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By F. E. Wood, H. W. Young, A. W. Buell

This paper summarizes the results of laboratory tests conducted to determine the properties of the paraffin or rod-wax encountered in the Salt Creek field, Wyoming. It also describes field tests and methods employed to cope with the paraffin problem. The conclusions to bo drawn from the laboratory work are: 1. Samples of Salt Creek paraffin range in consistency from soft lo hard, the melting points varying from 120" to 156" V. 2. Masses of soft paraffin are soluble to an appreciable extent in crude oil and its liquid fractions at temperatures somewhat below the melting point of the paraffin. Hard paraffin is very slightly soluble. under these conditions. 3. Agitation apparently increases the amount of paraffin that will go into solution. 4. Paraffin congeals from solutions upon cooling to the point of saturation ation, which is in all cnscs below thc melting point of the paraffin. 5. Crutltl oil is tlie most effective. of all the solvents for holding paraffin in solution. 6. Pressure alone does not appreciably affect the solubility of paraffin in crude oil nor does it aid materially in holding paraffin in solution when the temperature is reduced. 7. Natural gas in solution under pressure does not appreciably increase the solubility of paraffin in crude oil, hut is effective in holding paraffin in solution when the temperature is reduced. 8. A foreign body introduced into a solution of paraffin in oil is imrnediately coated with paraffin if the temperature of the solution is at or below the melting point of the paraffin, and the object is considerably cooler than the solution. It may not be entirely correct to ray that paraffin is taken into solution; it is impossible that the paraffin may be in suspension rather than in solution.

Jan 1, 1928

By John B. Hastings

Chief among the varied problems facing the mine-manager is that of vein-structure and origin, which is highly important as a guide to successful discovery and development. If metalliferous deposits can be traced to the intrusion of waters along definite lines, then is there something tangible for him to study. But when he is told by a geologist that metalliferous deposits are due to some other cause, like magmatic differentiation, while not perhaps discouraged, he is impressed with a vague sense of new worlds to be conquered. In 1897, while manager of the War Eagle mine at Rossland, B. C., where, previously, the ore-bodies had not been supposed to occur as veins, I suggested to visiting members of the Canadian Geological Survey that, perhaps, the structure of the pyrrhotite-bodies of that mine, which had been proved to occur along well-defined fractures, might throw some light on the similar deposits of Sudbury, then held to be basic aggregations from the original magma. Later investigation has at least provoked discussion of this last deduction, questioning its correctness and suggesting that, perhaps, the deposits are actual veins. The following extract from a paper by J. E. Spurr' is quoted, because it sets forth Mr. Spurr's theory of the quartz-occurrences of the Silver Peak mines, which will be discussed in this article. It also graphically describes the attendant geological features. "The Drinkwater group of mines, which is the most important part of the Blair gold properties, and which has produced practically all of the million dollars' worth of ore, as above stated, may be taken as typical of the gold-veins which, though widespread and numerons, show a wonderful similarity of character. On the surface two adjacent veins outcrop, the Crowning Glory and the

Jan 1, 1906

By Frederick G. Bulkley

That portion of the geological structure of the Leadville district which rests upon the Archæan is made up of sedimentary beds of Silurian and Carboniferous formation, consisting of many conformable strata of limestones, quartzites, and shales, which have a total present thickness of about five thousand feet. Interbedded with these strata are found, under somewhat fixed lams of regularity, sheets of intrusive igneous rock,' varying in thickness from a foot or two to several hundred feet. These consist for the most part of various types of felsite rocks, classed, by the sanction of common and long-continued usage, under the general term of porphyries. Mr. S. F. Emmons, in the abstract of his " Report upon the Geology and Mining Industry of Leadville," says in this connection : In their mode of occurrence the type-feature is that of intrusive masses, which are developed on a scale of unprecedented magnitude, and follow certain horizons with remarkable regularity.... It is probable that this mode of occurrence of eruptive rocks, viz., as intrusive masses which originally did not reach the surface but were forced up to a certain horizon and then spread out bettween the beds, is far more common than has hitherto been suspected by geologists. It is difficult to conceive of the conditions under which a fused mass could pry open strata to a width of one thousand feet or more, overcoming the weight often thousand feet of superincumbent rocks, and spread itself out in a continuous sheet between the beds to a distance of ten miles beyond the point or line of eruption. That they did exist, however, can be clearly demonstrated in this region.... In one single section over fifteen sheets, many several hundred feet thick, were counted between the Blue Limestone and the top of the Carboniferous. The region here under discussion is made up of a series of great

