INDUSTRIAL A N D ENGINEERING CHEMISTRY
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Mr. Holds remark t h a t the durometer and plastometer measure “elastic compressibility” signifies nothing to a rubber physicist. Rubber is substantially incompressible, but i t is readily deformable. The stress-strain curve of rubber may be determined either in compression or tension, b u t what these instruments really measure seems to be the property of rigidity, a characteristic of all solid substances. To say, therefore, t h a t rubber has greater “hardness” (rigidity) than iron, cannot correctly characterize the material. Rubber probably has no elastic limit except its rupture strength; i t does not follow Hooke’s law, and every stress, however slight, produces some permanent deformation, and i t is, therefore, quite impossible to measure “hardness” above the elastic limit of the material. The “resilient energy” capacity, regarding the measurement of which Mr. Holz asks t o be informed, was determined by the previously published methods of Wiegand [Can. Chem. J., 4 (1920), 1601 and of Gurney and Tavener [THISJOURNAL, 14 (1922), 1341, a planimetric determination of the area between the stress-strain (tensile) curve and the elongation axis. The energy capacity may also be determined from compression stress-strain curves. I have not attempted t o define “toughness” of rubber further than to say t h a t i t is usually considered t o be an optimum combination of tensile strength, abrasion
Vol. 15, No. 7
resistance, endurance of flexing, resilience, and relatively low permanent set. Resilience may be defined as the ability of the material t o return t o its original conformation and dimensions following the application of a deforming stress, and in rubber i t has at least two elements-high rate of return and absence of great permanent deformation (permanent set). While these quantities are perhaps not as yet accepted “standard” units, they are, at any rate, generally recognized by rubber technologists. I s$all not undertake t o defend laboratory tests of abrasion resistance ; their value is already sufficiently appreciated in the rubber industry. Mr. Holz is correct in saying t h a t laboratory abrasion tests do not exactly duplicate road conditions, but i t is neither necessary nor desirable t h a t they should. I am heartily in accord with his emphasis on the desirability of further investigations in the field of abrasion resistance, b u t find myself unable to agree with the claim t h a t “we do not yet know anything regarding the resilient energy, toughness, or hardness of rubber.” H. W. GREIDER MELLON INSTITUTE OF INDUSTRIAL RESEARCR PITTSBURGH, PA. M a y 14, 1923
TOKYO .LETTER B y K.KASHIMA, 994 Ikebukuro, near Tokyo, Japan
ANNUAL MEETINGS April is the month of cherry blossoms and general meetings. On the 1st and 2nd, the annual meeting of the Mathematical and Physical Society of Japan was held in Tokyo. On the 7th and 8th, the 45th annual meeting of the Chemical Society of Japan was held at the chemical laboratory of the Faculty of Science of the Tokyo Imperial University. The Sakurai Medal was awarded t o Shintaro Kodama for which the medalist read a paper on amino acids and aldehydes. Professor Katayama gave the presidential address, on stoichiometry. The general meeting of the Pharmaceutical Society of Japan was held at the City of Tokushima on the 14th and 15th of April. The 26th annual meeting of the Society of Chemical Industry was held in Tokyo on the 5th and 6th of May. Shuichiro Nagai, of the Faculty of Applied Chemistry of the Tokyo Imperial University, was awarded with the society’s medal for the work on safrol from camphor oils. K. Saegi gave the presidential address. SYIiTHESIS O F
PETROLEUM
Petroleum in this country is not abundant. For some time chemists have been conducting experiments to investigate the origin of petroleum. Kiuhei Kobayashi, of Waseda University, has made studies on Japanese acid clay (fuller’s earth), and has published a book, “Acid Clay,” which is the only book on this subject. On distilling a mixture of sodium chloride and the clay, he obtained hydrochloric acid. This curious fact led him to seek further facts. Fish oil was then used instead of salt. H e distilled a mixture of the oil and the clay, covered with the same amount of the clay. A petroleum-like oil having greenish fluorescence was distilled over. After washing with sulfuric acid, caustic soda solution, and water, as in the petroleum industry, the insoluble oil was fractionally distilled into gasoline (about 30 per cent), lamp oil (50 per cent), and middle oil (10 per cent). He claims t h a t the petroleum which he has prepared from fish oil has physical properties which are almost identical with those obtained from the natural petroleum, the yields being about 60 per cent of the oil. The product is mainly composed of naphthenic hydrocarbons containing a comparatively large amount of olefinic hydrocarbons. Based on these results, he proposes an hypothesis on the cause of formation of natural petroleum, Other chemists have also engaged in this work and many papers have been published in Chemical Industry ( J a p a n ) , The Journal of
the Chemical Society of Japan, and the Patent Journal; readers will be able t o get their outlines through Chemical Abstracts. As material, fish oils of different origin-vegetable oils, calcium salts of fatty acids from soy bean, pine resin, sodium salts of f a t t y acids from herring oil, pupa oil, etc., were used. Acid clay is a curious substance; when a mixture of the clay and camphor is heated, petroleum is formed. Not only Fare fish oils used for the manufacture of petroleum, but also calcium or sodium salts of fatty acids. When treated with lime, glycerol is produced from the oil, the yield of this material being about 10 per cent. This reduces the price of the oil by 13 to 45 per cent and also that of the petroleum. The process has now passed the period of laboratory experiment. When the writer had a chance t o journey through Echigo for inspection of the petroleum industry two years ago, one company was manufacturing petroleum from fish oil in apparatus with a capacity about 10 koku (1koku = 180.39 liters). The annual production of fish oils in this country is not clearly recorded, but i t is estimated to be about 3,000,000 kan (1 kan = 3.75 kg.). Some of this is used for lubricating oils, etc., but a large part may be used for the manufacture of petroleum. J. Takahashi in his book, “A New Treatise on the Mineral Deposit of Petroleum,’’ reports a comprehensive and complete investigation of the mineral deposit in the petroleum fields of Japan. GASOLINE FROM NATURAL GAS This subject is a n internationally popular one. The drying material of Dr. Ikeda, mentioned in a previous letter and now called “adsole,” has proved t o be a powerful drying agent and is now being used in many industries. Fish are easily dried by this material. It has also been found t h a t adsole will absorb gasoline from natural gas, from which the gasoline is recovered. The T B y B Gas Laboratory has been founded for the utilization of adsole, manufacture of gasoline and other connected works, being connected with the Rikwagaku Kenkyujo (Institute of Physical and Chemical Research). A plant was built in Echigo, a famous petroleum field in Japan, and the work is now progressing. I n the future some report will be written on the work of this plant. May 26, 1923
