528 



KINETICS OF BIOLUMINESCENT REACTION. I 



of film is the absorption of various known percentages of light by the 

 filters. The method integrates upon the film the effect of a rapidly 

 changing, but always homogeneously radially distributed, light 

 source, over a sufficient length of time to produce photographic 

 densities lying in the same region of the curve, of blackening as those 

 caused by the unknown intensities of the moving records which are 

 to be evaluated. I believe that Fig. 1 will give sufl&cient indication 

 that this is an altogether feasible experimental method. In no case 



Fig. 2. Diagram of calibration method. The film, F, upon the lower two 

 thirds of which the moving records have previously been impressed, is clamped 

 between the rigid back, C, and a movable strip, B, carrying the fifteen filters of 

 known transmissions. The unexposed third of the film comes opposite to the 

 fifteen openings. Calibration exposures are impressed by light from a luminescent 

 solution ring. A, at the level of the filters, giving light with homogeneous radial 

 distribution. 



are the density values in error from the mean curve by more than the 

 known error inherent in the photographic material itself. Table I 

 tabulates the known transmission values of the fifteen filters used. 

 Filters 1 to 12 follow a decreasing order of transmission. Filters 13 

 to 15 give control exposures to check the radial distribution of Ught. 



