October 10, 1931
INDUSTRIAL
AND ENGINEERING
considerably decreased. The price of raw rubber has decreased throughout the world. Transportation and freight rates, how ever, are so high that Hungarian rubber factories have been unable t o reduce their prices. August, 1931
Mysore M. SREENIVASAYA, Department of Biochemistry, Indian Institute of Science, Bangalore Raman Honored The South Indian Science Association, under whose auspices Sir C. V . Raman first announced to the world his great discovery,
Medallion P r e s e n t e d to Sir C. V. R a m a n
has struck off a medallion in commemoration of his winning the Nobel Prize. On one side of the medallion Raman's profile is set in the heart of the Indian peninsula, while Alfred Nobel's is s e t in Sweden on the other side. Cantharidin Made from Indian Sources A t present, dried insects or extracted cantharidin preparations are being imported into the country a t high prices. I t has now been found possible to obtain this drug from the locally avail able blister beetle, which has been identified as Mylabris Pustulata Fb. by the government entomologist, Coimbatore. The maximum yield of cantharidin hitherto recorded is 1.9 per cent from Chinese beetles, but experiments at t h e Indian Institute of Science have shown a yield of 2.3 per cent from the Indian beetles. I t could be produced at about 12 cents per gram, while the imported product sells at 70 cents. Oil Being Made from Sandal Seed In addition to the well-known essential oil from the heartwood, sandal yields a valuable fixed oil which is present in its seeds. The oil can either be extracted by a solvent or pressed o u t h o t in a suitable press. I t is highly viscous, thicker than castor oil. I t contains in solution an unsaponifiable resin which has a very high iodine value. The oil itself has an iodine value of 130, and dries up in the course of 24 hours when exposed to air in thin films. On boiling, the oil gradually thickens and the reaction proceeds rapidly when t h e operation is carried out with manganese or lead oxide. Sulfur reacts violently with the oil at about 200° C , yielding a rubber-like mass. Colophony, copal, dammar, and ester gums can be dissolved in the oil to obtain oil varnishes suitable for wood and iron work. Further investigations on this oil are in progress in t h e biochemical laboratories of the Indian Institute of Science. Symposium Held on Indigenous Drugs T h e South Indian Science Association recently held a sym posium on indigenous drugs, when several aspects of t h e problem were discussed. A standing committee has been formed, which has been entrusted with the task of making a survey of the Mysore forests with regard t o the occurrence and distribution of medicinal plants. This committee, which is presided over by the senior surgeon to the Government of Mysore, has initiated the investigation of many important drugs i n the state.
Sand Turned into Steel At Taranaki, on the west coast of the north island of New Zealand, sand will soon be converted into steel, by American capital and American machinery. T h e beaches on this coast are composed of millions of tons of a h e a v y black sand—iron oxide. Previous attempts t o work t h e deposits profitably have failed. The new method, which an American syndicate is using, however, is said t o produce steel s o economically t h a t it will have a world market.
CHEMISTRY
301
Carbon Tetrachloride May Replace Ether in the Extraction of Rotenone Preliminary Report HOWARD A. JONES, Insecticide Division, Bureau of Chemistry and Soils. Washington, D . C . The extraction of the insecticide, rotenone, from Deguelia (Derris) sp. root and cube root (Lonchocarpus nicon) is a subject of increasing importance. Numerous solvents have been used in the extraction of these plant materials, b u t for obtaining ro tenone the majority of recent investigators have used ether, be cause of the readiness and purity with which, in general, rotenone separates from the evaporated ether extract. Roark («?) has outlined a method devised by Clark, of this labo ratory, for the determination of rotenone in these roots. It consists in extracting the ground root in a Soxhlet apparatus with ether, allowing the crystalline material to separate from the evapo rated extract, and filtering and weighing this in a tared Gooch crucible. I n a survey made in this laboratory of numerous samples of Deguelia and cube roots, it was found that in many cases in which this method was used the rotenone crystallized readily on stand ing overnight and filtered without difficulty. However, in some cases the rotenone separated from the extract only very slowly, and the gummy nature of the extract made filtration difficult. In other cases the separated crystalline material when examined under the microscope was found to contain only a small propor tion of rotenone, or none. I n an attempt to overcome some of these difficulties, carbon tetrachloride was substituted for ether in this method. This solvent was tried because its solvent power for rotenone (2) is so nearly that of ether. Rotenone separates from solutions in carbon tetrachloride as a solvate containing one mole of the sol vent to one of rotenone (2). This material can be dried in air and weighed, a factor being applied t o obtain the equivalent weight of rotenone. It was found that the rotenone separated from the evaporated carbon tetrachloride extracts of most roots more readily than from the corresponding ether extracts, and the amount of rotenone obtained b y the use of the two solvents checked very well. Some of the samples from which crystalline materials other than rotenone were obtained by means of ether gave almost no crystalline material from the carbon tetrachloride extracts. On the other hand, two or three roots from which no rotenone could be separated by means of ether (even when t h e latter was seeded with a weighed quantity of pure rotenone), gave carbon tetra chloride extracts from which rotenone separated readily—as much as 2 per cent being obtained from one sample. I t would thus seem that for assaying purposes carbon tetrachloride gives a quicker and more selective separation of the rotenone. Ether has been used in this laboratory for some time t o obtain rotenone from Deguelia and cube roots on a large scale. The sub stitution of carbon tetrachloride for this purpose would also seem to be advantageous. For instance, a recent sample of cube root received by this division was found to contain more than 10 per cent rotenone. Two 2-kilogram samples of this root were ex tracted simultaneously by percolation at room temperature—one with ether and the other with carbon tetrachloride. Sixty liters of ether were required to extract the same amount of rotenone as was obtained by the use of only 35 liters of carbon tetrachloride. In both cases the rotenone separated readily from the evaporated extract (separating as the solvate from the carbon tetrachloride extract), and had a high degree of purity. The loss of solvent by evaporation was much less in the case of carbon tetrachloride. Further, it i s reasonably certain that the amount of carbon tetrachloride used in this test could have been considerably reduced if the percolator had been heated t o 60-70 ° during the extraction, as this greatly increases the solubility of the rotenone. Although the increase in solubility with increase in temperature in the case of ether may also be great, this fact cannot be taken advantage of because of the low boiling point. Large quantities of Deguelia root have also been successfully extracted with carbon tetrachloride for their rotenone content in this laboratory. The solvate obtained in these extractions m a y be freed of its carbon tetrachloride of crystallization by recrystallizing from alcohol. This may also be accomplished by heating at 8 0 - 9 0 ° under reduced pressure if convenient. (The solvate does not melt under these conditions.) T h e amount of carbon tetrachloride lost in this way is practically negligible, being only 39 per cent of the weight of the recovered rotenone. A further advantage of carbon tetrachloride over ether in the commercial extraction of rotenone i s the absence of fire hazard, a very important item. Literature C i t e d CD Jones, Η . Α., / . Am. Chem. Soc, 53, 2738-41 (1931). (2) Jones, Η. Α., a n d Smith, C. M-, Ibid., 52, 2554-62 (1930). (3) Roark, R . C , Soap, 7, No. 3 , 97-9 (1931).
