 cubic centimeters of normal sulphuric acid or its equivalent, diluted to 100 cubic centimeters with water. Collect about 100 cubic centimeters of distillate which will contain all the pyridine. 146 Put the distillate in an ammonia distillation flask with 10 cubic centimeters of normal sodium hydroxide solution and distil into 50 cubic centimeters of water in a 250 cubic centi- meter beaker. Collect 100 cubic centimeters of distillate which will contain the pyridine together with considerable ammonia. The beaker now contains 150 cubic centimeters. Add 6 drops of phenolphthalein indicator solution (5 grams per liter) and run in normal sulphuric acid till the pink color is just discharged. Read the burette and run in 0.13, cubic centimeter more. (A test will show that with this volume of solution and amount of indicator, the phenolphthalein color will be dis- charged by 0.13 cubic centimeter less of normal acid than is required to completely neutralize the ammonia when methyl orange indicator is used.) Noting the reading of the burette, add I drop of methyl orange and titrate to the pink color. The amount of acid used to turn the methyl orange indicates the amount of pyridine present. One cubic centimeter of acid indicates 0.079 gram of pyridine, equivalent to 0.017 gram of ammonia. Acid Radicals. The following methods are taken from the 1909 and previous Reports of the Chief Inspector under the Alkali, etc., Works Acts. They represent the result of work covering several years, carried on in the laboratories of the Chief Inspector in England. Carbonate: 10 cubic centimeters of liquor (more if dilute) are diluted to 400 cubic centimeters and 10 cubic centimeters of 2N ammoniacal solution of calcium chloride are added. The whole is then heated for i T /2 to 2 hours in a water bath at 100 C., the flask being closed by a Bunsen valve. (That is the flask is closed by a rubber stopper carrying a short glass tube over which is slipped a piece of rubber tubing plugged at its top end. Between the plug and the glass tube, a slit about J4 mc h long is made in the rubber tube. Gases can escape but air from outside cannot enter.) The precipitated calcium carbonate is filtered off, washed by de- 147 cantation, and dissolved in N/2 hydrochloric acid. The small amount of calcium carbonate left on the filter paper is best recovered by incineration and is added to the solution. The excess of acid is titrated with N/2 sodium carbonate. Sulphide: 10 cubic centimeters of liquor are diluted to 500 cubic centimeters, acidified with hydrochloric acid, and titrated with N/io iodine (starch indicator). The volume of N/io iodine required determines how much liquor to take for the actual determination of sulphide to follow. Ten cubic centimeters (or more if the sulphide is apparently small in quantity) are run into an excess of N/5 ammoniacal zinc chlo- ride solution, diluted to about 80 cubic centimeters. The solu- tion is warmed to coagulate the sulphide, filtered, and washed with warm water of 40 to 50 C. temperature. The zinc sulphide on the filter is washed into excess of N/io iodine, acidified with hydrochloric acid (the last traces being washed through the filter with cold dilute acid). After vigorous shak- ing to complete the solution of the sulphide, the excess of iodine is titrated with N/io thiosulphate. Chloride: 250 cubic centimeters of liquor are boiled to expel sulphide, cooled, and made up to 250 cubic centimeters. Dilute 10 cubic centimeters of this to 150 cubic centimeters, add 25 to 50 cubic centimeters of hydrogen peroxide (3 per cent, or "10 volume" solution, free from chloride), boil for 15 minutes, add 6 drops of a 10 per cent, solution of potassium chromate, and continue the boiling 2 minutes. Should the organic matter resist oxidation, more peroxide must be added and the boiling continued with addition of potassium chromate as before. Add a slight excess of sodium carbonate, re-boil for I minute, filter, cool, make up to 250 cubic centimeters and titrate an aliquot portion with N/io silver nitrate (potassium chromate indicator) after bringing to the neutral point with dilute nitric acid. A blank experiment is made with 10 cubic centimeters N/io NaCl and the same volume of water, per- oxide, and chromate, to determine the correction for traces of chloride in the reagents used. (Twenty-five cubic centimeters 148 of peroxide should not contain more than the equivalent of 0.2 to 0.3 cubic centimeters N/io HC1. Thiocyanate: i. Ferrocyanide absent 50 cubic centimeters of the solution are treated with lead carbonate to remove sul- phide and the lead sulphide and carbonate filtered off and washed. To the filtrate, sodium bisulphite containing a little free sulphur dioxide is added, followed by a distinct excess of a 10 per cent, solution of copper sulphate. The solution is allowed to stand 5 to 10 minutes at 70 or 80 C. to coagulate the cuprous thiocyanate. It is then filtered and the precipitate washed with boiling water till the washings give no coloration with dilute potassium ferrocyanide. The residue is digested at 30 to 40 C. with 25 cubic centimeters of a 4 per cent, solu- tion of sodium hydroxide (free from chloride) and filtered. To the cold filtrate are added 5 cubic centimeters of nitric acid (50 per cent, strength and free from oxides of nitrogen) fol- lowed by i cubic centimeter of a saturated solution of iron alum. The solution is then filtered from separated organic matter, if necessary, and titrated with N/io silver nitrate. Thiocyanate: 2. Ferrocyanide present 50 cubic centime- ters of the liquor are slightly acidified with sulphuric acid, and ferric alum solution added in sufficient quantity to impart a decided red coloration. The solution is then warmed to 60 C., filtered from Prussian blue, and washed with water con- taining sodium sulphate. The filtrate is finally treated as in (i) above. Sulphate : 250 cubic centimeters of liquor are concentrated to about 10 cubic centimeters on the water bath, 2 cubic centi- meters of strong hydrochloric added, and the evaporation con- tinued to dryness. The residue is extracted with water and the filtered solution made up to 250 cubic centimeters. One hundred cubic centimeters of this solution are acidified with hydrochloric acid, heated to boiling and barium chloride added. After standing over night, the precipitate is filtered off and weighed. Total Sulphur: 50 cubic centimeters of liquor (100 cubic centimeters if weak) are slowly dropped into an excess of 149 bromine (free from sulphur) covered by water moderately acidified with hydrochloric acid. The oxidized solution is evaporated to dryness on the water bath, filtered, cooled, and made up to 250 cubic centimeters. One hundred cubic centi- meters are precipitated with barium chloride in the usual way. Sulphite and Thiosulphate : Sulphur present as sulphate, and thiosulphate, is found by subtracting from the total sul- phur that present as sulphate, thiocyanate, and sulphide. Ferrocyanide : To 250 cubic centimeters of liquor, acidified slightly with sulphuric acid, ferric alum solution is added in sufficient excess to impart a deep red coloration. The mixture is then heated to 60 C. and filtered, the filtrate being returned to the filter if necessary until a little of it shows no blue color after adding mercuric chloride. The precipitate is washed 2 or 3 times with water containing Na 2 SO 4 . The filter and precipitate are then boiled for 5 minutes with 10 cubic centi- meters of N sodium hydroxide, and the solution diluted to 150 cubic centimeters; 15 cubic centimeters of 3N magnesium chloride are then added to the boiling solution slowly with continual shaking in order to get a milky precipitate of magnesium hydrate. This is then boiled again and 100 cubic centimeters of boiling N/io mercuric chloride added and the boiling continued for 5 to 10 minutes. The flask is then con- nected to a condenser dipping into a receiver containing 25 cubic centimeters N sodium hydroxide. Thirty cubic centi- meters of 4N sulphuric acid is run from a stoppered funnel into the flask, and the contents distilled for 20 to 30 minutes, when the whole of the hydrocyanic acid is obtained in the receiver. The distillate is then titrated with N/io silver ni- trate, after addition of a little potassium iodide. Hydrocyanic Acid: 50 cubic centimeters of the liquor are added to an excess (50 to 100 cubic centimeters) of a satu- rated solution of lead nitrate contained in the distillation flask of the apparatus for determining free and fixed ammonia. The mixture is distilled into 25 cubic centimeters of N sodium hydroxide into which the exit tube of the condenser dips. Thirty to 40 minutes gentle boiling, at which time about 50 cubic centimeters of liquid will have been distilled, is usually sufficient. Frothing is liable to occur and the flask should be heated therefore very carefully. At the end of the distillation a current of air is passed through the apparatus for a short time, to ensure the removal of the hydrocyanic acid. The distillate is diluted to 400 cubic centimeters, a crystal of potassium iodide added and the solution titrated with N/io silver nitrate. Rapid Method for Estimation of Carbon Dioxide and Hydrogen Sulphide. In following the operation of apparatus in which a portion of the foul gases (carbon dioxide and hydrogen sulphide) are driven off from the liquor by heat, it is desirable to be able to determine those gases rapidly. For the purpose, the methods of the Alkali Inspector given above are too time-consuming. The following method is much more rapid and sufficiently accurate for control purposes. Ammoniacal Solution of Calcium Chloride: Dissolve 100 grams of calcium carbonate with hydrochloric acid, after add- ing a little water. Make alkaline with ammonia. Dissolve any precipitate that forms with hydrochloric acid, and again make alkaline. Continue this process of redissolving the precipitate till the solution finally remains clear on adding an excess of ammonia. Make the solution up to one liter. Barium Hydroxide Solution: Put 80 grams of good pure barium hydroxide in 2 liters of water, and dissolve as much of it as possible. After settling filter into another bottle. Normal sulphuric acid and tenth-normal iodine solutions are also needed. In the process which is being examined, it is very likely that the volume of the liquor will have changed between the inlet and outlet of the apparatus by the addition of steam or water. It is therefore more informing to report the foul gases present as a ratio of the equivalent of the free ammonia also present. A determination of the latter must therefore be made by direct titration. Free Ammonia : Pipette 10 cubic centimeters of liquor, add 50 cubic centimeters of water, and titrate with normal sul- phuric acid, with methyl orange indicator. Carbon Dioxide and Hydrogen Sulphide: In the distilling flask of the "total ammonia" apparatus, put 200 cubic centi- meters of water, and 10 cubic centimeters each of liquor, am- moniacal calcium chloride, and strong (0.900 S. G.) ammonia. In a 250 cubic centimeter flask to serve as a receiver, put 20 cubic centimeters of barium hydroxide solution, 10 cubic centi- meters of strong ammonia and fill with water to one-half inch from the bottom of the neck. The object of adding ammonia to the distilling flask is to keep the contents strongly ammoniacal during the distillation, as otherwise some of the calcium carbonate formed will be decomposed with loss of carbon dioxide. The object of add- ing barium hydroxide to the receiver is merely to show the possible presence of carbon dioxide in the distillate, which will occur in the distillation is conducted too long and the flask contents cease to be sufficiently ammoniacal. The barium hy- droxide solution almost always shows a slight scum, due to carbonic acid in the air, which must not be mistaken for car- bonic acid distilled over. Distil, slowly at first but with a larger flame as soon as the liquid in the flask commences to boil, and continue the dis- tillation for 5 minutes after increasing the flame. This length of distillation will distil off the hydrogen sulphide without de- composing the calcium carbonate. The residue in the flask may be tested with lead acetate paper to show the removal of hydrogen sulphide. Transfer the liquid in the receiver to a 600 cubic centimeter beaker and dilute to about 500 cubic centimeters. Add 3 drops methyl orange, acidify with hydrochloric acid, add 5 cubic centimeters of starch solution and titrate with tenth- normal iodine. Filter the liquid in the distilling flask through a close grained filter, wash thoroughly with water, and dissolve the precipitate in 15 cubic centimeters of normal sulphuric acid. The best 152 way to do this is to run the acid into the washed distillation flask, to dissolve the precipitate which lodges there, and then transfer it to a beaker into which is put the filter paper con- taining the main portion of the precipitate. Stir well, boil, cool and titrate back with ammonia solution, using cochineal as indicator. Since normal and tenth-normal solutions are used through- out, the ratio of the normal acid used by the calcium carbonate to that used in titrating the free ammonia, will show at once what portion of the ammonia may be considered to be com- bined with carbonic acid as the normal carbonate. The same is true for the titration of hydrogen sulphide by iodine, with allowance for the fact that the iodine solution is tenth-normal. Ammonium Sulphate. MOISTURE. Approximately 10 grams of the salt are dried at 105 C. to constant weight. FREE ACID. The dry salt from the moisture determination of approxi- mately 10 grams of a fresh sample is dissolved in about 200 cubic centimeters of water. A drop or two of methyl orange or sodium alizarin sulphonate is added and the free acid de- termined by titration with N/io sodium hydroxide solution. AMMONIA. Ten grams are dissolved in water and diluted to i liter. An aliquot of 100 cubic centimeter is taken for the determination of ammonia. This is placed with 100 cubic centimeters of water in a Kjeldahl distilling flask; 10 cubic centimeters of 30 per cent, caustic soda are added with a piece of granu- lated zinc and the ammonia distilled over into 80 cubic centi- meters of N/5 sulphuric acid. The excess acid is found by titration, etc., using sodium alizarin sulphonate or cochineal as indicator. 153 TARRY MATTER. Fifty grams of salt are dissolved in cold water and filtered on a Gooch crucible which is dried at 70 C. The tar is ex- tracted with ether and the ethereal extract is evaporated in a tared dish. The weight of dry extract is taken as total organic matter. NAPHTHALENE. The above weighed tarry extract is dissolved in cold alcohol and an equal weight of picric acid also in alcoholic solution is added. The naphthalene picrate is then filtered off, dried at 100 C. and weighed. Naphthalene picrate X 0.3586 = naphthalene. PYRIDINE. To a filtered solution of 50 grams of sale in 150 cubic centi- meters of water in a distilling flask is added about 20 cubic centimeters of normal caustic soda, sufficient to make it slightly alkaline, but not enough to decompose it. Distil into 100 cubic centimeters of water. Nearly neutralize with hydrochloric acid and redistil into 30 cubic centimeters of water until 70 cubic centimeters have come over. Make up the distillate to a volume of 150 cubic centimeters, add 6 drops of phenol- phthalein, and then run in normal acid till the pink color has just disappeared. Then add 0.13 cubic centimeter more of acid and read the burette. Add i drop of methyl orange and titrate to a pink color. Each cubic centimeter of acid used after adding the methyl orange equals 0.079 gram pyridine. THIOCYANATES PINK COLOR. To a filtered solution of 100 grams of salt, copper sulphate and sulphurous acid are added and the solution gently warmed. After settling, the copper thiocyanate is filtered off and washed free from copper salts as shown by testing the washings with potassium ferrocyanide. The precipitate is then dissolved in nitric acid, water added, and the solution boiled for several 154 minutes. The copper is determined in the solution as the oxide by precipitation with sodium hydroxide; or by elec- trolysis. The weight of copper X i-*974 equals equivalent amount of NH 4 SCN. FERRO FERRICYANIDE BLUE COLOR. One hundred grams of salt are dissolved in hot water and filtered on a folded filter in a hot water funnel. Wash with hot water until free from sulphates. The residue and filter are put into a flask with about 50 cubic centimeters of water, shaken and boiled to separate the residue from the filter as much as possible. To the contents of the flask N/5- 7-32. If it is necessary to use a quantity of oil less than 240 cubic centimeters, the following quantities can be employed and multiplied by the corresponding factor: Amount of oil put in, cc. 45 50 60 120 Amount of oil run out, cc. 25 40 50 100 Factor to change to 200 cc. run out and 240 cc. put in 5.55 3.62 2.79 1.65 The Committee recommends the use of the Saybold vis- cosimeter. In this country it is the most widely used stand- ard and has the advantage that small samples of 125 cubic centimeters are sufficient for the test. This instrument is shown in Fig. 58. The tests are carried out in practically the 235 same way as in the Engler, only that a flask graduated to 60 cubic centimeters is used for the receiver, and the seconds re- quired for the oil to fill the flask to the 60 cubic centimeter mark indicate the viscosity. FIG. 58. Specific Gravity. -Lubricating oils are practically always reported in degrees Baume. It is, therefore, sufficient to read the gravity by means of a hydrometer, correcting for tempera- ture. If the oil is too thick to float the hydrometer, heat to 90 or 1 00 F. The following table can be used for tempera- ture corrections : r-^00* ON O cs* ro -^ LOO t^-00* ON o' M cs ro TT Tf LOO t^-X ON O* HI ^ co-^f ,_ w cs CS CM CM CS CM CM CM CM CS CO CO CO ro CO CO CO CO rO tO CO * >q- Tf -3- ^3- 00 00 00 00 f^ H M O O ON ON ON ONOO OO o t- r-o v v \ 10 u * TJ- ^t- * ro to 00 (^ O *-< fi ^O ^J" LO^O r-^-OO O\ O\ O r-c 01 CS M CS P) M CM . r>. t 00 CT\ 6 M pi ro TJ- i/xo r^-od ON O - ' ' w M -! <** rOTfLOO* t^-CO ON O* ' CM ro T^- LOO' r^-OC ^ O ^ cs" ro -^ LOO* t^ 00* O O ON ON ON ONOO ,xi 00 OO 00 OO ON O CM' ro rf lovd vO r^-oc cf\ O ' CM' rO rt- tO^O l^-oo' ON O -' CM' rO -rTr-^-i3--^- cscMMi-iMi-iHMp-i)-iqqqqqqONONq^qNON ONOC oq oq oq oq oq r^. r^. t--. ON o' >-< cs' ro TJ- LO\O t^-oo' ON o' M cs" ro -4- TJ- ir>\6 t-^-od - cs ro -^- LOO' i^-oo' 1-1 CM CS CM CM CM CS CS CS CM CM rOCOrOrOrOCOCOfOrOrOCO-S-Tj-Tj-Ti-Tj-Ttf-Tr^-Tj- O\ O ^ CM rO "^" *OO' t-^00* ON O HI CM ro -^ LOO' r^-GO O\ O HI CM* CO ^ LOO* r^-OO ON ON o" HI (N ro ^f LOO" r-*-Oo" ON O* -. cs' CO ^t" LO\O t^-00 ON O* ^ CM" rO rf LOO r~--00' ON HI CM CS CM CMM CM CS CM CS CM P> IO fO W tO W *>*> tO ** 0 HI CS ONONONONONONONONONONONONON ONOO OO 00 00 00 00 00 00 OO 00 00 00 CO OO 00 OO OO ' q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q < O *> O HI CM CO TT LOOI t^OO ON O M CM co * LO>O t^OO O^ O M cs rO TT LOO r^oC ON O < *" CU ^ ^ N N ^ ^ ^ ^ ^ ^ rorOrOcOrOcOrOcOcocO^'^'^-Tf^-'^-^-Tj-Tj-T^-LO "^ 237 Cold Test. Twenty cubic centimeters of the oil are trans- ferred to a narrow bottle or test tube, stoppered with a rubber stopper, through which is inserted a thermometer, the bulb of which remains an inch or more into the oil. The bottle is placed in a mixture of ice and salt, or other freezing compound, and retained there until the oil becomes solid. It is then removed and allowed to warm until the con- tents become somewhat thinner in consistency. The bottle is inclined from side to side until the oil begins to flow, when the temperature is taken. At this particular temperature the oil is neither at its nor- mal fluidity, nor is it solid, and while this method does not correctly indicate the exact temperature of the solidify ing- point, it does show the point at which the oil ceases to flow readily, the important one to the oil inspector. These methods are in part taken from Stillman's "Analysis of Lubricating Oil." SOLDER. Tin and Antimony Determination. Tin Determination. Dissolve 0.5 gram of very finely di- vided sample (best done with hacksaw) in 50 cubic centi- meters of concentrated hydrochloric acid till action ceases, passing a stream of CO 2 gas, during the whole operation to prevent oxidation, cool, still, passing CO 2 . Add starch paste and titrate with IO/N iodine solution. Cubic centimeters used x 1.18 = per cent. tin. Antimony Determination. Dissolve 0.5 gram metal in hy- drochloric acid (as in tin determination, except not using CO 2 gas). After action ceases, add small quantities of iodine crystals. Boil off excess iodine, cool, dilute to 150 cubic centimeters (put in 500 cubic centimeter flask), add 50 cubic centimeters of Rochelle salt solution (10 20 grams salt in the 50 cubic centimeters of water, keep cold, and nearly neu- tralize with sodium bicarbonate, then completely neutralize with sodium hydrate, keep cold (using litmus paper). Add 16 2 3 8 quickly concentrated sodium bicarbonate solution till milky. Add starch paste and titrate with lo/N iodine solution. Cubic centimeters used x 1.2 = per cent, antimony. Lead is seldom determined but instead is taken by differ- ence. It may, however, be determined by the method described under Babbitt. One-tenth normal iodine solution: 6.35 grams iodine and 9 grams of potassium iodine to 500 cubic centimeters of water. HARD L,E)AD AND BABBITT. To determine antimony in hard lead, the method for Babbitt metal can be used. To Determine Copper and Lead. Five-tenth gram of the finely divided sample in nitric acid adding 0.5 gram of chem- ically pure copper (to avoid sponging of the lead on the cathods) evaporate until almost dry and redissolve in 88 cubic centimeters of nitric acid with 50 cubic centimeters of distilled water, filter, wash well with water and electrolyze (see Copper Alloys), deduct the 0.5 gram C added from your weight of the cathods, the remainder in the C in the Babbitt. The increase of the weight of the annode multiplied by 0.868 x 2 x 100 gives the lead as metallic lead. COPPER AU.OYS. Weigh out I gram of the clean borings into a 250 cubic centimeter beaker, dissolve in 20 cubic centimeters of diluted nitric acid and evaporate to dryness. Redissolve with 10 cubic centimeters concentrated nitric acid and 40 cubic centimeters of water and filter off the oxide of tin, running the filtrate into a 250 cubic centimeter beaker, wash well with distilled water and fill the beaker to within l / 2 inch of the top. The solution is then electrolyzed by placing two platinum electrodes previously weighed and connected with a 4-volt direct current (storage battery or Edison Laland cells are best fitted for the purpose) at a rate of about y 2 ampere per 239 hour. After about 10 to 12 hours all of the copper will be deposited on the negative electrode as metallic copper, the lead on the positive electrode as. black peroxide. The elec- trolyte is then quickly removed by lowering the beaker and washed by replacing it with a beaker of distilled water and then a beaker of alcohol. The electrodes are then dried and weighed. The increase gives the per cent, of copper direct; the lead is calculated by multiplying the weight of the oxide with 0.868. The oxide of tin is burned off and weighed. The weights multiplied by 0.7881 gives the per cent, of metallic tin. To the electrolyte from the electrolysis, ammonia is added until decidedly ammoniacal, boil off excess and filter off any iron hydroxide present, burn off and weigh. If zinc is present, precipitate with hydrogen sulphide, filter and burn to zinc oxide, weigh and calculate to metallic zinc. In alloys containing nickel, the electrolyte after the copper has been deposited and weighed is made alkaline with an ex- cess of ammonia and the electrode coated with the copper re- placed and a current of 6 volts passed through it to deposit the nickel as metallic nickel. It is advisable to use the copper plated cathod, since the nickel when deposited direct on the platinum is hard to remove. LIME. In works practice the analysis is confined to determine the quality of the lime as a binder for mortar and as an alkaline for setting free ammonia from its fixed salts. A high percentage of calcium oxide is most desirable and the determination of CaO therefore suffices for most purposes. In selecting the sample, about a bucket full of lumps are quickly broken up into pieces the size of a pea, and quartered down until one-quarter fills approximately a pint bottle ; pre- caution should be taken to prevent the sample from absorbing moisture or CO 2 from the air. One hundred grams of this sample are weighed into a i 240 liter flask. The sample is next slaked and the flask filled to the mark with water and well shaken. One hundred cubic centimeters of this milk of lime, with- out letting it settle are transferred to another liter flask again filled to the mark and well shaken. Fifty cubic centimeters of this solution are transferred to an Erlenmeyer flask of 250 cubic centimeters capacity, adding a few drops of phenace- tolin as an indicator, and titrated with normal hydrochloric acid solution until the solution becomes a faint pink. The caustic lime is calculated from the number of cubic centi- meters of HC1 neutralized. FIG. 59. The titration is then continued until the solution changes first to red and finally to yellow, the second titration giving the 241 carbonate of lime. It is sometimes desirable to determine the unburned lime by determining the CO 2 and calculating it therefrom. It can best be done by means of an alkalimeter. See Fig. 59. FIG. 60. The latter consists of a glass vessel having a glass stoppered opening at the side through which the sample is introduced, a separatory funnel with a glass stopper at one side of the top and a gas scrubbing tube at the other. To use the apparatus the gas scrubbing tube is first filled y$ full with concentrated sulphuric acid. The separatory fun- 242 nel is then filled with diluted HC1 (y 2 acid, y 2 water) and the apparatus weighed. Then approximately 5 grams of the powdered sample are in- troduced through the glass stoppered opening and the whole is again weighed. The acid in the separating funnel is next FIG. 61. run into the vessel through the stop-cock, and after the reac- tion ceases, the flask is slightly warmed. After cooling it is again weighed. The difference between the second and third weights represents the CO 2 driven off. By dividing the differ- ence between the first and second weight (the weight of the 243 sample), into the third and mutliplied by 100, the percentage of CO, is found and the percentage of calcium carbonate can be calculated therefrom. MAGNESIUM. For the determination of magnesium follow scheme under Refractories or Water Analysis. Efficiency Test. For Use in Ammonia Still. Five grams of the sample are placed in a Kjeldahl flask and slaked. The flask is next connected with the condenser of an ammonia dis- tilling apparatus. Through a separatory funnel are then added 10 grams of ammonium sulphate previously dissolved in water. The am- monia liberated on boiling is absorbed in a beaker containing standard sulphuric acid. The operation is the same as in the determination of ammonia in ammoniacal liquors. From the ammonia thus determined, the efficiency of the lime can be determined as follows : a = NH 3 found b = CaO used f* X 5 6\ \ 34 ' b CO 2 IN AIR. For the determination of CO 2 in air, there are two appara- tuses generally used, the one is Haldane's (Fig. 60) and the other Patterson's (Fig. 61). These apparatuses differ from the Orsat apparatus that the gas volume can be read as close as o.ooi of a cubic centimeter and CO 2 can, therefore, be determined in o.oooi by volume. CEMENT. STANDARD SPECIFICATIONS FOR CEMENT, AS PUBLISHED BY THE AMERICAN SOCIETY FOR TESTING MATERIALS. Adopted, 1904; Revised, 1908, 1909. GENERAL OBSERVATIONS. i. These remarks have been prepared with a view of point- 244 ing out the pertinent features of the various requirements and the precautions to be observed in the interpretation of the results of the tests. 