(c} Fig. 4.14— Autoradiograph, photograph, and photomicrograph of Biljirf dredged sand. (a) Actual size autoradiograph of Biijiri and Rojoa dredged sand on %-in, scotch tape. (b) Photograph of same sand preparation partially illuminated from below through a positive transparency of its own autoradiograph. Magnification, 1.8 x. (c) Photomicrograph of the large radioactive particle near top center of (b). This irregular chalky particle weighed 0.6 mg when removedto a piate on May 18, 1953, and counted 5300 c/m in the Nucleometer. Magnification, 20x. ’