098 Vroi'. 0. \V. Richardson on the Positive 



of the alkali metals carry. the same charge as that carried by 

 an (i(om of hydrogen in electrolysis, since this assumption has 



I n made in calculating the values of m and leads to cou- 



sistent result-. We therefore conclude that the positive 

 ions emitted by these substances when heated have the same 

 structure as thai which is generally attributed to the nuclei 

 of the positive ions to which the same substances give rise 

 in solution. In other words, they consist of one atom of the 

 basic metal which lias lost a negative electron. 



The similarity between the thermions and the electrolytic 

 ions appears to end with the positive ions. So far the only 

 negative thermions which have been detected have a very 

 large value of e/m and are negative electrons. There is no 

 evidence < 1' the existence of negative thermions similar in 

 structure to those which occur in solution. 



Tic presenl investigation does not throw any definite 

 lighi en the chemistry of the processes involved. Since the 

 positive ions are atoms oi the metal, it is clear that they 

 musi gel free from the rest of the molecule somehow. It is 

 possible thai the firsl decomposition consists of a splitting up 

 of the sulphate into positively charged atoms of the metal 

 and a negatively charged So, group, as is the case in 

 solution. This would then presumably be followed by the 

 breaking up of the negatively charged group into its chemical 

 constituents together with a negative electron. The results 

 of the experiments neither affirm nor deny this view, it 

 seems possible thai valuable evidence in this connexion 

 might be obtained by Looking for a relation between the 

 amount el' positive and of negative ionization produced by 

 heated salts. Experiments with this cud in view are being 

 instituted. In any event, the present investigation shows 

 that the expulsion of a positively charged atom of the metal 

 tlieni feature of the ionization of heated salts. 



The balance of evidence at present is not in favour of the 

 view that the positive ions produced by salt vapours in 

 flames at a high temperature are identical with those here 

 investigated. Their velocities have been measured by dif- 

 ferent experimenters, and there is a general agreement that 

 the positive ions produced by the salts of all the alkali 

 metals have the same velocity under unit field. This result 

 would not be expected if the ions were atoms of the metals. 

 The absolute values of this common velocity given by different 

 observers are rather divergent. For instance, H. A. Wilson 

 finds 62 cm. per sec, Marx finds 200 cm. per sec, and Moreau 

 80 cm. per sec. Nevertheless, all these values are higher 

 than what would be expected if the ions were atoms of the 



