CHEMICAL NEWS, Alloys. important industries employ but a few of them. Some of these, in the metallic state, have market prices which are not yet controlled by the cost of production, nor by the infrequency of occurrence, but rather by the lack of development of a utility. Beginning with gold, which we may assume is the one element whose exchange value depends upon its commonness in nature plus its cost of production; and passing over iron, copper, lead, and zinc, whose values may be said to be well fixed by occurrence and costs of production, we soon reach other metals, for which a new demand might well greatly reduce the cost. Among these are many whose ores occur in abundance. In the case of this type of element the interest attached to research work is doubly great. It is highly improbable that the cost of copper will ever be greatly changed by the discovery of new uses. This is because the world's supply of the ore is pretty well known; the demands are high, and the cost of production of metal from ore have been so studied that further reduction will probably only be of what I like to call the second order of magnitude. This was not true of the metal aluminium a few years ago, and it is still possible that considerably wider uses and reduction of production costs may develop in its future. There is apparently a much wider divergence | between the occurrence of the aluminium in nature and its price in metallic state than in the case of copper. In case of aluminium, only selected and purified ores are used at present, while other compounds of it occur everywhere in nature. On the other hand, in the case of copper, ores containing even less than 2 per cent of copper are worked for the metal. Aluminium may thus still be considered in the transition state, a state long ago passed by copper and iron, and not reached by some of the metals considered below. We have all been witnesses of the interesting advance of aluminium. From 1869-74 its properties were becoming generally known. The inefficient process by which it was then reduced from its ores made it impossible to sell the metal below to dols. per pound. Advance was then made so that in the 80's the price was about 5 dols. There was not a great demand for it at this price. In the year 1907 something like 26,000,000 lbs. of this metal were made in America alone. The price is now about 20 cents per pound. The element calcium, which a few years ago was listed only as museum specimens and at several dollars per grm., was sold in 1908 at 1.50 dols. per pound, and could certainly be sold for a small part of this price if a greater use could be found for the metal. It slowly decomposes water, giving hydrogen, and it differs from the alkali metals in producing such a feeble alkaline solution that it is generally harmless. It ought to serve as a good deoxidiser, and should be a very cheap metal. It is not fair to relegate it to a list of useless metals. History of the metallic arts points to there being no such list. Thallium is an element quite similar to lead, but probably possessing some property which will some day warrant its exploitation. It is softer and heavier, and could be obtained in quantity if a demand were created. The elements chromium, molybdenum, tungsten, and| tantalum, the three latter now obtainable in wire-form, are tempting elements to study in mixtures with others. Who knows the useful properties of a chromium bronze, for example? Tellurium has long been an apparently useless metal, and any market price is fictitious, as there is but little isolated in metallic state. It is not necessary that a great use, such as a substitute for zinc in brass, should be found for it. Our industries are so great, that if a pound of tellurium added to the ton of aluminium was of benefit to the latter, the production of the necessary tellurium would be real industry. Consider cobalt a moment. The world's rate of supply of ore has been greatly augmented. It may take time to actually realise a greatly reduced cost of metallic cobalt, but we ought, notwithstanding, to realise it when uses have been developed. Our natural impulse in such a case 29 is to try direct substitution of one metal for another in some well developed use. Cobalt, for example, might replace nickel in most uses when the cost fell below that of nickel, but this is a second order use. A first order use would be the supplying of a want which no metal previously supplied, or supplied distinctly less perfectly. In this connection an interesting alloy of cobalt and chromium has just been described by Elwood Haynes in the October number of the Journal of Industrial and Chemical Engineering, and it is altogether probable that technical use will soon be made of it. Many tons of metals are annually consumed as resistance wire for electrical purposes. At one time iron was the element most used. German silver replaced it in some cases, where a lower temperature coefficient was needed and the increased cost was permissible. Now there are a dozen or