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hold when the properties under consideration are measured at other temperatures and pressures. Other types of evidence, however, such as the reaction between vulcanized rubber a n d alcoholic potash described b y Whitby a n d Jane (22), seem to constitute valid evidence for a two-stage reaction. Definite conclusions, however, cannot’ be drawn until the mechanism of the reaction of rubber with sulfur is established.
Literature Cited (1) Blake, J. T., ISD. EXG.CHEM., 22, 737-40 (1930). (2) Ibid., 26, 1283-6 (1934).
(3) Bostrom, Sigfried, Kolloidchem. Beihefte, 26, 439-70 (1928). 14) Corning Glass Co., unpublished data: International Critical Tables, T’ol. 11, p. 93, New I’ork, hlcGraw-Hill Book Co., 1927.
(5) Curtis, H. L., McPherson, A. T., and Scott, A. H., Bur. Standards, Sci. Papers 22, 383-418 (1927); Sci. Paper 560. ( 6 ) Daries, B. L., Inst. Rubber Ind. Trans., 10, 176-88 (1934). (7) Daynes, H. A., paper presented at meeting of Institution of
Rubber Industry, Dec. 10, 1934. (8) Gee, W. ‘8. H., and Terry, H. L., Rept. Brit. Assoc. Advancement Sei., 1889, 516-17; Mem. Proc. Manchester Lit.Phil.
..
sot.. r4i 4. 38 m90-91). -, (9) Glancey, W. E., Wright, D. D., and Oon, K. H., 1x0. ENG. CHEM.,18, 73-5 (1926). (10) Hada, K., Fukaya, K., and Nakajima, T., J . Rubber SOC. I
March 6, 1935
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Japan, 2, 389-97 (1931); Rubber Chem. Tech., 4, 507-14 (1931). (11) Jessup, R. S., and Cummings, 8.D., J . Research Natl. Bur. Standards, 13, 357-69 (1934) (Research Paper 713).
(12) Kimura, S., hizawa, T., and Takeuchi, T., J . Inst. Elec. Engrs. Japan, 1928, 1274-7. (13) Kimura, S.,and Namikawa, N., J . SOC.Chem. Ind. Japan, Suppl. Binding, 32, 196B (1929). (14) Kirchhof, F., and Wagner, A., Gummi-Ztg., 39, 572-4 (1924-5). (15) Kitchin, D. W.,J . Am. Inst. Elec. Engrs., 48, 2 8 1 4 (1929). (16) LeBlanc, M., and Kroger, M., Z. Elektrochem., 34, 231-4 (1928). (17) Levin, M.,and Schottky, H., Ferrum, 10, 193-207 (1913). (18) Lewis, G. N., and Randall, Merle, J. Am. Chem. SOC.,33, 476
(1911) : “Thermodynamics,” New York, McGraw-Hill Book Co., 1923. (19) McPheraon, A. T., and co-workers, Bur. Standards J . Research,
8, 751-8 (1932) (Research Paper 449). (20) Mondain-Monval, P., Bull. SOC. chim., [41 39, 1349-68 (1926). (21) Ruhemann, Martinn, and Simon, Frana, Z . physik. Chem., -4138. 1-20 (1928). ( 2 2 ) Whitby; G. S.,‘ana Jane, R. S., Trans. Roy. Soc. Canada, [ 3 1 20, 121-31 (1926). (23) Williams, Ira, and Beaver, D. J., IND.ESG. CHEV.,15, 255-8 (1923). RECEIVEDFehruary 9, 1933. Presented before the Division of Rubber Chemistry a t the 8 9 t h Meeting of the American Chemical Society, New York, N. Y . , April 22 t o 26, 1936. Publication approved by the Director, National Bureau of Standards.
Vitamins in Canned Foods SIR: I have read with Considerable interest the correspondence under this head appearing on page 235 of the February, AND ENGISEERING CHEMISTRY.In 1935, issue of INDUSTRIAL reading the original paper by E. F. Kohman and others, on which C. M. McCay comments in the correspondence, a point of criticism occurred to me that has not been mentioned so far. The reason is, I think, that the paper on which my criticism rests had not appeared a t the time of the original publication by Kohman and others, though advance indications of the general conclusions had actually appeared a t least a year earlier. I refer to the work of H. M. Bruce and R. K. Callow, published in detail in the Biochemical Journal [Vol. 28, p. 517 (1935)], amplifying and confirming the tentative views that these authors had expressed in a letter to the British Medical Journal some eighteen months earlier (1932, 11, p. 172). I n this paper they show conclusively that the rachitogenic properties of a vitamin-Dfree diet are not controlled simply by the ratio of calcium to phosphorus and by the limiting quantity of the second element, but actublly by the form in which the phosphorus is combined. An appreciable amount of phosphorus present as phytin (inositolhexaphosphate) may confer rachitogenic properties on a diet, even though the total amount of phosphorus may be greater than in a less rachitogenic regime. Apart from the important fact that this discovery enables us to dispense with the toxamine theory first propounded by Mellanby, it bears directly on our interpretation of results such as those reported by Kohman and colleagues. Their conclusion, that ordinary foods contain much greater quantities of vitamin D than had previously been supposed, is not necessarily and inevitably to be drawn from their results. It is a t least as likely, and I consider it much more likely, that the phosphorus in a general mixed diet of foods, whether fresh, cooked, or canned, is more available-that is, is to a much less extent present in phytin and similar substances-than is the phosphorus in the typical rachitogenic diets of Gteenbock and others. Without actual analyses on the lines described by Bruce and Callow, this point cannot be settled, but its importance in general dietetics is obvious quite apart from its bearing on the interpretation of biochemical experiments. GLAXOLABORATORIES A. L. BACHARACH 56 OSNABURQAST.,LONDON, N. W. 1, ENQLAND
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Correspondence SIR: The number of the Biochemical Journal, referred to by Mr. Bacharach as containing a paper by Bruce and Callow, was received by the Department of Agriculture Library June 29, 1931. Since our article appeared in your issue of July 1, it is obvious that we could not have seen the data of Bruce and CalIow previous to publication of our article. We knew a t the time that the question was raised as to the availability of phosphorus in different foods. We appreciate the importance of this and. realize that it may necessitate a revision of interpretation of a considerable amount of data in various directions. There is no doubt that the foods we used in the diet of our experiment showed remarkable properties in calcification or bone formation. We feel sure that bringing this property out has been as interesting to others as it has to us. Where there is. such a degree of calcification, there is going to be no rickets. I t does not seem particularly important from the practical standpoint whether it is due to the presence of phosphorus in an optimum condition or to the presence of vitamin D. I t is apparent that vitamin D in the form of cod liver oil imparted no benefit under the conditions of our experiments. There is a definite tendency toward incorporating other foods than the usual cereals earlier and earlier in the infant’s diet. If,. as Mr. Bacharach implies, the phosphorus in these foods is more available, as a result of which they may lessen the tendency for rickets to develop, the incorporation of these foods in the infant’s diet a t a younger age is on a sound basis. The canning industry is playing an important role in making available a constant supply of these foods in a fine state of division and with coarse fiber removed. This effort is apparently being favorably received by pediatricians and the medical profession. I predict that in the near future it will be not uncommon to incorporate various vegetables and fruits in the infant’s diet a t the age of two or three months. N A T I O K A L C.4NNERS ~ ~ S S O C I A T I O N
WASHINGTON, D. C. March 2 6 . 1935
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E. F. KOHMAN
