On August 21, 1948, several smear samples of contamination from the inner rod room at 100-F Area were submitted for beta identification. This contamination was spread as a result of maintenance work on the horizontal rods. Urine sample were deemed advisable for two men who had been exposed while working on the rods. These urine samples were also submitted for beta analyses. The analyses of the smears showed the contamination to consist of primarily S{sup 35} (65%) and Fe{sup 59} (30%)and minor amounts of Ca (5%) and C{sup 14} (3%). No significant amount of radio iron or sulfur was found in either the feces or urine samples.

In the course of some kinetic studies on photosynthesis of barley seedlings, it has been found that plants utilize C{sup 12}O{sub 2} faster than C{sup 14}O{sub 2}. The plants were placed in a closed system containing an infra-red absorption-cell for the analysis of total CO{sub 2} and an ionization chamber for the determination of C{sup 14}O{sub 2} in the gas phase, both instruments recording continuously. Carbon dioxide, containing about 2% C{sup 14}O{sub 2}, was introduced in the dark and the specific activity at this point taken as unity. After a short dark period, the lights were turned on and photosynthesis was allowed to take place. A figure shows the result of a typical experiment. During the initial dark period the specific activity fell because of dilution by inactive respired CO{sub 2}. However, as photosynthesis proceeded, the specific activity of the residual CO{sub 2} rose until, when only 1/6 of it remained, the specific activity reached a peak some 20% higher than it had been at the start of photosynthesis. At this point the steady respiratory dilution became an appreciable fraction of the total remaining CO{sub 2}, and the specific activity dropped rapidly.