more special alloys for this particular electrical use. The new ones have far out-classed the old in most of those properties for which the electrical engineer uses them. In such alloys, nickel, chromium, manganese, and others are now used by the ton. Silicon, which in 1900 was a curiosity and sold for 40 cents per grm., is now a necessary component of special iron alloys and of high-grade_transformer iron, and the world uses thousands of tons of the alloy annually. Silicon is now sold at about 5 cents per pound. The use of this metal in other alloys is still quite limited. In the case of iron it greatly decreases hysteresis loss and increases electrical resistance. Boron, still a quite expensive material in metallic state, is coming into commercial use in assisting the making of solid copper castings of high electrical conductivity. Vanadium seems to be a young wonder working metal. Its use has increased very rapidly in the past few years, but the quantities consumed are not known to us. As several companies are producing the iron alloy, it is safe to assume that it is being sold by the ton. The price for the metal in the alloy is not far from 5.00 dols. per pound. Cadmium is a beautiful metal in many respects, and it is certainly awaiting use. It is whiter and less crystalline than zinc, and doubtless the high price of nearly a dollar a pound keeps practical workers from trying it in their experiments. It should be produced as cheaply as aluminium, if there were a good demand for it. Titanium is an element long the subject of criminal negligence. It is a high-melting ductile white metal, which, at present, is only separable from its ores at high cost. It exists in many cheap ores widely distributed in nature. It is now apparently coming into use in steel manufacture, particularly for railroad rails, and for this purpose it is fortunately unnecessary to isolate the pure titanium from its ores, an iron titanium alloy being produced directly. What will happen when the pure element has been tried in special fields can only be surmised. The optimist sees great chances. The pessimist feels himself busy living with the optimist. If one omits the common alloys, brass, bronze, solder, &c., and considers only possible alloys of two metals, and still confines himself to twenty of the common metals, like vanadium, manganese, chromium, boron, &c., he is interested at once to recognise that there must be one hundred and ninety different pairs of binary alloys. When, in addition, the effect of varying proportions in these alloys is considered, it becomes evident that the field of alloyresearch is truly a large one. Many of the alloys apparently unstudied are those which melt at extremely high temperatures. The brass founder who knows the upper limiting temperature of his melting furnaces may at once point out that this temperature is fixed both by the life of crucibles and the particular coke or oil-heating schemes with which he is familiar. If he thought that a molybdenum bronze of 80 per cent molybdenum would have useful properties compared with all other alloys, he might at once conclude that he must give up his alloy because of the difficulty of melting it. If it were not for the advances in our available temperatures, there would seem to be little more than amusement in considering alloys high in tantalum, in chromium, in titanium, in molybdenum, in silicon, in uranium, in vanadium, and a number of other high-melting metals, but hand in hand with the discoveries leading to isolation of such metals go also discoveries of aluminothermics, oxyacetylene and oxyhydrogen temperatures, and electric furnace processes. The time is always ripe for the study of new alloys with new tensile strengths, elasticities, colours, and wearing powers. The automobile and the aeroplane have forced the aluminium and iron alloys to make rapid strides, and it is natural that we should want to inventory our possibilities. The physical chemist has started along the way of a systematic co-ordination of certain properties of binary, and in a few cases tertiary alloys. He has shown how to plot a few freezing points of two-metal and three-metal mixtures, and to construct therefrom curves showing not only all possible alloys, but what may be expected in the way of segregation and structure and such effects as caused by annealing or quenching. modified the old familiar ones. For a harder iron he used steel, a carbon alloy; for a harder steel, or one capable of cutting iron more readily, he added tungsten, nickel, chromium, and other metals. For permanent magnets molybdenum was added; for high electrical resistance nickel, chromium, &c., were added; for low electrical resistance and low hysteresis silicon and aluminium were added; for toughness in springs a little vanadium was used, and for wearing qualities titanium is now introduced. These are only a few of the successful alloying experiments with iron. They will probably be repeated with other metals, such as copper, zinc, and aluminium, where