TFIE STRUCTURK OF THE NUCLEUS. 



67 



could be made to virtually (ill up, ihv, square content across tlie line of vision. 

 Hence, .04 X 113'- = 512 cm., or about 5 meters of column would be needed to 

 virtually blot out the unaffected white light (excepting th;it which filters between 

 rectangularly contiguous, co-planar s[)heres). At the end of the experiment a col- 

 umn .096 X 1132 = 1280 cm. or about 13 meters long would be needed if axial 

 color is to be seen. In the above experiments the colunui or drum was nearly 2 

 meters long and this proved to be insufficient. 



TABLE 7.— DIMENSIONS AND NUMBERS OF CI.OUl) PARTICLES PRODUCING 

 AXIAL COLOR. CONTENTS AS IN TABLE 19, CHAP. H. 7V„ = 15,000 panicles. 



14. Summari/.— In conclusion, I give a tabulated summary of the chief 

 constants relating to the coronas and axial colors, produced by water particles. In 

 this table the colors of the coronas have been again overhauled, and the data refer 

 to punk nuclei. iV is the i-elative number of particles, n the al)solute number per 

 cub. cm.; <l denotes th« diameter of the particle in cm., 1/ Vn the edge of a cube 

 containing on the average just one particle. It may be useful to recall that 



where z denotes the number of the exhaustion or order of the corona in the series, 

 b is the coefBcient of the time losses apai't from exhaustion, // the ratio of densities 

 before and after exhaustion regarded as an adiabatic pi-ocess, but corrected for the 

 heat evolved by the precipitated water. In measuring the diameter, "?, of the 

 particles, the normal coronas succeeding the 20th exhaustion were used directly by 

 comparing their angular apei'ture, .s, with the coronas due to lycopodium spores, 

 assumiug'for the latter, diameter ./'„ =^.0032 cm., while ,s'„ = .45 cm., by observation. 



