May, 1925
1,VDUSTRIAL B,YD EAVGINEERING CHEMISTRY
milk powders variously supplemented. In one diet there are included 35 per cent of skimmed milk powder and 61.9 per cent of rolled oats. I n this laboratory very good reproduction was observed in the first generation on a diet in which 60 per cent of oat groats furnished all the protein and all the vitamins. Another diet employed by Sure contained 35 per cent of skimmed milk powder and 61.9 per cent of polished rice. From the chart it appears that the females weighed about 70 grams when started on this diet. The writers have had some success with reproduction on Diets 14 and 15, but in this case the rats were started a t an initial weight of from 80 to 100 grams. Some young were weaned on Diet 14. No doubt this was possible only because of the comparatively advanced age of the experimental animals when placed on the diet. On a diet of polished rice 50, commercial casein 40, dextrin 10, and a liberal supply of whole milk, Sure secured four successful generations. The favorable effect of whole milk in tlie diet upon reproduction has been clearly pointed out by Palmer and Kennedy,1z who say: Our results might also be interpreted t o indicate a lack of something required for normal lactation, were it not for extensive unpublished data which we have showing that the addition of 10 cc. of whole milk (1.25 grams of milk solids) to the diet of rats which fail to grow normally, as well as reproduce, has resulted in the securing of normal rats in experiments which have, to date, reached the third generation.
EvansI3 has indicated that the oil of the wheat germ is a very potent source of a factor which favorably influences reproduction. There are in progress experiments designed
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to test the supplementary value of an ether extract of wheat germ, as well as a variety of other materials. Should these additions favorably affect reproduction on a ration well balanced with reference to salt, protein, the known vitamins, fat, and carbohydrate, it will be considered evidence in favor of a factor, probably a vitamin, having to do with reproduction. In the meantime, the writers wish to accumulate further experimental data in an attempt to determine whether the assumption of an additional vitamin, or some other explanation, is the correct one. Acknowledgment
The writers desire to thank the Merrell-Soule Company for the liberal supply of milk powders and the Fleischmann Company for the yeast. Bibliography 1-Mathews, “Physiological Chemistry,” 3rd. ed. 2-Merrell-Soule Co., “Ktim,” a pamphlet, 1921. 3-Mattill and Stone, J . Biol. Chem., 66, 443 (1923). 4-Nelson, Heller, and Fulmer, I b l d . , 67, 415 (1923). 5-McCollum and Davis, I b i d . , 19, 245 (1914). 6-McGowan and Crichton, Biochem. J., 18, 265 (1924). 7--Anderegg, J . Bioi. Chem., 59, 587 (1924). 8-Osborne and Mendel, Zbid., 15, 311 (1913). 9-Osborne and Mendel, Zbid., 34, 537 (1918). 10-McCollum and Davis, I b i d , 20, 415 (1915). 11-Sure, Zbid., 68, 6S1, 693 (1924). 12-Palmer and Kennedy, Proc. Soc E x p U . Biol. M e d . , 30, 506 (1923). 13-Evans, Science, 60, 20 (1924)
Water Solubility of Various Wood Tars‘ By H. N. Calderwood, Jr. FOREST PRODUCTS LABORATORY, MADISON, Wrs
The raw settled hardwood tar was the material obtained by allowing the crude condensate from the retort to stand until it was no longer turbid. The boiled tar was obtained of the different tars used. The method used was one devised from the raw settled tar by heating in an oil bath held at by the writerZ for solubility studies of the dissolved tar from 150” C. until no further distillate was secured. The steamed tar was obtained by subjecting a portion of the boiled hard maple. The tar and distilled water were mixed in definite propor- tar to steam distillation until the oil condensate had a tions in a separatory funnel and stirred vigorously for an specific gravity greater than the water condensate. The hour a t room temperature with a motor-driven stirrer. The preparation of the dissolved tar has been described elsetar and water mixture was then allowed to stand overnight where.* before separation. A portion of the water layer was then disExamination of the results shows that removal of the The results more volatile constituents decreases very markedly the tilled for dissolved tar by the usual m e t h ~ d . ~ of this work are shown in the accompanying table. All water solubility of the hardwood settled tar. Probably the hardwood tars had been prepared in the experimental the constituents whose removal caused the decreased soluretort in this laboratory, but the pine tar was a commercial bility were those soluble in the aqueous portions of the d i e sample. The ratios of water to tar are expressed in parts tillates, although this point was not checked by returnby weight. These ratios correspond to those existing be- ing the oil portions of the distillates to their respective tars tween the tars and their respective pyroligneous acids. and again determining the water solubility. This point would not be of commercial importance, because the wood disSolubility of Various Wood Tars in Water (Grams of tar per 100 ml. of water) tillation plants are able to dispose of the oil distillates very -RATIOreadily as “chemical oils,” while the residual hardwood KINDon TAR Water Tar Solubility Hard maple: tars are very rarely disposed of other than as a source‘of Raw settled 10 1 1.05 fuel in the plant. A discussion of the solubility of the disBoiled 10 1 0.60 Steamed 10 1 (a) solved tar has been given elsewhere.2 Other than to menDissolved 3.38 1 8.60 Pine tar, raw 5 1 0.226 tion the low solubility of the pine tar no discussion can be (a) This tar was so viscous that good mixing with the water was imgiven because its history is unknown. possible. 1 Received February 19, 1925. The data are of value in all cases where any of these tars * Dissertation, University of Wisconsin, 1923. Abstract in THIS are used in mixture with water or in cases where after a p JOURNAL, 17, 149 (1925). U.S . Dcpt. A g r . . Bull. 149, p. 6. plication they will be exposed to action of water. T H E course of an investigation of the suitability of vaIof Nrious wood tars for treating fish-net twine, A. V. Ruiz, Vera Cruz, Mexico, determined the solubility in water