the cost of the base metal is not high. He has found that there is a solubility of metals in one another which varies just about as the solubility of sub-first be determined and made known. As a metal it is only stances in water varies. Metals may be melted together and well mixed, but the quality and permanency of the mixture is determined by just such solubility laws as control ordinary solutions. We know that in some cases well-mixed melted metals will separate into two layers if allowed to remain even a few moments in molten condition at low temperatures. They act like a mixture of water and ether. The two separated layers contain both metals, no matter what the temperature, but the quantitative compositions depend on the temperature. The other extreme of metal solubility is found in such a case as zinc-cadmium, which acts much like a mixture of alcohol and water, the two components going into solution in all proportions and remaining in solution at all temperatures. Having seen this analogy between the facts of solubility of substances in water, it is natural to search among the metal mixtures for all the peculiar kinds of solution observed in aqueous solutions. Two such classes interest us at once. They are those corresponding to aqueous solubilities where temperature widely influences the quantities dissolved, and those in which the solvent (as water) combines with the dissolved substance more intimately than by simple solutions, as by chemical combination. In the case of zinc and lead we have one of the metal alloys of limited solubility. If these two metals are well mixed in liquid state they separate into layers-one, the zinc, carrying a few per cent of dissolved lead floats on an alloy made up of lead carrying a few per cent of dissolved zinc. In general, the quantity of the one metal dissolved and held in solution by the other depends on the temperature, and the higher the temperature the greater the solubility. Between 900° and 1000° C. they are apparently completely soluble. It follows from this that when a dissolved pair of metals is cooled slowly, one of them may separate on cooling if the limiting solubility is reached, and the extent of effective separation may depend on the rate of cooling. Our second case, that of chemical combination between the metals, is made most evident by the form of the freezing-point curve of the possible alloys. A compound of two metals which is stable at a temperature above the melting-point of one or both of the metals shows very clearly on the melting-point curve, and acts towards each of the elements just as a new or third element. Its meltingpoint cannot yet be predicted from any knowledge of the component metals. It may even melt higher than either of the components. Such cases are seen in alloys of aluminium-antimony, in lead-tellurium, &c. On the other hand, the study of those metals which have not yet advanced to a stage where first order cost-reduction is impossible is equally interesting. Consider again the element chromium. What do we know about it? Is it a workable metal? Can it be hammered or cast? Is it permanent in the air? Is there a considerable possible ore supply? Has the cost of obtaining the metal been reduced to what seems a reasonable rate? &c., &c. As it is unlikely that such an element will suggest itself for use by men as did copper and iron, it is probable that its properties must about fifteen years old. It is made in the metallic state by reduction of the oxide by metallic aluminium, and also by electrolysis of its salt solutions. It cannot yet be produced at a lower cost than that of the aluminium required, and it now sells at about 80 cents per pound. In the oxide from which it was made it may be had for less than half this cost, and in its alloys with iron, which are made by direct reduction with carbon, it is sold for 29 cents per pound. This gives a rough idea that ultimately, by perfection of metallurgical processes, &c., we may possibly obtain the metal much below 80 cents per pound. It withstands heat exceedingly well. When pure it melts at very high temperature (Ostwald, about 3000° C.), and it does not scale when heated red hot in air as copper and iron do. It is for this reason that it is used in resistance alloys for electric heating devices. It has been plated on to metals, and then looks and acts like nickel plate. Doubtless its use will quite rapidly increase in special alloys, as it has already come into use in tool steel. - The Chemical Engineer, xiv., No. 4. ISOMERIC PHENYLPHTHALIMIDES AND SOME ALLIED COMPOUNDS.