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APPLICATIONS for loan contracts for the exploration, development and mining of strategic and critical metals and minerals are now being accepted by the Department of the Interior. The RFC is authorized and directed by Executive Order 10161 to make such loans but the Secretary of the Interior must pass on the necessity for the loan. Applications should be addressed to James Boyd, acting deputy administrator, Defense Minerals Administration, Department of the Interior, Washington, D.C. rather than to the Field Offices of the Bureau of Mines as was first planned. Application forms are not yet available but it has been learned that data accompanying the application should include the known quantity and grade of reserves, the anticipated rate of production, the equipment, supplies, and man power required for the additional production, etc.

Jan 12, 1950

Robert T. Hill, Washington, D. C.: Having studied very minutely the geology of the district referred to by Prof. Branner, I beg to state that his quotation of my classification of the Cretaceous deposits of Arkansas is not the one which I originally gave,* nor is it the one which has since been published and is now generally accepted.? I did not assign ally of the Cretaceous formations of Arkansas to the " middle Cretaceous,"

Jan 1, 1898

By NEWTON B. KNOX

PERU, lying south of Ecuador and having common frontiers with Brazil, Chile, and Bolivia, includes over a thousand miles of the Andean mountains. The coastal plain is arid and narrow and the Amazonian jungle region is of interest only on account of its oil and gold placer possibilities. The mountain zone, however, here forms one of the world's most highly mineralized regions. The Peruvian Andes, like their Bolivian and Ecuadorian counterparts, form two distinct chains separated by the great Apurimac and Maralion valleys; but these rivers cut through the Eastern range to join the Amazon drainage, and the central valley is missing north of the passes thus formed by these rivers; the localities where the ranges are joined are aptly called knots. In addition, in central Peru, there exists a third range lying to the east of the first two and separated from them by the Urubamba and Huallaga Rivers. The Eastern range, however, is of little importance to the miner for few metal deposits are to be found therein except for the gold mineralization in the South. In general, deposition of metals in the Peruvian Andes accompanied igneous intrusions which invaded the folded Paleozoic and Mesozoic rocks during the Tertiary; thus the ore bodies are all typical of shallow or moderate depths.

Jan 1, 1945

By Leo J. Miller

It is both an honor and a pleasure for me to be the keynote speaker for the Paul F. Kerr's Symposium on Applied Mineralogy. Professor Kerr was a man for all seasons to his students, and he treated all students as distinct individuals. Philip Bethke in his memorial to Dr. Kerr summed up our remembrance best by stating that "We have lost our most successful educator-administrator-scholar, who was our steadfast teacher-counselor-mentor-friend." His unique trait was the ability to bring out the best in a variety of individuals In order that their performance was at the peak of quality.

Jan 1, 1985

By Edward Keller

THE present ruling principle in shop and factory, induced by conditions of. keen competition, is to do the greatest amount of work in the shortest time, or in other words, to secure the greatest output at least cost, a condition which generally necessitated the substitution of machinery for manual labor. The chemical laboratory in our industrial establishments has remained a factor of minor importance, and, for this, reason, not only has progress been permitted to lag, but the methods of analytical work have been carried on along individual traditional lines. Some works-laboratories are equipped with such conveniences as Gooch filters, suction-pumps, compressed air, shaking-machines, centrifugal machines, crushers, etc., yet there is much room for improvement, particularly in laboratories of metal smelting and refining plants, in which long series of filtrations and stirrings are performed singly by hand in a slow and laborious manner. There are also many other instances in which collective handling appears rational. As a rule the chemist wastes much time by such manual labor, which, in a modern establishment and under up-to-date management, could be more advantageously applied to useful chemical work; and such higher chemical work is gradually and surely becoming recognized as an essential extension of old-time methods of assaying. While it maybe said that in some laboratories, boys and not chemists do the manual labor, it should be borne in mind that all chemical work requires care and accuracy and in these respects boys are naturally a source of concern to the responsible chemist. Moreover, the cheapness of child-labor is largely offset by the increase in the expense-account of laboratory materials, caused chiefly by breakages resulting from care¬lessness. Having; been authorized by the Anaconda Copper Mining

Mar 1, 1905

By AIME AIME

AMERICAN participation in the World Engineering Congress in Japan will be generous. Nearly seventy papers have been prepared and for- warded for printing and the A. I. M. E. is well represented in the list. At our San Francisco meeting four of these will be briefly reviewed by the authors for the benefit of those who are unable to go on to Tokyo. They constitute a group dealing with the present economic status as seen by engineers of the world's iron, coal, petroleum and non-ferrous metals. Messrs. Leith, Smith and Tryon, Requa, and Probert have written papers that constitute a notable series. Messrs. Jeffries, Sweetser and Kinney, and other Institute members have written papers dealing more closely with technologic progress. The latest list of delegates and members is printed below, names of A. I. M. E. members being set in italics.