2. The Committee would suggest that the acceptance or rejection under these specifications be based on tests made by an experienced person having the proper means for making the tests. SPECIFIC GRAVITY. 3. Specific gravity is useful in detecting adulteration. The results of tests of specific gravity are not necessarily conclu- sive as an indication of the quality of a cement, but when in combination with the results of other tests may afford valu- able indications. FINENESS. 4. The sieves should be kept thoroughly dry. TIME OF SETTING. 5. Great care should be exercised to maintain the test pieces under as uniform conditions as possible. A sudden change or wide range of temperature in the room in which the tests are made, a very dry or humid atmosphere, and other irregulari- ties vitally affect the rate of setting. CONSTANCY OF VOLUME. 6. The tests for constancy of volume are divided into two classes, the first normal, the second accelerated. The latter should be regarded as a precautionary test only, and not in- fallible. So many conditions enter into the making and inter- preting of it that it should be used with extreme care. 7. In making the pats the greatest care should be exercised to avoid initial strains due to molding or to too rapid drying- out during the first 24 hours. The pats should be preserved under the most uniform conditions possible, and rapid changes of temperature should be avoided. 8. The failure to meet the requirements of the accelerated 245 tests need not be sufficient cause for rejection. The cement may, however, be held for 28 days, and a retest made at the end of that period, using a new sample. Failure to meet the require- ments at this time should be considered sufficient cause for rejection, although in the present state of our knowledge it cannot be said that such failure necessarily indicates unsound- ness, nor can the cement be considered entirely satisfactory simply because it passes the tests. SPECIFICATIONS. General Conditions. 1. All cement shall be inspected. 2. Cement may be inspected either at the place of manu- facture or on the work. 3. In order to allow ample time for inspecting and testing, the cement should be stored in a suitable weather-tight build- ing having the floor properly blocked or raised from the ground. 4. The cement shall be stored in such a manner as to permit easy access for proper inspection and identification of each shipment. 5. Every facility shall be provided by the Contractor and a period of at least 12 days allowed for the inspection and nec- essary tests. 6. Cement shall be delivered in suitable packages with the brand and name of manufacturer plainly marked thereon. 7. A bag of cement shall contain 94 pounds of cement net. Each barrel of Portland cement shall contain four bags, and each barrel of natural cement shall contain three bags of the above net weight. 8. Cement failing to meet the 7-day requirements may be held awaiting the results of the 28-day tests before rejection. 9. All tests shall be made in accordance with the methods proposed by the Committee on Uniform Tests of Cement of the American Society of Civil Engineers, presented to the So- ciety January 21, 1903, and amended January 20, 1904, and 2 4 6 January 15, 1908, with all subsequent amendments thereto. (See addendum to these specifications.) 10. The acceptance or rejection shall be based on the fol- lowing requirements: Natural Cement. 11. Definition. This term shall be applied to the finely pul- verized product resulting from the calcination of an argillace- ous limestone at a temperature only sufficient to drive off the carbonic acid gas. FINENESS. 12. It shall leave by weight a residue of not more than 10 per cent, on the No. 100, and 30 per cent, on the No. 200 sieve. TIME oi? SETTING. 13. It shall not develop initial set in less than 10 minutes; and shall not develop hard set in less than 30 minutes, or in more than 3 hours. TENSILE STRENGTH. 14. The minimum requirements for tensile strength for bri- quets i square inch in cross section shall be as follows, and the cement shall show no retrogression in strength within the periods specified : Neat Cement. Age Strength 24 hours in moist air 75 pounds 7 days (i day in moist air, 6 days in water) 150 pounds 28 days (i day in moist air, 27 days in water) 250 pounds One Part Cement, Three Parts Standard Ottawa Sand. 7 days (i day in moist air, 6 days in water) 50 pounds 28 days (i day in moist air, 27 days in water) 125 pounds CONSTANCY OF VOLUME. 15. Pats of neat cement about 3 inches in diameter, y 2 inch thick at center, tapering to a thin edge, shall be kept in moist air for a period of 24 hours. (a) A pat is then kept in air at normal temperature. 247 (b) Another is kept in water maintained as near 70 F. as practicable. 1 6. These pats are observed at intervals for at least 28 days, and, to satisfactorily pass the tests, shall remain firm and hard and show no signs of distortion, checking, cracking, or disinte- grating. Portland Cement. 17. Definition. This term is applied to the finely pulverized product resulting from the calcination to incipient fusion of an intimate mixture of properly proportioned argillaceous and calcareous materials, and to which no addition greater than 3 per cent, has been made subsequent to calcination. SPECIFIC GRAVITY. 1 8. The specific gravity of cement shall not be less than 3.10. Should the test of cement as received fall below this requirement, a second test may be made upon a sample ignited at a low red heat. The loss in weight of the ignited cement shall not exceed 4 per cent. FINENESS. 19. It shall leave by weight a residue of not more than 8 per cent, on the No. 100, and not more than 25 per cent, on the No. 200 sieve. TIME OF SETTING. 20. It shall not develop initial set in less than 30 minutes; and must develop hard set in not less than i hour, nor more than 10 hours. TENSILE STRENGTH. 21. The minimum requirements for tensile strength for bri- quets I square inch in cross section shall be as follows, and the cement shall show no retrogression in strength within the periods specified: 248 Neat Cement. Age Strength 24 hours in moist air 175 pounds 7 days (i day in moist air, 6 days in water) 500 pounds 28 days (i day in moist air, 27 days in water) 600 pounds One Part Cement, Three Parts Standard Ottawa Sand. 7 days (i day in moist air, 6 days in water) 200 pounds 28 days (i day in moist air, 27 days in water) 275 pounds CONSTANCY OF VOLUME. 22. Pats of neat cement about 3 inches in diameter, y 2 inch thick at the center, and tapering to a thin edge, shall be kept in moist air for a period of 24 hours. (a) A pat is then kept in air at normal temperature and ob- served at intervals for at least 28 days. (b) Another pat is kept in water maintained as near 70 F. as practicable, and observed at intervals for at least 28 days. (c) A third pat is exposed in any convenient way in an atmosphere of steam, above boiling water, in a loosely closed vessel for 5 hours. 23. These pats, to satisfactorily pass the requirements, shall remain firm and hard, and show no signs of distortion, check- ing, cracking, or disintegrating. SULPHURIC ACID AND MAGNESIA. 24. The cement shall not contain more than 1.75 per cent, of anhydrous sulphuric acid (SO 3 ), nor more than 4 per cent, of magnesia (MgO). ADDENDUM. METHODS FOR TESTING CEMENT. 1 Recommended by the Special Committee on Uniform Tests of Cement of the American Society of Civil Engineers. SAMPLING. i. Selection of Sample. The selection of samples for testing should be left to the engineer. The number of packages sampled and 1 Accompanying Final Report of Special Committee on Uniform Tests of Cement of the American Society of Civil Engineers, dated January 17, 1912. 249 the quantity taken from each package will depend on the importance of the work and the facilities for making the tests. 2. The samples should fairly represent the material. When the amount to be tested is small it is recommended that I barrel in 10 be sampleti ; when the amount is large it may be impracticable to take samples from more than I barrel in 30 or 50. When the samples are taken from bins at the mill I for each 50 to 200 barrels will suffice. 3. Samples should be passed through a sieve having twenty meshes per linear inch, in order to break up lumps and remove foreign mate- rial; the use of this sieve is also effective to obtain a thorough mixing of the samples when this is desired. To determine the acceptance or rejection of cement it is preferable, when time permits, to test the samples separately. Tests to determine the general characteristics of a cement, extending over a long period may be made with mixed samples. 4. Method of Sampling, Cement in barrels should be sampled through a hole made in the head, or in one of the staves midway between the heads, by means of an auger or a sampling iron similar to that used by sugar inspectors; if in bags, the sample should be taken from surface to center; cement in bins should be sampled in such a manner as to represent fairly the contents of the bin. Sampling from bins is not recommended if the method of manufacture is such that ingredients of any kind are added to the cement subsequently. CHEMICAI, ANALYSIS. 5. Significance. Chemical analysis may serve to detect adultera- tion of cement with inert material, such as slag or ground limestone, if in considerable amount. It is useful in determining whether certain constituents, such as magnesia and sulphuric anhydride, are present in inadmissible proportions. 6. The determination of the principal constituents of cement, silica, alumina, iron oxide, and lime, is not conclusive as an indication of quality. Faulty cement results more frequently from imperfect prepa- ration of the raw material or defective burning than from incorrect proportions. Cement made from material ground very finely and thoroughly burned may contain much more lime than the amount usually present, and still be perfectly sound. On the other hand, cements low in lime may, on account of careless preparation of the raw material, be of dangerous character. Furthermore, the composition of the product may be so greatly modified by the ash of the fuel used in burning as to affect in a great degree the significance of the results of analysis. 2 5 7. Methods. The methods to be followed, except for determining the loss on ignition, should be those proposed by the Committee on Uniformity in the Analysis of Materials for the Portland Cement Industry, reported in the Journal of the Society for Chemical Industry, Vol. 21, p. 12, 1902; and published in Engineering News, Vol. 50, p. 60, 1903; and in Engineering Record, Vol. 48, p. 49, 1903, and in addition thereto, the following : (a) The insoluble residue may be determined as follows : To a i -gram sample of the cement are added 30 cubic centimeters of water and 10 cubic centimeters of concentrated hydrochloric acid, and then warmed until effervescence ceases, and digested on a steam bath until dissolved. The residue is filtered, washed with hot water, and the filter paper and contents digested on the steam bath in a 5 per cent, solution of sodium carbonate. This residue is filtered, washed with hot water, then with hot hydrochloric acid, and finally with hot water, and then ignited at a red heat and weighed. The quantity so obtajped is the insoluble residue. (b) The loss on ignition shall be determined in the following manner: One-half gram of cement is heated in a weighed platinum crucible, with cover, for 5 minutes with a Bunsen burner (starting with a low flame and gradually increasing to its full height) and then heated for 15 minutes with a blast lamp; the difference between the weight after cooling and the original weight is the loss on ignition. The temperature should not exceed 900 C., or a low red heat; the ignition should preferably be made in a muffle. SPECIFIC GRAVITY. 8. Significance. The specific gravity of cement is lowered by adulteration and hydration, but the adulteration must be considerable to be detected by tests of specific gravity. 9. Inasmuch as the differences in specific gravity are usually very small, great care must be exercised in making the determination. 10. Apparatus. The determination of specific gravity should be made with a standardized Le Chatelier apparatus. This consists of a flask (D), Fig. 62, of about 120 cubic centimeters capacity, the neck of which is about 20 centimeters long; in the middle of this neck is a bulb (C), above and below which are two marks (F) and () ; the volume between these two marks is 20 cubic centimeters. The neck has a diameter of about 9 millimeters, and is graduated into tenths of cubic centimeters above the mark (/*) 11. Benzine (62 Baume naphtha) or kerosene free from water should be used in making the determination. 12. Method. The flask is filled with either of these liquids to the lower mark (B), and 64 grams of cement, cooled to the temperature of the liquid, is slowly introduced through the funnel (B}, the stem of 251 which should be long enough to extend into the flask to the top of the bulb (Oi taking care that the cement does not adhere to the sides of the flask, and that the funnel does not touch the liquid. After all the cement is introduced, the level of the liquid will rise to some division of the graduated neck; this reading, plus 20 cubic centimeters, is the volume displaced by 64 grams of the cement. FIG. 62. Le Chatelier's Specific Gravity Apparatus. \ 13. The specific gravity is then obtained from the formula, Weight of cement, in grams, Specific gravity = Displaced volume, in cubic centimeters. 14. The flask, during the operation, is kept immersed in water in a jar (A), in order to avoid variations in the temperature of the liquid in the flask, which should not exceed J4 C. The results of repeated tests should agree within o.oi. The determination of specific gravity 252 should be made on the cement as received ; if it should fall below 3.10, a second determination should be made after igniting the sample in a covered dish, preferably of platinum, at a low red heat not exceed- ing 900 C. The sample should be heated for 5 minutes with a Bunsen burner (starting with a low flame and gradually increasing to its full height) and then heated for 15 minutes with a blast lamp; the ignition should preferably be made in a muffle. 15. The apparatus may be cleaned in the following manner : The flask is inverted and. shaken vertically until the liquid flows freely, and then held in a vertical position until empty ; any traces of cement remaining can be removed by pouring into the flask a small quantity of clean liquid benzine or kerosene and repeating the operation. FINENESS. 16. Significance. It is generally accepted that the coarser particles in cement are practically inert, and it is only the extremely fine powder that possesses cementing qualities. The more finely cement is pul- verized, other conditions being the same, the more sand it will carry and produce a mortar of a given strength. 17. Apparatus. The fineness of a sample of cement is determined by weighing the residue retained on certain sieves. Those known as No. 100 and No. 200, having approximately 100 and 200 wires per linear inch, respectively, should be used. They should be 8 inches in diam- eter. The frame should be of brass, 8 inches in diameter, and the sieve of brass wire cloth conforming to the following requirements: No. of sieve Diameter of wire, inches Meshes, per linear inch Warp Woof 100 2OO 0.0042 to 0.0048 O.OO2I to O.OO23 95 to IOI 192 to 203 93 to 103 190 to 205 The meshes in any smaller space, down to 0.25 inch, should be pro- portional in number. 18. Method. The test should be made with 50 grams of cement, dried at a temperature of 100 C (212 F.). 19. The cement is placed on the No. 200 sieve, which, with pan and cover attached, is held in one hand in a slightly inclined position, and moved forward and backward about 200 times per minute, at the same time striking the side gently, on the up stroke, against the palm of the other hand. The operation is continued until not more than 0.05 gram will pass through in I minute. The residue is weighed, then placed 253 on the No. 100 sieve, and the operation repeated. The work may be expedited by placing in the sieve a few large steel shot, which should be removed before the final I minute of sieving. The sieves should be thoroughly dry and clean. NORMAI, CONSISTENCY. 20. Significance. The use of a proper percentage of water in making pastes 1 and mortars for the various tests is exceedingly impor- tant and affects vitally the results obtained. FIG. 63. Vicat Apparatus. 21. The amount of water, expressed in percentage by weight of the dry cement, required to produce a paste of plasticity desired, termed 1 The term "paste" is used in this report to designate a mixture of cement and water and the word "mortar" to designate a mixture of cement, sand and water. 17 254 "normal consistency," should be determined with the Vicat apparatus in the following manner: 22. Apparatus. This consists of a frame (A}, Fig. 63, bearing a movable rod (B), weighing 300 grams, one end (C) being I centimeter in diameter for a distance of 6 centimeters, the other having a remov- able needle (D), I millimeter in diameter, 6 millimeters long. The rod is reversible, and can be held in any desired position by a screw (B), and has midway between the ends a mark (F) which moves under a scale (graduated to millimeters) attached to the frame (A). The paste is held in a conical, hard-rubber ring (G), 7 centimeters in diameter at the base, 4 centimeters high, resting on a glass plate (//) about 10 centimeters square. 23. Method. In making the determination, the same quantity of cement as will be used subsequently for each batch in making the test pieces, but not less than 500 grams, with a measured quantity of water, is kneaded into a paste, as described in paragraph 45, and quickly formed into a ball with the hands, completing the operation by tossing it six times from one hand to the other, maintained about 6 inches apart; the ball resting in the palm of one hand is pressed into the larger end of the rubber ring held in the other hand, completely filling the ring with paste ; the excess at the larger end is then removed by a single movement of the palm of the hand; the ring is then placed on its larger end on a glass plate and the excess paste at the smaller end is sliced off at the top of the ring by a single oblique stroke of a trowel held at a slight angle with the top of the ring. During these operations care must be taken not to compress the paste. The paste confined in the ring, resting on the plate, is placed under the rod, the larger end of which is brought in contact with the surface of the paste; the scale is then read, and the rod quickly released. 24. The paste is of normal consistency when the cylinder settles to a point 10 millimeters below the original surface in l / 2 minute after being released. The apparatus must be free from all vibrations during the test. 25. Trial pastes are made with varying percentages of water until the normal consistency is obtained. 26. Having determined the percentage of water required to pro- duce a paste of normal consistency, the percentage required for a mortar containing, by weight, I part of cement to 3 parts of standard Ottawa sand, is obtained from the following table, the amount .being a percentage of the combined weight of the cement and sand. 255 PERCENTAGE OF WATER FOR STANDARD MORTARS. One cement, One cement, One cement, Neat three standard Neat three standard Neat three standard Ottawa sand Ottawa sand Ottawa sand 15 8.0 23 9-3 31 10.7 16 8.2 24 9-5 32 10.8 17 8-3 25 9-7 33 II.O 18 8.5 26 9.8 34 II. 2 19 8.7 27 10.0 35 ii. 3 20 8.8 28 10.2 36 H.5 21 9.0 29 10.3 37 11.7 22 9.2 30 10.5 38 11.8 TIME OE SETTING. 27. Significance. The object of this test is to determine the time which elapses from the moment water is added until the paste ceases to be plastic (called the "initial set"), and also the time until it acquires a certain degree of hardness (called the "final set" or "hard set"). The former is the more important, since, with the commencement of setting, the process of crystallization begins. As a disturbance of this process may produce a loss of strength, it is desirable to complete the operation of mixing or molding or incorporating the mortar into the work before the cement begins to set. 28. Apparatus. The initial and final set should be determined with the Vicat apparatus described in paragraph 22. 29. Method. x\ paste of normal consistency is molded in the hard rubber ring, as described in paragraph 23, and placed under the rod (B), the smaller end of which is then carefully brought in contact with the surface of the paste, and the rod quickly released. 30. The initial set is said to have occurred when the needle ceases to pass a point 5 millimeters above the glass plate; and the final set, when the needle does not sink visibly into the paste. 31. The test pieces should be kept in moist air during the test; this may be accomplished by placing them on a rack over water con- tained in a pan and covered by a damp cloth ; the cloth to be kept from contact with them by means of a wire screen; or they may be stored in a moist box or closet. 32. Care should be taken to keep the needle clean, as the collection of cement on the sides of the needle retards the penetration, while cement on the point may increase the penetration. 33. The time of setting is affected not only by the percentage and temperature of the water used and the amount of kneading the paste receives, but by the temperature and humidity of the air, and its deter- mination is, therefore, only approximate. 2 5 6 STANDARD SAND. 34. The sand to be used should be natural sand from Ottawa, 111., screened to pass a No. 20 sieve, and retained on a No. 30 sieve. The sieves should be at least 8 inches in diameter; the wire cloth should be of brass wire and should conform to the following requirements : No. of sieve Diameter of wire, inches Meshes, per linear inch Warp Woof 2O 30 0.016 to 0.017 O.OII tO O.OI2 19.5 to 20.5 29.5 to 30.5 19 to 21 28.5 to 31.5 FIG. 64. Details for Briquet. 257 Sand which has passed the No. 20 sieve is standard when not more than 5 grams passes the No. 30 sieve in I minute of continuous sift- ing of a 5oo-gram sample. 1 FORM OF TEST PIECES. 35. For tensile tests the form of test piece shown in Fig. 55 should be used. 36. For compressive tests, 2-inch cubes should be used. MOLDS. 37. The molds should be of brass, bronze, or other non-corrodible material, and should have sufficient metal in the sides to prevent spreading during molding. 38. Molds may be either single or gang molds. The latter are pre- ferred by many. If used, the types shown in Figs. 65 and 66 are recommended. FIG. 65. Details for Gang Mold. FIG. 66. -Mold for Compression Test Pieces. 39. The molds should be wiped with an oily cloth before using. MIXING. 40. The proportions of sand and cement should be stated by weight; the quantity of water should be stated as a percentage by weight of the dry material. 41. The metric system is recommended because of the convenient relation of the gram and the cubic centimeter. 42. The temperature of the room and of the mixing water should be maintained as nearly as practicable at 21 C. (70 F.). * This sand may now (1912) be obtained from the Ottawa Silica Co., at a cost of two cents per pound, f. o. b. cars, Ottawa, 111. 258 43. The quantity of material to be mixed at one time depends on the number of test pieces to be made; 1,000 grams is a convenient quan- tity to mix by hand methods. 44. The Committee has investigated the various mechanical mix- ing machines thus far devised, but cannot recommend any of them, for the following reasons: (i) the tendency of most cement is to "ball up" in the machine, thereby preventing working it into a homo- geneous paste; (2) there are no means of ascertaining when the mix- ing is complete without stopping the machine; and (3) it is difficult to keep the machine clean. 45. Method. The material is weighed, placed on a non-absorbent surface (preferably plate glass), thoroughly mixed dry if sand be used, and a crater formed in the center, into which the proper per- centage of clean water is poured ; the material on the outer edge is turned into the center by the aid of a trowel. As soon as the water has been absorbed, which should not require more than i minute, the operation is completed by vigorously kneading with the hands for i minute. During the operation the hands should be protected by rubber gloves. MOLDING. 