ETHYLENE CHLORHYDRIN BY M. GOMBERG1 CHEMICAL LABORATORY, UNIVERSITY OF MICHIGAN Communicated, July 30, 1919 Within a few days after the so-called "Mustard Gas" was introduced (July 12-13, 1917) as a means of offence, it was definitely identified as B-B-dichlorethylsulphide. There was good reason to believe that it had been manufactured from ethylene chlorhydrin, according to the method described some thirty years previously by V. Meyer. The reactions involved in that method are these: (1) Ethylene chlorhydrin in solution reacts with sodium sulphide and gives, in good yield, dihydroxyethylsulphide, which is non-poisonous; (2) this product gives on treatment with concentrated hydrochloric acid the highly toxic ß-ß-dichlorethylsulphide: = 2 HOCH2CH2Cl + Na2S (HOCH2CH2)2S + 2 NaCl The problem however was,-how to get the chlorhydrin itself? From the practical standpoint, a process based upon the additive reaction between ethylene and hypochlorous acid seemed most promising, notwithstanding the facts that this acid could only resist in concentrations of 1 to 3%, and that the best yield of chlorhydrin by this method was known to be not more than 30% of the theory. The reaction between chlorine and water was employed as the source of hypochlorous acid. As is well known, this reaction yields extremely little hypochlorous acid, the equilibrium favoring largely the left-hand side of the equation. Nonetheless, it was found that if ethylene and chlorine in equimolecular amounts are passed into cold water and the mixture is well stirred, chlorhydrin, and not ethylene chloride, is the principal product. This is explained on the assumption that reaction II proceeds with considerably greater velocity than reaction I. While a concentration up to 15% of chlorhydrin can be attained in this way, in practice it has been found advisable to stop with a concentration of 7 to 8%. The progress of the reaction is ascertained by distilling a small sample of the product and determining its refractive index, that of water being 1.333 while that of chlorhydrin was found to be 1.442. It was established that not only is it unnecessary to keep on neutralizing the hydrochloric acid produced with the progress of the reaction, but that in fact it is inadvisable to do so. Separation of chlorhydrin.-Pure chlorhydrin boils at 128°C. It was found, however, that when mixed with water in proportion of 42.5 parts of the former and 57.5 parts of the latter, the two form a constant boiling mixture which distills at 95.8°. Consequently, aqueous solutions of chlorhydrin poorer than 42.5% tend to give on distillation initial frac tions approaching in composition the constant boiling mixture; solutions richer than 42.5% give as the final fractions pure chlorhydrin. With the addition of salt or calcium chloride to the liquid to be distilled, concentrations of chlorhydrin up to 80% can be readily obtained. The diagram shows what happens when 5, 10 and 15% solutions of chlorhydrin are subjected to distillation. Chlorhydrin is miscible with water in all proportions. It has, however, been found that it can be salted out from its aqueous solutions, provided that the proper conditions as to initial concentration, etc., are observed. Solutions containing 70% of chlorhydrin can readily be obtained in this manner. It was also found possible to extract the chlorhydrin from its aqueous solutions by some immiscible solvent, benzene suggesting itself as the best from the practical standpoint. Thus, by a judicious combination of the three methods, distillation, salting out and extraction,-chlorhydrin could readily be obtained in any desired concentration and purity. 1 The investigation was done under the auspices of the Bureau of Mines, War Gas Investigations Department, December 1917-July, 1918. The paper in detail, approved for publication by Major-General William L. Sibert, Director of the Chemical Warfare Service, U. S. A., will appear in the Journal of the American Chemical Society. 2 Meyer, V., Berlin, Ber. D. chem. Ges., 19, 1886, (3260). Clarke, H. T., London, J. Chem. Soc., 101, 1912, (1583). STUDIES OF THE CONSTITUTION OF STEEL BY EDWARD D. CAMPBELL CHEMICAL LABORATORY, UNIVERSITY OF MICHIGAN Communicated by M. Gomberg, July 30, 1919 Researches on steel, considered as a solid solution, were carried on in this laboratory by the late J. W. Longley prior to 1876.1 Other investigations of iron and steel were carried on in the interval between 1876 and 1891, at which latter time the present writer began a series of researches on the chemical constitution of the carbides of iron. The results of these investigations have gone to show that the carbides found in steel have a much more complex structure than would be indicated by the commonly accepted formula Fe C. The idea that the carbides of iron and many other metals can best be studied if the carbides are regarded as metallic substitution products of hydrocarbons was advanced2 in 1896. In addition to recognizing the complex molecular constitution of the carbides, the assumption has been made that the atomic relations existing between the carbides or other solutes dissolved in iron are essentially the same as those which exist between the molecules of substances in aqueous solution and the water in which they are dissolved. Some further evidence in support of the hypothesis of the unity of mechanism of all solutions without regard as to whether the solvent is solid or liquid, metallic or a