Jan 1, 1929

By AIME AIME

MINERAL production of the United States is valued at over five billion dollars a year at present and the industry employs close to a million workmen, yet such maps as are available that might indicate the geographical distribution of this industry show only the location of coal and oil fields and of other mineral deposits. No recent map is available that shows this distribution in a quantitative way. The purpose of the maps and graphs here presented is twofold: (1) to give the mining engineer a clear conception of the relative value and the pattern of distribution of minerals in the United States; (2) to test the so-called block-pile (or grouped pillar) system of statistical mapping, which makes this presentation possible. (I discussed this method of mapping in an article which appeared in Economic Geology in 1939, Vol. 15, p. 185-188.)

Jan 1, 1941

By J. Hall Carpenter, James E. Lawver

Shortly after the passage of the Taconite Amendment in Minnesota, several mining companies announced their intention to build new magnetite taconite plants and another announced its intention to augment present facilities. It is clear that Minnesota will enjoy an expanding magnetite taconite industry, but despite the fact that the reserves are large, eventually they will have to be supplemented by oxidized deposits. Furthermore, not all producers have magnetite taconite reserves. Due to the extensive oxidation of most of the western part of the Mesabi Range, there are no large blocks of unaltered magnetite taconite that lend themselves to open pit operations. Unless a commercial process can be developed to concentrate the oxidized, or so- called "nonmagnetic", taconite and semi-taconite, the existing mines operating in the western part of the range will be forced to shut down when the direct shipping, wash and gravity ores are depleted, or are no longer salable, because of their poor quality compared to high-grade pellets. KNOWN PROCESSES COSTLY The enormous reserves of the oxidized iron- bearing formation have offered a tantalizing challenge to metallurgists for many years. In fact, several processes for concentrating certain types of oxidized ore have been successful at both laboratory and pilot plant level, but to date no process for concentrating semitaconite or oxidized taconite has reached commercial fruition. Magnetic roasting, followed by low-intensity magnetic separation1, has shown considerable promise because the high iron recovery makes the ratio of concentration of many of the oxidized ores more favorable than that of magnetite taconite. However, the capital and operating costs are high and, in many cases, a high- grade concentrate cannot be made without resorting to flotation of the magnetic concentrate. Hence, most research groups are investigating alternate methods of concentration with the hopes of reducing the cost.

Jan 9, 1965

By AIME AIME

T HE Board of Directors of the A. I. M. E. held a meeting at Institute headquarters on Jan. 28, 1921. There were present 10 directors and 14 guests, the secretary and the assistant secretary. The following actions of the Executive and Finance Committees were approved: Wilkes-Barre Meeting, Sept. 12 to 17, 1921; authorization of Oregon Section; authorization of Upper Peninsula Section; appointment of Philip W. Henry and Thomas H. Leggett on special committee on Code of Ethics; and presentation of five copies of Raymond Memorial Volume to T. A. Rickard, who edited it. The By-Laws of the Ohio Section were approved. The resolutions in reference to the payment of certain contributions and assessments to the Library Board of the United Engineering Societies, adopted by the Board of Directors on June 27, 1919, were rescinded, and the resolution adopted that the income of the James Douglas Trust of $100,000 be paid over to the Library or otherwise applied by it for the purpose of maintaining the Scientific Library of this Institute in such manner as may be deemed advisable in furtherance of the purposes of such trust, and that said income shall be paid on account of and included in. the assessment levied by the United Engineering Societies on the Institute for the maintenance of the joint libraries of the Founder Societies.