* II. By MITSURU KUHARA and SHIGERU KOMATSU. IN the authors' previous article (Memoirs of the College of Science, &c., i., 391) it was shown that two isomers of phenylphthalimide are simultaneously formed instead of phthalophenylisoimide, from phenylphthalamic acid by the action of acetyl chloride. Of those two isomers thus formed, one consists of fine colourless needles melting at 83-84°, and the other of light yellow rhombic crystals possessing the melting-point of 125-126°. The authors have designated the former as Ba-phenylphthalimide, whose constitution has been considered to be probable to stand in agreement with the following Formula I., and assigned Formula II. to the latter for its probable constitution, based upon some analogies which seem to exist between its properties and those of phthalyl superoxide :C=N.C6H5 I. C6H4>O II. C6H1N.C6H5 CO Nevertheless, the authors have been led to the assumpMan first used the metals as he found them; then, as he tion that the latter compound, that is, one which is yellow reduced them from the ores, and finally, when specified requirements became more and more exacting, he not only Memoirs of the College of Science and Engineering, Kyoto brought into use previously unused metals, but also greatly | Imperial University, ii., No. 12. CHEMICAL NEWS, Chemical Nature of Soil Organic Matter. 31 sence of a chromophoric group and the white one the .CO. YELLOW. C-N.C6H2(CH3)3 and melts at 125—126°, should be the real unsymmetrical | would take the asymmetrical structure owing to the prephenylphthalimide, its constitution being preferably represented by Formula I. The reason is as follows:-It is now almost universally accepted that the group >C=Nis a trivalent unsymmetrical chromophor whose action is rendered conspicuous, especially in the aromatic series, and that its chromophoric character is highly strengthened when an aromatic residue is linked to the nitrogen of the group (see H. Kauffmann, "Ueber den Zusammenhang zwischen Farbe und Constitution bei Chemischen Verbindungen," Ber., xxvii., 3317; xxxi., 2250). On referring to the literatures concerning the compounds which are recognised to contain the group >C-N.Ar, such as >C=N.C6H5, >C=N.C6H4R', >CN.C6H4X, &c. (Ber., xiii., 420; xxi., 1415; xxiv., 3518, 3522; XXV., 2056; xxvi., 2292; xxviii., 58, 74, 1120; xxxii., 1678; xlii,, 4018; Ann. der Chem., clxxxvii., 199, 215; ccxcv., 31, 90; Am. Chem. Fourn., xviii., 813; xxv., 22; Journ. Chem. Soc., lxxix., 1212), we always find that they are all coloured particularly yellow or yellowish almost without exception, while the compounds in which an aliphatic residue or hydrogen is linked to the nitrogen are colourless (Ber., xxx., 3006; Am. Chem. Journ., xxx., 26; Ann. Chim. Phys., [6], xxii., 289; Rec. Trav. Chim. xii., 22; xiii., 98, 99). which shows the presence of the chromophoric group >C=N.C6H5, should be applicable to one of the authors' compounds which is yellow, in harmony with the above views. Then, the isomer so called 8-phenylphthalimide, which is colourless and melts at 83-84°, must possess other constitution different from that ever given, but the authors cannot yet give any satisfactory explanation for the possibility of such an isomer. Now the authors declare that Formula I., On conducting the experiments for the action of other different aromatic amines, such as orthotoluidine, paratoluidine, as-metaxylidine, v-orthoxylidine, paraxylidine, and pseudocumidine upon phthalyl chloride. two kinds of isomeric substituted phthalimides, namely, colourless and yellow, similar to those from aniline, were invariably observed to be produced from each amine. The colourless varieties must be the normal compounds of symmetrical constitution like s-phenylphthalimide, some such as normal tolyl (o- and p) and pseudocumylphthalimides, being already known; but in inferring the constitution of their respective isomers from the view of their coloured nature, the authors assert that they should possess the unsymmetrical structure analogous to a-phenylphthalimide, Owing to the presence of the chromophoric groups, as will be represented in the following table : C6H4 N.C6H2(CH3)3 C6H4 s-Pseudocumylphthalimide (known). >0 CO a-Pseudocumylphthalimide. In the case of using xylidines and pseudocumidine there are formed simultaneously, as the reaction products, the substituted phthalamides of the C6H4(CO.NH.Ar)2, which are readily transformed to the general formula corresponding yellow coloured diimides by the method analogous to that of the formation of von Gerichten's dianil from phenylphthalamide, as previously described in 402). while it is strange that with toluidines the analogous our last article (Memoirs of the College of Science, &c., i., compounds could not be obtained at all, although the effort to do so was repeated. The substances thus obtained must therefore be constituted as represented below: a-Phenylphthalimide. C=N.C6H4.CH3 a-Orthotolylphthalimide. C6H4 >0 CO -Orthotolylphthalimide (known). C=N-C6H3(CH3)2 a-as-Metaxylylphthalimide. (NOTE.