Jan 1, 1885

By M. Amsterdam, F. Rothwarf, L. Muldawer

SILVER-cadmium near the composition AgCd shows three equilibrium phases. As with 13 brass, the high temperature phase is disordered body-centered cubic (8) and the low temperature phase has the ordered CsCl structure . However, there is an intermediate temperature phase which is hexagonal close-packed ((). In a recent paper, Speich and Mack' report on a study of the Ag-Cd eutectoid near the AgCd composition. Unfortunately, the phase diagram upon which they base some of their conclusions is incorrect. That diagram is taken from the Metals Handbook' and the error is that the 0 and ( phases have been interchanged. The Handbook gives the low temperature phase as hexagonal (designated 5) and the intermediate temperature phase as cubic ordered (designated . The error may be typographical or it may be one of confusion resulting from the use of 5, ,, and 0 for the intermediate phase in various papers. A careful search of the literature reveals that a number of authors have indicated the correct relative positions of the 13, 5, and 0 phases. The comprehensive work of Fraenkel and Wolf clearly stated that the high and the low temperature phases are either identical or are very similar. olander,' on the basis of electrochemical measurements, showed that the 13 phase is disordered and the 1 phase (designated 8" in his paper and in refs. 3 and 5) is ordered. Further work by Durrant5 using thermal and metallographic analyses provided a more precise phase diagram. A summary of these works was given by Hansen6 and shows the correct relative positions of the phases. Owen, Rogers, and Guthrie7 located correctly the upper two phases by X-ray diffraction. Their failure to find the low tem-

Jan 1, 1954

By Arthur L. Bishop

INTRODUCTION Purpose The in-situ leach method for uranium extraction is a relatively new and innovative method of uranium mining. In 1975, the first commercial in-situ facility began operation in south Texas. Since that time numerous other operations have been initiated as either pilot or commercial ventures. Considerable literature has been published that deals primarily with generalities of the process or environmental concerns. Several federal agencies have published documents which do not reflect the true operating or environmental nature of the in-situ leach method of uranium extraction. From an environmental standpoint, this is also evident in the promulgation of rules and regulations. Hence, the purpose of this paper is to present experience with an environmental concern--non- production zone excursions--such that the industry and the regulatory agencies will gain greater insight devoid of preconceived ideas and misconceptions. General Process Description In south Texas, in-situ leach mining is utilized to extract uranium from permeable sandstone ore deposits 61 to 213 meters (200 to 700 feet) below the surface. Uranium is present as an insoluble uranium oxide. In the in-situ or solution mining technique, anoxidizing lixiviant is injected into the formation through injection wells. The solution reacts with the insol uble carbonate complex. This soluble uranium complex is produced at recovery wells, each containing a submersible pump. During production there is a constant sweeping of lixiviant through the formation from the injection wells to the recovery wells. Injection and recovery wells can be arranged in any of a number of geometric patterns dependent upon ore body configuration, aquifer permeability, and operator preference. Submersible pumps in the recovery wells pump the uranium rich pregnant solution to the initial processing facility. Monitor wells surrcsund the pattern area and are screened in appropriate stratigraphic horizons (production and non-production zones) to detect any lixiviant migration that may occur (Fig. 1).

Jan 1, 1980

By E. I. Larsen, F. R. Hensel

According to statements by Guertler1 Smith and Hamilton were the first to study the copper-titanium alloys, but owing to the presence of large amounts of impurities their data are inconclusive. M. A. Hunter and I. W. Bacon later investigated the electrical conductivity and the temperature coefficients at room temperature. The present writers reported their results2 in November, 1930. Recently Kroll published data on copper-titanium alloys3 which agree closely with those obtained by the authors. Material Tested The titanium used was in the form of square sintered rods, the analysis of which runs as follows: titanium, 95.4 per cent; silicon, 0.7; iron,l.8; aluminum, 1.4; copper, 0.1; manganese, 0.05. The ingots were prepared in a high-frequency induction furnace in air atmosphere. Their analyses are given in Table 1. Up to 5 per cent titanium the alloys could be forged. Above that amount they were red short and broke up easily. Owing to their rapid absorption of nitrogen and oxygen from the air, the alloys with the higher amounts of titanium tend to form surface films which greatly increase the casting difficulties, especially when small masses of metal are handled. It was, however, possible to prepare sound ingots up to 25 per cent titanium. Thermal and X-ray Investigation The cooling curves of some of the alloys are plotted in Fig. 1, and R tentative diagram constructed from these data is given in Fig. 2. From this it is evident that the solid solubility of copper for titanium is approxi-mately 4 to 5 weight per cent titanium at 878" C., which is the eutectic temperature. The melting point of copper is lowered gradually by adding

