Gnade ay is that in the adults at least only about 25% of the bone caleiua 4s exchangeable. But I thought that all of the assumptions which we showld make should be that the part which is exchangeable is in places which are close to tissue which can develop caricer. Tanft that right? fo the cutaide of the bone, and therefore, only the level aatters and not the actual amount. MITCHELL I followed the same line of reasoning that Dr. Bethe did except that I did it with strontiwa instead of with caloium and ons of the reasons that X did it,besides the ones I've mentioned so far, is that you assene that this 7/10 of a gran is the total amount of strontius in the skeleton. A growing person deposits an average of 100 aicrograms of strontium a day and its pretty easy to caleulate that he ia getting far in excess of that in bis diet, so that there is some selective mechariom in the way in which this stuff is being deposited. KEANISH Yar in excess with respect to the excess to the excess calcium. Ro one Imoew the connection between those two. Tes, tut tell me isnft the only number in which we are interested in, or the only two ounbers — these two mumbers, afmlts and soil, what~ ever eoil may be? Well the other one I consider from the discussion before as discredited because it is an old measurement. I don't know whether that’s right tut certainly the new measurements seem to give very mush lower uumbers. a7 i DUE ARCHIVES