Jan 1, 1921

By O. F. Walker, W. C. Hahn, V. A. Johnson, J. D. Wood

The diffusion coefficients of zinc in single-crystal zinc and carbon in single-crystal and poly crystalline nickel were measured by means of radioactive tracer techniques both with and without the application of ultrasonic vibrations under conditions such that the temperature of the sample was closely controlled. The results of this investigation indicate no enhancement of diffusion in any of the samples. It is suggested that previously reported enhancement may have been due either solely to temperature increases caused by ultrasonic vibrations or in combination with changes in the boundary conditions. A number of observations have been reported in the literature in which it has been implied or inferred that the application of ultrasonics enhances diffusion (see, for example, Refs. 1-5). The present study was undertaken in an attempt to observe this effect under carefully controlled conditions, particularly with regard to measurement and control of the temperature of the sample. Two different types of systems were studied; these were the self-diffusion of zinc and the diffusion of carbon in nickel. EXPERIMENTAL For diffusion with ultrasonic energy applied, the samples were included as part of a resonant ultrasonic system operating at 58.5 kcps. The ultrasonic generators used were rated at 100 and 250 w and could be tuned over a frequency from 10 to 100 kc. A PZT (lead titanate/lead zirconate) ceramic transducer provided the driving vibration. This system requires no metallurgical joining of the specimen to the acoustical transmission line since the ultrasonic driver and the follow-up section clamp the specimen in position by means of a constant pressure of 50 lb developed by an air cylinder. The ultrasonic driver and follow-up section, both made of titanium, were 4 in. in length from clamping point to the end in contact with the specimen. Using the relationship given by Mason,6 A = V/f, the resonant wavelength, A, in titanium is calculated to be 3.3 in. at a frequency, f, of 58.5 kc, taking the velocity of sound in titanium, V, as 1.95 X 105 in. per sec. The 4-in. driver and follow-up section, therefore, are each 4.0/3.3 =1.21 times the resonant wavelength. Clamping pressure must be applied at stress nodes of the transmission line in order to preserve resonance. Therefore, a specimen length of 0.58 times the wavelength in the specimen was required to place the clamping pressure application points at stress nodes exactly three wavelengths apart. A stress antinode was contained in the center 3 in. of the specimen. A small PZT ceramic disc attached to the follow-up section provided an output voltage proportional to the intensity of the standing wave. This output voltage was monitored on an oscilloscope and the ultrasonic system was tuned to resonance by varying the frequency until the output signal was a maximum amplitude. The amplitude of the output signal was maintained constant throughout the diffusion anneal. A split cylindrical stainless-steel chamber, which was purged with argon prior to and during the runs, was placed around the specimen. The chamber in turn was surrounded by a movable furnace whose temperature could be controlled to 7C. Heat exchangers were used to cool the driver, follow-up section, and ultrasonic transducer. Great care was taken to obtain the true specimen temperature in all cases. Several different methods were tried; the most successful was that in which the thermocouple was held in contact with the midlength of the specimen by means of an asbestos insulating pad and wire straps. In the case of zinc, single-crystal specimens of 99.999 pct purity were used. The samples were 0.25 by 0.25 in. square and of the proper length for resonance, that is 1.1 in. long with the c axis parallel to the long dimension of the specimen for the case of diffusion perpendicular to the c axis and ultrasonic motion parallel to the c axis, and 1.9 in. long with the c axis perpendicular to the long dimension of the specimen for the case of diffusion parallel to the c axis and ultrasonic motion perpendicular to the c axis. In each case, one of the rectangular faces was electroplated with a thin film of zinc containing Zn The constant pressure used to clamp the specimen in place in the ultrasonic system caused some deformation in some of the samples. For these samples the deformation was concentrated in either end of the specimen; thus, for all samples (both zinc and nickel) the center in. was cut from the specimen after the diffusion anneal to be used for sectioning and counting. The nickel single-crystal samples, of 99.999 pct purity, were used in the form of rods 0.25 by 0.187 by 2.07 in. long with the (100) direction parallel to the rod axis. The polycrystalline nickel samples of 99.97 pct purity had an average grain diameter of 0.007 in. and were used in the form of rods 0.25 by 0.125 by 1.87 in. long. The direction of ultrasonic motion was parallel to (100) direction (bar axis) for the single-cqstal samples and parallel to the bar axis for the polycrystalline specimens. A thin film of c14 suspended in methanol was applied to the diffusing face of the specimen. Two specimens were butted together lengthwise for each diffusion anneal to minimize oxidation. After diffusion, a precision lapping device similar to the one described by Goldstein7 and a radiation detector were used to obtain a plot of specific activity vs penetration distance for each specimen. (A scintil-

Jan 1, 1969

By Elliott J. Roberts

The theory is developed that the tons ground through a given mesh per day in a wet ball mill is proportional to the percent plus that mesh in contact with the balls and the net power applied to the balls at this point. A grindability test is described.