Jan 1, 1932

By Gerhard Derge

THE introductory paper1 of this series described the potential behavior of tin in sodium carbonate and bicarbonate solutions whose pH ranged from 8.4 to 11.2 and demonstrated that significant and reproducible results could be obtained by proper attention to experimental technique. In examining the corrosion of tin under such conditions, it is desirable to know the effects of anions, aside from carbonate, that are likely to be present in commercial materials packaged in tin. Therefore, in this paper the potential behavior of tin in carbonate solutions to which sodium fluoride, chloride, bromide, iodide, sulphate, nitrate, monobasic phos-phate, dichromate, perborate and acetate have been added will be described. For most of the additions, solutions containing 0.001 and 0.01 .moles of the added material were studied. The experimental procedure was exactly the same as that described in the first paper; the pH of the electrolyte was controlled by adjusting the ratio of carbonate to bicar-bonate as follows: pH 0.1 M NaHCO3 8.4 2 parts 0.1 M NaHCO3, 1 part 0.1 M Na2CO3 9.5 1 part 0.1 M NaHCO3, 2 parts 0.1 M Na2CO3 10.0 0.1 M Na2CO3 11.2 The reagents used were all of C.P. grade. The anions studied may be divided into three groups: (1) anions that had little or no effect upon the potential curves-sulphate, nitrate, and acetate; (2) those that helped to prevent corrosion at low pH only-fluoride, chloride, bromide, and iodide; (3) those that helped to prevent corrosion at high pH also-phosphate, perborate, and chromate.

Jan 1, 1939

By F. Weinberg

INTEREST is currently being directed toward grain boundary morphologies in zinc in terms of grain boundary facetingl and grain boundary energies.' Some years ago the present author attempted to measure grain boundary energies in 99.999 pct purity Zn as a function of boundary angle, using the standard procedure of measuring equilibrium angles of the boundary traces at triple points. This followed an investigation he carried out on preferential melting of |H (112) Fig. 1—Electron transmission micrograph of a stacking fault, grain boundary intersection in copper. GRAIN BOUNDARY STACKING FAULT Fig. 2—Schematic representation of the intersection of Fig. 1, indicating inclination angles 0 and trace angles $. specimens were prepared by the Bollman technique in an electrolyte of 70 pct methanol, 30 pct HNO3 main-tained at -30°C. The interfacial free energy of the high angle grain boundary and of the stacking fault is assumed to be thermodynamically equivalent to the corresponding in-terfacial tensions. In terms of the true dihedral angles & between the intersecting interfaces, the equilibrium of interfacial tensions in the direction parallel to the stacking fault yields: ysF = -ygb(cos F1+ cos ±cosF2) Here, ysF is the stacking fault free energy and ygb is the grain boundary free energy, assumed equal on both sides of the intersection. Forces acting normal to the grain boundary, of the form ??gb/?F,l are assumed negligible as the grain boundary remains straight for a considerable distance on either side of the intersection. The micrograph of Fig. 1 may actually consist of several closely spaced stacking faults on the same slip plane. The actual point of intersection between the grain boundary and the first stacking fault, and the equilibrium configuration of the intersection, should not be affected by the presence of the other faults, as

