ON THE POSSIBILITY OF OBSERVING PHOTOCW~MICAL REACTKONS

biphenyl induced by three- photon absorption and estimated the cross sec- tion from the chemiluminescent emission of the fragmentation products. They were, however, not able to isolate or measure the concentration of the photolysis products. This is to be expected since the efficiency of n-photon absorption de- creases progressively with the order of the ab- sorption process. Typical ranges for n-photon absorption cross sections, S,, reported