-Piutti and Abati describe the production of p-methoxy- and p-ethoxyphenylphthalimides, and pmethoxyphenyl-A1-hydrophthalimide, each in two distinct modifications, yellow and white (of ethoxyphenyl-Arhydrophthalimide only yellow form), and ascribe such a phenomena to dimorphism (Ber., xxxvi., 996). The authors, however, are of the opinion that two modifications may be structural isomers, so that the yellow one CHEMICAL NATURE OF SOIL ORGANIC By OSWALD SCHREINER and EDMUND C. SHOREY. ACIDS OF UNKNOWN CONSTITUTION. THERE are a great many chemical compounds, especially of natural origin, to which, while the group to which they belong is well established and their general properties are known, no structure or constitution has been assigned. This is simply another way of stating that all the properties are not known. This meagre knowledge regarding con stitution is marked among the higher fatty acids, especially those of infrequent occurrence. Two acids of this character have been isolated from soils. These acids are isomeric, having the same ele * Bulletin No. 74, U.S. Department of Agriculture, Bureau of Soils mentary composition, and while one can be regarded as a well-established chemical compound, there is still some doubt whether the other is a single body or a mixture. Paraffinic Acid, C24H48O2. The cold alcoholic solution from which a-hydroxystearic acid has separated in the manner just described is yellow in colour, and evaporation of the alcohol leaves a semisolid oily mass. On standing some time crystals form in this mass, but the nature of the material was such that they could not be separated without great loss, and so this was not attempted. The oily mass was dissolved again in alcohol and an alcoholic solution of lead acetate added. This gave a yellow precipitate, which was sepa- | rated by filtration, washed with alcohol, suspended in alcohol, and treated with hydrogen sulphide. After separation from the lead sulphide the alcoholic solution was allowed to evaporate slowly, leaving a somewhat waxy mass of leaflets. This mass was purified by dissolving again in alcohol and repeating the operation of precipitation with lead acetate and finally drying on a porous plate. The body so obtained was light yellow in colour and melted at 45-48° C. gave the following figures: Elementary analysis Calculated for C24H48O2. 78.20 13.00 8.80 This composition, the melting-point, and physical properties correspond with paraffinic acid, C24H4802, described by Pouchet as obtained by the action of fuming nitric acid on paraffin (Bull. Soc. Chem., 1875, xxiii., 111). The research of Pouchet, on which alone the existence of paraffinic acid rests is, as published, inconclusive as to this body being a definite chemical compound. The quantity of this substance obtained from the soil was sufficient for any extended research, and so far the character of the compound obtained from paraffin has not been studied except that the following facts were established. Paraffin was treated with fuming nitric acid in the manner described by Pouchet and a compound obtained having the properties and composition stated by him. Elementary analysis of this substance gave the following figures: Lignoceric Acid, C24H48O2. When a soil high in organic matter is carefully heated in a closed tube, there is obtained a dark coloured tarry distillate, which in some cases sets on cooling to a semisolid crystalline mass. A peat soil containing 27 per cent organic carbon treated in this way gave a distillate of this character in considerable quantity. The semisolid mass on washing with cold alcohol was freed from much of its colour with little loss of solid matter. The material so washed was completely soluble in hot alcohol, from which it separated on cooling in a bulky microcrystalline form. On repeating this solution and separation several times the material was obtained nearly free of colour. Treatment at this stage with cold petroleum ether removed the remaining colour and a small quantity of oily matter. The body after this purification melted at 80-81° C., was soluble in ether and hot alcohol, little soluble in cold alcohol, and insoluble in water. elementary composition was found to correspond to the formula C24H4802. Found. Calculated for C24H48O2. Carbon .. Hydrogen Oxygen.. 78.1 13.2 8.7 78.2 Its The compound dissolved in aqueous alkalis, and was set free from such solution unchanged on addition of a mineral acid. The properties, melting-point, and composition indicate the identity of this compound with lignoceric acid first described as obtained by Hell and Hermanns (Ber., 1880, xiii., 1713) from the solid residue or "paraffin of beechwood tar. It is also found (Krealing, Ber., 1888, xxi., 880) as a glyceride in peanut oil. It is generally assumed that the lignoceric acid found in wood tar is the result of decomposition effected by the method of treatment, and that it does not occur as such in the wood. In the case of the soil, however, certain obserin-vations indicated that this might not be the case. It was observed that if the soil was heated to a high temperature or the heating done rapidly the yield of solid matter in the distillate was very small. When the heating was done carefully, and the temperature raised only to the point where a distillate could be obtained, the solid product seemed to be the result of distillation directly from the soil, and when the operation was carried on in a glass tube such distillation could actually be observed, the melted distillate collecting on the upper cooler side of the tube and being driven forward as heat was applied, just as water would be. It was also found that the purified lignoceric acid obtained from the soil in the manner described could by carefully heating be distilled with little or no decomposition. Calculated for C24H48O2. 