Jan 1, 1970

By D. G. Deveraux

A BRIEF SKETCH OF THE DAVE JOHNSTON MINE The Dave Johnston coal mine is located near the southwestern extremity of the Powder River Basin in central Wyoming. This mine is operated entirely for the purpose of furnishing fuel to the 750,000 Kw Dave Johnston power generation station located five miles east of Glenrock, Wyoming on the North Platte River about 24 miles east of Casper, Wyoming. Coal is delivered to the power plant by a company-owned railroad moving the coal 15 miles downgrade from the mine to the power plant. The mine first belonging to Pacific Power & Light Company has now been transferred to Northern Energy Resources Company (NERCO), a mining subsidiary of Pacific Power & Light Company. The coal beds which make up the field at the Dave Johnston Mine are locally referred to as the School and Badger seams and occur beneath gently rolling terrain in the Fort Union formation. The School seam is found approximately 180 feet beneath the Badger in the southern portion of the field and about 110 feet beneath the Badger towards the north. The coal beds dip down toward the northeast on about a four percent average inclination. The School seam has an average thickness of about 35 feet and the Badger seam about 16 feet. The climate at the Dave Johnston Mine is semi-arid, with annual precipitation varying between 10 and 12 inches with 70 percent occurring during the months of April to September, with the maximum occurring in May. A few storms occur in July and August which are usually torrential in character, often causing erosion damage to un- protected soils. Snowfall averages 50 inches a year at the mine with 12 to 15 inches of snow yielding one inch of moisture. However, snow seldom

Jan 1, 1983

By G. A. Reinhardt

THE Youngstown Sheet & Tube Co. has produced a large tonnage of 0.35 to 0.45 carbon forging steel, the acceptance of which was based on the physical properties of test specimens obtained by forging the original 5 3/4 in. (14.5 cm.) square bloom to a ¾ in. (1.9 cm.) round. Annealed and tempered specimens were required. The test bars were annealed by heating from 900 ° to 950° C. and cooling slowly in mica. The test bars were tempered by heating to 825° to 875° C., quenching in water, and drawing to 515° to 535° C. Immediately after heat treatment, the test pieces were machined to a diameter of 0.534 in. (1.38 cm.) and tested. Very good physical properties were obtained and no difficulty was experienced in meeting the specifications called for. ULTIMATE STRENGTH, ELONGATION, LB. PER SQ. IN. PER CENT. IN 4 IN. NOT LESS THAN Annealed specimens 78,230 to 92,450 18 Tempered 120,000 to 149,350 9 After experience oil this material, production of slightly higher carbon forging steel was started. The method of testing this material required that test blooms be either normalized or annealed. The normalizing consisted in heating to 850° to 900° C. and cooling in still air; the annealing, in heating to 850° to 900° C. and cooling in the furnace or in mica. From the treated bloom, the test pieces were taken either by core drilling or by sawing from points midway between the edges and the intersection of the diagonals. The cores or blocks were turned to a standard 2-in. test piece with a diameter of 0.564 in. and tested without further treatment. The physical requirements of the test pieces were:

Jan 7, 1919

By O. U. Bradley

The methods of handling the oil output of the Mid-Continent fields are not unlike those practised in other oil fields of the United States, and it is not expected that this paper will present any entirely novel ideas. Some features of the practice of handling this oil may be of interest, however. Wooden Gaging Tanks Practically all of the oil sold to pipe line? and other purchasing agencies throughout the Mid-Continent field is gaged from wooden tanks. Steel gaging tanks are slowly coming into use, and are preferable in many ways—leakage and evaporation are reduced, and the strapping and recalculation of capacities are unnecessary. The wooden tanks are slightly coned to facilitate tightening the hoops. The sizes in common use are 250, 500, 800 and 1600 bbl. The number and the capacity of the gaging tanks upon any producing oil property depend upon its production, and the facilities for disposing of the output. The 1600-bbl. size was the most common in the Cushing field, particularly during the period of flush production. The tanks are distributed over the leased premises in groups of two, three, and four tanks each, and these are filled from flow tanks, or through direct pipe connections with the heads of the wells. Flow tanks are merely temporary reservoirs to facilitate the transfer of oil from the wells to the gaging tanks. They diminish fire risk, and are considered indispensable on small producing properties where water is pumped with the oil, as they permit the refuse and water to 'settle out before the production is run to the gaging tanks. strapping and Calculations After a gaging tank has been strapped (measured) and its contents computed, a deduction of 3 per cent. is made from its computed volume. The strapping of a tank requires four steps: (1) The outer circumferences

