10 SUMMARY OF 1956 RESULTS The range of 1956 results on the various materials sampled and the median values are given in Table 8. Table 8 —Sr*™ IN BIOLOGICAL MATERIALS IN 1956 Sr®® activity, yyc/g of Ca Material No. of samples Max. Grass (acid hill soils) Grass (normal soils) Sheep bones (hills) Sheep bones (lowland) Milk (Somerset) 3 61 6 T 13 2100 17 170 15.6 5.7 Milk {other areas) 10 10.3 Min. Median 91 11 24 7.8 2.9 130 37 57 13.7 4.4 3.9 6.7 Human bones (femora and tibiae) 0-5 years 5—20 > 20 25 10 2 1.55 0.38 0.13 0.15 0.15 0.06 0.70 0.26 11 ACKNOWLEDGMENTS Weare indebted to K. H. Jones and to all members of the National Agricultural Advisory Service of the Ministry of Agriculture, Fisheries and Food who obtained samples for us. Dr. Rice Williams, in particular, gave very valuable advice and practical help in obtaining the Welsh samples. We are indebted to Dr. M. Bodian, Dr. J. S. Faulds, Dr. R. H. Mole, Dr. A. H. Cameron and Dr. C. A. Jones who went to great trouble to provide the human bone specimens,to Dr. J. F. Loutit, Dr. E. E. Pochin and Dr. R. Scott Russell for helpful discussions. 222