No. 4028 January I I. 1947 NATURE 65 inhibits the reaction, but does so apparently by a lie within the wide range 7 ·5-39 mgm. These values different mechanism, since it markedly depresses are considerably higher than those generally assumed cellulose production even at a concentration (m/100) for English . Moreover, a number of seedling in which it does not affect the respiration-rate. It varieties raised at this Station gave values com• should be noted that the reaction of cellulose pro• parable with those in the table, for of sixteen varieties duction is independent of the specific addition of tested nine came within the range 15-27 mgm./100 phosphate to the medium of the cells ; but this does gm. not, of course, exclude the possibility that the syn• Ascorbic acid Ascorbic acid Dessert varieties (mgm./ Culinary varieties fmgm./ thesis is dependent on intracellular presence of 100 gm.) 100 gm.) phosphate. Miller's Seedling 7·9 Golden Noble 6·9 It is intended to discuss implications of these find• Laxton's Superb 13·9 Edward VII 8·5 Cox's Orange Pippin 14·4 Early Victoria 10 ·8 ings for the mechanism of cellulose biosynthesis at a Allington 15·0 Crawley Beauty 11 ·8 future opportunity. Because cellulose production is Ellison's Orange 15·5 14·6 Worcester Pearmaln 16·0 Arthur Turner 16·3 linked with respiration, the possibility is being further 17·2 Lane's Prince Albert 15 ·4 examined whether similar energy transfer systems 18·4 Bramley's Seedling 22 ·3 are involved in production of cellulose, as in pro• Rival 22·5 duction of starch or glycogen from plain glucose. As the highest concentration of ascorbic 'acid is S. HESTRIN in the skin of the fruit, the values found after Hormone Research Laboratory, peeling are always lower than those for the entire M. ASCHNER fruit ; for example, the pulp of Bramley's Seedling J. MAGER was found to contain 15·5 mgm./100 gm. as against Department of Hygiene and Bacteriology, 22·2 mgm. for the unpeeled fruit. Taking into Hebrew University, account such losses on peeling, it is still evident that Jerusalem. the can be a fairly good source of ascorbic acid Nov. 17. and one easily accessible. The actual level of the 1 Farr, W. K., Nature, 146, 153 (1940). vitamin in a given variety will naturally depend on • Farr, W. K., "Colloidal Chemistry", 5, 610 (1944) (New York: many factors still be to determined, while the effect Reinhold Publishing Corp.1. of storage must also be considered : there is evidence, • Mark, H., and Susich, G., Z. phys. Chem., 4, 431 (1929). 'Barsha, J., and Hibbert, H., Canad. J. Res., 10, 170 (1934). however, that storage losses need not be large•,•. 'Sisson, W., Ind. and Eng. Chem., 27, 51 (1935). Although the ascorbic acid is readily oxidized when ' Gross, S., and Clark, G., Z. Krist., 99, 357 (1938). the juice is pressed out of the fruit, the loss is not 'Franz, E., and Schoebold, E., J. Makromolekulare Chem., 1, 4 (1943), excessive in the ordinary methods of baking or stew• cited In Biol. .Abst., 20, 341 (1946). • Aschner, 1\1., and Hestrin, S., Nature, 157, 659 (1946). ing (with or without sugar). Tests on samples drawn • Hestrin, S., et al., Biochem. J., 37, 450 (1943); 38, 2 (1944); and from a batch of Bramley's Seedling showed that from 39, 167 (1945). a half to two thirds of the vitamin remained in the •• Hehre, E. ;r,, Science, 93, 237 (1941); J. Biol. Chem., 163, 221 (1946). cooked fruit, a value similar to that found by Olliver'. 11 Jarr, J., and Hibbert, H., Canad. J. Rei., 4, 372 (1931). No evidence was found for the production of appreci• "!Khouvine, Y ., Bull. Soc. Chem., 18, 1325 (1936). able amounts of interfering reducing substances dur• ing cooking. MARGARET E . KIESER Vitamin C in English Apples A. POLLARD University of Bristol Research Station, THE restriction< in the national diet during recent Dept. of Agricultu:ce and Horticulture, years have encouraged the search for foodstuffs rich Long Ashton, Bristol. in particular nutrients, and considerable attention Nov. 25. has been paid to sources of vitamin C. But while 1 Nutritive Values of Wartime Foods. Med. Res. Council War Memo• many rare or unusual fruits and plants have been randum No. 14, 16 (1945). examined, the typical English fruit, the apple, has 1 Boas-Fixen, 1\1. A., and :aoscoe, 1\1. H., Nutr . .Abstr. and Rev., 9, 826 been practically neglected. For it has been generally (1939-40). 1 West, C., and Zilva, S. S., Biochem. J., 38, 105 (1944). assumed that most varieties, with the exception of 'Jennerup, E., Fruktodlaren, No. 2, 62 (1945); (Hort. Abstracts, Bramley's Seedling, are very poor sources of the Sept. 1945, No. 1302). vitamin. For example, the value given by the 1 Kldson, E . B., New Zealand J. Sci. and Tech ., 25, 134 (1943). 1 • Pollard, A., Kieser, 1\1. E., and Bryan, J.D., Ann. Rep. Agric. and Medical Research Council tables is only 5 mgm. Hort. Res. Stn., Long Ashton, p. 200 (1945). ascorbic acid/100 gm. of edible tissue. The tables 'Olliver, 1\1., Chem. and Ind., 62, 146 (1943). of Fixen and Roscoe•, however, quote values lying within the wide range 0·1-31·8 mgm./100 gm., and even higher values have recently been reported for Bramley's Seedling and Sturmer Pippins,4,6. Nitrogen Fixation by Farmyard Manures Tests on a limited number of apple varieties were IN previous communications1 it was reported that made at Long Ashton in 1945, and the results have the value of farmyard manure (cow dung) is due not already been described'. Values higher than 10 only to its nitrogen content but also to its power to mgm./100 gm. were only given by some of the fix nitrogen of the air. Our field experiments show culinary and varieties, the latter being richest that when wet, fresh collected cow dung is added to in ascorbic acid with values up to 34 mgm.flOO gm. soil at the rate of 25 tons per acre, 33 lb. of nitrogen for the whole fruit. During the 1946 season, more present in the cow dung is added and 135 lb. of comprehensive tests have been carried out on freshly nitrogen per acre is actually fixed from air, while in picked samples, and the values for the dessert and the dark the fixation is 65 lb. per acre. culinary varieties are shown in the accompanying These experimental results regarding the fixation table, expressed as mgm./100 gm. whole fruit. In of nitrogen by cow dung appear to be supported by addition, twenty-nine cider varieties have been the field trials at Rothamsted2 and at Woburn•. In tested and their contents of ascorbic acid found to the Rothamsted field experiments, no combination

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