INDUSTRIAL AND ENGINEERIXG CHEMISTRY
February, 1925
yeast as the only source of this vitamin. It was shown that yeast is a good source of vitamin B and that reproduction was possible on levels of yeast corresponding to 1.5 per cent and more, but that the mortality of the young was high even when yeast composed as much as 8 per cent of the ration. On the latter quantity of yeast the mortality was 75 per cent. 260 230
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source of vitamin B produce more litters, more young to the litter, and rear a far larger percentage than do the females on yeast as the only source of this vitamin. Nelson, Heller, and FulmerS have stated that it is unnecessary to assume a new vitamin for reproduction, as claimed by Evans and B i ~ h o pbut , ~ just why cane molasses i s better than yeast for the rearing of young we are a t a loss to explain. It is a significant fact that not only was growth, reproduction, and rearing of young abnormal on beet molasses but the mothers after birth oi the young became very emaciated and died. The curve illustrating the behavior of the animals on 25 per cent of beet molasses shows t8hatgrowth was resumed at the normal rate when yeast to the extent of 5 per cent was incorporated in the ration, but no young were produced. In the case of the sorghum at the 20 per cent level, growth was also below normal, and when yeast to the extent of 5 per cent of the ration was added growth was resumed at the normal rate; some young were born and reared. Acknowledgment
80 50 Figure 7-Results
Obtained o n 20 Per c e n t Sorghum. Yeast Added a t P o i n t X
5 Per c e n t
Apparently, yeast is richer in vitamin B than cane molasses, but the results on reproduction and rearing of young are not so good with yeast. The females on cane molasses as the sole
The writers desire to thank Carl S. Miner, of The Miner Laboratories, Chicago, Ill., and C. U. Snyder & Co., Mobile, Ala., for their conperation and generosity in supplying some of the materials necessary for this work. Thanks are also due the Fleischmann Company for supplying the yeast. 4
Science, 66, 650 (1922).
Compensation of Temperature and Instrument Factors in Determination of Alcoholic Content' By E. A. Vuilleumier DICKINSON COLLEGE, CARLTSLD, PA.
HI< regulations of the Internal Revenue Department require that the alcoholic content of liquids be reported in terms of the temperature of 60" F. (15.56' C.) referred to water as unity a t the same temperature, and most alcoholometric tables are made up on this basis. Obviously, it is desirable that the specific gravities of distillates be determined a t exactly this temperature. Frequently, however, this is not practicable, and in such a case a temperature correction, which varies with the alcoholic percentage, must be introduced. This correction may have a large influence upon the final result, and is especially important (though not greatest) in the analysis of liquids of low alcoholic content. The specific gravity a t 15.56' C. of a distillate containing 0.5 per cent alcohol by volume is 0.9992, referred to water as unity at the same temperature. But pure water itself has a value of 0.9992 at 20' C., and of 0.9980 at 25' C., referred to water at 15.56' C. If the temperature corrections were not introduced, these specific gravities would seem to indicate an alcoholic content of 0.5 and 1.3 per cent, respectively. The need for adjusting the temperature of the alcoholic distillate to the standard temperature, as well as the complication of introducing temperature corrections, can readily be eliminated. The procedure is 40 determine the specific gravity of the distillate at any convenient temperature, referred to water a t the same temperature. This makes it possible for the results to be applied directly to the alcoholometric tables. Probably the most convenient apparatus for determining the specific gravity of distillates is the Mohr-Westphal 1
Received September 21, 1924.
balance. Unfortunately, so far as alcoholometry is concerned, these instruments appear to refer to water at 4" C. I t is possible to correct the instrument to the standard temperature by adding 0.00096 to the readings. If, however, the temperature of the distillate is not 15.56' C., a second temperature correction is necessary. Finally, a given instrument may not have been accurately adjusted for 4" C., and this necessitates a third correction. All three difficulties can be eliminated a t the same time by taking readings with water and the distillate a t the same temperature. The difference between the two readings subtracted from unity gives the *tablespecific gravity of the distillate. Thus, if the water reading is 0.9980, and the distillate reading is 0.9974, the difference is 0.0006. This value subtracted from 1.0000, or 0.9994, is the table value of the distillate, and corresponds to 0.4 per cent alcohol by volume. The method of compensation described above, although not absolutely rigid mathematically, is well within the limits of experimental error.
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Increased Imports of Bromine Compounds
-4review of the imports of bromine and its compounds entered for consumption in the United States shows that importations in 1923 were valued at $19,062 and increased considerably in the first nine months of 1924, particularly in the third quarter, to $157,466, according to the Chemical Division of the Department of Commerce. Increased importations are attributed to the demand for bromides required in the production of tetraethyl lead, used as an anti-knock compotind in gasoline engines.
