REMARKS ON LIST OF ELEMENTS. Barium.-The lines cross at an atomic volume of 36.5, equal to 3.74 specific gravity. This is between the values recorded for the element, which vary from 3.5 to 4 (mean 3.75). Bismuth. The specific gravity of liquid bismuth at the melting-point is taken; this is the highest specific gravity of the element.' Calcium.-The point taken in the chart was found by the crossing of the lines. It corresponds to an atomic volume of 25.3, equal to 1.577 specific gravity. Matthiessen gives 1.57, and this apparently is the only published result. Germanium.-The point taken is c 15.34, which is a little too high. 15.3 would be better, and this corresponds to a specific gravity of 5.44. Winkler gives 5.469. Hydrogen.-An atomic volume of 14.6 is assigned in the chart. This is about two-tenths higher than the figure recently given by Dewar. The lines drawn through this element place it in atom-analogy with Group I. It is sometimes placed in Group VII.. Silicon. The lines indicate an atomic volume of 12.5, equal to 2.26 specific gravity. This value is between the values given by Wöhler (2.49 at 10° C.) and Winkler (2.149-2.197). Strontium.-The point at which the lines intersect is 34.5, 1 Vincentini : J. Chem. Soc., 1891, II, 518. equal to 2.53 specific gravity. The determinations made with doubtfully pure specimens vary from 2.4 to 2.58. Sulphur.-Deville's results for monoclinic sulphur. Thallium.-The chart indicates a somewhat higher gravity (11.98) than Crookes obtained from the metal in the form of wire (11.91). Zirconium.-The atomic volume apparently should be a little greater than 21.2. THE THE OIL OF CORN.' BY C. G. HOPKINS. Received September 22, 1898. HE presence of oil in the corn kernel was discovered by Bizio in 1823. A partial analysis by Hoppe-Seyler gave the following as the percentage composition of the oil: The statement is made that the oil contains stearin, palmitin, and much olein, and the melting-point of the fatty acids is given as 51° to 54° F. (11° to 12° C.). Some of the so-called physical and chemical "constants,” which have been determined by several investigators are given below : 1 From advance sheets of the author's thesis "The Chemistry of the Corn Kernel," for the degree of Doctor of Philosophy, Cornell University, 1898, which will be published as Bulletin No. 53 of the University of Illinois Agricultural Experiment Station. 2 J. Chem. u. Phys., 1823, 37, 377 8 Med. Chem. Untersuchungen, 1, 162; Bull. Soc. Chim., 1866, [2], 6, 342; Jsb. Fortschritte der Chem., 1866, 698. 4 I have not been able to see Hoppe-Seyler's original paper. Presumably the protogon is the substance now termed lecithin, and the methods employed in estimating it and cholesterol were similar to those which are discussed herein. 5 Dingler's poly. J., 1887, 264, 626. 6 J. Soc. Chem. Ind., 1892, 11, 504. 7 Ibid., 1894, 13, 257, from Chem. Ztg., 17, 1522. 8 Inaugural Dissertation, St. Petersburg, 1894; Pharm. Ztschr. Russland, 1894, 33, 712; Chem. Centrbl., 1895, [4], 7, I, 22. The oil used by Spüller was the ordinary ether extract. Rokitianski used a petroleum ether extract. Hart worked with a "dark brown" sample presumably found on the market. Smith's material was obtained on the market, but was of a "bright golden color" and was probably a fair sample of corn oil. Spüller observed that the oil absorbed no oxygen from the air even after fourteen days' exposure. Smith states that the freezing-point of the oil is below -20°. Hart gives the meltingpoint of the fatty acids as 25°. Rokitianski reports further qualitative chemical work which showed the oil to contain oleic and linolic acids. It is evident from the specific gravity and the iodine absorption that the material with which he worked was not ordinary corn oil. Wiley and Bigelow' have recently found the heat of combustion of oil of corn to be 9280 calories per gram. EXPERIMENTAL. In a preliminary study a small amount of oil was obtained by collecting the ether extract from a large number of proximate analyses of corn. In this, advantage was taken of the fact that the oil is moderately soluble in alcohol when hot and but slightly so at ordinary temperatures.* The oil was transferred from the small flasks, used in its extraction, by means of hot alcohol to a single vessel. On cooling the oil precipitated and settled to the bottom, the alcohol being each time decanted from the collected oil, and used in transferring the next lot. Finally the alcohol was evaporated, and the oil dried to constant weight in a water oven. When freshly obtained from white dent corn the oil is nearly colorless, but on standing a pale yellow and finally a deep golden color develops, plainly indicating a gradual change in its condition, presumably due to absorption of oxygen. This was confirmed by determining the iodine absorption which was found to be 115.5 per cent. A large quantity of corn oil, including samples from four different sources,' was then secured in order to make a more 1 This Journal, 20, 309. 2 Smith has found the solubility of corn oil in alcohol by volume to be two per cent. at 16° and thirteen per cent. at 63°. 3 Samples of corn oil were very kindly furnished me by President Wm. F. Piel, Jr., of The National Starch Manufacturing Company, New York City; by The Chas. Pope Glucose Company, Geneva, Ill.; by The Glucose Sugar Refining Company, Chicago; and by Messrs. Elbert and Gardner, New York City. |