46. The Committee has not been able to secure satisfactory results with existing molding machines ; the operation of machine molding is very slow; and is not practicable with pastes or mortars containing as large percentages of water as herein recommended. 47. Method. Immediately after mixing, the paste or mortar is placed in the molds with the hands, pressed in firmly with the fingers, and smoothed off with a trowel without ramming. The material should be heaped above the mold, and, in smoothing off, the trowel should be drawn over the mold in such a manner as to exert a moderate pressure on the material. The mold should then be turned over and the opera- tion of heaping and smoothing off repeated. 48. A check on the uniformity of mixing and molding may be afforded by weighing the test pieces on removal from the moist closet; test pieces from any sample which vary in weight more than 3 per cent, from the average should not be considered. STORAGE OF THE TEST PIECES. 49. During the first 24 hours after molding, the test pieces should be kept in moist air to prevent drying. 50. Two methods are in common use to prevent drying: (i) cov- ering the test pieces with a damp cloth, and (2) placing them in a moist closet. The use of the damp cloth, as usually carried out, is objectionable, because the cloth may dry out unequally and in conse- 259 quence the test pieces will not all be subjected to the same degree of moisture. This defect may be remedied to some extent by immersing the edges of the cloth in water; contact between the cloth and the test pieces should be prevented by means of a wire screen, or some similar arrangement. A moist closet is so much more effective in securing uniformly moist air, and is so easily devised and so inexpen- sive, that the use of the damp cloth should be abandoned. Roller turned and accurately bored to easy turning fit FIG. 67. Form of Clip. 51. A moist closet consists of a soapstone or slate box, or a wooden box lined with metal, the interior surface being covered with felt or broad wicking kept wet, the bottom of the box being kept covered with water. The interior of the box is provided with glass shelves on which to place the test pieces, the shelves being so arranged that they may be withdrawn readily. 260 52. After 24 hours in moist air, the pieces to be tested after longer periods should be immersed in water in storage tanks or pans made of non-corrodible material. 53. The air and water in the moist closet and the water in the storage tanks should be maintained as nearly as practicable at 21 C. (70 P.). TENSILE STRENGTH. 54. The tests may be made with any standard machine. 55. The clip is shown in Fig. 67. It must be made accurately, the pins and rollers turned, and the rollers bored slightly larger than the pins so as to turn easily. There should be a slight clearance at each end of the roller, and the pins should be kept properly lubricated and free from grit. The clips should be used without cushioning at the points of contact. 56. Test pieces should be broken as soon as they are removed from the water. Care should be observed in centering the test pieces in the testing machine, as cross strains, produced by imperfect centering, tend to lower the breaking strength. The load should not be applied too suddenly, as it may produce vibration, the shock from which often causes the test pieces to break before the ultimate strength is reached. The bearing surfaces of the clips and test pieces must be kept free from grains of sand or -dirt, which would prevent a good bearing. The load should be applied at the rate of 600 pounds per minute. The average of the results of the test pieces from each sample should be taken as the test of the sample. Test pieces which do not break within J4 inch of the center, or are otherwise manifestly faulty, should be excluded in determining average results. COMPRESSIVE STRENGTH. 57. The tests may be made with any machine provided \vith means for so applying the load that the line of pressure is along the axis of the test piece. A ball-bearing block for this purpose is shown in Fig. 68. Some appliance should be provided to facilitate placing the axis of the test piece exactly in line with the center of the ball-bearing. 58. The test piece should be placed in the testing machine, with a piece of heavy blotting paper on each of the crushing faces, which should be those that were in contact with the mold. CONSTANCY OF VOLUME. 59. Significance. The object is to detect those qualities which tend to destroy the strength and durability of a cement. Under normal conditions these defects will in some cases develop quickly, and in 26 1 other cases may not develop for a considerable time. Since the detec- tion of these destructive qualities before using the cement in con- struction is essential, tests are made not only under normal conditions but under artificial conditions created to hasten the development of these defects. Tests may, therefore, be divided into two classes : (i) Normal tests, made in either air or water maintained, as nearly -as practicable, at 21 C. (70 F.) ; and (2) Accelerated tests, made in ^%^%^ FIG. 68. Ball-bearing Block for Testing Machine. air, steam or water, at temperature of 45 C. (113 F.) and upward. The Committee recommends that these tests be made in the following manner : 60. Methods. Pats, about 3 inches in diameter, % inch thick at the center, and tapering to a thin edge, should be made on clean glass plates (about 4 inches square) from cement paste of normal consist- ency, and stored in a moist closet for 24 hours. 61. Normal Tests. After 24 hours in the moist closet, a pat is immersed in water for 28 days and observed at intervals. A similar 262 pat, after 24 hours in the moist closet, is exposed to the air for 28 days or more and observed at intervals. 62. Accelerated Test. After 24 hours in the moist closet, a pat is placed in an atmosphere of steam, upon a wire screen I inch above boiling water, for 5 hours. The apparatus should be so constructed that the steam will escape freely and atmospheric pressure be main- tained. Since the type of apparatus used has a great influence on the results, the arrangement shown in Fig. 69 is recommended. 63. Pats which remain firm and hard and show no signs of crack- ing distortion, or disintegration are said to be "of constant volume" or "sound." 64. Should the pat leave the plate, distortion may be detected best with a straight-edge applied to the surface which was in contact with the plate. 65. In the present state of our knowledge it cannot be said that a cement which fails to pass the accelerated test will prove defective in the work ; nor can a cement be considered entirely safe simply because it has passed these tests. METHODS FOR TESTING CEMENT. 1 Condensed for Use in Specifications. i. SAMPLING. Cement in barrels shall be sampled through a hole made in the head, or in one of the staves midway between the heads, by means of an auger or a sampling iron similar to that used by sugar inspectors; if in bags, the sample shall be taken from surface to center. Cement in bins shall be sampled in such a manner as to represent fairly the contents of the bin. The number of samples taken shall be as directed by the engineer, who will determine whether the samples shall be tested separately or mixed. The samples shall be passed through a sieve having twenty meshes per linear inch, in order to break up lumps and remove foreign material. 2. CHEMICAL, ANALYSIS. The methods to be followed, except for determining the loss on ignition, should be those proposed by the Committee on Uniformity in the Analysis of Materials for the Portland Cement Industry, re- ported in the Journal of the Society for Chemical Industry, Vol. 21, p. 12, 1902, and published in Engineering News, Vol. 50, p. 60, 1903, and in Engineering Record, Vol. 48, p. 49, 1903, and in addition thereto the following: 1 Accompanying Final Report of Special Committee on Uniform Tests of Cement of the American Society of Civil Engineers, dated January 17, 1912. 263 * fed \ If 1 . i ^ ^ i llJ_ t ir^ ^ \ ! ( ^ ^.l-ft - > ! K;*- : 7,9 i ! I j 1 kl IFTj // i Re \ 5 il 111 *\i ill / rrHfe ^r-F S oJ |i li 5^ 2 rr 264 (a) The insoluble residue may be determined as follows : To a i -gram sample of the cement are added 30 cubic centimeters of water and 10 cubic centimeters of concentrated hydrochloric acid, and then warmed until effervescence ceases, and digested on a steam bath until dissolved. The residue is filtered, washed with hot water, and the filter paper and contents digested on the steam bath in a 5 per cent, solution of sodium carbonate. This residue is filtered, washed with hot water, then with hot hydrochloric acid, and finally with hot water, and then ignited at a red heat and weighed. The quantity so obtained is the insoluble residue. (&) The loss on ignition shall be determined in the following manner : One-half gram of cement is heated in a weighed platinum crucible, with cover, for 5 minutes with a Bunsen burner (starting with a low flame and gradually increasing to its full height) and then heated for 15 minutes with a blast lamp; the difference between the weight after cooling and the original weight is the loss on ignition. The temperature should not exceed 900 C., or a low red heat ; the ignition should preferably be made in a muffle. 3. SPECIFIC GRAVITY. The determination of specific gravity shall be made with a stand- ardized Le Chatelier apparatus. This consists of a flask (D), Fig. 62, p. 251, of about 120 cubic centimeters capacity, the neck of which is about 20 centimeters long; in the middle of this neck is a bulb (C), above and below which are two marks (F) and (B) ; the volume between these two marks is 20 cubic centimeters. The neck has a diameter of 9 millimeters, and is graduated into tenths of cubic centi- meters above the mark (F). Benzene (62 Baume naphtha) or kerosene free from water shall be used in making the determination. The flask is filled with either of these liquids to the lower mark () and 64 grams of cement, cooled to the temperature of the liquid, is slowly introduced through the funnel (B), the stem of which should be long enough to extend into the flask to the top of the bulb (C), taking care that the cement does not adhere to the sides of the flask, and that the funnel does not touch the liquid. After all the cement is introduced, the level of the liquid will rise to some division of the graduated neck; this reading, plus 20 cubic centimeters, is the volume displaced by 64 grams of the cement. The specific gravity is obtained from the formula, Weight of cement, in grams Spec ic gravity = Displaced volume> j n cu bi c centimeters. The flask, during the operation, is kept immersed in water in a jar (A) in order to avoid variations in the temperature of the liquid in the flask, which shall not exceed T / 2 C. The results of repeated tests shall agree within o.oi. The determination of specific gravity shall be made on the cement as received; if it should fall below 3.10, a second determination shall be made after igniting the sample in a covered dish, preferably of platinum, at a low red heat not exceeding 900 C. The sample shall be heated for 5 minutes with a Bunsen burner (starting with a low flame and gradually increasing to its full height) and then heated for 15 minutes with a blast lamp; the ignition should preferably be made in a muffle. 4. FINENESS. The fineness shall be determined by weighing the residue retained on No. 100 and No. 200 sieves. The sieves, 8 inches in diameter, shall be of brass wire cloth conforming to the following requirements : No. of sieve Diameter of wire, inches Meshes, per linear inch Warp Woof 100 200 0.0042 to 0.0048 0.0021 to 0.0023 95 to ioi 192 to 203 93 to 10 3 190 to 205 The meshes in any smaller space, down to 0.25 inch, shall be pro- portional in number. Fifty grams of cement, dried at a temperature of 100 C. (212 F.), shall be placed on the No. 200 sieve, which, with pan and cover attached, is held in one hand in a slightly inclined position, and moved forward and backward about 200 times per minute, at the same time striking the side gently, on the up stroke, against the palm of the other hand. The operation is continued until not more than 0.05 gram will pass through in I minute. The residue is weighed, then placed on the No. 100 sieve, and the operation repeated. The work may be expedited by placing in the sieve a few large steel shot, which should be removed before the final I minute of sieving. The sieves should be thoroughly dry and clean. 5. NORMAI, CONSISTENCY. The amount of water, expressed in percentage by weight of the dry cement, required to produce a paste 1 of the plasticity desired, termed "normal consistency," shall be determined with the Vicat apparatus : 1 The term "paste" is used in these specifications to designate a mixture of cement and water, and the word "mortar" to designate a mixture of cement, sand and water. 266 This consists of a frame (A), Fig. 63, p. 253, bearing a movable rod (#), weighing 300 grams, one end (C) being I centimeter in diameter for a distance of 6 centimeters, the other having a removable needle (D), i millimeter in diameter, 6 centimeters long. The rod is reversible, and can be held in any desired position by a screw (), and has midway between the ends a mark (F) which moves under a scale (graduated to millimeters) attached to the frame (A). The paste is held in a conical, hard-rubber ring ((7), 7 centimeters in diam- eter at the base, 4 centimeters high, resting on a glass plate (H ) about 10 centimeters square. In making the determination of normal consistency, the same quantity of cement as will be used subsequently for each batch in making the test pieces, but not less than 500 grams, together with a measured amount of water, is kneaded into a paste, as described in Section 9, and quickly formed into a ball with the hands, completing the operation by tossing it six times from one hand to the other, main- tained about 6 inches apart; the ball resting in the palm of one hand is pressed into the larger end of the rubber ring held in the other hand, completely filling the ring with paste; the excess at the larger end is then removed by a single movement of the palm of the hand; the ring is then placed on its larger end on a glass plate and the excess paste at the smaller end is sliced off at the top of the ring by a single oblique stroke of a trowel held at a slight angle with the top of the ring. During these operations care must be taken not to compress the paste. The paste confined in the ring, resting on the plate, is placed under the rod, the larger end of which is carefully brought in contact with the surface of the paste ; the scale is then read, and the rod quickly released. The paste is of normal consistency when the cylinder settles to a point 10 millimeters below the original surface in Y? minute after being released. The apparatus must be free from all vibrations during the test. Trial pastes are made with varying percentages of water until the normal consistency is attained. Having determined the percentage of water required to produce a paste of normal consistency, the percentage required for a mortar containing, by weight, I part of cement to 3 parts of standard Ottawa sand, shall be obtained from the following table, the amount being a percentage of the combined weight of the cement and sand. 267 PERCENTAGE OF WATER FOR STANDARD MORTARS. Neat One cement, three standard Ottawa sand Neat One cement, three standard Ottawa sand Neat One cement, three standard Ottawa sand 15 8.0 23 9-3 31 10.7 16 8.2 24 9-5 32 10.8 17 8-3 25 9-7 33 II.O 18 8.5 26 9.8 34 II. 2 19 8.7 27 IO.O 35 "3 2O 8.8 28 10.2 36 H-5 21 9.0 29 I0. 3 37 ii. 7 22 9.2 30 10.5 38 ix.8 6. TIME; OF SETTING. The time of setting shall be determined with the Vicat apparatus in the following manner: A paste of normal consistency is molded in the hard-rubber ring, as described in Section 5, and placed under the rod (5), the smaller end of which is then carefully brought in contact with the surface of the paste, and the rod quickly released. The cement is considered to have acquired its initial set when the needle ceases to pass a point 5 millimeters above the glass plate ; and the final set, when the needle does not sink visibly into the paste. The test pieces must be kept in moist air during the test. 7. STANDARD SAND. The sand shall be natural sand from Ottawa, 111., screened to pass a No. 20 sieve, and retained on a No. 30 sieve. The sieves shall be at least 8 inches in diameter, and the wire cloth shall be of brass wire and shall conform to the following requirements : No. of sieve Diameter of wire, inches Meshes, per linear inch Warp Woof 20 30 0.016 to 0.017 O.OII tO 0.012 19.5 to 20.5 29-5 to 30.5 19 tO 21 28.5 to 31.5 Sand which has passed the No. 20 sieve is standard when not more than 5 grams pass the No. 30 sieve in I minute of continuous sifting of a 5OO-gram sample. 1 1 This sand may now (1912) be obtained from the Ottawa Silica Co., at a cost of two cents per pound, f . o. b. cars, Ottawa, 111. 268 8. FORM OE TEST PIECES. For tensile tests, the form of test pieces shown in Fig. 64, p. 256^. shall be used. For compressive tests, 2-inch cubes shall be used. 9. MIXING AND MOLDING. The material shall be weighed, placed on a non-absorbent surface, thoroughly mixed dry if sand be used, and a crater formed in the center, into which the proper percentage of clean water shall be poured; the material on the outer edge shall be turned into the center by the aid of a trowel. As soon as the water has been absorbed, the operation of mixing shall be completed by vigorously kneading with the hands for I minute. Immediately after mixing, the paste or mortar shall be placed in the mold (Figs. 65 and 66, p. 257) with the hands, pressed in firmly with the fingers, and smoothed off with a trowel without ramming. The material shall be heaped above the mold, and, in smoothing off,, the trowel shall be drawn over the mold in such a manner as to exert a moderate pressure on the material ; the mold shall then be turned over and the operation of heaping and smoothing off repeated. The temperature of the room and of the mixing water shall be maintained as nearly as practicable at 21 C. (70 F.). 10. STORAGE OF THE TEST PIECES. During the first 24 hours after molding, the test pieces shall be stored in a moist closet. This consists of a box of soapstone or slate, or of wood lined with metal, the interior surface being covered with felt or broad wicking kept wet, the bottom of the box being kept cov- ered with water. The interior of the box is provided with glass shelves on which to place the test pieces, the shelves being so arranged that they may be withdrawn readily. Test pieces from any sample which vary more than 3 per cent, in weight from the average, after removal from the moist closet, shall not be considered in determining strength. After 24 hours in the moist closet, the pieces to be tested after longer periods shall be immersed in water in storage 'tanks or pans made of non-corrodible material. The air and water in the moist closet and the water in the storage tanks shall be maintained, as nearly as practicable, at 21 C. (70 F.). 11. TESTS OF TENSILE STRENGTH. The tests may be made with any standard machine. The clip is shown in Fig. 67, p. 259. It must be made accurately, the pins and rollers turned, and the rollers bored slightly larger than 269 the pins so as to turn easily. There should be a slight clearance at each end of the roller, and the pins should be kept properly lubricated and free from grit. The clips shall be used without cushioning at the points of contact. The test pieces shall be broken as soon as they are removed from the water. The load shall be applied at the rate of 600 pounds per minute. Test pieces which do not break within J4 inch of the center, or are otherwise manifestly faulty, shall be excluded in determining average results. 12. TESTS OF COMPRESSIVE STRENGTH. The tests may be made with any machine provided with means for so applying the load that the line of pressure is along the axis of the test piece. A ball-bearing block for this purpose is shown in Fig. 68, p. 261. The test pieces as soon as they are removed from the water shall be placed in the testing machine, with a piece of heavy blotting paper on each of the crushing faces, which should be those that were in contact with the mold. 13. CONSTANCY OF VOLUME. Tests for constancy of volume comprise "normal tests" which are made in air or water, maintained as nearly as practicable,, at 21 C. (70 F.), and the "accelerated test," which is made in steam. These tests shall be made in the following manner : Pats about 3 inches in diameter, ~*/2 inch thick at the center, and tapering to a thir edge, shall be made on clean glass plates (about 4 inches square) from cement paste of normal consistency, and stored in a moist closet for 24 hours. Normal Tests. After 24 hours in the moist closet, a pat is im- mersed in water and observed at intervals. A similar pat, after 24 hours in the moist closet, is exposed to the air for 28 days or more and observed at intervals. The air and water are maintained, as nearly as practicable, at 21 C. (70 F.). Accelerated Test. After 24 hours in the moist closet, a pat is placed in an atmosphere of steam, upon a wire screen I inch above boiling water, for 5 hours, the apparatus being such that the steam will escape freely and atmospheric pressure be maintained. The apparatus is shown in Fig. 69, p. 263. The cement passes these tests when the pats remain firm and hard, with no signs of cracking, distortion, or disintegration. 18 270 APPENDIX. METHODS FOR THE CHEMICAL ANALYSIS OF LIMESTONES, RAW MIXTURES AND PORTLAND CEMENTS. Recommended by the Committee on Uniformity in Technical Analysis of the New York Section of the Society for Chemical Industry. Solution. One-half gram of the finely powdered substance is to- be weighed out and, if a limestone or unburned mixture, strongly ignited in a covered platinum crucible over a strong blast for 15 minutes, or longer if the blast is not powerful enough to effect com- plete conversion to a cement in this time. It is then transferred to an evaporating dish, preferably of platinum for the sake of celerity in evaporation, moistened with enough water to prevent lumping, and 5 to 10 cubic centimeters of strong HC1 added and digested with the aid of gentle heat and agitation until solution is complete. Solution may be aided by light pressure with the flattened end of a glass rod. 1 The solution is then evaporated to dryness, as far as this may be possible on the bath. Silica (5V0 2 ). The residue without further heating is treated at first with 5 to 10 cubic centimeters of strong HC1, which is then diluted to half strength or less, or upon the residue may be poured at once a larger volume of acid of half strength. The dish is then covered and digestion allowed to go on for 10 minutes on the bath, after which the solution is filtered and the separated silica washed thoroughly with water. The filtrate is again evaporated to dryness, the residue without further heating, taken up with acid and water and the small amount of silica it contains separated on another filter paper. The papers containing the residue are transferred wet to a weighed platinum, crucible, dried, ignited, first over a Bunsen burner until the carbon of the filter is completely consumed, and finally over the blast for 15 minutes and checked by a further blasting for 10 minutes or to constant weight. The silica, if great accuracy is desired, is treated in the crucible with about 10 cubic centimeters of HF1 and four drops of H 2 SO4 and evaporated over a low flame to complete dryness. The small residue is finally blasted, for a minute or two, cooled and weighed. The difference between this weight and the weight previously obtained gives the amount of silica. 2 1 If anything remains undecomposed it should be separated, fused with a little Na 2 COo, dissolved and added to the original solution. Of course a small amount of separated non-gelatinous silica is not to be mistaken for undecomposed matter. 2 For ordinary control in the plant laboratory this correction may, perhaps, be neg- lected; the double evaporation never. 271 Alumina and Iron (A1 2 3 and Fe z O 3 ). The filtrate, about 250 cubic centimeters, from the second evaporation for SiOz, is made alka- line with NHUOH after adding HC1, if need be, to insure a total of 10 to 15 cubic centimeters strong acid, and boiled to expel excess of NH 3 , or until there is but a faint odor of it, and the precipitate iron and aluminum hydrates, after settling, are washed once by decanta- tion and slightly on the filter. Setting aside the filtrate, the precipitate is dissolved in hot dilute HC1, the solution passing into the beaker in which the precipitation was made. The aluminum and iron are then reprecipitated by NHUOH, boiled and the second precipitate collected and washed on the same filter used in the first instance. The filter paper, with the precipitate, is then placed in a weighed platinum crucible, the paper burned off and the precipitate ignited and finally blasted 5 minutes, with care to prevent reduction, cooled and weighed as A1 2 O 3 -f FesOs. 1 Iron (Fe^Os). The combined iron and aluminum oxides are fused in a platinum crucible at a very low temperature with about 3 to 4 grams of KHSO<, or, better, NaHSO-i, the melt taken up with so much dilute H 2 SO4 that there shall be no less than 5 grams absolute acid and enough water to effect solution on heating. The solution is then evaporated and eventually heated till acid fumes come off copiously. After cooling and redissolving in water the small amount of silica is filtered out, weighed and corrected by HF1 and HzSCk 2 The filtrate is reduced by zinc, or preferably by hydrogen sulphide, boiling out the excess of the latter afterwards while passing CO 2 through the flask, and titrated with permanganate. 3 The strength of the perman- ganate solution should not be greater than 0.0040 gram Fe 2 O 3 per cubic centimeter. Lime (CaO). To the combined filtrate from the A1 2 O 3 + Fe 2 O 3 precipitate a few drops of NH 4 OH are added, and the solution brought to boiling. To the boiling solution 20 cubic centimeters of a saturated solution of ammonium oxalate are added, and the boiling continued until the precipitated CaCaCX assumes a well-defined granular form. It is then allowed to stand for 20 minutes, or until the precipitate has settled, and then filtered and washed. The precipitate and filter are placed wet in a platinum crucible, and the paper burned off over a small flame of a Bunsen burner. It is then ignited, redissolved in HC1, and the solution made up to 100 cubic centimeters with water. 