Jan 1, 1920

By W. N. Lacey, B. H. Sage, W. M. Morris

The volumetric behavior of isobutane at temperatures below its critical temperature has been studied by several investigators. Seibert and Burrelll measured the vapor pressure of isobutane from the ice point to the critical temperature. Dana and co-workers2 determined among other thermodynamic quantities the density of the saturated liquid and the saturated gas and the vapor pressure from approximately 0 to 130 F. Sage and Lacey3 studied a number of the thermodynamic properties of this hydrocarbon from 70" to 250" F. The specific volume in the gas and liquid region was determined at pressures up to 3000 Ib. per sq. in.? throughout this temperature interval. In addition, the vapor pressures were measured at 30" intervals. These data taken together serve to establish the thermodynamic behavior of isobutane at temperatures between 0" and 250" F. with reasonable accuracy. However, apparently there are no data available at the higher temperatures. For this reason an investigation of the volumetric behavior of isobutane at temperatures between 100" and 460" F. was carried out with apparatus that has been described in another paper (p. 136, this volume). Materials The isobutane used in this investigation was obtained from the Philgas Division of the Phillips Petroleum Co. That company's special analysis upon this sample indicated it to contain less than 0.03 mol per cent of impurities. In order to avoid traces of noncondensable gases, this hydrocarbon material was subjected to two successive fractionations at a high reflux ratio in a column approximately 4 ft. long and % in. in diameter, which was packed with small glass rings. The middle portion of distillate from the first fractionation was used in the second fraction-ation and a portion of the overhead from this second distillation process was repeatedly condensed at liquid-air temperatures at a pressure only slightly above the sublimation pressure of isobutane at this temperature.

Jan 1, 1940

By Walter P. Jenney

In the limestone area of Tintic and other mining districts of the Great Basin region of Utah, it has been observed that surface-outcrops of ore occur but seldom, and are mainly confilled to points of relatively low elevation, where the veins cross some basin or ravine. Nowhere does a considerable body of ore outcrop on the tops or high up on the slopes of the hills. Mining operations, on the other hand, have shown that large and continuous ore-deposits frequently occur in depth in the limestone, beneath large masses of barren rock. Such orebodies, when followed upward in the lodes, are found to terminate at well-defined levels, without reaching the surface. Yet the minerals-bearing fissures themselves extend above the top of the ore, being often traceable, though barren of all valuable minerals, for hundreds of feet above the stopes in the mines, and even observable in outcrops at the surface. This abrupt cessation of the ore at a uniform horizon does not appear to be connected with any change in the countryrock adjacent to the lodes. The strata above and below this horizon seem to be in every way equally favorable to ore-deposition. Explorations above it have developed an open-fissured country, barren not only of ore, but also of indications that minerals bearing gold, silver, lead or copper were ever deposited in the strata at that elevation. The height reached by the ore, while usually constant throughout the length of a given lode, may vary in particular sections, from the operation of local causes. Each lode in a district has its own distinct horizon, above which the oredeposits do not extend. Where the ore-bodies are continuous

Jan 1, 1903

E. A. Peretti (University of Notre Dame, Notre Dame, Ind.)—Mr. Deitz and Professor Halpern are to be congratulated on a fine piece of work which adds to our knowledge of precious metal—cyanide-solution reactions. I should like to offer the following comments: The authors state, "the rate plots were always linear, indicating a zero order reaction rate." This appears to conflict with the data of Fig. 6 which clearly show the rate to vary with the NaCN concentration. It seems to me that the rate curves are linear because of the experimental setup. The volume of solution is so large that over a three-hour period the change in NaCN concentration is very small. A rough calculation for the experiments of Table I where the initial NaCN strength was 0.0096 mol per liter show a change of NaCN concentration of about 0.0009 mol per liter at the end of three hours. In short, over the period of time that the experiment was in progress, the NaCN strength was practically constant; hence the rate of dissolution remained practically constant. Eq. 10, as written, specifies that 1 mol of H202 and 2 mol of hydroxyl ion are formed when 2 mol of silver react. Is this true? The effect of H,O2 on the rate was made in solutions having an oxygen pressure of 4.8 atm. Were any tests made in solutions containing hydrogen peroxide, but no oxygen? G. M. Willis (University of Melbourne, Melbourne, Australia)—The authors have shown that, under their experimental conditions of high O2 concentrations, the rate of solution of silver in aqueous cyanide solutions is controlled by diffusion of O2 or CN- to the metal surface. With diffusion control, it is generally not possible to obtain further information about the mechanism of a process.