78.2 13'0 8.8 The properties and composition of this compound corresponded with those of the substance obtained from the soil, and there is little doubt that they are identical. With this understanding the name paraffinic acid is applied to the soil compound. This body has so far been obtained from but one soil, the Elkton silt loam already described. A number of soils have been examined that gave, at the point where paraffinic acid was obtained in the case of the Elkton silt loam, a precipitate with alcoholic lead acetate, but the quantity of material has been either too small for identification or as had other properties and composition. Very little can be said regarding the possible origin of paraffinic acid in the soil. Several solid hydrocarbons of the paraffin series have been shown to occur in plants, and may therefore be a part of the organic matter added to the soil. Oxidation of these in the soil might give rise to the body found. It may be noted in this connection that it is well established that paraffin can be oxidised in the laboratory, but usually by rather vigorous treatment. Gill and Mensel (Zeit. Chem., 1869, p. 65) found that on treating paraffin with dilute nitric acid or chromic acid it was oxidised to cerotic acid, C27H5402, acetic acid, and succinic acid. Pouchet in the research referred to found succinic acid in addition to paraffinic acid, but no cerotic acid. With the object of extracting the lignoceric acid from the soil if it existed as such, the soil was treated with boiling 95 per cent alcohol, the extract filtered hot, and allowed to cool. On cooling, a voluminous precipitate separated from the dark coloured extract. This was separated by filtration and purified by dissolving several times in hot alcohol, from which it separated on cooling, and finally by washing with cold petroleum ether. The compound so obtained corresponded in all properties with that obtained by distillation. It melted at 80-81° C., and elementary analysis gave the following figures :— CHEMICAL NEWS Jan. 19, 1912 other vegetable oils and be somewhat widely distributed in plants in small amounts, in which case it might occur in the soil as a residue of the decomposition of such gly. cerides. Lignoceric acid is obtained by the distillation of wood, presumably through the decomposition of woody tissue. It is possible that similar decomposition through the agency of micro-organisms may take place in the soil. Resin Acids. There have been separated from a peaty soil from North Carolina three fractions having the properties of resin acids. While their identity as single chemical compounds has not been established, there is enough known concerning their properties and composition to warrant their descrip tion under this division of acids of unknown constitution. When the alkaline or humus extract of a soil is acidified, the humus extract filtered off, washed, and treated with boiling 95 per cent alcohol, a portion of the humus precipitate goes into solution. If the alcohol is removed by evaporation and water added to keep the volume constant, a dark coloured precipitate is formed, which, after filtration, washing, and drying, is a red or brown resinous powder. This procedure was the preliminary stage in the separation of a-hydroxystearic acid and paraffinic acid, these being removed from this resinous material by boiling petroleum ether. The resin acids to be described were obtained from a peaty soil, the same from which lignoceric acid was ob tained. The treatment was, as just outlined, the extraction of the humus precipitate with hot alcohol, resulting in a resinous mass which was extracted with petroleum ether. The portion insoluble in petroleum ether, which was the greater portion of the precipitate, was then repeatedly treated with boiling ether until no more material was dis solved. The ether solution was then shaken successively with water solutions of alkaline salts in the following order :-First, I per cent ammonium carbonate solution; second, I per cent sodium carbonate solution; and finally, I per cent sodium hydroxide solution. The extraction with each solution was repeated till no more material was taken from the ether before the next in order was used. This treatment extracted about go per cent of the matter originally soluble in the ether. The several alkaline solutions thus obtained were acidified with hydrochloric acid. The resin acids were set free, and being insoluble in water were separated by filtration. They were further purified by dissolving again in ether and repeating the extraction with aqueous solution of the same salts in the same order, the