Jan 12, 1950

Executive ARTHUR S DWIGHT, Chairman B THAYER CHARLES F RAND P MATHEWSON J V W REYNDERS Membership WILLIAM H BASSETT, Chairman W Y WESTERVELT Vice-chairman P MATHEWSON H G MOULTON F T RUBIDGE Finance WALTER H ALDRIDGE, Chairman GEORGE D BARRON GALEN H CLEVENGER

Jan 1, 1923

Preliminary plans of this meeting, together with a most interesting series of papers that have been received or promised, were published in the May Bulletin. The plans are being carried out enthusiastically and hospitably by the Colorado members and all indications point to an interesting and valuable meeting.

Jan 6, 1918

By L. VOGELSTEIN

OUTSTANDING among the year's events in copper has been the reimposition of an import duty of 4r. per pound in this country which became effective June 21. In consequence of this action by Congress, the Ottawa Empire conference recommended a duty of 2d. per pound equivalent at normal rate of exchange to our 4c. duty, on all copper originating outside of the Empire. Lip to the middle of this year only Russia and Japan had a closed market; the import duty on copper in Russia is 30 per cent ad valoremm and in Japan about 2c. Russia's consumption has always been in excess of production and she has imported from 2(1,000 to 40,000 ton, of copper per annum. Japan, with a production of 6,000 to 7,000 tons per month, has absorbed, in normal times, its production, but during recent: sears has exported varyiug quantities in 1929. 2,200 ton-: in 1930, 2,700 tons, and in 1931. 3,600 ton-. Aside from the-e two countries, the international market has heretofore been free. It and when the British Empire duty become, effective the world's markets will be divided into four unit: 1. Russia and Japan, 2. United States. 3. British Empire. 4. Rest of the world. The world's production at present is rennin it the rate of 930.000 tons per annum. This year's production will be over 1,000,000 tons because the several curtailment did not become effective until the second quarter. consumption will be slightly in excess. Deducting from 30,000 tons Russia's and Japan's production of 121.000 tons, 806,000 tons is left divided a, follows:

Jan 1, 1932

By Jim F. Lemons

INTRODUCTION A nickel doesn't buy much anymore. That's even true in the cost of recovering nickel -- the commodity. A 5[C] per pound (11 [c] per kilogram) increase in the nickel price won't cover a 10-percent increase in fuel costs for processing laterite ores, nor will it cover a 10- percent increase in wages for recovering nickel from a sulphide ore. It won't even cover a 5- percent increase in the capital cost necessary to mine and process ocean nodules. The basis for this statement and a quantitative analysis of the variations in costs to recover nickel from different types of nickel ores will be discussed in this paper. During the early part of the 1970's, the interest in nickel and its potential development was shifting from Canada to the Pacific Basin area. Canadian growth rate was slowing and each additional increase in nickel capacity was very expensive (Argall, G.O., 1970). Laterite ores were attractive to developers since they were easy to mine at a low labor cost, and technologies were being developed that would allow the recovery of nickel in marketable forms (Mohide, T.P., Warden, C.L., Mason, J.D., 1977). During the last decade, new laterite production was achieved in the Philippines and Botswana, and a significant increase in production from Indonesia and New Caledonia occurred. However, recent reports on nickel identify numerous problems plaguing the industry, i.e., high energy costs that are forcing shutdowns (INCO, 1980), (Mohide, T.P., Warden, C.L., Mason, J.D., 1977), high Canadian sulphide mining labor costs (Anon., 1976), and rapid inflation of nickel capital costs (Anon., 1981b). No definitive study has been made to determine how sensitive the total cost of production is to rising energy, labor, or capital costs, or to identify to what extent increased byproduct revenues could be used to offset these production costs. The purpose of this paper is to quantify the effects of increases in energy, labor, capital costs, and by-product credits on the future cost of production from nickel reserves and/or resources. METHODOLOGY OF ANALYSIS In order to evaluate the sensitivity of nickel production costs to changes in energy, labor, and capital costs, and in byproduct revenues, an analysis was made of existing and proposed nickel operations, their costs, and their sensitivity to change. The data for these analyses were obtained from numerous sources including international govern¬ment and university publications, professional journals, company reports, private communications, U.S. Bureau of Mines contracts, and estimates by Bureau of Mines personnel. These data were collected, in part, as an ongoing effort of the U.S. Bureau of Mines Minerals Availability System (MAS) to systematically measure and classify identified mineral resources according to their respective extraction technologies, economics, and commercial availability. The MAS Program is currently evaluating the present and potential availability of nickel to the United States in relation to mining, beneficiation, smelting, refining, leaching, transportation, infrastructure, environment, land use, labor, productivity, technology efficiencies, operating capacities, deposit life, and political factors. As a summary of this data, the following briefly describes nickel ore types as each relates to energy, labor, capital, and byproducts. Sulphide Operations Nickel is currently available from sulphide deposits. Roughly 55 percent of the current world nickel production in market economy countries is from sulphide ores, although only about 20 percent of the known land-based nickel reserves and/or resources are sulphides (INCO, 1981). In 1979, the Western World sulphide reserves were estimated at about 9.2 million metric tons of nickel (Little, A.D., 1979). Sulphide ores are typically mined underground, thus resulting in high mining costs; however, these ores can often be upgraded by flotation prior to final nickel recovery and require about one-third of the energy required to recover nickel from laterites (Anon., 1981c). In addition, nickel in sulphide ores may be associated with economically recoverable byproducts, which include copper, cobalt, gold, silver, and other precious metals. Laterite Operations Forty-five percent of current nickel production is from laterite deposits. Laterite deposits account for 80 percent of the known land-based nickel reserves and/or resources (INCO, 1981). In 1979, the Western World laterite reserves were estimated at over 35 million metric tons of nickel (Little, A.D., 1979). Nickeliferrous laterites are residual soils formed by weathering, typically under tropical or near tropical conditions. They can be easily mined by open-cut methods, but generally cannot be beneficiated; thus, recovery of nickel must entail processing of the total mined ore. Usually, these ores have high moisture content (20 to 30 percent by weight) that result in additional fuel costs to dry the ore. Nickel silicates, garnierites, are, processed by pyrometallurgical methods; limonite nickel oxides are normally leached. Byproduct cobalt is not recovered from most ferronickel operations, and is only recovered to a limited extent from many leach operations.

Jan 1, 1982

By Samuel S. Wyer

THE following description of methods for conducting gas-producer tests is probably the first attempt to give the subject an analytical, thorough and comprehensive treatment. In some cases where tests have been made, the methods have been so unsystematic and ambiguous that it has been impossible to secure comparable results. To eliminate this difficulty, the following provisional code of gas-producer tests-which has some resemblance to the code of boiler-trials of the American Society of Mechanical Engineers-has been developed. The primary object in testing a gas-producer is to determine whether the producer is working satisfactorily or, what is the same. thing, to see if the efficiency is as high as it should be with the type of producer in question, and also to find out if the composition of the resulting gas is adapted to the work it has to do. In order that the test shall be of any value, it must be thorough and comprehensive, and must be conducted with skill and care. When so conducted, the test will reveal the economy of the producer; and, by making suitable changes, the efficiency will often be increased very much. As a result of the tests made by Jenkins, 1 the efficiency was raised from 56.2 to 71.2 per cent. This shows the large saving that may frequently be made in the fuel-consumption by studying the results of a careful test.. The log of the test, given in Fig. 1, shows that, just as soon as the temperature became regular, the percentage of CO, decreased and that of CO increased.

Mar 1, 1905

By Walter W. Bradley

AT ONE TIME OR ANOTHER and in greater or less amounts, gold has been mined in at least 40 of California's 58 counties. It may not be inappropriate, by way of introduction, to give a brief historical statement relative to her production of the yellow metal. The presence of gold in the gravels of San Gabriel, San Francisquito, and other streams near Los Angeles, was known and they were worked in a small way by the Indians, at least as early as. 1841' and possibly 1820. -On March 2, 1844, Don Manuel Castanares, deputy for California to the Congress of Mexico, reported' to his government that placers near Los Angeles had yielded up to December, 1.843, a total of 2000 oz. of gold dust, most of which had been sent (via Mexico) to tile United States Mint at Philadelphia.