1 This precipitate contains TiO 2 , P2O 5 , Mn 3 O 4 . * This correction of A1 2 O 3 Fe 2 O 3 for silica should not be made when the HF1 cor- rection of the main silica has been omitted, unless that silica was obtained by only one evaporation and nitration. After two evaporations and nitrations i to 2 mg. of SiO are still to be found with the A1 2 O 3 Fe 2 O 3 . 3 In this way only is the influence of titanium to be avoided and a correct result obtained for iron. 272 Ammonia is added in slight excess, and the liquid is boiled. If a small amount of A1 2 O 3 separates this is filtered out, weighed, and the amount added to that found in the first determination, when greater accuracy is desired. The lime is then reprecipitated by ammonium oxalate, allowed to stand until settled, filtered and washed, 1 weighed as oxide by ignition and blasting in a covered crucible to constant weight, or determined with dilute standard permanganate. 2 Magnesia (MgO). The combined filtrates from the calcium pre- cipitates are acidified with HC1 and concentrated on the steam bath to about 150 cubic centimeters, 10 cubic centimeters of saturated solution of Na(NH 4 )HPO 4 are added, and the solution boiled for several minutes. It is then removed from the flame and cooled by placing the beaker in ice water. After cooling, NH 4 OH is added drop by drop with constant stirring until the crystalline ammonium-magnesium orthophosphate begins to form, and then in moderate excess, the stirring being continued for several minutes. It is then set aside for several hours in a cool atmosphere and filtered. The precipitate is redissolved in hot dilute HC1, the solution made up to about 100 cubic centimeters, I cubic centimeter of a saturated solution of Na(NH 4 )HPO4 added, and ammonia drop by drop, with constant stirring until the precipitate is again formed as described and the ammonia is in moderate excess. It is then allowed to stand for about 2 hours, when it is filtered on a paper or a Gooch crucible, ignited, cooled and weighed as M^PaOi. Alkalies (K 2 and A^a 2 0). For the determination of the alkalies, the well-known method of Prof. J. Lawrence Smith is to be followed, either with or without the addition of CaCO 3 with NH 4 C1. Anhydrous Sulphuric Acid (SOa), One gram of the substance is dissolved in 15 cubic centimeters of HC1, filtered and residue washed thoroughly. 3 The solution is made up to 250 cubic centimeters in a beaker and boiled. To the boiling solution 10 cubic centimeters of a saturated solution of BaCl 2 is added slowly drop by drop from a pipette and the boiling continued until the precipitate is well formed, or digestion on the steam bath may be substituted for the boiling. It is then set aside over night, or for a few hours, filtered, ignited and weighed as BaSCX. Total Sulphur. One gram of the material is weighed out in a large platinum crucible and fused with Na 2 CO s and a little KNO 3 , being careful to avoid contamination from sulphur in the gases from source of heat. This may be done by fitting the crucible in a hole in 1 The volume of wash-water should not be too large; vide Hillebrand. - The accuracy of this method admits of criticism, but its convenience and rapidity demand its insertion. 3 Evaporation to dryness is unnecessary, unless gelatinous silica should have sep- arated and should never be performed on a bath heated by gas; vide Hillebrand. 273 an asbestos board. The melt is treated in the crucible with boiling water and the liquid poured into a tall narrow beaker and more hot water added until the mass is disintegrated. The solution is then filtered. The filtrate contained in a No. 4 beaker is to be acidulated with HC1 and made up to 250 cubic centimeters with distilled water, boiled, the sulphur precipitated as BaSO* and allowed to stand over night or for a few hours. Loss on Ignition. Half a gram of cement is to be weighed out in a platinum crucible, placed in a hole in an asbestos board so that about three-fifths of the crucible projects below, and blasted 15 min- utes, preferably with an inclined flame. The loss by weight, which is checked by a second blasting of 5 minutes, is the loss on ignition. May, 1903 : Recent investigations have shown that large errors in results are often due to the use of impure distilled water and reagents. The analyst should, therefore, test his distilled water by evaporation and his reagents by appropriate tests before proceeding with his work. STEEL. METHODS OF CHEMICAL ANALYSIS FOR PLAIN CARBON STEEL, AS PUBLISHED BY THE AMERICAN SOCIETY FOR TESTING MATERIAL. ADOPTED, 1914. DETERMINATION OF CARBON BY THE DlRECT-COMBUSTION METHOD. The method of direct combustion of the metal in oxygen is recommended, the carbon dioxide obtained being absorbed in barium-hydroxide solution, the precipitated barium carbon- ate filtered off, washed, dissolved in a measured excess of hydrochloric acid and the excess titrated against standard alkali. The use of potassium-hydroxide solution or soda lime for the absorption of carbon dioxide, with suitable purifying train following the furnace, is recognized as being capable of very satisfactory refinement and as possessing merit where the time element is of prime significance. Owing to the diversity of apparatus by which correct results may be obtained in the determination of carbon, the recom- 274 mendations are intended more to indicate what is acceptable than to prescribe definitely what shall be used. Apparatus. Purifying Train. The method employed eliminates the necessity of a purifying train following the furnace, inasmuch as no precautions are necessary to prevent access of water vapor, or sulphur trioxide the impurities usually guarded against from the absorbing apparatus. All that is needed is a calcium-chloride tower filled with stick sodium hydroxide placed before the furnace, or between the furnace and cata- lyzer, if, as recommended, the latter is used for the purpose of oxidizing organic matter in the oxygen. Material for Lining Boats. Alundum, "RR Alundum, al- kali-free, specially prepared for carbon determination," as sup- plied by dealers is suitable, and is recommended. The 90- mesh or finer grades are used. Chromite, properly sized and freed from materials causing a blank, may also be employed. No substance containing alkali or alkaline earth metals, or car- bon as carbonates or in other form, should be used as a lining material. Quartz sand, owing to its liability to fuse or to slag with the oxides of iron, causing bubbles of gas to be enclosed, is objectionable. Aluminum oxide, made by calcining alum or otherwise, often contains sulphate not easily destroyed, or may contain objectionable substances of an alkaline nature. Catalyzers. Suitable catalyzers are copper oxide, platinized quartz or asbestos, or platinum gauze. One of these should be used in the forward part of the combustion apparatus, as well as in the purifying train preceding the combustion tube (see above). Platinized materials sometimes give off volatile sub- stances on heating, and whatever material is used should not be subject to this defect. Combustion Apparatus. Any apparatus heated by gas or electricity which will bring the sample to a temperature of 950 to 1,100 C. may be used. Combustion tubes may be porce- lain, glazed on one or both sides, quartz or platinum. Quartz is liable to devitrification when used continuously at tempera- 275 tures above 1,000 C., and may then become porous. Com- bustion crucibles of platinum may be heated by blast or by Meker burners. Boats or Other Containers of Samples being Burned. These may be of porcelain, quartz, alundum, clay, platinum, or nickel, and should always receive a lining of granular alun- dum. Purifying Train before Combustion Apparatus. This con- sists of a tower filled with stick sodium hydroxide, preceded by a catalyzer. The Train after the Combustion Apparatus. This consists merely of the Meyer tube for absorption of the carbon dioxide, protected by a soda-lime tube at the far end. Meyer tubes with 7 to 10 bulbs of 10 to 15 cubic centimeter capacity each, and large bulbs at the ends, having volumes equal to the com- bined capacity of the small bulbs, have been used and found satisfactory. FIG. 70. Apparatus for Filtration in Determination of Carbon by the Direct-Combustion Method. Filtering Apparatus. In filtration for accurate work, care should be taken to protect the solution from access of extra- neous carbon dioxide. This is accomplished in the apparatus shown in Fig. 70. For work requiring less accuracy, the barium 276 carbonate may be filtered off on a filter made by fitting a car- bon funnel with a perforated porcelain disk and filtering by suction. The precipitate is then washed with distilled water from which the carbon dioxide has been removed by boiling. Reagents. Oxygen. Oxygen of not less than 97 per cent, purity is recommended. Endeavor should be made to obtain oxygen which gives no blank, since the correction for or elimination of this is troublesome and uncertain. For the most accurate work, particularly with low-carbon products, such as ingot iron, etc., the blank should be completely eliminated by the use of a catalyzer before the furnace, with a carbon-dioxide ab- sorbent interposed between furnace and catalyzer. Tenth-normal Hydrochloric Acid. This may be standard- ized by any of the accepted methods, or as follows : Twenty cubic centimeters of the approximately N/io acid is measured out with a pipette, and the silver chloride precipitated by an excess of silver-nitrate solution in a volume of 50 to 60 cubic centimeters. After digesting at 70 to 80 C., until the super- natant liquid is clear, the chloride is filtered off on a tared Gooch filter and washed with water containing 2 cubic centi- meters of nitric acid per 100 cubic centimeters of water until freed from silver nitrate. After drying to constant weight at 130 C., the increase of weight over the original tare is noted and from this weight, corresponding to the silver chlo- ride, the strength of the hydrochloric acid is calculated, after which it is adjusted to the strength prescribed. The standard- ization should be based upon several concordant determinations using varying amounts of acid. i cc. N/io HC1 = 0.0006 g. carbon. Methyl Orange. Dissolve 0.02 gram in 100 cubic centi- meters of hot distilled water and filter. Tenth-normal Sodium-Hydroxide Solution. This is stand- ardized against the hydrochloric acid. Methyl orange is used as the indicator. The sodium-hydroxide solution should be stored in a large bottle from which it may be driven out by air 277 pressure, protecting against carbon dioxide by soda-lime tubes. Barium-Hydroxide Solution. A saturated solution is fil- tered and stored in a large reservoir from which it is delivered by air pressure, protecting from carbon dioxide by a soda-lime tube. Three or four small bulbs of the Meyer tube are filled, and CO 2 -free water is added until the remaining small bulbs are filled. Factors Influencing Rapid Combustion. Size of Particles of Sample. The finer the chips the better, except with samples which burn too vigorously (see under "Rate of Admitting Oxygen"). Particles too coarse to pass a 2O-mesh sieve are not recommended, nor long curly drillings which will not pack closely. A ^-inch flat drill may be used for taking the sample and the pressure and speed of the drill- press regulated to secure the desired result ; or, better still, the sample may be obtained with a small milling machine suitable for sampling, or by a shaping machine. Oil, dust, and other foreign matter should be carefully excluded. Manner of Distributing Sample in Boat. This is of con- siderable importance. With all samples, close packing in a small space is conducive to rapid combustion. In the case of samples which burn too vigorously, a satisfactory regulation may sometimes be attained by spreading the sample loosely over the lining in the boat. Rate of Admitting Oxygen. The rate at which oxygen is admitted is also a factor in the velocity of combustion. Assum- ing the combustion apparatus to be heated to the temperature range recommended above (950 to 1,100 C.), it is possible, if the material is closely packed and if oxygen is admitted at too rapid a rate, that the combustion may be so violent as to cause excessive spattering of fused oxides, and such fluidity of the molten slag that the boat or other container may be injured or destroyed; therefore a moderate rate of burning is to be sought. This is desirable also from the standpoint of the com- plete absorption of the carbon dioxide by the barium-hydroxide solution. The factors, temperature of combustion apparatus, 2 7 8 manner of distribution of sample, and rate of admission of oxygen, can be governed so as to burn successfully steels of a very wide range of compositions, in either fine or coarse particles. Method. After having properly set up and tested the apparatus, place 2 grams of steel (see note No. i) in the form recommended above, in a moderately packed condition on the bed material and introduce the boat into the combustion apparatus, already heated to the proper temperature. After about a minute (to allow the sample and container to reach the temperature of the furnace), admit oxygen somewhat more rapidly than it is con- sumed, as shown by the rate of bubbling in the Meyer tube (see note No. 2). The sample burns completely in i or 2 minutes, and all that is now necessary is to sweep all the carbon dioxide into the absorption apparatus. This can be accomplished in 6 to 8 minutes by passing about i or 2 liters of oxygen. De- tach the Meyer tube (see note No. 2) and filter and wash the barium carbonate, using the special filtering apparatus shown. After solution in a measured excess of hydrochloric acid (the Meyer tube being washed out with a portion of the acid, to remove adhering barium carbonate), titrate the excess of acid against alkali and from the data thus obtained calculate the percentage of carbon. NOTES. 1. When working with steels high in carbon (above I per cent.) it is advisable not to use more than I gram in order that nitration may be sufficiently rapid. 2. As a precaution against error resulting from too rapid passage of the gases, it is well to attach a second barium-hydroxide tube to retain any carbon dioxide that may pass the first. 3. For the most accurate work the Meyer tubes should be washed with dilute acid before beginning work each day. After a determina- tion is finished the tube should be completely filled two or three times with tap water, then rinsed with distilled water, in order to remove the carbon dioxide liberated when dissolving the carbonate from the previous determination. 279 4. The flask containing the carbonate should be thoroughly agi- tated after adding the acid, since the carbonate sometimes dissolves rather slowly if this is not done ; this is particularly the case if it has packed much during nitration. Apparatus and Procedure for. Filtration. The apparatus is shown to approximately one-tenth size in Fig. 70, which is self-explanatory. The stop-cock is a three- way cock connected to the suction pipe. The rubber tubing connected to the Meyer tube should be of best-grade black rubber, and the lengths used should be so chosen as to permit of easy manipulation of the tube. The Meyer tube is con- nected or disconnected by the rubber stoppers which are left always attached to the rubber tubes. The carbon tube C is fitted with a perforated porcelain plate sliding easily. The funnel is prepared for filtration by making on the por- celain disk a felt of asbestos about 1 / 16 to 1 / 8 inch in thickness, using amphibole (not serpentine) asbestos which has been carefully digested with strong hydrochloric acid for several hours and washed with water until it gives no acid reaction. On top of the asbestos pad is placed a layer of similarly treated quartz, mixed with asbestos, of the height shown. A mixture of quartz grains of various sizes (approximately 50 per cent, passing a 2O-mesh sieve and 50 per cent, passing a lo-mesh and remaining on a 2O-mesh sieve) is suitable. The mixture of quartz and asbestos may be obtained by filling the funnel from a beaker (directing against it a stream from a wash-bottle) while maintaining a gentle suction. In this way the asbestos is properly mixed with the quartz. A little experience and attention to these details will enable one to prepare the quartz- bed in a manner that will greatly expedite filtration. The stopper is now inserted in the funnel, the Meyer tube connected as shown and the liquid and precipitate sucked into the funnel. Only a gentle suction should be used. When necessary P 3 is opened to admit air back of the column of liquid in the Meyer tube. When the contents of the Meyer tube have been trans- ferred, the large bulb nearest B is half filled with water by open- ing PI ; the stop-cock $ is operated during this and subsequent 2&D operations so as to maintain a gentle suction all the time. M is now manipulated so as to bring the wash water in contact with all parts of the interior, after which the water is sucked through C; P 2 is left open during this and subsequent wash- ings. After eight washings as directed, allowing the wash water to drain off thoroughly each time before adding more, M may be detached, the stopper removed from the funnel and the washings completed by filling C to the top with CO 2 -free water, sucking off completely and repeating the operation once. With care the washing may be done with 150 cubic centimeters of water. Air is now admitted through the side opening of $, C is removed and the porcelain disk carrying the asbestos, quartz and barium carbonate is thrust, by means of a long glass rod, into a flask, removing any adhering particles from the sides of C, by a stream of water from a wash bottle. An ex- cess of the standard acid is now added from a burette or pipette, using a portion to wash out M, and after the contents of the flask have been thoroughly agitated by shaking, the ex- cess of acid is titrated against the standard alkali, using 3 drops of the methyl-orange indicator. NOTES. The operation of filtering can be carried out very rapidly after a little practice. Glass wool should on no account be used as a substitute for the quartz, on account of the probability of errors arising from its attack by the alkali or acid. It is well to wash out the rubber tubes connected to the Meyer tube with a little water each day before beginning work. DETERMINATION OF CARBON BY THE COLORIMETRIC METHOD. (Routine.) Solution Required. Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, specific gravity 1.42, and 1,200 cubic centimeters of distilled water. 28l Method. In a small Erlenmeyer flask or test tube, dissolve 0.2 to 0.5 gram of steel, depending on the carbon content of the sample, in 5 to 20 cubic centimeters of the nitric acid. Boil gently until the solution is complete and the liquid is clear. Cool and compare with a solution of a standard steel treated under like conditions. NOTE. In order to obtain reliable results by this method the standard steel should be of the same kind, of approximately the same chemical composition, and in the same physical condition as the sample steel. The carbon content of the standard steel is determined by the direct combustion method. DETERMINATION OF MANGANESE BY THE BISMUTHATE METHOD. Solutions Required. Nitric Acid. Mix 500 cubic centimeters of nitric acid, spe- cific gravity 1.42, and 1,500 cubic centimeters of distilled water. Nitric Acid for Washing. Mix 30 cubic centimeters of nitric acid, specific gravity 1.42, and 970 cubic centimeters of distilled water. Stock Sodium Arsenite. To 15 grams of arsenious acid (As 2 O 3 ) in a 300 cubic centimeter Erlenmeyer flask, add 45 grams of sodium carbonate and 150 cubic centimeters of dis- tilled water. Heat the flask and contents on a water bath until the arsenious acid is dissolved, cool the solution and make up to 1,000 cubic centimeters with distilled water. Standard Sodium Arsenite. Dilute 300 cubic centimeters of stock-sodium-arsenite solution to 1,000 cubic centimeters with distilled water and titrate against potassium permanganate solution (about N/io), which has been standardized by using Bureau of Standards sodium oxalate. 1 Adjust the solution so that i cubic centimeter is equivalent to o.io per cent, of man- ganese, when a i-gram sample is taken. i Circular No. 40, Bureau of Standards, Oct. i, 1912. 282 The factor Na 2 C 2 O 4 ~* Mil = 0.16397 (using the 1913 atomic weights). Method. In a 300 cubic centimeter Erlenmeyer flask dissolve I gram of steel in 50 cubic centimeters of the nitric acid, and boil to expel the oxides of nitrogen. Cool, and add about T / 2 gram of sodium bismuthate and heat for a few minutes, or until the pink color has disappeared, with or without precipitation of manganese dioxide. Add small portions of ferrous sulphate (or any suitable reducing agent) in sufficient quantity to clear the solution, and boil to expel the oxides of nitrogen. Cool to 15 C., add an excess of sodium bismuthate and agitate for a few minutes. Add 50 cubic centimeters of 3 per cent, nitric acid and filter through an alundum filter or asbestos pad, wash- ing with 3 per cent, nitric acid. Titrate immediately with standard-sodium-arsenite solution to the disappearance of the pink color, each cubic centimeter required representing o.io per cent, manganese. NOTES. In the method, the preliminary treatment with sodium bismuthate has been found by a number of investigators to be apparently unneces- sary; however, the available data to confirm this position are not con- sidered sufficient to warrant its omission. In making the asbestos filter pad it is advisable to have a thin bed, and as much surface as possible. This insures rapid filtration, and the filter may be used until it becomes clogged with bismuthate. The filtrate must be perfectly clear, since the least particle of bismuthate carried through the filter will vitiate the results. DETERMINATION OF MANGANESE BY THE PERSULPHATE METHOD. (Routine.) Solutions Required. Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, specific gravity 1.42, and 1,200 cubic centimeters of distilled water. 283 Silver Nitrate. Dissolve 1.33 grams of silver nitrate in 1,000 cubic centimeters of distilled water. Stock Sodium Arsenite. To 15 grams of arsenious acid (As 2 O 3 ) in a 300 cubic centimeter Erlenmeyer flask, add 45 grams of sodium carbonate and 150 cubic centimeters of dis- tilled water. Heat the flask and contents on a water bath until the arsenious acid is dissolved, cool the solution and make up to 1,000 cubic centimeters with distilled water. Standard Sodium Arsenite. Dilute a sufficient quantity of stock-sodium-arsenite solution with distilled water, and stand- ardize against a steel of known manganese content, as deter- mined by the bismuthate method. This solution should be of such strength that each cubic centimeter will be equivalent to o.io per cent, of manganese on the basis of the weight of sample taken. Method. In a small Erlenmeyer flask or large test tube, dissolve o.i to 0.3 gram of steel, depending on the manganese content of the sample, in 15 cubic centimeters of the nitric acid. Boil gen- tly until the solution is complete and the liquid is clear. Add 15 cubic centimeters silver nitrate solution and I gram of am- monium persulphate, and continue heating the solution for T /2 minute after the oxidation begins and bubbles rise freely. Cool in running water and complete the determination by either of the following procedures : (a) C olorimetric . Compare the color of the solution with that of a standard steel treated under like conditions. (b) Titration. Titrate with standard-sodium-arsenite solu- tion to the disappearance of the pink color, each cubic centi- meter required representing o.io per cent, of manganese. NOTES. In order to obtain reliable results by the colorimetric procedure, the standard should be of the same kind and of approximately the same chemical composition as the sample steel. The manganese con- tent of the standard steel is determined by the bismuthate method. The ammonium persulphate should be kept in moistened condition by small additions ot" distilled water at required intervals. 284 DETERMINATION OF PHOSPHORUS BY THE MoiyYBDATE-MAGNESIA METHOD. Solutions Required. Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, specific gravity 1.42, and 1,200 cubic centimeters of distilled water. Nitric Acid for Washing. Mix 20 cubic centimeters nitric acid, specific gravity 1.42, and 1,000 cubic centimeters of dis- tilled water. Potassium Permanganate. Dissolve 25 grams of potassium permanganate in 1,000 cubic centimeters of distilled water. Ammonium Bisulphite. Dissolve 30 grams of ammonium bisulphite in 1,000 cubic centimeters of distilled water. Ammonium Hydroxide, approximately 10 per cent. Mix 1,000 cubic centimeters of ammonium hydroxide, specific grav- ity 0.90, and 2,000 cubic centimeters of distilled water. Ammonium Molybdate Solution No. i. Place in a beaker 100 grams of 85 per cent, molybdic acid, mix it thoroughly with 240 cubic centimeters of distilled water, add 140 cubic centimeters of ammonium hydroxide, specific gravity 0.90, filter, and add 60 cubic centimeters of nitric acid, specific gravity 1.42. Solution No. 2. Mix 400 cubic centimeters of nitric acid, specific gravity 1.42, and 960 cubic centimeters of distilled water. When the solutions are cold, add solution No. I to solution No. 2, stirring constantly; then add o.i gram of ammonium phosphate dissolved in 10 cubic centimeters of distilled water, and let stand at least 24 hours before using. Magnesia Mixture. Dissolve 50 grams of magnesium chlo- ride and 125 grams of ammonium chloride in 750 cubic centi- meters of distilled water, and then add 150 cubic centimeters of ammonium hydroxide, specific gravity 0.90. Method. In a 300 cubic centimeter Erlenmeyer flask dissolve 5 grams of steel in 75 cubic centimeters of the nitric acid. Heat to boiling; while boiling add about 12 cubic centimeters of the potassium-permanganate solution, and continue boiling until manganese dioxide precipitates. Dissolve this precipitate by additions of the ammonium bisulphite solution, boil until clear and free from brown fumes, cool to 35 C., add 100 cubic centimeters of the ammonium-molybdate solution at room tem- perature, let stand I minute, shake or agitate for 3 minutes, filter on a 9-centimeter paper and wash the precipitate at least 3 times with the 2 per cent, nitric-acid solution to free it from iron. Treat the precipitate on the filter with the 10 per cent, am- monium-hydroxide soluion, letting the solution run into a loo-cubic centimeter beaker containing 10 cubic centimeters of hydrochloric acid, specific gravity 1.20, and 0.5 gram of citric acid; add 30 cubic centimeters of ammonium hydroxide, spe- cific gravity 0.90, cool, and then add 10 cubic centimeters of the magnesia mixture very slowly, while stirring the solution vigorously. Set aside in a cool place for 2 hours, filter and wash with the 10 per cent, ammonium hydroxide solution. Ig- nite and weigh. Dissolve the precipitate of magnesium pyro- phosphate with 5 cubic centimeters of nitric acid, specific gravity 1.20, and 20 cubic centimeters of distilled water, filter and wash with hot water. Ignite and weigh. The difference in weights represents pure magnesium pyrophosphate contain- ing 27.84 per cent, of phosphorus. NOTE. The ammonium molybdate solution should be kept in a cool place and should always be filtered before using. DETERMINATION OF PHOSPHORUS BY THE Ai, KALI METRIC METHOD. (Routine.) Solutions Required. Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, 19 286 specific gravity 1.42, and 1,200 cubic centimeters of distilled water. Nitric Acid for Washing. Mix 20 cubic centimeters of nitric acid, specific gravity 1.42, and 1,000 cubic centimeters of distilled water. Potassium Permanganate. Dissolve 25 grams of potassium permanganate in 1,000 cubic centimeters of distilled water. Ammonium Bisulphite. Dissolve 30 grams of ammonium bisulphite in 1,000 cubic centimeters of distilled water. Ammonium Molybdate. Solution No. i. Place in a beaker 100 grams of 85 per cent, molybdic acid, mix it thoroughly with 240 cubic centimeters of distilled water, add 140 cubic centi- meters of ammonium hydroxide, specific gravity 0.90, filter and add 60 cubic centimet ers of nitric acid, specific gravity 1.42. Solution No. 2. Mix 400 cubic centimeters of nitric acid, specific gravity 1.42, and 960 cubic centimeters of distilled water. When the solutions are cold, add solution No. I to solution No. 2, stirring constantly; then add o.i gram of ammonium phosphate dissolved in 10 cubic centimeters of distilled water and let stand at least 24 hours before using. Potassium Nitrate, I per cent. Dissolve 10 grams of potas- sium nitrate in 1,000 cubic centimeters of distilled water. Phenolphthalein Indicator. Dissolve 0.2 gram in 50 cubic centimeters of 95 per cent, ethyl alcohol and 50 cubic centi- meters of distilled water. Standard Sodium Hydroxide. Dissolve 6.5 grams of puri- fied sodium hydroxide in 1,000 cubic centimeters of distilled water, add a slight excess of I per cent, solution of barium hydroxide, let stand for 24 hours, decant the liquid, and standardize it against a steel of known phosphorus content, as determined by the molybdate magnesia method, so that I cubic centimeter will be equivalent to o.oi per cent, of phos- phorus on the basis of a 2-gram sample (see notes). Protect the solution from carbon dioxide with a soda lime tube. Standard Nitric Acid. Mix 10 cubic centimeters of nitric acid, specific gravity 1.42, and 1,000 cubic centimeters of dis- 28; tilled water. Titrate the solution against standardized sodium hydroxide, using phenolphthalein as indicator, and make it equivalent to the sodium hydroxide by adding distilled water. Method. In a 300 cubic centimeter Erlenmeyer flask dissolve 2 grams of steel in 50 cubic centimeters of the nitric acid. Heat the solution to boiling and while boiling add about 6 cubic centi- meters of the potassium permanganate solution and continue boiling until manganese dioxide precipitates. Dissolve this precipitate by addition of the ammonium bisulphite solution, boil until clear and free from brown fumes, cool to 80 C., add 50 cubic centimeters of the ammonium molybdate solu- tion at room temperature, let stand I minute, shake or agitate for 3 minutes, and filter on a 9 centimeter paper. Wash the precipitate three times with the 2 per cent, nitric acid solu- tion to free it from iron, and continue the washing with the I per cent potassium nitrate solution until the precipitate and flask are free from acid. Transfer the paper and precipitate to a solution flask, add 20 cubic centimeters of distilled water, 5 drops of phenol- phthalein solution as indicator, and an excess of standard sodium hydroxide solution. Insert a rubber stopper and shake vigorously until solution of the precipitate is complete. Wash off the stopper with distilled water and determine the excess of sodium hydroxide solution by titrating with standard nitric acid solution. Each cubic centimeter of standard sodium hy- droxide solution represents o.oi per cent, of phosphorus. NOTES. The ammonium molybdate solution should be kept in a cool place and should always be filtered before using. All distilled water used in titration should be freed from carbon dioxide by boiling or otherwise. Bureau of Standards Standard Steel No. 19 (a) is recommended as a suitable steel for standardization of the sodium hydroxide solution. 288 DETERMINATION OF SULPHUR BY THE; OXIDATION METHOD. Solution Required. Barium Chloride. Dissolve 100 grams of barium chloride in 1,000 cubic centimeters of distilled water. Method. In a 400 cubic centimeter beaker dissolve 5 grams of the steel in a mixture of 40 cubic centimeters of nitric acid, spe- cific gravity 1.42, and 5 cubic centimeters of hydrochloric acid, specific gravity 1.20, add 0.5 gram of sodium carbonate and evaporate the solution to dryness. Add 40 cubic centimeters of hydrochloric acid, specific gravity 1.20, evaporate to dry- ness and bake at a moderate heat. After solution of the resi- due in 30 cubic centimeters of hydrochloric acid, specific grav- ity i. 20, and evaporation to sirupy consistency, add 2 to 4 cubic centimeters of hydrochloric acid, specific gravity 1.20, and then 30 to 40 cubic centimeters of hot water. Filter and wash with cold water, the final volume not exceeding 100 cubic centimeters. To the cold filtrate add 10 cubic centi- meters of the barium chloride solution. I^et stand at least 24 hours, filter on a 9 centimeter paper, wash the precipi- tate first with a hot solution containing 10 cubic centimeters of hydrochloric acid, specific gravity 1.20, and I gram barium chloride to the liter, until free from iron; and then with hot water till free from chloride. Ignite and weigh as barium sulphate. Keep the washings separate from the main filtrate and evaporate them to recover any dissolved barium sulphate. NOTE. A blank determination on all reagents used should be made and the results corrected accordingly. DETERMINATION OF SULPHUR BY THE EVOUJTION-TITRATION METHOD. (Routine.) Apparatus. Use a 480 cubic centimeter flask with a delivery tube and a 300 cubic centimeter tumbler of tall form (Fig. 71). 289 Capacity IB 02. 1 1 1 1 1 w , c c. ^^^ Ir^F "^ 1 ~ ~r r^r "i t- i L_ \ V FIG. 71 . Apparatus for Determination of Sulphur by the Evolution Method. Solutions Required. Dilute Hydrochloric Acid. Mix 500 cubic centimeters of hydrochloric acid, specific gravity 1.20, and 500 cubic centi- meters of distilled water. Ammoniacal Cadmium Chloride. Dissolve 10 grams of cadmium chloride in 400 cubic centimeters of distilled water and add 600 cubic centimeters of ammonium hydroxide, spe- cific gravity 0.90. Potassium lodate. Dissolve 1.116 grams of potassium iodate and 12 grams of potassium iodide in 1,000 cubic centi- meters of distilled water. Standardize with a steel of known sulphur content. Each cubic centimeter should be equivalent to o.oi per cent, of sulphur, when a 5 gram sample is used (see notes). 290 Starch. To 1,000 cubic centimeters of boiling distilled water, add a cold suspension of 6 grams of starch in 100 cubic centimeters of distilled water; cool, add a solution of 6 grams of zinc chloride in 50 cubic centimeters of distilled water, and mix thoroughly. Method. Place 5 grams of steel in the flask and connect the latter as shown in Fig. 62. Place 10 cubic centimeters of the ammoniacal FIG. 72. cadmium chloride solution and 150 cubic centimeters of dis- tilled water in the tumbler. Add 80 cubic centimeters of the dilute hydrochloric acid to the flask through the thistle tube, heat the flask with its contents gently until the solution of the steel is complete, then boil the solution for y 2 minute. Re- move the tumbler which contains all the sulphur as cadmium sulphide, and to it add 5 cubic centimeters of starch solution and 40 cubic centimeters of the dilute hydrochloric acid, ti- trating immediately with potassium iodate solution to a per- manent blue color. NOTES. Extremely slow or rapid evolution of hydrogen sulphide is to be avoided. Bureau of Standards Standard Steel No. 8 (a) is recommended for standardizing the potassium iodiate solution. vS /> FIG. 73. Editor's Note. Another very convenient apparatus is shown in Figs. 72 and 73. It can be heated without getting the cadmium chloride solution hot while heating the flask containing the steel. In using this 292 form, 10 cubic centimeters of the cadmium solution are drawn into the tube, Fig. 73, without diluting. After all the H 2 S has been driven over, the tube is disconnected and emptied into a 600 cubic centimeter beaker by pouring it out through a. The tube is then washed by filling it up first with water, then with dilute hydrochloric acid, and again with water. This is best accomplished by holding the nozzle of a wash bottle against b and blowing until the water or acid reaches the top of the tube. Remove wash bottle and empty the tube into beaker as above. DETERMINATION OF SILICON BY THE NITRO-SULPHURIC METHOD. Solutions Required. Nitro-Sulphuric Acid. Mix 1,000 cubic centimeters of sul- phuric acid, specific gravity 1.84, 1,500 cubic centimeters of nitric acid, specific gravity 1.42, and 5,500 cubic centimeters of distilled water. Dilute Hydrochloric Acid. Mix 100 cubic centimeters of hydrochloric acid, specific gravity 1.20, and 900 cubic centi- meters of distilled water. Method. Add cautiously 80 cubic centimeters of the nitro-sulphuric acid to 4.702 grams of steel, in a platinum or porcelain dish of 300 cubic centimeters capacity, cover with a watch glass, heat until the steel is dissolved and evaporate slowly until copious fumes of sulphuric acid are evolved. Cool, add 125 cubic centimeters of distilled water, heat with frequent stirring until all salts are dissolved, add 5 cubic centimeters of hydro- chloric acid, specific gravity 1.20, heat for 2 minutes, and filter on a 9 centimeter paper. Wash the precipitate several times with hot water, then with hydrochloric acid and hot water alternately to complete the removal of iron salts, and finally with hot water until free from acid. .Transfer the filter to a platinum crucible, burn off the paper carefully with the crucible covered, finally igniting over a blast lamp or in a muffle furnace at 1,000 C. for at least 20 minutes; cool in a 293 desiccator and weigh. Add sufficient sulphuric acid, specific gravity 1.84, to moisten the silica and then a small amount of hydrofluoric acid. Evaporate to dryness, ignite arid weigh. The difference in weights in milligrams divided by 100 equals the percentage of silicon. NOTE. A blank determination on all reagents used should be made and the results corrected accordingly. DETERMINATION OF SILICON BY THE SULPHURIC ACID METHOD. (Optional.) Solution Required. Dilute Hydrochloric Acid. Mix 100 cubic centimeters of hydrochloric acid, specific gravity 1.20, and 900 cubic centi- meters of distilled water. Method. To 2.351 grams of steel, in a beaker of low form of 500 cubic centimeters capacity, add 60 cubic centimeters of dis- tilled water, and then cautiously 15 cubic centimeters of sul- phuric acid, specific gravity 1.84. Cover with a watch glass, heat until the steel is dissolved and evaporate until copious fumes of sulphuric acid are evolved. Cool, add 100 cubic centimeters of distilled water and heat with frequent stirring until the salts are in solution. Filter on a 9 centimeter paper, wash the precipitate several times with cold water, then with cold dilute hydrochloric acid until free from iron, and finally with cold water until free from acid. Ignite and weigh. Add sufficient sulphuric acid, specific gravity 1.84, to moisten the silica and then a small amount of hydrofluoric acid. Evapo- rate to dryness, ignite and weigh. The difference in weights in milligrams divided by 50 equals the percentage of silicon. NOTE. A blank determination on all reagents used should be made and the results corrected accordingly. 294 DETERMINATION OF COPPER. Solutions Required. Sulphuric Acid. Mix 200 cubic centimeters of sulphuric acid specific gravity X 1.84, and 800 cubic centimeters of distilled water. Potassium Ferrocyanide. Dissolve 10 grams of potassium ferrocyanide in 100 cubic centimeters of distilled water. Standard Copper Nitrate. Dissolve 2 grams of purest elec- trolytic copper in 20 cubic centimeters of nitric acid (i : i), and dilute to 1,000 cubic centimeters with distilled water. Each cubic centimeter is equivalent to 0.02 per cent, of copper on the basis of a 10 gram sample. Method. In a 300 cubic centimeter beaker dissolve 10 grams of the steel in 75 cubic centimeters of the sulphuric acid, and then add 150 cubic centimeters of distilled water. Heat the solu- tion and saturate with hydrogen sulphide, filter and wash the precipitate free from iron with i per cent, sulphuric acid con- taining hydrogen sulphide. Incinerate the paper with its con- tents in a porcelain crucible and fuse with 0.5 gram of acid sodium sulphate. Extract with hot water, filter, and complete the determination colorimetrically as under i(a) or i(&), or electrolytically as under 2, as follows : i. Evaporate the filtrate to about 25 cubic centimeters, make faintly ammoniacal, filter into a 100 cubic centimeter Nessler tube and wash with hot water. (a) If the solution is a strong blue, to another 100 cubic centimeter Nessler tube add 50 cubic centimeters of distilled water, 5 cubic centimeters of ammonium hydroxide, specific gravity 0.90, and from a burette the standard copper nitrate solution until the blue colors match. (b) If the solution is a faint blue, to the filtrate in a Nessler tube add the dilute sulphuric acid to faint acidity and then a few drops of the potassium ferrocyanide solution. To an- other 100 cubic centimeter Nessler tube add 50 cubic centi- 295 meters of distilled water, a few drops of the potassium ferro- cyanide solution, and from a burette the standard copper ni- trate solution until the reddish brown colors match. 2. Make the nitrate slightly acid with sulphuric acid, dilute with distilled water to a suitable volume, and determine the copper electrolytically. DETERMINATION OF NICKEL BY THE GRAVIMETRIC DIMETHYI/- GLYOXIME METHOD. Solutions Required. Hydrochloric Acid. Mix 500 cubic centimeters of hydro- chloric acid, specific gravity, 1.20, and 500 cubic centimeters of distilled water. Dimethylglyoxime. Dissolve I gram of dimethylglyoxime in 100 cubic centimeters of 95 per cent, ethyl alcohol. Method. In a 150 cubic centimeter beaker dissolve I gram of the steel in 20 cubic centimeters of the hydrochloric acid, and add about 2 cubic centimeters of nitric acid, specific gravity 1.42, to oxidize the iron. Filter the solution and add to the filtrate 6 grams of tartaric acid, and water till the volume is 300 cubic centimeters. Make the solution faintly ammoniacal, then faintly acid with the hydrochloric acid and heat nearly to boiling; add 20 cubic centimeters of the dimethylglyoxime solution and then ammonium hydroxide, specific gravity 0.90, drop by drop till faintly alkaline, stirring vigorously. After standing i hour, filter on a weighed Gooch crucible, wash with hot water, dry at 110 to 120 C. and weigh. The precipitate contains 20.31 per cent, of nickel. NOTES. In making dimethylglyoxime solution, methyl alcohol may be sub- stituted for ethyl alcohol. The weight of sample taken should be varied according to the nickel content. 29 6 DETERMINATION OF NlCKEX BY THE VOLUMETRIC DlMETHYI,- METHOD. (Routine.) Solutions Required. Hydrochloric Acid. Mix 500 cubic centimeters of hydro- chloric acid, specific gravity 1.20, and 500 cubic centimeters of distilled water. Dimethylglyoxime. Dissolve I gram of dimethylglyoxime in 100 cubic centimeters of 95 per cent, ethyl alcohol. Silver Nitrate. Dissolve 0.5 gram of silver nitrate in 1,000 cubic centimeters of distilled water. Potassium Iodide. Dissolve 20 grams of potassium iodide in 100 cubic centimeters of distilled water. Standard Potassium Cyanide. Dissolve 2.29 grams of potas- sium cyanide in 1,000 cubic centimeters of distilled water. Standardize this solution by the procedure described below, against a steel of known nickel content as determined by the gravimetric dimethylglyoxime method, so that each cubic centi- meter is equivalent to 0.05 per cent, of nickel on the basis of a i -gram sample (see notes). Method. In a 150 cubic centimeter beaker dissolve I gram of the steel in 20 cubic centimeters of the hydrochloric acid, and add about 2 cubic centimeters of nitric acid, specific gravity 1.42, to oxidize the iron. Filter the solution and add to the fil- trate 6 grams of tartaric acid, and water until the volume is 300 cubic centimeters. Make the solution faintly ammoniacal, then faintly acid with the hydrochloric acid, and cool thor- oughly. Add 20 cubic centimeters of the dimethylglyoxime solution and then ammonium hydroxide, specific gravity 0.90, drop by drop, till faintly alkaline, stirring vigorously. After standing for a few minutes, filter on a Gooch crucible arid wash with hot water. Dissolve the precipitate on the filter with 10 to 20 cubic centimeters of nitric acid (hot), specific 297 gravity 1.42, added drop by drop, and then wash 5 times with hot water, using suction. To the solution in a 500 cubic centi- meter beaker add 3 grams of ammonium persulphate and boil for 5 minutes. Cool, make distinctly ammoniacal, add 10 cubic centimeters each of the silver nitrate and potassium iodide solutions, and titrate with the standard potassium cy- anide solution to a faint turbidity. NOTES. In making dimethylglyoxime solution, methyl alcohol may be sub- stituted for ethyl alcohol. Bureau of Standards Standard Steel No. 33 is recommended for standardizing the potassium cyanide solution. The weight of sample taken should be varied according to the nickel content. DETERMINATION OF CHROMIUM. Solutions Required. Hydrochloric Acid. Mix 500 cubic centimeters of hydro- chloric acid, specific gravity 1.20, and 500 cubic centimeters of distilled water. Sodium Carbonate. A saturated solution; approximately 60 grams of sodium carbonate and 100 cubic centimeters of distilled water. Barium Carbonate. Ten grams of finely divided " barium carbonate suspended in 100 cubic centimeters of distilled water. Standard Sodium Chromate. Dissolve 2.6322 grams of sodium chromate in 1,000 cubic centimeters of distilled water. Each cubic centimeter is equivalent to 0.02 per cent, chro- mium, when a 5-gram sample is used. Standard Potassium Permanganate. Dissolve 2 grams of potassium permanganate in 1,000 cubic centimeters of dis- tilled water. Standardize by using Bureau of Standards so- dium oxalate, 1 and dilute the solution with distilled water so that i cubic centimeter is equivalent to 0.02 per cent, chro- mium, when a 5-gram sample is taken. 1 Circular No. 40, Bureau of Standards, Oct. i, 1912. 298 The factor Na 2 C 2 O 4 -* Cr = 0.2584 (using the 1913 atomic weights). Ferrous Sulphate. Dissolve 25 grams of ferrous ammoni- um sulphate in 900 cubic centimeters of distilled water and 100 cubic centimeters of sulphuric acid ( I : I ) . Method. In a 300 cubic centimeter Erlenmeyer flask, covered, dis- solve 5 grams of steel in 50 cubic centimeters of the hydro- chloric acid. When completely dissolved, and gradually the saturated solution of sodium carbonate until practically all the free acid is neutralized; finish the neutralization with the ba- rium carbonate suspension, using an excess of about I gram of the carbonate. Boil the solution in the flask for 10 or 15 minutes, with the cover on. Filter the precipitate rapidly on paper and wash twice with hot water. Transfer the filter to a platinum crucible and after burning off the paper, fuse the residue for 10 minutes with a mixture of 5 grams of sodium carbonate and 0.25 gram of potassium nitrate. Dissolve the fusion in water, transfer to a beaker, add 2 cubic centimeters of 3 per cent, hydrogen peroxide, boil a few minutes and filter. Complete the determination of chromium in the filtrate by either of the following procedures: 1. If the solution is a strong yellow, add 10 cubic centi- meters of sulphuric acid (i : i), and then the ferrous sulphate solution in measured excess. Cool thoroughly and titrate with the standard potassium permanganate solution. The number of cubic centimeters of the potassium permanganate solution obtained, subtracted from the number corresponding to the volume of the ferrous sulphate solution used, will give the volume of the potassium permanganate solution equivalent to the chromium in the sample. 2. If the solution is a light yellow, cool the 'solution and transfer to a 100 cubic centimeter Nessler tube. To another Nessler tube add distilled water, and from a burette add the standard sodium chromate solution until the yellow colors match. 299 NOTE. If procedure No. I is used, all hydrogen peroxide must be destroyed by boiling before acidifying, otherwise chromic acid will be reduced at this stage. CHEMICAL ANALYSIS OF ALLOY STEELS AS PUBLISHED BY THE AMERICAN SOCIETY FOR TESTING MATERIALS. ADOPTED, 1915. NICKEL STEEL. Determination of Carbon. See the Determination of Carbon in Plain Carbon Steel by the Direct-Combustion Method. 1 Determination of Manganese. See the Determination of Manganese in Plain Carbon Steel by the Bismuthate Method. 1 See the Determination of Manganese in Plain Carbon Steel by the Persulphate Method (Routine). Determination of Phosphorus. See the Determination of Phosphorus in Plain Carbon Steel by the Molybdate Magnesia Method. 1 See the Determination of Phosphorus in Plain Carbon Steel by the Alkalimetric Method (Routine). 1 Determination of Sulphur. See the Determination of Sulphur in Plain Carbon Steel by the Oxidation Method. 1 See the Determination of Sulphur in Plain Carbon Steel by the Evolution-Titration Method (Routine). 1 NOTES. The Evolution-Titration Method should not be used with steels containing appreciable amounts of tungsten, or of copper or other metals precipitated by hydrogen sulphide from acid solutions. The annealing of the steel drillings has been found by a number of investigators to increase the degree of refinement of the method. 1 Standard Methods for Chemical Analysis of Plain Carbon Steel (Serial Designa- tion: A 33), 1915 Year-Book, p. 201. 300 Determination of Silicon. See the Determination of Silicon in Plain Carbon Steel by the Nitro-Sulphuric Method. 1 See the Determination of Silicon in Plain Carbon Steel by the Sulphuric Acid Method (Optional). 1 Determination of Nickel. See the Determination of Nickel in Plain Carbon Steel by the Gravimetric Dimethylglyoxime Method. 1 See the Determination of Nickel in Plain Carbon Steel by the Volumetric Dimethylglyoxime Method (Routine). 1 Determination of Nickel by the Ether Extraction-Cyanide Titratio n Meth o d . (Optional Routine.) SOLUTIONS REQUIRED. Hydrochloric Acid. Mix 600 cubic centimeters of hydro- chloric acid, specific gravity 1.20, and 400 cubic centimeters of distilled water. Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, specific gravity 1.42, and 1.200 cubic centimeters of distilled water. Potassium Iodide. Dissolve 20 grams of potassium iodide in 1,000 cubic centimeters of distilled water. Silver Nitrate. Dissolve 0.5 gram of silver nitrate in 1,000 cubic centimeters of distilled water. Standard Potassium Cyanide. Dissolve 4.589 grams of potassium cyanide in 1,000 cubic centimeters of distilled water. Standardize the solution by the procedure described below, against a steel of known nickel content as determined by the gravimetric-dimethylglyoxime method, so that I cubic centi- meter is equivalent to o.io per cent, nickel on the basis of a i -gram sample (see note). 1 Standard Methods for Chemical Analysis of Plain Carbon Steel (Serial Designa- tion: A 33), 1915 Year-Book, p. 201. 3 oi METHOD. In a 150 cubic centimeter beaker dissolve i gram of the steel in 20 cubic centimeters of the hydrochloric acid, add about 2 cubic centimeters of nitric acid, specific gravity 1.42, to oxidize the iron, and boil to expel the oxides of nitrogen. Cool, and transfer the solution into an 8-ounce separatory funnel, rinsing the beaker with small portions of the hydro- chloric acid. Add 50 cubic centimeters of ether, shake for 5 minutes, let settle for I minute, and then draw off lower clear solution into another 8-ounce separatory funnel. Add 10 cubic centimeters of hydrochloric acid, specific gravity 1.20, to the solution in the first separatory funnel, cool, shake thor- oughly, allow to settle for I minute, and then draw off the lower clear solution into the second separatory funnel. To the combined solutions in the second separatory funnel add 50 cubic centimeters of ether, shake for 5 minutes, let settle for i minute, and then draw off the clear layer into a 150 cubic centimeter beaker. Heat the aqueous solution gently to expel the ether, add 0.2 gram of potassium chlorate, boil until chlorate is decomposed, dilute to 100 cubic centimeters with hot water, make faintly ammoniacal, and boil for 5 minutes. Filter and wash with hot water. To the filtrate add 10 cubic centimeters of hydrochloric acid, specific gravity 1.20, heat just short of boiling and precipitate the copper with hydrogen sul- phide. Filter and wash with hot water. Boil the filtrate to expel hydrogen sulphide, reducing the volume by evaporation to approximately 100 cubic centimeters, cool, and make solu- tion distinctly ammoniacal, add 10 cubic centimeters each of the silver-nitrate and potassium-iodide solutions, and titrate with the standard potassium-cyanide solution to a clear solu- tion. NOTE. Bureau of Standards Standard Steel No. 33 is recommended for standardizing the potassium cyanide solution. 