acids being separated, washed, and dried. As so obtained, they were resinous powders varying in colour from light yellow to dark orange. These bodies have been designated for purposes of description, resin acid I., II., and III., I. having been extracted from ether by ammonium carbonate solution, II. by sodium carbonate solution after the extraction of I., and III. by sodium hydroxide solution after the extraction of I. and II. The melting-points of these acids were sharp and were as follows (uncorrected): -I., 100° C.; II., 95o C.; III., 190° C. They had the same general appearance and an indefinite crystalline structure under the microscope. They were readily soluble in alcohol and ether and in aqueous solution of sodium or potassium hydrate; I. and II. were soluble in ammonia, | but III. was very slightly so. All gave in alcohol solution a slight reddish colour with ferric chloride, but did not respond to Liebermann's cholesterol reaction. The elementary composition was found to be as follows, the per cent of ash being given, but the composition stated on an ash-free basis :: 33 Resin acids II. and III. gave figures so nearly alike that they might be considered identical were it not for the wide difference in melting-point and solubility in ammonia already mentioned. All gave somewhat similar products on fusion with potassium hydrate, a mixture of phenol derivatives, and lower fatty acids. The method used for the separation of these resin acids is that adopted by Tschirch in the examination of resins. The material left in the ether after shaking with alkalis he designates resin esters. This fraction will be described later. It is evident that in this process there is a separation into fractions that have quite distinct properties and composition in spite of general resemblances. However, the investigation at this stage is quite unsatisfactory in regard to the identity of these several fractions as single organic acids or even as acids at all. It is assumed that because a body goes from solution in ether into solution in an alkaline salt it is a case of a free acid in the ether forming a salt soluble in water. There was, however, in the case of the shaking with carbonates no evolution of carbon dioxide, and the process was not the simple one of a replacement of carbon dioxide and the formation of a salt with the resin acid. The whole chemistry of the resins and so-called resin acids is in a very unsatisfactory condition. A great many separations have been made similar to those made in this case, named and described as definite compounds, when all that was known was their elementary composition and some of their physical properties. The class of compounds known as phlobaphanes or anhydrides of tannic acid are closely related to the socalled resin acids in their physical properties, composition, and products formed on fusing with caustic potash. These anhydrides, of which there seems to be a series, adjacent members differing from one another by one molecule of water, are in the same unsatisfactory condition chemically as are the resin acids. The several members of the phlobaphane series differ in solubility, and any one of the series may change its solubility and other physical properties by losing water and being transformed into another. There is some evidence that in these fractions designated resin acids there is some such anhydride constitution and ready change of solubility. There is then in the three fractions here described a separation of a considerable portion of the organic matter of a soil into three separate substances having the same general properties but differing in melting-point, composition, and some other properties. No definite conclusion can be stated regarding the identification of these substances, because the chemistry of the natural products to which they are related and with which they must be compared is largely unknown. These fractions form a large proportion of the organic matter, and further research into their constitution and nature is necessary. Nearly all soils examined give by the method described substances of similar appearance and properties. ESTERS AND ALCOHOLS. This group finds its largest representation in nature in the oils, fats, and waxes of plant and animal life. Practically all the fats and oils are esters of the alcohol glycerol, C3H5(OH)3, and may be represented thus: C3H5(OR)3, where R is the acid radical of a fatty acid. The acid radical may be of one or more acids, but in most natural fats two acids are represented; for instance, oleo-distearin OC18H330 The waxes are usually esters is C3H5< ~(OC18H350) 2 * of higher alcohols, such as cetyl, C16H33OH, ceryl, C16H51OH, cholesterol, C26H43OH, with the same higher fatty acids that occur in glycerides. Both oils and fats frequently contain small quantities of the esters classed as waxes. Most of the natural waxes are complex mixtures of esters, higher alcohols, and higher fatty acids, but as in fats and oils the esters are usually the chief component. |