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linear roll paper by a fast recorder. All circuits are left on continuously. The target is irradiated, the cyclotron is turned off, and the excitation is observed immediately.With this arrangement measurements were taken using a onesixteenth-inch thick carbon plate as a target. Runs were made at twelve different proton energies chosen in the range between 20 and 110 Mev by varying the distance of the target from the center of the cyclotron tank. Owing to the occurrence of simple and spallation reactions, a variety of modes of disintegration was observed. By pulse-height analysis and varying the time of irradiation, additional discrimination was obtained. Previously known lifetimes as well as some new ones appeared with great consistency over various bombarding energies.The first part of our investigation was aimed at the detection of the Li 9 isotope. The activity has been first tentatively reported by Gardner et al. on the basis of the detection of delayed neutrons produced according to the following scheme : l Li 9 ->(Be 9 )*+j3, (Be 9 )*-VBe 8 +n, and Be 8 ->2«.The half-life obtained was 168±4 msec.By this first direct detection of the beta-decay particles a halflife of 170±5 msec has been obtained, thereby corroborating the California results. The spallation reaction leading to Li 9 is C 12 (p, 4^)Li 9 , with a threshold energy of about 47.5 Mev in the laboratory system.We wish to thank Mr. R. Brown and Mr. M. Hurley for their help in evaluating the large number of decay curves. SOLAR SPECTRUM COLUMBUS. OHIO FIG. 1. The solar spectrum near 4.7/*.

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