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Tin as a catalyst
Dec., 1923.1
CURRENT TOPICS.
853
T e s t for Olive Oil.roW. H. DICKHART,of the New York Produce Exchange (Hm. J. Pharm., I923, Io5, 684-686), has devised the following test for olive oil. Two reagents are used, ( I ) a mixture of one part of concentrated sulphuric acid and four parts of absolute alcohol, and (2) a 5 per cent. solution of furfurol in alcohol. A 5 c.c. sample of the oil is shaken in a test tube with 5 c.c. of the alcoholic sulphuric acid to form an emulsion; then ten drops of the alcoholic furfurol are added and incorporated into the emulsion by shaking. A pink color at this stage indicates the presence o{ sesame oil, which interferes with this test for olive oil, and, therefore, renders further procedure useless. In the absence of sesame oil, the tube and its contents are kept in a bath of hot water at a temperature of 94 ° to 95 ° C. for ninety seconds, shaking every few seconds. The tube is now removed from the bath; IO c.c. of cold water are added to its contents, and mixed by shaking. The tube and its contents are then permitted to stand for ten minutes. A red colored solution indicates the presence of olive oil. The other oils tested (refined cottonseed, corn, castor, chinawood, hempseed, kapok, peanut, perilla, palm, palm kernel, lumbang, mustard, rapeseed, teaseed, linseed, soy bean, cocoanut, and tobacco seed oils) yielded only a milky solution. Certain of these oils give a color prior to the addition of the water; thus a slight red is given by palm kernel, peanut, cocoanut, teaseed, and castor oils, and a greenish blue bv mustard oil ; however, these colors vanish and are replaced by a milky solution upon the addition of water. This test will show the presence of 2 per cent. of olive oil in another oil. If oil of rosemary be present in excess in olive oil, the volume of water added in the test should be increased to I5 c.c. ; the solution becomes a dark red approaching a chocolate color, while the oil also is much darker than usual. J.S.H. T i n as a Catalyst.mAccording to O. W. BROWN and C. O. HEt,'KE, of Indiana University (J. Phys. Chem., I923, 27, 739-76o), metallic tin may act as a catalyst in the reduction of nitrobenzene to aniline by hydrogen, also in the reduction of ortho nitrotoluene and ortho nitroanisole to ortho toluidine and ortho anisidine, respectively, The tin acts better in coarse lumps than in the powdered form. Catalvsis occurs at a lower temperature in an iron vessel than in one of glass. In some experiments, from 93 to 99 per cent. of the theoretic yield was obtained. J. $. H. Automobiles in Australia. (Machinery, Oct., x923.)--Australia is to-day, as it has been for some time past, the leading export market for American automobiles. The value of the cars exported to Australia in I922 was $23,000,0oo. In addition, considerable exports were made from Canada by American manufacturers having Canadian branches. Forty per cent. of the entire exports of the country were represented by eight of the best known makes of American cars.
CURRENT TOPICS.
853
T e s t for Olive Oil.roW. H. DICKHART,of the New York Produce Exchange (Hm. J. Pharm., I923, Io5, 684-686), has devised the following test for olive oil. Two reagents are used, ( I ) a mixture of one part of concentrated sulphuric acid and four parts of absolute alcohol, and (2) a 5 per cent. solution of furfurol in alcohol. A 5 c.c. sample of the oil is shaken in a test tube with 5 c.c. of the alcoholic sulphuric acid to form an emulsion; then ten drops of the alcoholic furfurol are added and incorporated into the emulsion by shaking. A pink color at this stage indicates the presence o{ sesame oil, which interferes with this test for olive oil, and, therefore, renders further procedure useless. In the absence of sesame oil, the tube and its contents are kept in a bath of hot water at a temperature of 94 ° to 95 ° C. for ninety seconds, shaking every few seconds. The tube is now removed from the bath; IO c.c. of cold water are added to its contents, and mixed by shaking. The tube and its contents are then permitted to stand for ten minutes. A red colored solution indicates the presence of olive oil. The other oils tested (refined cottonseed, corn, castor, chinawood, hempseed, kapok, peanut, perilla, palm, palm kernel, lumbang, mustard, rapeseed, teaseed, linseed, soy bean, cocoanut, and tobacco seed oils) yielded only a milky solution. Certain of these oils give a color prior to the addition of the water; thus a slight red is given by palm kernel, peanut, cocoanut, teaseed, and castor oils, and a greenish blue bv mustard oil ; however, these colors vanish and are replaced by a milky solution upon the addition of water. This test will show the presence of 2 per cent. of olive oil in another oil. If oil of rosemary be present in excess in olive oil, the volume of water added in the test should be increased to I5 c.c. ; the solution becomes a dark red approaching a chocolate color, while the oil also is much darker than usual. J.S.H. T i n as a Catalyst.mAccording to O. W. BROWN and C. O. HEt,'KE, of Indiana University (J. Phys. Chem., I923, 27, 739-76o), metallic tin may act as a catalyst in the reduction of nitrobenzene to aniline by hydrogen, also in the reduction of ortho nitrotoluene and ortho nitroanisole to ortho toluidine and ortho anisidine, respectively, The tin acts better in coarse lumps than in the powdered form. Catalvsis occurs at a lower temperature in an iron vessel than in one of glass. In some experiments, from 93 to 99 per cent. of the theoretic yield was obtained. J. $. H. Automobiles in Australia. (Machinery, Oct., x923.)--Australia is to-day, as it has been for some time past, the leading export market for American automobiles. The value of the cars exported to Australia in I922 was $23,000,0oo. In addition, considerable exports were made from Canada by American manufacturers having Canadian branches. Forty per cent. of the entire exports of the country were represented by eight of the best known makes of American cars.