Jan 1, 1955

By I. N. Zavarine

The present paper is a continuation of the work on the relationship between the magnetic and the phase transformations in carbon steels during quenching. An account was given by the author in a previous paperl† of an investigation of this relationship during a continuous quench. The experimental difficulties then encountered prevented a conclusive proof of the existence or absence of such a relationship. The conclusions of the previous paper were derived indirectly. The present paper deals with the same problem, but the method of attack is modified. The technique developed by Davenport and Bain2 in their well-known study of austenite transformation at subcritical temperature was adopted in the present investigation. They have shown that the austenite to martensite transformation can be caused to proceed at a relatively slow rate by quenching steels into a hot metal bath. Slowing down of the rate of transformation, together with an observation by Lewis3 that a eutectoid steel can be preserved in the nonmagnetic state by such quenching, pointed out a possibility of a study of both transformations under more favorable conditions than previously described. The preliminary steps were connected with the technique of the hot bath quench. To study this phase of the present work a modification of the apparatus previously described' was used. The modification consisted in the use of a hot quenching bath instead of brine, and in fixing the secondary and the primary coils of the apparatus in a stationary position in and around the bath. Tubular specimens, as in the previous investigation, were heated in a suitable furnace to a temperature in the austenitic range for the given steel and then were dropped into the quenching apparatus. The quenching bath was heated to a series of temperatures within the probable range at which the austenite to martensite transformation was expected to proceed at the slowest rate. Observations

Jan 1, 1936

By Alfred H. Bell

Drilling activity increased in Illinois in 1935. There were 34 com-pletions as compared with 26 in 1934 and 18 wells were drilling at the end of 1935. Some large blocks of acreage were leased in Marion and Clay counties near the central part of the Illinois structural basin. Production of oil in the state totaled 4,305,000 bbl., a decrease of 4 per cent from that of 1934 There was some curtailment of production in the early part of 1935 but none after April 30 as shown in the following table. Percentage Pro-duced of Potential ProductioN (USING September 1934 Period as BaSis) Jan. .l-Feb. 20............................................ 79 Feb. 21-Feb. 25............................................ 85 Feb. 26-Feb. 38............................................ 79 Mar. 1-Mar. 11............................................ 85 Mar. 12-Mar. 31............................................ 100 Apr. 1-Apr. 9.......................................... 80 Apr. 10-Apr. 30............................................ 86 May 1-Dec. 31........................................... 100 This is equivalent to an average curtailment throughout the year of 5 per cent. The price of Illinois crude oil at the wells remained constant during 1935 at $1.13 per barrel. A small amount of oil was sold at a 1ower price, notably from the Dupo field, but to arrive at a value for the state's production there would be little error in assuming an average price of 81.13, giving a total value of $4,864,465. The following table shows production in Illinois by moths in 1935, according to the U.S. Bureau of Mines. Jan............. 332,000 May.......... 382,000 Sept ,............. 370,000 Feb............. 295,000 June. ........... 858,000 Oct.............. 391,000 Mar............ 370,000 July............ 377,000 Nov............. 369,000 April............ 338,000 Aug............. 379,000 Dec............ 344,000

Jan 1, 1936

By W. E. Keck, Paul Jasberg

TheRe is a considerable tonnage of iron ore in the Menominee Range of Michigan that is unsalable only because it has too large a content of sulphur. Beneficiation of such ore is economically desirable, as a relatively large quantity of finished concentrate would be obtained (deleterious sulphur mineral content being generally less than 5 per cent) and because large blocks of such ore have been developed incidentally during search for low-sulphur ore. Research on the flotation beneficiation of these high-sulphur ores consisted of: (1) a study of the flotative properties of the principal mincrals in a nearly pure state, (2) flotation of synthetic mixtures of these pure minerals and (3) application of this experimental information to samples of the ores. Gypsum in iron ores is extremely deleterious; but when sufficiently free from impurities it is a valuable commodity. In 1934, the United States produced 1,500,000 tons of calcined and uncalcined gypsum valued at $13,700,0001. Of this quantity and value, Michigan produced approximately 19 per cent1. Thus this investigation may also prove to be of interest in connection with the gypsum industry if minerals separation, such as flotation, becomes necessary in the future processing of gypsum. Data on the flotative properties of gypsum would also be of interest to the science of flotation because such information has been extremely limited. The technical literature reveals one reference to the flotation of gypsum, in which was discussed the use of the mineral, with several others, to determine the relation between the floatability of minerals and the pH of the flotation solution2. This investigation necessarily was not comprehensive in regard to gypsum, but it did show that the mineral could be floated with oleic acid under varying pH conditions.