20 302 Determination of Carbon. See the Determination of Carbon by the Direct-Combustion Method. 1 Determination of Manganese by the Zinc Oxlde- Bismuthate Method. SOLUTIONS REQUIRED. Sulphuric Acid. Mix 200 cubic centimeters of sulphuric acid, specific gravity 1.84, and 800 cubic centimeters of dis- tilled water. Nitric Acid. Mix 500 cubic centimeters of nitric acid, specific gravity 1.42 and 1,500 cubic centimeters of distilled water. Nitric Acid for Washing. Mix 30 cubic centimeters of nitric acid, specific gravity 1.42, and 970 cubic centimeters of distilled water. Sodium Carbonate. A saturated solution; approximately 60 grams of sodium carbonate and 100 cubic centimeters of distilled water. Zinc Oxide. Twenty grams of zinc oxide (dry process) suspended in 100 cubic centimeters of distilled water (see notes). Stock Sodium Arsenite. To 15 grams of arsenious oxide (As 2 O 3 ) in a 300 cubic centimeter Erlenmeyer flask, add 45 grams of sodium carbonate and 150 cubic centimeters of dis- tilled water. Heat the flask and contents on a water bath until the arsenious oxide is dissolved, cool the solution and make up to 1,000 cubic centimeters with distilled water. Standard Sodium- Arsenite. Dilute 300 cubic centimeters of the stock-sodium-arsenite solution to 1,000 cubic centimeters with distilled water and titrate against potassium-permangan- ate solution (about N/io) which has been standardized by 1 Standard Methods for Chemical Analysis of Plain Carbon Steel (Serial Designa- tion: A 33), 1915 Year-Book, p. 201. 303 using Bureau of Standards sodium oxalate. 1 Adjust the solu- tion so that I cubic centimeter is equivalent to o.io per cent, of manganese on the basis of a i-gram sample. The factor Na 2 C 2 O 4 > Mn == 0.16397 (using the 1913 atomic weights). METHOD. In a platinum or porcelain dish of 300 cubic centimeters capacity, to 2.5 grams of the steel add 40 cubic centimeters of the sulphuric acid, cover with a watch glass, and heat until the steel is dissolved. Add about 4 cubic centimeters of nitric acid, specific gravity 1.42, to oxidize the iron and evaporate slowly until copious fumes of sulphuric acid are evolved. Cool, add 100 cubic centimeters of hot water, heat with fre- quent stirring until all salts are dissolved, then transfer the solution into a volumetric 500 cubic centimeter flask. Add the sodium-carbonate solution until near neutrality, and the pre- cipitate formed dissolves with difficulty, then add small por- tions of the zinc-oxide suspension, shaking vigorously after each addition, until after settling of the coagulated precipitate, the supernatant liquid is practically clear. Cool, and make up to the mark with water. Mix thoroughly by pouring the entire contents of the flask into a large, dry beaker, and back again to the flask, repeating several times. Allow the pre- cipitate to settle, filter off 200 cubic centimeters of the solution into a 300 cubic centimeter Erlenmeyer flask, add 25 cubic centimeters of the nitric acid solution, and boil to expel the oxides of nitrogen. Cool, add 0.5 gram of sodium bismuthate and heat for a few minutes, or until the pink color has disap- peared, with or without the precipitation of manganese dioxide. Add small portions of ferrous sulphate (or other suitable re- ducing agent) in sufficient quantity to clear the solution, and boil to expel the oxides of nitrogen. Cool to 15 C., add an excess of sodium bismuthate and agitate for a few minutes. Let settle and filter through an alundum filter or asbestos pad, washing with the 3 per cent, nitric acid. Titrate immediately 1 Circular No . 40 , Bureau of Standards, Oct. i, 1912. 304 * with the standard sodium-arsenite solution to the disappear- ance of the pink color. NOTES. In the method, the preliminary treatment with sodium bismuthate has been found by a number of investigators to be apparently unneces- sary ; however, the available data to confirm this position are not con- sidered sufficient to warrant its omission. In making the asbestos filter pad it is advisable to have a thin bed and as much surface as possible. This insures rapid filtration and the filter may be used until it becomes clogged with bismuthate. The filtrate must be perfectly clear since the least particle of bismuthate carried through the filter will vitiate the results. The zinc-oxide reagent should be free from manganese, or a cor- rection applied if it is present. Determination of Manganese by the Modified Bismuthate Method. (Routine.) SOLUTIONS REQUIRED. Nitric Acid. Mix 500 cubic centimeters of nitric acid, specific gravity 1.42, and 1,500 cubic centimeters of distilled water. Nitric Acid for Washing. Mix 30 cubic centimeters of nitric acid, specific gravity 1.42, and 970 cubic centimeters of distilled water. Stock Sodium Arsenite.To 15 grams of arsenious oxide (As 2 O 3 ) in a 300 cubic centimeter Erlenmeyer flask, add 45 grams of sodium carbonate and 150 cubic centimeters of dis- tilled water. Heat the flask and contents on a water bath until the arsenious oxide is dissolved, cool the solution and make up to 1,000 cubic centimeters with distilled water. Standard Sodium Arsenite. Dilute 300 cubic centimeters of the stock-sodium-arsenite solution to 1,000 cubic centimeters with distilled water and titrate against potassium-permangan- ate solution (about N/io) which has been standardized by using Bureau of Standards sodium oxalate. 1 Adjust the solu- i Circular No. 40, Bureau of Standards, Oct. i 1912. 305 tion so that i cubic centimeter is equivalent to o.io per cent, of manganese on the basis of a i-gram sample. The factor Na 2 C 2 O 4 - > Mn == 0.16397 (using the 1913 atomic weights). METHOD. In a 300 cubic centimeter Erlenmeyer flask dissolve I gram of the steel in 50 cubic centimeters of the nitric acid, and boil to expel the oxides of nitrogen. Cool to 60-70 C., add about 0.5 gram of sodium bismuthate, and heat for a few minutes, or until the pink color has disappeared, with or without the precipitation of manganese dioxide. Add sufficient sulphurous acid or sodium sulphite to clear the solution and to reduce all of the chromic acid. Cool to approximately o C. in ice water, add an excess of sodium bismuthate and agitate. After 30 seconds standing, filter rapidly through an alundum filter or asbestos pad, washing with 3 per cent, nitric acid previously cooled in ice water to approximately o C. Titrate immedi- ately with the standard sodium-arsenite solution to the disap- pearance of the pink color. NOTES. In the method, the preliminary treatment with sodium bismuthate has been found by a number of investigators to be apparently unneces- sary; however, the available data to confirm this position are not sufficient to warrant its omission. In making the asbestos filter pad it is advisable to have a thin bed, and as much surface as possible. This insures rapid filtration, and the filter may be used until it becomes clogged with bismuthate. The filtrate must be ice cold and perfectly clear, since any appre- ciable rise of temperature above o C., or the least particle of bis- muthate carried through the filter will vitiate the results. See the Determination of Manganese in Plain Carbon Steel by the Persulphate Method. 1 NOTE. In making the titration special care should be given to standard- izing the end-point reading, and the reading should be corrected by a blank, which varies with the amount of chromium present. 1 Standard Methods for Chemical Analysis of Plain Carbon Steel (Serial Designa- tion: A 33), 1915 Year-Book, p. 201. 36 Determination of Phosphorus. See the Determination of Phosphorus in Plain Carbon Steel by the Molybdate-Magnesia Method. 1 See the Determination of Phosphorus in Plain Carbon Steel by the Alkalimetric Method. 1 Determination of Sulphur. See the Determination of Sulphur in Plain Carbon Steel by the Oxidation Method. 1 See the Determination of Sulphur in Plain Carbon Steel by the Evolution-Titration Method (Routine). 1 NOTES. The Evolution-Titration Method should not be used with steels containing appreciable amounts of tungsten, or of copper or other metals precipitated by hydrogen sulphide from acid solutions. The annealing of the steel drillings has been found by a number of investigators to increase the degree of refinement of the method. Determination of Silicon. See the Determination of Silicon in Plain Carbon Steel by the Nitro-Sulphuric Method. 1 See the Determination of Silicon in Plain Carbon Steel by the Sulphuric Acid Method (Optional). 1 Determination of Chromium by the Fusion Method. SOLUTIONS REQUIRED. Sulphuric Acid. Mix 1,000 cubic centimeters of sulphuric acid, specific gravity 1.84, and 3,000 cubic centimeters of dis- tilled water. Sodium Carbonate. A saturated solution; approximately 60 grams of sodium carbonate and 100 cubic centimeters of distilled water. Magnesium Carbonate. Ten grams of finely divided mag- nesium carbonate suspended in 100 cubic centimeters of dis- tilled water. Barium Carbonate. Ten grams of finely divided barium carbonate suspended in 100 cubic centimeters of distilled water. 307 Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, specific gravity 1.42, and 1,200 cubic centimeters of distilled water. Potassium-Ferricyanide Indicator. Dissolve o.i gram of potassium ferricyanide in 50 cubic centimeters of distilled water (see notes). Standard Potassium Bichromate. Dissolve 5 grams of po- tassium bichromate in 1,000 cubic centimeters of distilled water, standardize against pure ferrous ammonium sulphate, and adjust to tenth-normal. Ferrous Sulphate. Dissolve 25 grams of ferrous ammonium sulphate in 900 cubic centimeters of distilled water and 100 cubic centimeters of sulphuric acid (i : i). METHOD. In a 300 cubic centimeter Erlenmeyer flask, covered, dissolve i gram of the steel in 50 cubic centimeters of the sulphuric acid (see notes). When completely dissolved, add 50 to 75 cubic centimeters of hot water, then gradually the sodium-carbonate solution until near neutrality, then add an excess of the mag- nesium-carbonate suspension (see notes), and boil vigorously for 15 minutes, with the cover on, adding fresh portions of the carbonate suspension during this time, so that there is present in the solution at the end of the operation an excess of 2 to 3 grams of the carbonate. Let settle and pour the supernatant liquid on a rapid filter, washing by decantation twice with cold water, pouring the washings through the filter. Transfer the filter to a platinum crucible and after burning off the paper, fuse the residue for 10 minutes with a mixture of 5 grams of sodium carbonate and 0.25 gram of potassium nitrate. Dis- solve the fusion in water, transfer to a beaker, add 2 cubic centimeters of 3 per cent, hydrogen peroxide, boil a few minutes and filter. Add 20 cubic centimeters of the sulphuric acid, stir vigorously, cool and titrate against the standardized ferrous-sulphate solution, using the potassium-ferricyanide solution as outside indicator, or add at once a measured amount (in excess) of the ferrous-sulphate solution, and titrate back 3 o8 against the potassium-bichromate solution, using the same in- dicator. NOTES. The solution of the steel may be in hydrochloric acid, specific gravity 1.20 or any other desired strength, adjusting the amount of acid used to avoid a large excess being present. Barium carbonate suspension may be substituted for the mag- nesium carbonate suspension when hydrochloric acid is used as solvent. All hydrogen peroxide must be destroyed by boiling before acidi- fying, otherwise chromic acid will be reduced at this stage. The insoluble residue remaining after extraction of the fusion should be examined for chromium. The potassium ferricyanide indicator should be prepared fresh on the day it is used. The ferrous sulphate solution should be standardized on the day it is used. In titrating with the ferrous sulphate solution it is convenient to divide the solution, roughly titrate one portion, add the other and finish carefully. Determination of Chromium by the Chlorate Method. (Routine.) ' SOLUTIONS REQUIRED. Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, specific gravity 1.42, and 1,200 cubic centimeters of distilled water. Potassium-Ferricyanide Indicator. Dissolve o.i gram of potassium ferricyanide in 50 cubic centimeters of distilled water (see notes). Standard Potassium Bichromate. Dissolve 5 grams of po- tassium bichromate in 1,000 cubic centimeters of distilled water, and standardize against pure ferrous ammonium sul- phate, and adjust to tenth-normal. Standard Potassium Permanganate. Dissolve 2 grams of potassium permanganate in 1,000 cubic centimeters of distilled water. Standardize by using Bureau of Standards sodium oxalate. 1 Adjust the solution so that I cubic centimeter is equivalent to o.io per cent, chromium on the basis of a i-gram 1 Circular No. 40, Bureau of Standards, Oct. i, 1912. 309 sample. The factor Na 2 C 2 O 4 > Cr 0.2584 (using the 1913 atomic weights). Ferrous Sulphate. Dissolve 25 grams of ferrous ammonium sulphate in 900 cubic centimeters of distilled water and 100 cubic centimeters of sulphuric acid (i : i). METHOD. In a 300 cubic centimeter Erlenmeyer flask dissolve I gram of the steel in 30 cubic centimeters of the nitric acid, and evaporate rapidly to approximately one-half volume. Add 50 cubic centimeters of nitric acid, specific gravity 1.42, and add i gram of sodium chlorate (see notes). Evaporate to boiling to approximately one-half volume and complete the determina- tion by either of the following procedures : 1. Dilute the solution with 100 cubic centimeters of distilled water and filter off the manganese dioxide, using suction, wash- ing with hot water. Cool the filtrate, dilute with cold water to 600 cubic centimeter volume, and titrate against the standard ferrous-sulphate solution, using the potassium-ferricyanide solution as outside indicator, or add at once a measured amount (in excess) of the ferrous-sulphate solution and titrate back against the standard potassium-bichromate solution, using the same indicator. 2. Add 10 cubic centimeters of hydrochloric acid (i : i) and boil until the solution is clear and all manganese dioxide dis- solved. Cool, dilute the solution with water to 300 cubic centi- meter volume, add the ferrous-sulphate solution in measured amount (in excess), and titrate back with the standard po- tassium-permanganate solution to a permanent pink color. NOTES. The potassium-ferricyanide indicator should be prepared fresh on the day it is used. The ferrous-sulphate solution should be compared on the day it is used, with the standard potassium-permanganete or standard potas- sium-bichromate solutions. Potassium chlorate may be used as oxidizing agent in the place of sodium chlorate. In titrating with the ferrous-sulphate solution it is convenient to divide the solution, roughly titrate one portion, add the other and finish carefully. 3 io . Determination of Chromium by the Permanganate Oxidation Method. (Optional Routine.) SOLUTIONS REQUIRED. Sulphuric Add. Mix 1,000 cubic centimeters of sulphuric acid, specific gravity 1.84, and 3,000 cubic centimeters of dis- tilled water. Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, specific gravity 1.42, and 1,200 cubic centimeters of distilled water. Potassium Permanganate. Dissolve 25 grams of potassium permanganate in 1,000 cubic centimeters of distilled water. Standard Potassium Permanganate. Dissolve 2 grams of potassium permanganate in 1,000 cubic centimeters of distilled water. Standardize by using Bureau of Standard sodium oxalate. 1 Adjust the solution so that i cubic centimeter is equivalent to o.io per cent, chromium on the basis of a i-gram sample. The factor Na 2 C 2 O 4 > Cr= 0.2584 (using the 1913 atomic weights). Ferrous Sulphate. Dissolve 25 grams of ferrous ammonium sulphate in 900 cubic centimeters of distilled water and 100 cubic centimeters of sulphuric acid (i : i). METHOD. In a 300 cubic centimeter Erlenmeyer flask, dissolve 1.25 grams (procedure No. i) or i gram (procedure No. 2) of the steel in 50 cubic centimeters of the sulphuric acid. When com- pletely dissolved, add 5 cubic centimeters of the nitric acid, and boil until clear and free from oxides of nitrogen. Dilute with hot water to approximately 150 cubic centimeter volume, heat, and while boiling add the potassium-permanganate solution slowly until a permanent brown precipitate appears (see notes). Complete the determination by either of the following procedures : 1 Circular No. 40, Bureau of Standards, Oct. i, 1912. 1. Add 25 cubic centimeters of ammonium hydroxide, spe- cific gravity 0.90, shake well, place on the cooler part of the hot plate to avoid bumping. Shake occasionally and digest for about 15 minutes, or until the permanganate is all decomposed, then add cautiously 20 cubic centimeters of the sulphuric acid and bring gently to a boil. Cool the solution and pour into a volumetric 250 cubic centimeter flask. Make up to mark with cold water and mix thoroughly. Allow precipitate to settle, filter off 200 cubic centimeters of the clear solution (equal to i gram), add the ferrous-sulphate solution in measured amount (in excess) and titrate back with the standard potassium-per- manganate solution to a permanent pink color. The number of cubic centimeters of the standard potassium-permanganate solution obtained, subtracted from the number corresponding to the volume of the ferrous-sulphate solution used, will give the volume of the standard potassium-permanganate solution equivalent to the chromium in the sample. 2. Add 10 cubic centimeters of hydrochloric acid (i : i), and boil until the solution is clear and all manganese dioxide dis- solved. Cool, dilute the solution with water to 300 cubic centi- meter volume, add the ferrous-sulphate solution in measured amount (in excess), and titrate back with the standard po- tassium-permanganate solution to a permanent pink color. NOTES. In oxidizing with the potassittm-permanganate solution care should be taken to avoid a large excess, since the manganese-dioxide precipi- tate tends to hold the chromic acid. In the solution of the manganese dioxide under procedure No. 2, the boiling should be continued until all chlorine fumes are expelled. The ferrous-sulphate solution should be compared on the day it is used with the standard potassium-permanganate solution. Determination of Nickel. See the Determination of Nickel in Plain Carbon Steel by the Gravimetric-Dimethylglyoxime Method. 1 i Standard Methods for Chemical Analysis of Plain Carbon Steel (Serial Designa- tion: A 33), 1915, Year-Book, p. 201. 312 See the Determination of Nickel in Plain Carbon Steel by the Volumetric Dimethylglyoxime Method (Routine). VANADIUM STEEL. Determination of Carbon. See the Determination of Carbon in Plain Carbon Steel by the Direct-Combustion Method. Determination of Manganese. See the Determination of Manganese in Chrome-Nickel Steel by the Zinc Oxide-Bismuthate Method. For the Routine Determination of Manganese, see the De- termination of Manganese in Plain Carbon Steel by the Bis- muthate Method. Determination of Phosphorus by the Modified Molybdate-Magnesia Method. SOLUTIONS REQUIRED. Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, specific gravity 1.42, and 1,200 cubic centimeters of distilled water. Nitric Acid for Washing. Mix 20 cubic centimeters of nitric acid, specific gravity 1.42, and 1,000 cubic centimeters of distilled water. Potassium Permanganate. Dissolve 25 grams of potassium permanganate in 1,000 cubic centimeters of distilled water. Sodium Bisulphite. Dissolve 30 grams of sodium bisulphite in 1,000 cubic centimeters of distilled water. Ammonium Molybdate. Solution No. I, Place in a beaker 100 grams of 85 per cent, molybdic acid, mix it thoroughly with 240 cubic centimeters of distilled water, add 140 cubic centimeters of ammonium hydroxide, specific gravity 0.90, fil- ter, and add 60 cubic centimeters of nitric acid, specific gravity 1.42. Solution No. 2. Mix 400 cubic centimeters of nitric acid, specific gravity 1.42, and 960 cubic centimeters of distilled water. When the solutions are cold, add solution No. I to solution No. 2, stirring constantly; then add o.i gram of ammonium phosphate dissolved in 10 cubic centimeters of distilled water, and let stand at least 24 hours before using. Magnesia Mixture. Dissolve 50 grams of magnesium chlo- ride and 125 grams of ammonium chloride in 750 cubic centi- meters of distilled water and then add 150 cubic centimeters of ammonium hydroxide, specific gravity 0.90. Ammonium Hydroxide, Approximately 10 per cent. Mix 1,000 cubic centimeters of ammonium hydroxide, specific gravity 0.90, and 2,000 cubic centimeters of distilled water. Ferrous Sulphate. A saturated solution; approximately 40 grams of ferrous sulphate and 100 cubic centimeters of dis- tilled water. METHOD. In a 300 cubic centimeter Erlenmeyer flask dissolve 5 grams of steel in 75 cubic centimeters of the nitric acid. Heat, and while boiling add about 12 cubic centimeters of the potassium- permanganate solution, and continue boiling until manganese dioxide precipitates. Dissolve the precipitate by additions of the sodium-bisulphite solution, boil until clear and free from oxides of nitrogen. Cool to 15-20 C., add 5 cubic centimeters of the ferrous-sulphate solution, and 2 or 3 drops of con- centrated sulphurous acid, and then 100 cubic centimeters of the ammonium-molybdate solution. Let stand I minute, shake or agitate thoroughly for 5 minutes, filter on a 9-centimeter paper and wash at least 3 times with the 2 per cent, nitric acid solution to free from iron. Treat the precipitate on the filter with the 10 per cent, am- monium-hydroxide solution, letting the solution run into a 100 cubic centimeter beaker containing 10 cubic centimeters of hydrochloric acid, specific gravity 1.20, and 0.5 gram of citric acid; add 30 cubic centimeters of ammonium hydroxide, 3*4 specific gravity 0.90, cool, and then add 10 cubic centimeters of the magnesia mixture very slowly, while stirring the solution vigorously. Set aside in a cool place for 2 hours, filter and wash with the 10 per cent, ammonium-hydroxide solution. Ig- nite and weigh. Dissolve the precipitate of magnesium pyro- phosphate with 5 cubic centimeters of nitric acid, specific gravity 1.20, and 20 cubic centimeters of water, filter and wash with hot water. Ignite and weigh. The difference in weights represents pure magnesium pyrophosphate containing 27.84 per cent, of phosphorus. NOTE. The ammonium-molybdate solution should be kept in a cool place and should always be filtered before using. Determination of Phosphorus by the Modified Alkalimetric Method. (Routine.) SOLUTIONS REQUIRED. Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, specific gravity 1.42, and 1,200 cubic centimeters of distilled water. Nitric Acid for Washing. Mix 20 cubic centimeters of nitric acid, specific gravity 1.42, and 1,000 cubic centimeters of distilled water. Potassium Permanganate. Dissolve 25 grams of potassium permanganate in 1,000 cubic centimeters of distilled water. Sodium Bisulphite. Dissolve 30 grams of sodium bisulphite in 1,000 cubic centimeters of distilled water. Ammonium Molybdate. Solution No. i. Place in a beaker 100 grams of 85 per cent, molybdic acid, mix it thoroughly with 240 cubic centimeters of distilled water, add 140 cubic centimeters of ammonium hydroxide, specific gravity 0.90, fil- ter, and add 60 cubic centimeters of nitric acid, specific gravity 1.42. Solution No. 2. Mix 400 cubic centimeters of nitric acid, specific gravity 1.42, and 960 cubic centimeters of distilled water. When the solutions are cold, add solution No. I to solu- tion No. 2, stirring constantly; then add o.i gram of ammoni- um phosphate dissolved in 10 cubic centimeters of distilled water, and let stand at least 24 hours before using. Ferrous Sulphate. A saturated solution; approximately 40 grams of ferrous sulphate and 100 cubic centimeters of dis- tilled water. Potassium Nitrate, I per cent. Dissolve 10 grams of potas- sium nitrate in 1,000 cubic centimeters of distilled water. Phenolphthalein Indicator. Dissolve 0.2 gram of phenol- phthalein in 50 cubic centimeters of 95 per cent, ethyl alcohol and 50 cubic centimeters of distilled water. Standard Sodium Hydroxide. Dissolve 6.5 grams of puri- fied sodium hydroxide in 1,000 cubic centimeters of distilled w r ater, add a slight excess of I per cent, solution of barium hydroxide, let stand for 24 hours, decant the liquid, and standardize it against a steel of known phosphorus content, as determined by the molybdate magnesia method, so that I cubic centimeter will be equivalent to o.oi per cent, of phos- phorus on the basis of a 2-gram sample (see notes). Protect the solution from carbon dioxide with a soda-lime tube. Standard Nitric Acid. Mix 10 cubic centimeters of nitric acid, specific gravity 1.42, and 1,000 cubic centimeters of dis- tilled water. Titrate the solution against the standardized sodium hydroxide, using phenolphthalein as indicator, and make it equivalent to the sodium hydroxide by adding dis- tilled water. METHOD. In a 300 cubic centimeter Erlenmeyer flask dissolve 2 grams of steel in 50 cubic centimeters of the nitric acid. Heat, and while boiling add 6 cubic centimeters of the potassium per- manganate solution and continue boiling until manganese dioxide precipitates. Dissolve this precipitate by additions of the sodium bisulphite solution, boil until clear and free from 3 i6 oxides of nitrogen, cool to I5-2O C., add 5 cubic centimeters of the ferrous sulphate solution and 2 or 3 drops of concen- trated sulphurous acid, and then 50 cubic centimeters of the ammonium molybdate solution. Let stand for i minute, shake or agitate for 5 minutes, filter on a 9 centimeter paper, wash the precipitate three times with the 2 per cent, nitric acid solution to free it from iron, and continue the washing with the i per cent, potassium nitrate solution until the pre- cipitate and flask are free from acid. Transfer the paper and precipitate to the solution flask, add 20 cubic centimeters of distilled water (see notes), 5 drops of phenolphthalein solution as indicator, and an excess of the standard sodium hydroxide solution. Insert a rubber stopper and shake vigorously until solution of the precipitate is com- plete. Wash off the stopper with distilled water and deter- mine the excess of standard sodium hydroxide solution by titrating with standard nitric acid solution. Each cubic centi- meter of standard sodium hydroxide solution represents o.oi per cent, of phosphorus. NOTES. The ammonium-molybdate solution should be kept in a cool place and should always be filtered before using. All distilled water used in titration should be freed from carbon dioxide by boiling or otherwise. Bureau of Standards Standard Steel No. 24 is recommended as a suitable steel for standardizing the sodium-hydroxide solution. Determination of Sulphur. See the Determination of Sulphur in Plain Carbon Steel by the Oxidation Method. See the Determination of Sulphur in Plain Carbon Steel by the Evolution-Titration Method (Routine). NOTES. The Evolution-Titration Method should not be used with steels containing appreciable amounts of tungsten, or of copper or other metals precipitated by hydrogen sulphide from acid solutions. The annealing of the steel drillings has been found by a number of investigators to increase the degree of refinement of the method. Determination of Silicon. See the Determination of Silicon in Plain Carbon Steel by the Nitro-Sulphuric Method. 