Jan 1, 1932

By Louis D. Huntoon

(New Haven Meeting, February, 1909.) THE Hammond Mining and Metallurgical Laboratory is the gift of Prof. John Hays Hammond to the Sheffield Scientific School of Yale University. Professor Hammond was graduated from this school in the class of 1876, and has always shown great interest in its welfare and progress. In 1903, he offered to build and equip for it a mining and metallurgical laboratory. This offer was gratefully accepted by the trustees; and in October of the same year the architect, W. Gedney Beatty, and the writer were employed to draw up plans for the building, which is the largest of its kind in this country. The Treasurer's report shows the total gift of Professor Hammond, including land, building, and equipment, to have been $128,741.53. This does not include $5,000 given by Professor Hammond to defray incidental expenses. The detailed cost of the machinery and installation, included in the above sum, is as follows: Machinery, $9,846.00 Pipe and fittings, 925.05 Hangers, shafting, pulleys, belts, etc., . 357.83 Steel-work, tanks, launders, etc., . 272.19 Screens for sizing ore, 411.37 Lumber, 1,896.36 General Supplies Hardware, . $135.96 Tools, 263.66 Paints, . 04.63 Electric and incidental, . 439.57 - 1,043.82 Machine-shop material, 259.44 Labor, 722.29 - 981.73

Mar 1, 1909

By Charles R. Simcoe

It was pointed out in a recent paper'g that the initial flow stress of as-quenched martensite is very low even in an alloy steel with an M, well above room temperature. It was also shown that the high ultimate tensile strength resulted from a very high rate of work

Jan 1, 1967

By R. H. Jacoby, M. J. Rzasa

Experimental equilibrium vaporization ratios (K values) were obtained for nitrogen, methane, carbon dioxide, ethane and hydrogen sulfide in two natural gas-absorber oil mixtures and in two natural gas-Elk Basin crude oil mixtures. For each mixture of constant over-all composition, data were obtained at 100°, 150° and 200°F and at various pressures in the range 200 to 5,000 psia. Some effects of composition on the K values were obtained to serve as a guide in choosing K's for engineering calculations on other mixtures. The pressure cell used to obtain the data is a new type and is described here for the first time. INTRODUCTION The phase equilibria of complex hydrocarbon mixtures such as natural gases, crude oils and their mixtures have been studied previously for the purpose of finding equilibrium vaporization ratios for the hydrocarbon constitutents. In a few cases, such non-hydrocarbon.: as nitrogen, carbon dioxide, and hydrogen sulfide were included in the mixture. studied because they occur. in the fluids obtained from petroleum reservoirs. The increasing occurrerce. of these non-liydrocarbon.; antl their growing economic importance. make it necessary to account for them more accurately in engineering calculation.: than is now possible using the meager published data. The available data for non-hydrocarbons may he classified into two groups: namely, binary mixtures of a hydrocarbon and a non-hydrocarbon. and mixtures containing three or more components, only one of which is a non-hydrocarbon. Amon: the former. phase analyses are available for two nitrogen-HC mixtures, tve carbon dioxide-HC mixtures and three hydrogen sulfide-HC mixtures. Data for more complex mixtures are available as follows: Nitrogen-Methane-Pentane'; Nitrogen-Methane-Hexane,'; Nitrogen-Methane-Heptane'; Carbon dioxide-Natural Gas-Natural Gasorline": Carbon dioxide-Natural Gas-Crude Oil". These data have been used generally lor engineering calculations, often with little regard for their precise applicability because data for the non-hydrocarbons in the complex mixtures being dealt with were not available. The use of K values from binary data for calculation:; involving complex mixtures is open to criticism because such K's are not a function of composition and very often show large differences from the K's for the same components in a complex mixture. Thus the effects of composition must be evaluated when obtaining K's for components in complex mixtures. Poettmann and Katz " varied the carbon dioxide content of their mixture.; from about five to ten mol per cent and found substantially no effect on the K values due to this change. This was not surprising since one might expect that changing a minor com-ponent by * three mol per cent would have little effect. It is more important to find the composition change which have the largest effect on the K values. For example. varying the methane or heptanes — plus compositions over a wide rangr may have a large effect on the K'. of all components in the mixture. Interesting data to this effect were obtained by Eilerts and Smith." It was toward these problems that the experimental data presented here were directed. EQUIPMENT The pressure cell used to obtain the data i:. somewhat dif-ferent from those which have been described in the past. Photographs of the equipment are shown in Figs. 1 and 2. Fig. 1 Shows. the front panel: from a .rated position at the right the

Jan 1, 1952