﻿272 Dr. L. Silberstein on a Quantum 



of individual clumps ; the following a's are gradually less 

 reliable ; from the 7-grain clumps onward the areas 

 (bracketed) are only extrapolated, but since here y has 

 practically reached 100, no greater accuracy is needed. 

 The fourth column contains the theoretical values of y 

 following from formula (12) with the constants, determined 

 from observations 1, 2, 4, 



n = 0*572* per a 2 , l 



„=O097^, I ■'•■<«•> 



or p — 0*176//-. The fifth column gives A?/=y ob8 . — z/ ca i c> . 

 The agreement is certainly very pronounced, the differences 

 being, perhaps with the exception of the third, well within 

 the limits of experimental error chiefly in the a-estimates. 

 The fitting could be made even closer by retouching the 

 constants n, a, but this is scarcely worth while, the formula 

 itself being of a statistical nature, and the agreement being 

 good enough as it stands. The same is manifest also from 

 the figure giving a graphical representation of the last 

 columns of the table. 



_fl - a oaoo — e — o — o o - o — o — ooo g ooooo c — e- 



— CALCULATED 

 • OBSERVED 



10 15 20 £5 



The reader might think that the finite section cr, or 

 whatever this parameter may stand for, has been forced 

 upon the light-quantum and that tho observations might 

 perhaps be as well represented with cr = 0, and another value 

 of n. But actually, just the contrary has been the case, 

 inasmuch as the author first tried the simpler formula 

 log (l — k/fil)=—na, and then only found himself compelled 

 to take in the correction factor as given in (12). In fact, 