1 See the Determination of Silicon in Plain Carbon Steel by the Sulphuric Acid Method (Optional). 1 Determination of Vanadium by the Phosphomolybdate-Pre- cipitation Method. SOLUTIONS REQUIRED. Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, specific gravity 1.42, and 1,200 cubic centimeters of distilled water. Nitric Acid for Washing. Mix 20 cubic centimeters of nitric acid, specific gravity 1.42, and 1,000 cubic centimeters of distilled water. Potassium Permanganate. Dissolve 25 grams of potassium permanganate in 1,000 cubic centimeters of distilled water. Sodium Bisulphite. Dissolve 30 grams of sodium bisulphite in 1,000 cubic centimeters of distilled water. Ammonium Phosphate. Dissolve 50 grams of ammonium phosphate in 1,000 cubic centimeters of distilled water. Ammonium Molybdate. Solution No. I. Place in a beaker 100 grams of 85 per cent, molybdic acid, mix it thoroughly with 240 cubic centimeters of distilled water, add 140 cubic centimeters of ammonium hydroxide, specific gravity 0.90, filter, and add 60 cubic centimeters of nitric acid, specific gravity 1.42. Solution No. 2. Mix 400 cubic centimeters of nitric acid, specific gravity 1.42, and 960 cubic centimeters of distilled water. When the solutions are cold, add solution No. I to solution No. 2, stirring constantly; then add o.i gram of ammonium phosphate dissolved in 10 cubic centimeters of distilled water, and let stand at least 24 hours before using. 1 Standard Methods for Chemical Analysis of Plain Carbon Steel (Serial Designa- tion: A 33), 1915 Year-Book, p. 201. 21 Acid Ammonium Sulphate. Mix 50 cubic centimeters of sulphuric acid, specific gravity 1.84, and 950 cubic centimeters of distilled water, and when cold add 15 cubic centimeters of ammonium hydroxide, specific gravity 0.90. Use at a tem- perature of 80 C. Standard Potassium Permanganate. Dissolve 0.35 gram of potassium permanganate in 1,000 cubic centimeters of dis- tilled water, and standardize by using Bureau of Standards sodium oxalate. 1 Adjust the solution so that i cubic centi- meter is equivalent to 0.02 per cent, vanadium on the basis of a 2.5 gram sample. The factor Na 2 C 2 O 4 > V = 0.7612 (using the 1913 atomic weights). METHOD. In a 300 cubic centimeter Krlenmeyer flask dissolve 2.5 grams of steel in 50 cubic centimeters of the nitric acid. Heat, and while boiling add 6 cubic centimeters of the potassium permanganate solution and continue boiling until manganese dioxide precipitates. Dissolve the precipitate by additions of the sodium bisulphite solution and boil until clear and free from oxides of nitrogen. Add 5 cubic centimeters of the ammonium phosphate solution and 10 grams of ammonium nitrate, heat to boiling, remove from the plate and add im- mediately 50 cubic centimeters of the ammonium molybdate solution. Let stand I minute, shake or agitate for 3 minutes, filter the supernatant liquid by suction through an asbestos filter, and wash three times with the hot acid ammonium sul- phate solution. The flask containing the bulk of the precipi- tate is then set under the funnel fitted into a bell- jar filter and the asbestos pad is treated with successive small portions of hot sulphuric acid, specific gravity 1.84. The solution is then heated until the precipitate is completely dissolved, a few drops of the nitric acid added, and the heating continued until copious fumes of sulphuric acid are evolved. Cool the solution, add hydrogen peroxide in small quantities, with vig- 1 Circular No. 40, Bureau of Standards, Oct. i, 1912. 319 orous shaking after each addition, until the solution takes on a deep brown color. Replace flask on the hot plate, fume for 4 or 5 minutes, cover the flask, cool, add 100 cubic centimeters of distilled water, heat to 80 C. and titrate with the stand- ard potassium permanganate solution to a permanent pink color. NOTE. If, after the addition of hydrogen peroxide and subsequent heating, the solution does not take on a clear green or blue color, it should be heated until fumes of sulphuric acid are evolved to rid of any traces of nitric acid which interferes with the reduction, then cooled and the treatment with hydrogen peroxide repeated. Determination of Vanadium by the Ether Extraction Hydro- chloric Acid Reduction Method. (Routine.) SOLUTIONS REQUIRED. Hydrochloric Acid. Mix 600 cubic centimeters of hydro- chloric acid, specific gravity 1.20, and 400 cubic centimeters of distilled water. Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, specific gravity 1.42, and 1,200 cubic centimeters of distilled water. Sulphuric Acid. Mix 500 cubic centimeters of sulphuric acid, specific gravity, 1.84, and 500 cubic centimeters of dis- tilled water. Potassium Permanganate. Dissolve 25 grams of potassium permanganate in 1,000 cubic centimeters of distilled water. Standard Potassium Permanganate. Dissolve 0.35 gram of potassium permanganate in 1,000 cubic centimeters of dis- tilled water, and standardize by using Bureau of Standards sodium oxalate. 1 Adjust the solution so that I cubic centi- meter is equivalent to 0.02 per cent, vanadium on the basis of a 2.5-gram sample. 1 Circular No. 40. Bureau of Standards, Oct. i, 1912. 320 The factor Na 2 C 2 O 4 > = 0.7612 (using the 1913 atomic weights). METHOD. . In a 150 cubic centimeter beaker dissolve 2.5 grams of the steel in 50 cubic centimeters of the hydrochloric acid, add small portions of the nitric acid to oxidize the iron, and heat to expel the oxides of nitrogen. Cool, and transfer the solu- tion into an 8-ounce separatory funnel, rinsing the beaker with small portions of the hydrochloric acid. Add 50 cubic centi- meters of ether, shake for 5 minutes, let settle for i minute, and then draw off lower clear solution into another 8-ounce separatory funnel. Add 10 cubic centimeters of hydrochloric acid, specific gravity 1.20, -to the solution in the first separa- tory funnel, shake thoroughly, allow to settle for i minute, and then draw off the lower clear solution into the second separatory funnel. To the combined solutions in the second separatory funnel add 50 cubic centimeters of ether, shake for 5 minutes, let settle for I minute, and then draw off the clear layer into a 150 cubic centimeter beaker. Heat the aqueous solution gently to expel the ether, add 25 cubic centi- meters of the sulphuric acid, and heat until copious fumes are evolved. Cool, dilute with 25 cubic centimeters of water, add a slight excess of the potassium permanganate solution, and boil. Add 15 cubic centimeters of hydrochloric acid, specific gravity 1.20, and heat to fuming for 10 minutes. Cool, add loo cubic centimeters of water, heat to 80 C., and titrate with the standard potassium permanganate solution to a per- manent pink color. NOTE. In heating the solution to expel oxides of nitrogen care should be taken not to boil. CHROMA- VANADIUM Determination of Carbon. See the Determination of Carbon in Plain Carbon Steel by the Direct Combustion Method. 1 1 Standard Methods for Chemical Analysis of Plain Carbon Steel (Serial Designa- tion: A 33), 1915 Year-Book, p. 201. 321 Determination of Manganese. See the Determination of Manganese in Chrome-Nickel Steel by the Zinc Oxide Bismuthate Method. See the Determination of Manganese in Chrome-Nickel Steel by the Modified Bismuthate Method. Determination of Phosphorus. See the Determination of Phosphorus in Vanadium Steel by the Modified Molybdate Magnesia Method. See the Determination of Phosphorus in Vanadium Steel by the Modified Alkalimetric Method (Routine). Determination of Sulphur. See the Determination of Sulphur in Plain Carbon Steel by the Oxidation Method. 1 See the Determination of Sulphur in Plain Carbon Steel by the Evolution-Titration Method (Routine). NOTES. The Evolution-Titration Method should not be used with steels containing appreciable amounts of tungsten, or of copper or other metals precipitated by hydrogen sulphide from acid solutions. The annealing of the steel drillings has been found by a number of investigators to increase the degree of refinement of the method. Determination of Silicon. See the Determination of Silicon in Plain Carbon Steel by the Nitro-Sulphuric Method. See the Determination of Silicon in Plain Carbon Steel by the Sulphuric Acid Method (Optional). Determination of Chromium by the Fusion Method. SOLUTIONS REQUIRED. Sulphuric Acid. Mix 1,000 cubic centimeters of sulphuric acid, specific gravity 1.84, and 3,000 cubic centimeters of dis- tilled water. 1 Standard Methods for Chemical Analysis of Plain Carbon Steel (Serial Designa- tion: A 33), 1915 Year-Book, p. %oi. 322 Sodium Carbonate. A saturated solution; approximately 60 grams of sodium carbonate and 100 cubic centimeters of distilled water. Magnesium Carbonate. Ten grams of finely divided mag- nesium carbonate suspended in 100 cubic centimeter of distilled water. Barium Carbonate. Ten grams of finely divided barium carbonate suspended in 100 cubic centimeters of distilled water. Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, specific gravity 1.42, and 1,200 cubic centimeters of distilled water. Potassium Ferricyanide Indicator. Dissolve o.i gram of potassium ferricyanide in 50 cubic centimeters of distilled water (see notes). Standard Potassium Bichromate. Dissolve 5 grams of potassium bichromate in 1,000 cubic centimeters of distilled water, standardize against pure ferrous ammonium sulphate, and adjust to tenth-normal. Ferrous Sulphate. Dissolve 25 grams of ferrous ammonium sulphate in 900 cubic centimeters of distilled water and 100 cubic centimeters of sulphuric acid (i: i). The strength of this solution should be expressed in terms of chromium and vanadium. METHOD. In a 300 cubic centimeter Erlenmeyer flask, covered, dissolve i gram of steel in 50 cubic centimeters of the sulphuric acid (see notes). When completely dissolved, add 50 to 75 cubic centimeters of hot water, then gradually the sodium carbonate solution until near neutrality, and then add an excess of the magnesium carbonate suspension (see notes), and boil vigor- ously for 15 minutes, with the cover on, adding fresh portions of the carbonate suspension during this time, so that there is present in the solution at the end of the operation an excess of 2 to 3 grams of the carbonate. Let settle and pour the supernatant liquid on a rapid filter, washing by decantation 3^3 twice with cold water, pouring the washings through the filter. Transfer the filter to a platinum crucible and after burning off the paper, fuse the residue for 10 minutes with a mixture of 5 grams of sodium carbonate and 0.25 gram of potassium nitrate. Dissolve the fusion in water, transfer to a beaker, add 2 cubic centimeters of 3 per cent, hydrogen peroxide, boil a few minutes and filter. Add 20 cubic centimeters of the sulphuric acid, stir vigorously, cool and titrate against the standardized ferrous sulphate solution, using the potassium ferricyanide as outside indicator, or add at once a measured amount (in excess) of the ferrous sulphate solution and titrate back against the standard potassium bichromate solu- tion, using the same indicator. From the number of cubic centimeters of the standard fer- rous sulphate solution required deduct the number of cubic centimeters of the standard ferrous sulphate solution equiva- lent to the vanadium in the steel, as determined by the Phos- phomolybdate Precipitation Method for Vanadium Steel, and the result will be the number of cubic centimeters of the standard ferrous sulphate solution equivalent to the chromium in the steel. NOTES. The solution of the steel may be in hydrochloric acid, specific gravity 1.20 or any other desired strength, adjusting the amount of acid used to ?,void a large excess being present. Barium-carbonate suspension may be substituted for the mag- nesium-carbonate suspension when hydrochloric acid is used as solvent. All hydrogen peroxide must be destroyed by boiling before acidi- fying, otherwise chromic acid will be reduced at this stage. The insoluble residue remaining after extraction of the fusion should be examined for chromium. The potassium ferricyanide indicator should be prepared fresh on the day it is used. The ferrous sulphate solution should be standardized on the day it is used. In titrating with the ferrous sulphate solution it is convenient to divide the solution, roughly titrate one portion, add the other and finish carefully. 324 Determination of Chromium by the Chlorate Method. (Routine.) SOLUTIONS REQUIRED. Nitric Acid. Mix 1,000 cubic centimeters of nitric acid, specific gravity 1.42, and 1,200 cubic centimeters of distilled water. Potassium Ferricyanide Indicator. Dissolve o.i gram of potassium ferricyanide in 50 cubic centimeters of distilled water (see notes). Standard Potassium Bichromate. Dissolve 5 grams of potassium bichromate in 1,000 cubic centimeters of distilled water, standardize against pure ferrous ammonium sulphate, and adjust to tenth-normal. Standard Potassium Permanganate. Dissolve 0.5 gram of potassium permanganate in 1,000 cubic centimeters of distilled water. Standardize by using Bureau of Standards sodium oxalate. 1 Adjust the solution so that I cubic centimeter is equivalent to 0.05 per cent, vanadium on the basis of a I gram sample. The factor Na 2 C 2 O 4 > V = 0.7612 (using the 1913 atomic weights). Ferrous Sulphate. Dissolve 25 grams of ferrous ammonium sulphate in 900 cubic centimeters of distilled water and 100 cubic centimeters of sulphuric acid ( I : I ) . The strength of this solution should be expressed in terms of chromium and vanadium. METHOD. In a 300 cubic centimeter Erlenmeyer flask dissolve I gram of the steel in 30 cubic centimeters of the nitric acid, and evaporate rapidly to approximately one-half volume. Add 50 cubic centimeters of nitric acid, specific gravity 1.42, and I gram of sodium chlorate (see notes). Evaporate by boiling to one-half volume, dilute with 100 cubic centimeters of water and filter off the manganese dioxide, using suction, 1 Circular No. 40, Bureau of Standards, Oct. i, 1912. 325 washing with hot water. Cool the solution to room tempera- ture and complete the determination by either of the follow- ing procedures : 1. Titrate against the ferrous sulphate solution, using the potassium ferricyanide solution as outside indicator (see notes). From the number of cubic centimeters of the ferrous sulphate solution required deduct the number of cubic centi- meters of the ferrous sulphate solution equivalent to the va- nadium in the steel, as determined by the Phosphomolybdate Precipitation Method for Vanadium Steel, and the result will be the number of cubic centimeters of the ferrous sulphate solution equivalent to the chromium in the steel. 2. Titrate against the ferrous sulphate solution, using the potassium ferricyanide solution as outside indicator (see notes). Cool to 15 C. and titrate against the standard potas- sium permanganate solution to a pink color permanent for 10 seconds. Deduct the number of cubic centimeters of the standard potassium permanganate solution consumed, which gives a direct measure of the vanadium content of the steel, from the first titration; the remainder will represent the chromium content of the steel. NOTES. The potassium-ferricyanide indicator should be prepared fresh on the day it is used. The ferrous-sulphate solution should be compared on the day it is used with the standard potassium-permanganate or potassium- bichromate solutions. Potassium chlorate may be used as oxidizing agent in the place of sodium chlorate. In titrating with the ferrous-sulphate solution it is convenient to divide the solution, roughly titrate one portion, add the other and finish carefully. Determination of Vanadium. See the Determination of Vanadium in Vanadium Steel by the Phosphomolybdate Precipitation Method. 326 Determination of Vanadium by the Ether Extraction Hydro- chloric Acid Reduction Method. (Routine.} SOLUTIONS REQUIRED. Hydrochloric Acid. Mix 500 cubic centimeters of hydro- chloric acid, specific gravity 1:20, and 500 cubic centimeters of distilled water. Standard Potassium Permanganate. Dissolve 2 grams of potassium permanganate in 1,000 cubic centimeters of dis- tilled water, and standardize by using Bureau of Standards sodium oxalate. 2 Adjust the solution so that I cubic centi- meter is equivalent to o.io per cent, vanadium on the basis of when a 5-gram sample. The factor Na 2 C 2 O 4 > V = 0.7612 (using the 1913 atomic weights). METHOD. In a 150 cubic centimeter beaker, dissolve 5 grams of the steel in 60 cubic centimeters of the hydrochloric acid, add small portions of nitric acid, specific gravity 1.42, to oxidize the iron, avoiding an excess, and heat to expel the oxides of nitrogen. Cool, and transfer the solution into an 8-ounce separatory funnel, rinsing the beaker with small portions of the hydrochloric acid. Add 50 cubic centimeters of ether, shake for 5 minutes, let settle for i minute, and then draw off lower clear solution into another separatory funnel. Add 10 cubic centimeters of hydrochloric acid, specific gravity 1.20, to the solution in the first separatory funnel, shake thoroughly, allow to settle for i minute, and then draw off the lower clear solution into the second separatory funnel. To the combined solution in the second separatory funnel add 50 cubic centi- meters of ether, shake for 5 minutes, let settle for i minute, and then draw off the clear layer into a 150 cubic centimeter beaker. Heat the aqueous solution gently to expel the ether, evaporate to approximately one- fourth original volume, add 2 Circular No. 40, Bureau of Standards, Oct. i, 1912. 327 O.5 gram of potassium chlorate and boil down to a volume of 10 cubic centimeters. Add 25 cubic centimeters of hydro- chloric acid, specific gravity 1.20, and again evaporate to 10 cubic centimeters. Add 20 cubic centimeters of sulphuric acid, specific gravity 1.84, and evaporate until copious fumes of sulphuric acid are evolved. Cool, dilute with water to 100 cubic centimeters volume, and titrate against the standard potassium permanganate to a pink color permanent for 10 seconds. Deduct the chromium blank and the remainder is equivalent to the vanadium content of the steel. NOTE. If much chromium relative to the vanadium is present the result will be high due to the oxidation of a portion of the chromium by the permanganate, and should be corrected by a blank which varies with the amount of the chromium present. This blank is conveniently made by putting a suitable amount of a chrome or chrome-nickel steel, free from vanadium, through the above process. By using varying amounts of this steef, so as to vary the chromium correspondingly, a curve may be constructed showing the relation between amount of chromium present and the amount of blank, and this curve can then be used in all subsequent work. SIUCO-MANGANESE; Determination of Carbon. See the Determination of Carbon in Plain Carbon Steel by the Direct Combustion Method. 1 Determination of Manganese. See the Determination of Manganese in Plain Carbon Steel by the Bismuthate Method. . ' See the Determination of Manganese in Plain Carbon Steel by the Persulphate Method (Routine). Determination of Phosphorus. See the Determination of Phosphorus in Plain Carbon Steel by the Molybdate Magnesia Method. i Standard Methods for Chemical Analysis of Plain Carbon Steel (Serial Designa- tion: A 33), 1915 Year-Book, p. 201. 3 28 See the Determination of Phosphorus in Plain Carbon Steel by the Alkalimetric Method (Routine). Determination of Sulphur. See the Determination of Sulphur in Plain Carbon Steel by the Oxidation Method. See the Determination of Sulphur in Plain Carbon Steel by the Evolution-Titration Method (Routine). NOTES. The Evolution-Titration Method should not be used with steels containing appreciable amounts of tungsten, or of copper or other metals precipitated by hydrogen sulphide from acid solutions. The annealing of the steel drillings has been found by a number of investigators to increase the degree of refinement of the method. Determination of Silicon. See the Determination of Silicon in Plain Carbon Steel by the Nitro-Sulphuric Method. See the Determination of Silicon in Plain Carbon Steel by the Sulphuric Acid Method (Optional). CONVERSION TABLE USED IN WATER ANALYSIS. Factor Na 2 to Na 2 SO. t 2.29 S0 3 " " J-775 Cl ' NaCl 1.6486 NaCl " Na 2 O 0.53028 Na 2 O V NaCl 1.8858 Na 2 " Na 2 CO 3 1.71 CaO " CaC0 3 1.7844 MgO " MgC0 3 2.1 S0 3 " CaSO 4 1-7 S0 3 11 MgS0 4 i-5 Cl " CaCl 2 - 1-563 MgO " MgCl 2 2.4 Cl " MgCl, 1-34 MgO " Mg 0.6 MgO " MgS0 4 3-o CaS0 4 " CaCO 3 0.736 Mg 2 P 2 T " MgO 0.36 BaSO 4 " S 0.137 BaSO 4 " S0 3 0-343 Factor AgCl to Cl 0.247 CaC0 3 " CO 2 -439 MgC0 3 C0 2 0.521 Na 2 S0 4 " Na 2 O 0.4366 CaO " CaCl 2 1.9777 CaO " CaS0 4 2.4 CaS0 4 " CaO 0.412 Na 2 C0 3 ' C0 2 0.415 SO 3 " CaS0 4 1.7005 CaO " CaCO 3 1.7844 NgO " NgC0 3 2.0912 Na 2 " NaCl 1.8858 Cl " NaCl 1.6486 CaC0 3 " C0 2 0.4396 MgC0 3 ' C0 2 0.5218 NaCl " Na 0-3934 Na " Na 2 1-3478 Na 2 O " Na 0.7419 MgO V Mg 0.603 Mg " MgO 1-657 3 2 9 TABLES FOR CALCULATING ANALYSIS. Sought Found Factor Ag AgBr 0-5744 AgCl 0.7527 Ag 2 S 0.8707 Al A1 2 O 3 0.5303 As As 2 S 3 0.0093 As 2 S 5 0.4834 (NH 4 MgAsO0 2 .H 2 O 0.3938 Mg 2 As->O 7 0.4828 Mg 2 P 2 6r 0.6736 BaS0 4 O.2I4I As 2 O 3 As 2 S 3 0.8042 As.Ss 0.6381 (NH 4 MgAsO 4 ) 2 .H 2 O 0.5198 MgaAsaOr 0.6373 Mg 2 P 2 O 7 0.8891 BaSO 4 0.2827 As 2 O 8 As 2 S 3 0.9342 As 2 Ss 0.7412 (NH 4 MgAsO 4 ) 2 .H 2 0.6038 Mg^SaOi 0.7403 Mg 2 P 2 7 1.0328 BaSO 4 0.3284 AsOa As 2 S 3 0.9992 As 2 S 5 0.7928 (NH 4 MgAsO 4 ) 2 .H 2 O 0.6458 Mg 2 As 2 O 7 0.7918 Mg 2 P 2 Oi 1.1046 BaSO 4 0.3512 AsO* As 2 S 3 I.I29I As 2 S 0.8959 (NH 4 MgAsO 4 ) 2 .H 2 O 0.7298 Mg 2 As 2 O 7 0.8947 Mg 2 P 2 O 7 1.2483 BaSO* 0.3969 Ba BaC0 3 0.6961 BaCrO 4 0.5420 BaS0 4 0.5886 BaSiF 6 0.4906 BaCO 3 BaCr0 4 0.7787 Ba(NOi), BaCr0 4 I.03I4 BaO BaC0 3 0-7771 BaCrO 4 0.0051 BaSO 4 0.6571 BaSiF 6 0.5478 Be BeO 0.3626 Bi Bi 2 O 3 0.8968 BiOCl O.8OI9 Bi 2 S 3 0.8125 Br AgBr 0.4255 I,og .75924 .87665 .93986 .72455 .78480 .68431 .59528 .68375 .82837 .33070 .90538 .80489 .71586 .80433 .94895 45128 .97044 .86995 .78092 .86939 .OI4OI .51634 .99965 .89916 .81013 .89860 .04322 54555 .05275 .95226 .86323 .95170 .09632 .59865 .84266 73401 .76981 .69077 89135 .01342 .89049 .78184 .81764 .73860 55937 .95209 .90414 .90985 .62895 330 TABLES FOR CALCULATING ANALYSIS. (Continued) Sought Found C CO 2 CN AgCN C0 2 CaC0 3 CaO MgO CO 3 ... CO 2 Ca CaCO 3 CaO CaSO 4 CaCOs CaS0 4 CaO CO 2 CaCO 3 CaSO 4 CaSO 4 .2H 2 O CaSO., BaS0 4 Cd CdO CdS CdSO 4 CdO CdS Ce Ce 2 O 3 CeO 2 Cl Ag AgCl Co Co 3 O 4 CoSO 4 CoO Co CoSO 4 Cr Cr 2 O 3 PbCrO* Cr 2 O 3 PbCrO 4 CrOs Cr 2 O 3 PbCrO 4 Cr0 4 Cr 2 3 PbCrO 4 Cs Cs 2 S0 4 Cu CuO CUaS CuFeS 2 Cu 2 S Cu 2 O CuO CuO Cu Cu 2 S CuSO 4 .sH 2 O Cu Cu 2 S Er Er 2 O 3 F , ' CaF 2 Factor l*g 0.2727 43573 0.1944 .28860 04394 .64289 0.7839 89425 I.09O2 .03750 1.3636 .13470 0.4008 .60291 0.7149 -85427 0.2947 46932 0.7352 .86641 1-2757 .10575 0.5606 .74864 O4I2I .61505 0.3259 .51312 0.5833 .76588 0.8754 .94220 0-7779 .89000 0.5391 .73166 0.8886 .94870 0.8539 .93139 0.8140 .91064 0.3285 .51650 0.2473 .39315 0-7344 .86595 0.3804 .58024 1.2712 .10421 04837 .68456 0.6847 .83550 0.1613 .20776 0.2356 .37226 I-3I53 .11902 0.3099 49128 1.5255 .18341 0-3595 .55567 0-7344 .86596 0.7990 90255 0.7987 .90238 2.3056 .36279 0.8995 .95400 1.2516 .09745 0.9996 .99983 3-9267 .59403 3-1362 49641 0.9737 .94136 0.4870 .68756 TABLES FOR CALCULATING ANALYSIS. (Continued) Sought Found Factor I/>g Fe Fe 2 O G 0.6996 .84482 FeO Fe 1.2863 -10935 Fe 2 O 6 0.8999 .95417 Fe 2 O 3 Fe 1.4295 .15518 FePO 4 0.5294 .72375 FeS 2 Fe 2 O 6 1.5022 .17674 H H 2 O 0.119 .04869 HBr . AgBr 0.4309 .63439 HC1 AgCl 0.2543 40532 HJ AgJ 0.5448 .73626 HNO 3 NH 4 C1 1.1781 .07117 (NHOJPtCl. 0.2842 ' 45363 NO 2.0989 .32199 Pt 0.6473 .81113 H 2 SOi BaSO 4 0.4201 .62331 Hg HgCl 0.8493 .92904 HgS 0.8617 .93535 J AgJ 0.5405 .73282 PdJ 2 0.7046 .84795 K KC1 0.5248 .71999 KC1O 4 0.2825 .45097 K 2 PtCl 6 0.1612 .20730 K 2 SO 4 0.4491 .65231 Ft 0.4019 .60417 K 2 O KC1 0.6320 .80074 KC1O 4 0.3402 .53172 K 2 PtCl 6 0.1941 .28805 K 2 SO 4 0.5408 .73306 Pt 0.4841 .68492 K 2 SO, BaS0 4 0.7468 .87318 La La 2 O 3 0.8527 .93078 Mg MgO 0.6036 .78073 MgzPaOi 0.2188 -33999 MgCOo Mg 2 P 2 O 7 0.7576 .87945 MgO Mg 2 P 2 Oi 0.3625 .55926 Mn Mn 3 O 4 0.7205 .85764 Mn 2 P 2 Or 0.3873 .58807 MnS 0.6315 .80034 MnCO 3 Mn 3 O 4 1.5066 .17798 MnO Mn 3 O 4 0.9301 .96854 MnS 0.8152 .91124 Mo MoO 3 0.6667 .82391 MoS 2 0.5096 .77788 N NH 4 C1 0.2623 .41885 (NH 4 ) 2 PtCl 0.06329 .80131 Pt 0.1441 .15881 NH 3 0.8235 .91566 \ 332 TABLES FOR CALCULATING ANALYSIS. (Continued) Sought Found NH 8 ...................... NH 4 C1 (NH 4 ) 2 PtCl 6 Pt NH 4 ....................... NH 4 C1 (NH 4 ) 2 PtCl 8 Pt NO 3 .................... ... NH.C1 (NH4) 2 PtCl 6 NO Pt N 2 O 5 ...................... NH 4 C1 (NH 4 ) 2 PtCl 6 NO Pt Na ........................ NaCl Na 2 SO 4 Na 2 O ...... ............... NaCl Na 2 SO* Ni ......................... NiO NiO ....................... Ni P ......................... Mg 2 P 2 O? (NH 4 ) 3 PO 4 .i2MoO 3 P 2 O 5 .24MoO 3 P 2 O 6 ...................... MgiPaOr (NH 4 ) 3 PO 4 .i2MoO 3 P 2 O 5 .24MoO 3 PO 4 ....................... Mg 2 P 2 O 7 (NH 4 ) 3 PO 4 .i2MoO 3 P 2 O 5 .24MoO 3 P 2 O 5 ....... ................ P Pb ........................ PbCrO 4 PbO PbO 2 PbS PbSO 4 PbO ....................... PbCrO 4 PbO 2 PbS PbSO 4 PbS ....................... PbSCX Rb ........................ Rb 2 SO 4 S .......................... BaSO 4 50 3 ....................... BaSO 4 50 4 ....................... BaSO* Sb .. ....................... Sb 2 O 4 Sb 2 S:j Factor 0.3177 0.07690 0.1752 0.3376 0.08145 0.1855 1.1592 0.2796 2.0652 0.6370 1.0097 0.2436 1.7090 0.5548 0.3940 0.3243 0.5308 0.4368 0.7858 1.2726 0.2784 0.01639 0.01723 0.6376 0.03753 0.03947 0.8532 0.05022 0.05281 2.3 0.6405 0.9282 0.8660 0.8658 0.6829 0.6901 0.9330 0.9328 0.7357 0.7888 0.6402 0.1373 0.3429 0.4114 0.7898 0.7142 0.5999 .50346 .88592 .24342 .52844 .91090 .26840 .06415 .44661 .31497 .8041 1 .00430 .38666 .25502 .74416 -59551 .51092 .72490 .64031 .89532 .10468 .44467 .21448 .23633 .80457 -57438 .59623 .93103 .70084 .72269 .36172 .80654 .96765 .93754 .93743 .83438 .83889 .96989 .96978 -86673 .89695 .80633 .13769 .53515 .61427 ,89749 .85382 333 TABLES FOR CALCULATING ANALYSIS. (Continued) Sought Found Factor I,og SbzOs V. SbsO* 0.9475 .97656 Sb 2 S 3 0.8568 .93289 Sb 2 S 5 0.7198 .85718 Sb 2 S 3 Sb 2 O 4 1.1058 .04367 SeO 2 Se 1.4040 .14737 SeO 3 , Se 1.6061 .20576 Si SiO 2 0.4702 .67228 SiO 3 SiO 2 1.2649 .10205 Shd SiO 2 1-3973 -I453O SiO* SiO 2 1.5298 .18463 Sn SnO 2 0.7881 .89657 Sr SrCO 3 0.5936 .77350 SrCCX 0.4771 .67859 SrCOa Sr(NO 3 ) 2 0.6973 -84344 Sr(OH) 2 .8H 2 0.5555 -74468 SrS 1.2334 .09111 SrS.Os 0.7391 .86869 Sr(OH) 2 .8H 2 Sr(N0 3 ) 2 1.2553 .09876 Sr(SH) 2 1.7283 .23762 SrS 2 O 3 1.3305 -12401 SrSO* '. BaSO* 0.7868 .89584 TeO 2 Te 1.2508 .09718 TeO 3 Te 1.3762 .13867 Th Th(NO 3 ) 4 4H 2 O 0.4207 .62393 ThO 2 0.8700 -94399 Ti TiO 2 0.6007 .77866- U Na 2 U 2 Ot 0.7511 .87568 UO 2 0.8817 .94532 U 3 O 8 0.8482 .92852 W WO 3 0.7931 .89933 Y Y 2 O 3 0.7876 .80631 Zn ZnO 0.8035 -90496 ZnS 0.6710 .82675 ZnO ZnS 0.8352 .92179 ZnS ZnO I.I973 -07821 ZnSO4.7H 2 O ZnO 3-5329 -548i3 ZnS 2.9507 .46992 Zr ZrO 2 0.7300 .86864 22 334 GAS FACTORS. Grams per M3 X 43-7 = grains per 100 cubic feet. Grams per M3 X 0.437 grains per cubic foot. Grains per cubic foot X 2.288 = grams per M3. Grains per 100 cubic feet X 0.02288 = grams per M3. Grams per cubic foot X 35-31 = grams per M3. Grams benzine per MS X 0.0088 = gallons per 1,000 cubic feet. I MS of gas at o C. and 760 millimeters = 1.05505 M3 at 15 C. and 760 millimeters. i M3 of gas at o C. and 760 millimeters = 1.0734 M3 at 20 C. and 760 millimeters. i MS of gas at 15 C. and 760 millimeters = 0.94782 MS at o C. and 760 millimeters. i MS of gas at 20 C. and 760 millimeters = 0.93162 MS at o C. and 760 millimeters. Vapor tension divided by total pressure = percentage by volume of vapor in saturated gas. 22.37 liters of any true gas or vapor, at o C. and 760 millimeters pres- sure, has a weight in grams equal to its molecular weight. Hence it follows that the molecular weight of any gas or vapor divided by 22.37 gives the weight in kilos of a cubic meter of that gas. Gas at o C. X 1.367 = volume at 100 C. 335 O M o 8* $ vS * *- O ^O t*** g 8 o ^t -^ "if . M 6 o 6 3 fj O Q rh CS io ON to g o o ON io co M g t^ g ^ o o g g co o o o to O O O O O O M O O M o* O O O o a o 00 CO O o *>. N .w M f^ VO IO VO HH M 00 10 o io ro o t^ rf Q M O ^t" OO O fO O Meter M VO IO t^. o w 1-1 oo 10 O >O rO O l^ rj- O O vo c 10 ^ M fO f^ i M > M o M 2 o- *? H ON o W VO O o ^> _S to 5 St^vO d g ^ fO ^ ""bo w <^ ll II 2 . t t 1 > HH 3.8 i i cs vo bi) So o i-i to 10 O w N O cs M M a* /*"S> S w O O 10 M v> O D til rr 1 O O O M rj-vD CO MO rt B w C W 06 IO M * I M 3 N" 11| w ft &"J3 fc 10 g TJ- g) rO ^ ?i*J > "q M co c/3 1 ON rO VO o oo co C^H II II II OO>HOOO-I^O CO ^f oo o C o II II II Sr"* bio M CO^^ o cT M o o 10 M o' M' d 1" tA 6 H g a i-i 10 CO t^ O Tt O . T^- HH CO CN M M 00 ro P IO O C r^ co -. vO CO M G || % 3-^ S? ? ON CO % O O rj- O CN * CN O S M Is (N CO M co ON ON M i, CO 85 IF ~ t^ M CN M O O co M 3 ? | vO O CO 5 $" * CN M X 00 VO rj- CO CN t^ CN "sT S V CJ ON 10 CN TJ- M CO o P fl VO M vo O O O O t^ CO O 5f * co co VO Tj- OO VO co CO ^ CN o n- o o o 1 1 * &" M O O O O O o o o imeter = 14.2232 pounds per '.2048 pound per square foot. square meter = 0.091 gross OJ 1 II VH' 3 1 n cu * I cn . cu 03 1 o a -n cy "S S -s a> .C IH s s 'M O^ cu G ft I? H cu ON O N VH ,J CU II 3 en ^C U g Ui CU CU CU ^ Cti CU CU cn 2 S s 1 o "S CU S ft ^ ro tu ^ Pn cu IH cu cn H G ? CU 03 rt o M s & %z H. en x-s en >> JS Q u! *3 u cu 1-1 -*2 cu qj o o ft d ft a S -H x ' en CJ 8 X cu o ^2 S o O V s * c^J ft 3 cn 15 fO ^t &as t N_^- lJ CN 00 || fe ON o 00 || ft *> TJ- S o M O cn - -g ^ >> li S II ll Mi - 1 "I "> *0 cu ft g b^ c 9 *- t; si N lr 03 ,d ^ i N i t J3 O J3 j_ D^ G en '** en Q^ II & g . cn J5 s_ cu e C 4i ** &s 1 * I cu a ft o "S s o 2 ft bo M M &| n a C CL cu .1-1 cn O So C cu -*- o cu -rj ,d a s s g * JQ HH 14 t^ ro 339 3 ! 2 8 4 o s I a * & J 5 a o H & o 9 '* M . S g i ^^ & "5 .ti 5 z 3 8> s*i to ^3 . o H f * w J B ^ c ^ ^ so. il p o*2 j Icl Name of gas or vapor n^OI^-^l- i/5 04 r w /5\g ON O T> 1---00 1^ LO P) ^^SofofofofofS'SofSSofof C S'S .' 2 >*S**SS .' ' i .' .' ' N u-j 10 ej q <* q i q vq oq q IN N r-. M . "? 9 9 ! 9 N . ". 9? 9 ON co co o_ -; ir> o<_ o_ r>- 10 co o_oo_ < i CO W CN l-OD T- o (S o -r^roiD cu 8&4M:&*2&S8fc*a&a O. CT* ON co cr\ 04_ i-_ n_ 04_ co t~;*O.>O_ O uo . 04 ON*O vOnr^CNOO^f^JNcO^iOOi^O 04 CO 1/5--O 00 ON CO -<3-\O 00 CO Tf . o . **> LO M OOCO^UTJCS MO -00 * ON uS 10^0 00 -^ N "-I iilNPIM -.ncogN* d d o' d d d 6 d d 6 o' o' d d d d 6 d d 6 d d d d d d d 6 d d d d d d d r S o? ONO" co g' F- * oo inx '& 04 \o co o' r^oo o ub ' K i-f 1/5 - vb" F- o> ^ x 8o8S'S-Mt?S x ?!S-n2- < ;2^22-8oT^coKg s o r o^8 < ?2r:3' v S ! ON ON to'o vo * t~ ^ rr O N 04 O\00 - t^ t^ 10x0 ^0 uouoiO t^. if) O^ W ^2 OO OOOO UOC4VO CO^MVO O O^ ^ iO c'JOO CO (S GO *O iO ^ r^od vO iO ^J- cf^vC ^^ffOtOCS -* C) tOr^'^'>-o6od ^ 10 M COCO -*0\r^rOiO of?, d d iS'fti .coo . . i H $ 66 "6 00 ^^5 .10 OOOOOOM o' o' o' M :v<* 1 ++-}- ++ +++ 04 04 M 04 ONX vg >T;cOi-i\O * *> "- 1 * f*3 "- 1 <*5-> oi o' M CM to * w o' o' - SM ^- 1/5 t^OO 04 M ( 04 ON OM-i O4 UO O I M 00 II 04 O t^ I M 10 up\q o< 11 o\ i M ' p-i d 04" M d > g23^*,,'2=,oSS a u*o u cfu cJcJcJcfo'u'tj uu'o o 055 ' 1st Pf o r ill 340 - *i C 88| < 1 O * S s i 1 I S " ^ H fc *l 4J > |o h? tfl * & i*. S2*e o6'3 n RRJ, ;28 : + 1 I COM tOO^iOOxNlNNMTtOON -^-00 >iQt-~ CO Q CO IDvO T ^J" ^d" ^"OO O 1/3OO ^fMOCO OK O O q q - w -; ro co s to co co co Tr . . \q \o to oicococococococococococococotococo w" 6 . T T "1" T . N . J . M . "*. J ( M N o" 00 <9-cOcOcOcocOcOCOcOcOcOtOtOCOcOrOcoi i-iWTtN^Or^OvO "O^O vOvC\OrOO'OcOt^OO-^-t-i'-iO cO^O N CO --rtt^N 1-1 lOCONOO OsCOcOcOCOi-i UOO M -^-CS UOOO <-> M - f>) ^O O CO , i/-) T}-\O COM r*.iOcOC4OOOOOOOO COOO M co tO t^OO ChMt-Tt-cO^^O > M ci Tt" r^-vp 10 u*) 10 10 i:: q q q q q q q q q q q q q q q q q q q q 19 10 o o M cs CO TJ- IO\O t^-CM cO'i'U'iM CS rOcO 1 ^ lO^O T^-tHtHO . .cJcO q o q q q q q q q q q q q q q q q q q q q q q q q . pi M . ' CN co <* in\d cs co -*r 10 pj co Ti-yD t-^od cf O . . M *i M M ei lOO COCOOOO uorOOOO (OCOOOO COOOOOO lOO O OOOON>-i O UOOO 1O . oor--CM3Nr-.Tf^ ooo ioioococo>ot?.0"-. CM f? "? <>< <^ M cooq q N rt- ^r up CTMTJ co >-< co ^- GS oi cl G\vo co-*od u"5Tj-Moo IOM cfs^o lococor^-r^r^coioc^TJ-r^ 1 ^- AUTHORITIES AND METHODS OF CALCULATION In column IX the figures given in Hempel's "Gas Analysis," p. 375, were selected for the fundamental weight of oxygen, nitrogen, hydrogen, carbonic oxide and air. The formula used for the conversion to English units is, grams per liter at o C. and 760 mm. -f 0.05922 = pounds per cu. ft. at 60 F. and 30" pressure. The derivation of the factor employed is 28.316 X 0.0022046 Xso-oo X 492 29.9* X 520 The weights of the compound gases are calculated from these data by Avogadro's law. Column IV is calculated by the formula: sp. gr. = ft ' and the figures thus obtained agree with the theoretical formula, mol. wt. S P' r ' = -5TiT Columns V and VI are taken chiefly from Lunge's "Coal Tar and Ammonia." Column VII is from Ganot's "Physics," edition 1896, page 445. Columns X and XXIII are from Julius Thomsen's "Thermo- chemical Investigations," and his results are translated into English units in columns XI-XII and XXIV-XXV. Columns XIII and XVIII are calculated on the assumption that air == 20.9% oxygen + 79.1% nitrogen by volume. air = 23.13% oxygen -f- 76.87% nitrogen by weight. Comparison of Degrees Baume with Specific Gravity, American Standard, for Liquids Lighter than Water. Sp. gr. , at 60 F. 1.30 -f- B Deg. Baum6 Specific gravity o.o O.I O.2 0.3 0.4 o.5 0.6 0.7 0.8 0.9 10 ii 12 I.OOOO 0.9929 0.9859 0-9993 0.9922 0.9852 0.9986 0.9915 0.9845 0.9838 0.9972 0.9901 0.9831 0.9964 0.9894 0.9825, 0.9818 0.9950 0.9880 0.9811 0-9943 0.9873 0.9804 0.9936 0.9886 0.9997 13 14 15 0.9790 0.9722 0.9655 0.9783 0.9715 0.9649 0-9777 0.9709 0.9642 0.9770 0.9702 0.9635 0.9763 0.9695 0.9629 0.9756 0.9689 0.9622 0.9749 0.9682 0.9615 0-9743 0.9675 0.9609 0.9736 0.9669 0.9602 0.9729 0.9662 0.9596 16 11 0.9589 0.9524 0-9459 0.9582 0.9517 -9453 0.9576 0.95II 0.9447 0.9569 0.9505 0.9440 0.9563 0.9498 0.9434 0.9556 0.9492 0.9428 0.9550 0.9485 0.9421 0-9543 0.9479 0.9415 0-9537 0.9472 0.9409 0.9530 0.9466 0.9402 19 2O 21 0.9396 0-9333 0.9272 0,9390 0.9327 0.9265 0-9383 0.9321 0.9259 0.9377 0.9315 0.9253 0-9371 0.9309 0.9247 0.9365 0.9302 0.9241 0.9358 0.9296 0.9235 0.9352 0.9290 0.9229 0.9346 0.9284 0.9223 0.9340 0.9278 0.9217 22 23 24 0.9211 0.9150 0.9091 0.9204 0.9144 0.9085 0.9198 0.9138 0.9079 0.9192 0.9132 0.0073 0.9186 0.9126 0.9067 0.9180 0.9121 0.9061 0.9174 0.9115 0.9056 0.9168 0.9109 0.9050 0.9162 0.9103 0.9044 0.9156 0.9097 0.9038 2? 0.9032 0.8974 0.8917 0.9026 0.8969 0.8912 0.9021 0.8963 0.8906 0.9015 0.8957 0.8900 0.9009 0.8951 0.8895 H 0.8997 0.8940 0.8883 0.8992 0.8934 0.8878 0.8986 0.8929 0.8872 0.8980 0.8923 0.8866 28 29 30 0.8861 0.8805 0.8750 0.8855 0.8799 0.8745 0.8850 0.8794 0.8739 0.8844 0.8788 0.8734 0.8838 0.8783 0.8728 0.8833 0.8777 0.8723 0.8827 0.8772 0.8717 0.8822 0.8766 0.8712 0.8816 0.8761 0.8706 0.8811 0.8755 0.8701 31 32 33 0.8696 0.8642 0.8589 0.8690 0.8637 0.8584 0.8685 0.8631 0.8578 0.8679 0.8626 0.8573 0.8674 0.8621 0.8568 0.8669 0.8615 0.8563 0.8663 0.8610 0.8557 0.8658 0.8605 0.8552 0.8653 0.8600 0.8547 0.8647 0.8594 0.8542 34 35 36 0.8537 0.8485 0.8434 0.8531 0.8480 0.8429 0.8526 0.8475 0.8424 0.8521 0.8469 0.8418 0.8516 0.8464 0.8413 0.8511 0.8459 0.8408 0.8505 0.8454 0.8403 0.8500 0.8449 0.8398 0.8495 0.8444 0.8393 0.8490 0.8439 0.8388 i 39 0.8383 0.8333 0.8284 0.8378 0.8328 0.8279 0.8373 0.8323 0.8274 0.8368 0.8318 0.8269 0.8363 0.8314 0.8264 0.8358 0.8309 0.8260 0.8353 0.8304 0.8255 0.8348 0.8299 0.8250 0.8343 0.8294 8.8245 0.8338 0.8289 0.8240 40 4i 42 0.8235 0.8187 0.8140 0.8230 0.8182 0.8135 0.8226 0.8178 0.8130 0.8221 0.8173 0.8125 0.8216 0.8168 0.8121 0.8211 0.8163 0.8116 0.8206 0.8159 0.8111 0.8202 0.8154 0.8107 0.8197 0.8149 0.8102 0.8192 0.8144 0.8097 43 44 45 0.8092 0.8046 0.8000 5.8088 0.8041 0-7995 0.8083 0.8037 0.7991 0.8078 0.8032 0.7986 0.8074 0.8028 0.7982 0.8069 0.8023 0.7977 0.8065 0.8018 0.7973 0.8060 0.8014 0.7968 0.8055 0.8009 0.7964 0.8051 0.8005 0-7959 46 % 0.7955 0.7910 0.7865 0.7950 0.7905 0.7861 0.7946 0.7901 0.7856 0.7941 0.7896 0.7852 0.7937 0.7892 0.7848 0.7832 0.7887 0.7843 0.7928 0.7883 0.7839 0.7923 0.7878 0.7834 0.7919 0.7874 0.7830 0.7914 0.7870 0.7826 4 9 50 51 0.7821 0.7778 0.7735 0.7817 0.7773 0.7731 0.7812 0.7769 0.7726 0.7808 0.7765 0.7722 0.7804 0.7761 0.7718 0.7799 0.7756 0.7713 0-7795 0.7752 0.7709 0.7791 0.7748 0.7705 0.7786 0-7743 0.7701 0.7782 0-7739 0.7697 52 53 54 0.7692 0.7650 0.7609 0.7688 0.7646 0-7605 0.7684 0.7642 0.7600 0.7680 0.7638 0.7596 0.7675 0.7634 0.7592 0.7671 0.7629 0.7588 0.7667 0.7625 0.7584 0.7663 0.7621 0.7580 0.7659 0.7617 0.7576 0.7654 0.7613 0.7572 57 0.7568 0.7527 0.7487 0.7563 0.7523 0.7483 0-7559 0.7519 0.7479 0-7555 0.7515 0-7475 0.7551 0.7511 0.7471 0-7547 0.7507 0.7467 0-7543 0.7503 0.7463 0-7539 0.7500 0-7459 0-7535 0-7495 0-7455 o.753i 0.7491 0-7451 58 59 60 0-7447 0.7407 0.7368 0-7443 0.7403 0.7365 0-7439 0.7400 0.7361 0-7435 0.7396 0.7357 0.7431 0.7392 0-7353 0.7427 0.7388 0-7349 0.7423 0.7384 0.7345 0.7419 0.7380 o.734i 0.7415 0.7376 0.7338 0.7411 0.7372 0.7334 61 62 63 0.7330 0.7292 0.7254 0.7326 0.7288 0.7250 0.7322 0.7284 0.7246 0.7318 0.7280 0.7243 0.7315 0.7277 0.7239 0.7311 0.7273 0.7235 0.7307 0.7269 0.7231 0.7303 0.7265 0.7228 0.7209 0.7261 0.7224 0.7295 0.7258 0.7220 64 65 66 0.7216 0.7179 0.7143 0.7213 0.7176 0.7139 0.7209 0.7172 0.7136 0.7205 0.7168 0.7132 0.7202 0.7165 0.7128 0.7198 0.7161 0.7125 0.7194 o.7i57 0.7121 0.7191 0.7154 0.7117 0.7187 0.7150 0.7114 0.7183 0.7147 0.7110 67 68 69 0.7107 0.7071 0.7035 0.7103 0.7067 0.7032 0.7099 0.7064 0.7028 0.7096 0.7060 0.7025 0.7092 0.7056 0.7021 0.7089 0.7053 0.7018 0.7085 0.7049 0.7014 0.7081 0.7046 0.7011 0.7078 0.7042 0.7007 0.7074 0.7039 0.7004 70 7i 72 0.7000 0.6965 0.6931 0.6997 0.6962 0.6927 0.6995 0.6958 0.6924 0.6990 0.6955 0.6920 0.6986 0.6951 0.6917 0.6983 0.6948 0.6914 0.6979 0.6944 0.6910 0.6976 0.6941 0.6907 0.6972 0.6938 0.6903 0.6969 0.6934 0.6900 73 74 75 0.6897 0.6863 0.6829 0.6893 0.6859 0.6826 0.6890 0.6856 0.6823 0.6886 0.6853 0.6819 0.6883 0.6849 0.6816 0.6880 0.6846 0.6813 06876 0.6843 0.6809 0.6873 0.6839 0.6806 0.6869 0.6836 0.6803 0.6866 0.6833 0.6799 76 77 78 0.6796 0.6763 0.6731 0.6793 0.6760 0.6728 0.6790 0.6757 0.6724 0.6786 0.6753 0.6721 0.6783 0.6750 0.6718 0.6780 0.6747 o 6715 0.6776 0.6744 0.6711 0.6773 0.6740 0.6708 0.6770 0.6737 0.6705 0.6767 0.6734 0.6702 79 80 0.6699 0.6667 0.6695 0.6692 0.6689 0.6686 0.6683 0.6679 0.6676 0.6673 0.6670 CONVERSION TABLE FOR CONVERTING BaSO 4 TO SULPHUR. Mgs. of BaSO 4 Milligrams of Sulphur 0.0 O.I O.2 o.3 0.4 0-5 0.6 0.7 08 0.9 p i 2 o.oo 0.14 0.28 O.OI 0.15 .29 0.02 0.17 0.30 0.03 0.18 0.32 0.04 0.19 0.33 0.06 0.21 0.34 0.08 0.22 0.36 O.OIO 0.23 0-37 O.OI I 0.25 0.39 0.012 0.26 0.40 3 4 5 0.41 0-55 0.68 43 .56 .70 0.44 0.58 0.72 0-45 0-59 0-73 0.47 0.60 0.74 0.48 0.62 0.76 0.49 0.63 o.77 0.51 0.65 0.78 0.52 0.66 0.80 0-53 0.67 0.81 6 7 8 0.82 0.96 1. 10 .84 .98 .11 0.85 0.99 13 0.86 1. 00 14 0.88 1. 02 1.16 0.89 1.03 1. 17 0.91 1.04 1.18 O.Q2 1. 06 1.20 0-93 1.07 1. 21 o-95 1.09 23 9 10 it 1.24 1-37 I-5 1 25 39 53 .27 .40 54 .28 42 55 1.29 1-43 1-57 I-3I 1.44 1.58 1.32 1.46 1-59 1-33 1-47 1.61 1-35 1.49 1.62 36 50 .64 12 13 14 1.65 1.79 1.92 .66 .80 1.94 .68 .81 1-95 69 83 1.97 1.70 1.84 1.08 1.72 1.86 1.99 1-73 1.87 2.01 1-75 1.88 2.02 1.76 1.90 2.03 77 9i 2.05 15 17 2.06 2.20 2.34 2.08 2.21 2-35 2.09 2.23 2-37 2.10 2.24 2.38 2.12 2.26 2-39 2.13 2.27 2.41 2.15 2.28 2.42 2.l6 2-30 2.44 2.17 2.31 2-45 2.19 2.32 2.46 18 19 20 2.48 2.61 2.75 2.49 2.63 2.77 2.51 2.64 2.78 2.52 2.66 2-79 2.53 2.67 2.81 IS 2.82 2.56 2.70 2.84 2.57 2.71 2.85 2-59 2-73 2.86 2.60 2-74 2.88 21 22 23 2.89 3.03 3.16 2.90 3-04 3-i8 2.92 3-06 3J9 2-93 3-07 3-21 2.95 3.08 3.22 2.96 3-10 3-23 2-97 3-ii - 3-25 2.99 3.12 3.26 3.00 3-14 3-27 3-oi 3-15 3-29 24 II 3-30 3-44 3-58 3-12 3.45 3-59 3-33 3-47 3-6i 3-34 3.48 3-62 3.36 3-49 3-63 3-37 3-51 3.65 3-39 m 3.40 3-54 3.67 3-41 3-55 3-69 3-43 3.56 3-70 3 29 3-71 3.85 3-99 3-73 3-87 4.00 3-74 3-88 4.02 3.76 3.89 4-03 3-77 3.9i 4-05 3-78 3-92 4.06 3-80 3-94 4.07 3-8i 3-95 4.09 3-82 3.96 4.10 3-84 3.98 4.11 30 3i 32 4.13 4.26 4-40 ' 4-14 4.28 4.41 4-15 4.29 4-43 4-17 4-30 4-44 4.18 4-32 4.46 4.19 4-33 4-47 4.21 4.22 4-36 4-50 4.24 4-37 4-51 4-25 4-39 4-52 33 34 35 4-54 4.68 4.81 4.83 4-57 4.70 4.84 4.58 4.72 4.86 4-59 4-73 4.87 4.61 4-75 4.88 4.62 4.76 4.90 4-63 4-77 4-91 4-65 4-79 4-92 4.66 4.80 4-94 36 y 4-95 5-09 5-23 4-97 5-10 5-24 4.98 5-12 5-26 4-99 5-13 5-27 5-01 5-15 5.28 5-02 5.16 5.30 5-03 5-17 5-3 1 5-05 5-19 5-33 5-06 5-20 5-34 5.08 5-22 5-35 39 40 4i 5-37 5-50 5-64 5.38 S 5-39 5-53 567 5-41 1! 5-42 5-56 5-70 5-44 5-57 5-71 5-45 559 5-72 5-46 5-60 5-74 5.48 5.61 5-75 5-49 5.63 5-77 42 43 44 5-78 5-92 6.05 5-79 5-93 6.07 5-8i 5-94 6.08 5-82 5.96 6.09 5-83 5-97 6.11 5.85 5.98 6.12 5-86 6.00 6.14 5-87 6.01 6.15 5-89 6.03 6.16 5-90 6.04 6.18 9 47 6.19 6.33 6.47 6.20 6.34 6.48 6.22 6.36 6.49 6.23 6.37 6.51 6.26 6.38 6.52 6.26 6.40 6.53 6.27 6.41 6.55 6.29 6.42 6.56 6.30 6.44 6.58 6.31 6.45 6-59 48 49 50 6.60 6.74 6.88 6.62 6.75 6.89 6.63 6.77- 6.90 6.64 6.78 6.92 6.66 6.80 6-93 6.67 6.81 6.94 6.69 6.82 6.96 6.70 6.84 6.97 6.71 6.85 6.99 6.73 6.86 7.00 5i 52 53 7.01 7-15 7.29 7-03 7.16 7.30 7.04 7.18 7-3i 7-05 7.19 7.33 7.07 7.20 7-34 y.o8 7.22 7.36 7.10 7-23 7-37 7.11 7-25 7.38 7.12 7.26 7.40 7.14 7.27 7-41 54 n g 7-44 7.58 7.71 7.45 7-59 7-73 7-47 7.60 7.74 7.48 7.62 7.76 7-49 7.63 7-77 7-5 1 m 7 .8o 7-54 7.67 7.81 j'te il 59 8.12 7.85 7-99 8.13 7.87 8.01 8.14 7.88 8.02 8.15 7.89 8.03 8.17 7.91 8.05 8.19 7.92 8.06 8.20 7-94 8.08 8.21 7-95 8.09 8.23 7.96 8.10 8.24 60 61 62 8.26 8.39 8-53 8.27- 8.41 8.55 8.28 8.42 8.56 8.30 8.43 8.57 8.31 8.45 8-59 8.32 8.46 8.60 8.34 8.48 8.61 8-35 8.49 8.63 8-37 8,50 8.64 8.38 8.51 8.66 8 6 5 8.67 8.81 S.QS 8.68 8.82 8.96 8.70 8.84 8-97 8.71 8.85 8.99 8.73 8.86 Q.OO 8.74 8.88 9.02 8.75 8.89 9-03 8.77 8.90 9.04 8.78 8.92 9.06 8.79 8-93 9.07 66 67 68 9.09 9.22 9.36 9.10 9.24 9.38 9.11 9-25 9-39 9-13 9.27 9.40 9.14 9.28 9.42 9-15 9.29 9-43 9.17 9-31 9-45 9.18 9-32 9.46 9.20 9-33 9 47 9.21 9-35 9-49 69 70 7i 72 9-50 9-63 9-77 9.91 9-52 9.64 9.78 9.92 9-53 9.66 9.80 9-93 9-54 9.67 9.81 9-95 9-57 9.68 9-82 9.96 9-57 9.70 9-84 9.98 9-59 9.71 9.85 9-99 6.60 9-73 9.86 10.00 9.61 9-74 9.88 10.02 9.62 9-75 9.89 10.03 344 CURVE FDR CALCULATING LJLL AEE5 OF CYLINDRICAL TANK5 WITH CURVED HEADS IN HDRIZDNTALFD5ITIDN. ft h ls< s U 3 it 2t /j o n z 25 JO 4-0 AJ 345 INTERNATIONAL ATOMIC WEIGHTS. Revision of 1915 As Published by the American Chemical Society. Name of element Symbol Atomic Weight Name of element Symbol Atomic Weight Al Sb A As Ba Bi B Br Cd Cs Ca C Ce Cl Cr Co Cb Cu & Eu F Gd Ga Ge Gl Au He Ho H In I Ir Fe Kr La Pb Li Lu Mg Mn Hg Mo 27.1 IO2.2 39.88 74.96 137-37 208.0 II.O 79. 9 2 112.40 40.07 I32.8I 12. OO 14025 3546 52.0 58.97 93-5 63.57 162.5 167.7 152.0 19.0 157.3 69.9 72.5 9.i 197.2 3-99 163.5 i. 008 114.8 126.92 I93- 1 55.84 82.92 139.0 207.10 6.94 174.0 24.32 54-93 200.6 96.0 Nd Ne Ni Nt N Os O Pd P Pt K Pr Ra Rh Rb Ru Sa Sc Se Si Ag Na Sr S Ta Te Tb Tl Th Tm Sn Ti. W U V Xe Yb Yt Zn Zr 144-3 20. 2 58.68 222.4 14.01 I 9 0.9 16.00 106.7 31.04 195-2 39- 10 140.6 226.4 102.9 8545 . 101.7 150.4 44.1 79.2 28.3 107.88 23.00 87.63 32.07 181.5 127.5 159-2 204.0 2324 168.5 119.0 48.1 184.0 238.5 51-0 130.2 172.0 89.0 65.37 90.6 Nickel Niton (Radium Praseodymium .... Rhodium Pnhalt Ruthenium Scandium Silver Sulfur Pnlrl Tellurium Terbium Thallium Thulium Tin Lanthanum T pad Ytterbium (Neoyt- terbium Yttrium Zinc INDEX. A ACID PAGE in oils 230 in tar 199-205 carbonic, in air 243 carbonic, in boiler scale 240 carbonic, in gas 120 AIR composition of volume and weight 341 determination of carbon monoxide in (see Gas Analysis) determination of carbon dioxide in 243 ALKALIES in ash 224 in cement 272 in fire-clay 224 in water 215 alkalinity of boiler water 214 ALUMINUM in boiler water 214 in bolier scale 214 in fire-brick 223 in fire-clay 223 AMMONIA in concentrated liquor 133 in gas 167 in weak liquor 133 in waste liquor 133 AMMONIUM SULPHATE analysis of 152 impurities in 153 free acid in 152 ASBESTOS analysis of (see Refractories) ASH general analysis 42 determination of, in coke and coal 17-30 ATOMIC WEIGHTS table of 345 B BABBITT METAL analysis of 238 347 BAUME HYDROMETER TABLE correspondence with specific gravity ....................... 342 correction table ........................................... 236 BEARING METAL analysis of ............................................... 238 BENZENE in gas .................................................... 79 in tar .................................................... 197 in drip oil ................................................. 186 analysis of commercial product ............................ 180 BENZOL (see Benzene) BOILER scale, analysis of ........................................ ' . . 213 water, analysis of ......................................... 213 BOILING POINT determination of .......................................... 53 BROMINE NUMBER determination of ......................................... 44 BRONZE (see Bearing Metal) C CALCIUM OXIDE in lime ................................................... 239 CALORIFIC VALUE determination of, in coal ................................... 30 determination of, in coke .................................. 30 determination of, in gas ................................... 112 determination of, in oil .................................... 30 determination of, in tar (see Oil) CARBON determination of, in steel .................................. 273 fixed, determination of, in coal and coke ................... 17 free, determination of, in tar .............................. 197 total, determination of, in iron and steel .................... 273 CARBONATES determination of, in boiler scale (see Lime) determination of, in lime .................................. 240 determination of, in water (see Water Analysis) CARBONIC ACID (see Carbon Dioxide) CARBON DIOXIDE in air .................................................... 243 in furnace gases .......................................... 120 in illuminating gas ........................................ 84 CARBON DISULPHIDE in gas .................................................... 1 78 348 CEMENT PAGE general 243 analysis of 270 testing of 244 CHIMNEY GASES (see Fuel Gases) CHLORINE determination of, in water 214 CHROMIUM determination of, in steel 297-306-321-324 Cl,AY (FlRE) analysis of 221 CO 2 (see Carbon Dioxide) COAL analysis of 3 determination of nitrogen 28 determination of oxygen 29 elementary or ultimate analysis 24 heating value, determination of 30 proximate analysis of 12 determination of sulphur 18 COKE analysis of (see Coal) shatter test 37 COLD TEST OE OILS 237 COMBUSTIBLE GASES heating value 112 CONGEALING TEST (see Cold Test) CONVERSION TABLE metric to English 335-336-337 chemical 328-329 COPPER determination of, in alloys 238 in steel 294 CYANOGEN in coal gas 177 in spent oxide 156 in cyanide mud 156 D DEAD Oil, analysis of (see Tar products) 349 DISTILLATION PAGE method for creosote oil 200 method for drip oil 186 method for gas oil 46 method for tar 193 DRIP Oily analysis of 186 DEW POINT OF GAS determination of 126 E ENGLER VISCOSIMETER description and use 233 ETHYLENE determination of, in gaseous mixtures 86 ETHANE determination of, in gaseous mixtures 86 F FATS AND FATTY ACIDS IN LUBRICATING OIL determination of 230 FERRIC OXIDE analysis of new 59 analysis of spent 65 FIRE SAND (see Fire-Clay ) FIXED AMMONIA determination of 145 FIXED CARBON determination of, in coal and coke 17 FLASH AND FIRE TESTS OF OILS methods of determination, gas oil 48 lubricating oil 233 FLUE GASES (see Furnace Gases) FOULING TEST FOR PURIFYING OXIDE method 63 FUEL OIL analysis of 42 heating value of 30 FURNACE GASES analysis of 120 23 350 GAS PAGE general properties table 339 analysis of coal and water gas by U. G. I. modification of Hempel's apparatus 71 Elliot apparatus 89 Morehead apparatus 96 analysis of flue gas 120 cyanogen in gas 177 ammonia in gas 167 hydrogen sulphide, determination of 160 sulphur, total determination of by Referee test apparatus... 169 calorimeter, Junkers 112 factors 334 naphthalene in 173 carbon disulphide 1 78 GASES AND VAPORS table of constants 339 GAS Oil, analysis of 42 heating value 52 H HARDNESS OF WATER determination 213 HEATING VALUE OF COAL determination in calorimeter 30 determination of gas 112 determination of oil 30 HYDROGEN determination of, in coal and coke 24 determination of, in gases 88-123 HYDROGEN SULPHIDE determination of, in gas 160 HYGROMETER use of 126 I IRON oxide, analysis of 59 oxide (sponge) , analysis of 59 IRON CARBONYL determination of, in gas 179 K KJEU)AHI/S METHOD PAGE for the determination of nitrogen 28 L LEAD in bearing metal 239 in bronze and brass 239 in Babbitt metal ' . 238 in solder 238 LIGHT On, analysis of 199 LIME determination of, in boiler scale (see Water Analysis) determination of, in boiler water 215 analysis of 240 LUBRICATING OILS analysis of 228 M MAGNESIA in lime 243 in cement 272 in refractories 224 in water 215 MANGANESE in iron and steel 281-302 MARSH GAS determination of 86 METHANE (see Marsh Gas) METRIC SYSTEM tables of English equivalents 335~33O-337 MIDDLE OILS analysis of (see Tar Oils) MOISTURE in coal and coke 12 in oxides 60 MOLECULAR WEIGHT determination of 53 352 N NAPHTHALENE PAGE in gas 173 in tar 186-199 melting point of 211 NICKEL in steel 295-300 NITROGEN in coal and coke 28 O OILS creosote 200 gas 42 lubricating 228 tar 199 OLIFIANT GAS (see Ethylene) OXIDE FOR GAS PURIFICATION analysis of 59 fouling test 63 OXYGEN in flue gas 123-124 in illuminating gas 85 in coal 24 P PAINT analysis of 217 PHENOL in tar 199 PHOSPHORUS in iron and steel 284-312 in coal and coke 24 PIGMENTS analysis of, in paint 217 R REFEREE TEST description of method and apparatus 169 REFRACTIVE INDEX determination in oils 52 REFRACTORIES analysis of 221 353 S SAMPLING PAGE coal and coke 4-8 gas 71 oxide 65 tar 130 SILICA in iron and steel 292 in refractories 222 in water 214 SOLDER analysis of 237 SOLIDS, TOTAL in water 213 SPECIFIC GRAVITY of coke 38 of gases in of oils 56-137-205 STEEL analysis of 273 SULPHATES in water 215 in boiler scale (see Water Analysis) SULPHUR in coal and coke 18 in oil 57 in gas 169 in iron and steel 288 free, in spent oxide 67 total, in spent oxide 66 SULPHURETED HYDROGEN in gas 160 T TABLES atomic weights 345 calculating water analysis 328 conversion of barium sulphate to sulphur 343 conversion of English to metric 335~33^-337 conversion of specific gravity to Baume 342 conversion of elements to compounds 329 curve for calculating ullages of tanks 344 354 TAR PAGE analysis of 130 acids 200 free carbon in 197 in spent oxide 67 water in 132-190 TIN in bearing metal 239 in bronze 239 in solder 237 TITANIUM in fire-brick 225 V VANADIUM in steel - 317-325 W WATER boiler, analysis of 213 estimation of, in tar 132-190 Z ZINC determination of, in brass 239 THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW AN INITIAL FINE OF 25 CENTS WILL BE ASSESSED FOR FAILURE TO RETURN THIS BOOK ON THE DATE DUE. THE PENALTY WILL INCREASE TO SO CENTS ON THE FOURTH DAY AND TO $1.OO ON THE SEVENTH DAY OVERDUE. Off: j-r DO^ ' 1 wo DEC tOT33 MAY 18 19- 8 t aOAug'eovr .wD -^ H- - w r C ^ stvs epi'lT ON \ l L JAN 1 *t 1938 U. C. BERKELEY LD 21-100m-8,'34 UNIVERSITY OF CALIFORNIA LIBRARY