non-conductor of electricity, is given in two papers, one of which will be read at the Autumn meeting of the Iron and Steel Institute and the other at a forthcoming meeting of the Faraday Society. In the first of these it is shown that from twelve samples of steels, including straight carbon steel, high silicon, high phosphorus, manga nese, five nickle steels, chrom-steel, chrom-tungsten and chrom-molybdenum steel, most of the carbon and a considerable proportion of the sulphur may be removed by heating bars of the metal in a slow stream of moist hydrogen, the temperature being maintained for from four to twelve days between 950°C. and 1000°C. Since the elements other than carbon and sulphur are not affected by hydrogen, this method of treatment affords a very satisfactory means of changing the carbide concentration without material change in composition, since the percent of sulphur is usually quite low in commercial steels. The experimental data given in the second paper, "The Solution Theory of Steel and the Influence of Changes in Carbide Concentration on the Electrical Resistivity" demonstrate clearly that Benidicks' Law,3 "Equiatomic concentrations in iron possess equal resistivities," is not tenable. It is the molecular, not the atomic concentration in metallic solutions, which determines the electrical resistivity, just as it is the molecular and not the atomic concentration which determines conductivity in aqueous solutions. The fallacy contained in the conclusion drawn by Le Chatelier that chromium, tungsten and molybdenum have but slight influence on the electrical resistance of steel, may be explained by the fact that when these elements are present in steel, they form with carbon complex carbides, so that the molecular concentration of the carbides is little if any greater than if chromium, tungsten and molybdenum were absent. If, however, the carbon is removed, the chromium, tungsten or molybdenum will itself combine with or dissolve in the iron, each thus producing an increase in electrical resistivity nearly equal to that which would be produced by an equal atomic concentration of carbon alone. The force-field theory of solution developed by E. C. C. Baly by a series of investigations of the action of light on aqueous solutions, may be applied to solid solutions in metals and, assuming the unity of mechl anism of these and of aqueous solutions, can be made to give a rationaexplanation for thermal and electrical resistivity, as well as for the thermo-electromotive properties of solutes in solid solutions. Many other properties of solid solutions will also probably be found capable of explanation by the force-field theory. 1 On the Relationship of Structure, Density and Chemical Composition of Steel, Amer. Chemist, 7, Nov. 1876, (175-178). 2 Campbell, E. D., Amer. Chem. J., 18, 1896, (719–723). 3 Zs. physik. Chem., 40, 1902, (545). 4 Le Chatelier, Paris, C. R. Acad. Sci., 126, 1898, (1709, 1782). 5 Baly, E. C. C., J. Amer. Chem. Soc., Easton, Pa., 37, 1915, (979). INHERITANCE OF QUANTITY AND QUALITY OF MILK PRODUCTION IN DAIRY CATTLE By W. E. CASTLE BUSSEY INSTITUTION FOR RESEARCH IN APPLIED BIOLOGY, FOREST HILLS, Mass. Communicated, August 1, 1919 In 1911 the late T. J. Bowlker undertook at his farm in Framingham, Mass., an experimental study of inheritance in dairy cattle by the modern method of crossing pure breeds and looking for a recombination in the second crossbred generation of the characters differentiating the breeds crossed. The breeds which he selected for study were the Holstein-Friesian and the Guernsey, one supreme among dairy breeds in quantity production, the other of very high rank as regards quality of milk produced. It was his belief that if quantity and quality of milk production were independently inherited characters, it should be possible to combine them in a single race by the method of crossbreeding, in accordance with Mendel's law. The desired recombination of qualities, if attainable, would be of much importance to the dairy industry, and at any rate the knowledge whether such recombination is attainable would be a valuable contribution to science. With rare insight into the difficulties surrounding the problem and the proper method of attacking it, Mr. Bowlker planned his experiment on a considerable scale. He had a herd of some 40 pure-bred registered cows, about two-thirds of them being Holsteins, the rest being Guernseys. He also had a pure-bred registered bull of each breed, and in the pedigrees of these bulls excellent blood-lines were represented. He decided to cross-breed the entire herd, mating the Holstein cows to the Guernsey bull and the Guernsey cows to the Holstein bull. In this way what are known as reciprocal crosses were made between the two breeds. In all about 140 F, calves were produced between the years 1912 and 1919. As fast as the F1 heifers attained suitable age they were bred to F1 bulls in order to secure the desired F2 generation, in which combination of characters might be expected. About 35 living F2 calves have been produced in this way of which the heifers have been saved for milking tests, for which, however, they are still too young. Mr. Bowlker did not live to see the completion of his experiment but died in February, 1917. His family undertook to complete the unfinished work, with such scientific advice as I could give them, but practical difficulties having arisen which make it impossible to carry the work |