68 



Proceedings of the Royal Irish Academy. 



was 1800, having diminished from 1,000,000 ia that time, whereas the value 

 should he ahout 10,000 if the formula held true during that period. 



The Charge on the Large Ion. 



In some of the earlier experiments on the decay of the ions and nuclei 

 from the same mass of flame-gas iu the gasometer, it was found that in certain 

 cases the total number of nuclei per e.e. was less than the number of large 

 ions per c.c. as calculated on the assumption that each ion carries the 

 electronic charge. This leads to the conclusion that the ions eai-ry multiple 

 charges, and an attempt was made as follows to determiae the charge. The 

 flame-gas was drawn slowly — at about 60 c.c. per second — thi-ough the funnel 

 A and the large vessels B and C — each of about 70,000 c.c. capacity — as 

 illustrated in fig. 10, so that on lea^ang C the ions and nuclei had reached 

 their stable size. The method adopted was to determine the total charge 



Fio. 10. 



per c.c. by the electrometer, and to measure the total number (?i) of nuclei 

 by means of the counting-apparatus, and also the number (ji,) of uncharged 

 nuclei left in the air-stream, when all the charged nuclei had been removed 

 by an electric field, n - n^ is the total nimiber of charged nuclei, and, as in 

 the gas from flames, the positive and negative charges per c.c. are equal, half 



thisnimiber, — - — ', may be taken as the number of nuclei carrying the 



charge per c.c. measured by the electrometer, and from this the average 

 charge may be calculated. The results of a nvmiber of such experiments, 

 made on different occasions, are given in the following table, the positive 

 charge per c.c. being given in the fourth column as the multiple N of the 

 electronic charge i. The average charge E on the ion is given in the fifth 

 column as a multiple of «. 