Jan 1, 1938

By Lester Tarnopol, Ralph Hultgren

A considerable interest in the subject of superlattices has been manifested by many papers and reviews that have recently appeared, both in physical and metallurgical publications. This interest is due largely to the apparent simplicity of the ordering process, which permits the explanation of many phenomena on the basis of elementary theory. Moreover, ordering may cause important changes in the physical properties of alloys. In this paper, we shall discuss the causes of superlattices in terms of simple properties of the elements that give rise to them, together with a series of experiments performed to test our conclusions. Evidence is presented that in some cases the process of ordering is more complex than might be supposed. While the different species of atoms are usually found in random positions in alloy lattices, in some cases unlike atoms tend to be nearest neighbors. Bethe's1 "order of neighbors" is a statistical measure of thib tendency. At suitable compositions it is possible for atoms in large regions to be regularly arranged, which causes superlattice lines to appear. in X-ray diffraction patterns. Bragg and Williams2 haw dealt with this "long-distance order" in their fundamental work 011 superlattices. Excellent discussions of superlattices are to be found in current reviews TheRmodynamic Considerations Thcrmal vibration tends to destroy order. The magnitude of the effect can be determined from the entropy of mixing, which is calculate from first principles. Since the ordered state has the lower entropy, it must also have a lower internal energy to be stable at any temperature. The difference in internal energy determines the critical temperature at which long-distance order disappears. According to the, theory of Bragg and Williams,~

Jan 1, 1939

By Joseph Ames

THERE are two distinct questions associated with the concept of temperature: one is practical, the other is theoretical. Our fundamental ideas of temperature come from our senses; we know what we mean by the words "hot" and "cold," or by saying one body is "hotter than another." But for scientific purposes words require definition. We are guided in this matter, as in all other scientific questions, by our knowledge of facts of observation. When two bodies at different temperatures are intimately associated, e.g., a hot stone is, dropped into a pail of water, our experience is that ultimately they come to the smile temperature as far as our senses can tell; the hot body becomes colder and the cold body hotter. In the case of a block of ice, immersed in, water, the ice melts, forming cold water, which then mixes with the other water, the final result being water colder than the original water. From our knowledge of the nature of heat phenomena, we learn that in this process one body loses, heat and the other gains heat, the condition of equilibrium being, one in which each body gains Is much heat as it loses. It is distinctly assumed in this statement that only two bodies are concerned in the transfer of heat, all other bodies being rendered in some way impervious to heat. The body that in the process loses heat is said to have the ?higher temperature" while the body that gains the heat is said to have the "lower temperature;" and, when thermal equilibrium is reached, the two bodies are said to have the "same temperature." Consequently, the temperature of a body may be defined, is it was by Maxwell, as "its thermal state considered with reference to its power of communicating heat to other bodies."

Jan 9, 1919

By Benjamin LeRoy Miller, Joseph T. Singewald

The ore deposits at Firmeza have been worked continuously since 1884; those at Daiquiri since 1895. It is surprising, therefore, that they have not been the object of careful geologic study until quite recently. It is true that considerable attention was paid to these deposits by A. C. Spencer, in 1901, in the report on the geology of Cuba, by Hayes, Vaughan, and Spencer,l but this was only incidental to a hasty general reconnaissance of the Island. As far as the Daiquiri deposits are concerned, this gap has been filled by the appearance of the two papers by Prof. James F. Kemp2 and by Prof. Waldemar Lind-gren and Clyde P. Ross respectively.3 Max Roesler, first holder of the Emmons fellowship, made a detailed study of the Firmeza deposits during the past summer, so that soon we can expect a full description of them. Consequently, there is no, demand at the present time for a description of the deposits from other sources, and that is not the purpose of this paper. The papers on Daiquiri, however, leave unsolved problems in regard to the age of the rocks of the district and certain phases of the genesis of the deposits, and it is with the hope of aiding in the solution of some of these problems that this contribution is offered. Kemp, and Lindgren and Ross agree in assigning these deposits to the type of contact metamorphic deposits. They disagree in part on the question of their localization. The deposits occur in an extensive area of diorite which includes numerous blocks of limestone, and sometimes are found in the contact zones between these blocks and the diorite, and in other instances are completely enveloped in the diorite, showing no apparent connection with the limestone. The latter class includes

Jan 1, 1916