isotopes that promised to bo present in quantities waieh would & be of sirmificance and choesing these which would give us a breac t+ faniliay. ¥Y of you avo “ “4 ie © fale vhich wasby the Faeubnyes cnmordrnent with wi i Tho noxt slide incdicntcs ono way we studicd this, Taking 1CG srars of soil contaminating with tress, we howe vant to study, tho io ‘ 52 wn n B & B en i] oy) uniformly distri fe strontiun-30 or idedine, or whatever it may be, getting this dish aporoninately so (illustra- ns) in diamoter and then scadiny in hore 100 barley seods which gives a very dense population and gives maximum penetration of this soil by the root system and probably an annvoach toward &@.maximun uptake into the aardal parts. The acrial parts were then harvested at the end of 18 to 20 days, which cave a maximun consentratien under the condios tions in foliaze,. — ‘ The next slide shows the results of this kind of experi- ment, and in ordsr to got an emphasis on concentration which ws feol is quite invortant hore, and in order to put a basis for conparison of these studics with some nutrient studies, which a we will describe later, wo are expressing our results as a con-~ \ centration factor which is simply the concentration in the aerial portion as conpared with the concentration in the root envirentment, in this ¢2 ase, it woulda be the concontration in tho dry. harvested barley leaves as compared with tho concentration of strontinua, or