68 



Mr. J. Enright on Electrifications due 



Reacting substances. 



Escaping 



1. HCl+Zn 



2. HCl+CaC0 3 



3. H,S0 4 +Na 2 C0 3 



4. H;S0 4 +Na 2 S0 3 1 



5. HCl+Na 2 S0 3 



6. H 2 S0 4 +Zn (50°/ o acid) 



7. HCl+FeS 



8. H 2 S0 4 +FeS 



9. HCl+Bleaching-powder 



10. H 2 S0 4 -f Bleach. -powder 



11. HN0 3 +Bleach.-powder 



12. HN0 3 +CaC0 3 



13 -{cOHO+* a 



14 -{coW Fe 



15. H 2 S0 4 +CaC0 3 



16. H 2 S0 4 +]\ T aCl 



H 

 C0 2 



co 2 

 so, 



so; 



H 



SH 2 

 SH 2 



CI 



CI 



CI 



CO, 



Gas passing 



Through acid. 



H 



H 



C0 2 

 HC1 



Through salt 

 solution. 



Quantity 

 D. P. in 



volts. 



Could not gei 

 this to reverse 



Couldnotgetthe 



usual positive 



deflexion. 

 Could not get 



positive deflex- 

 ion. 

 Could not 



either case gei 



the normal )■ 



positive deflex- | 



ion. \) 



Could not 



+ 



Nil 



the reversal. 

 Nil 



get 



42 

 9 



16 



It will be seen that there are nine instances in which the elec- 

 trifications occur normally — that is to say, in which the charge 

 is of one sign when the ejected gas passes through acid, but of 

 the opposite sign when the corresponding salt gets into solu- 

 tion. I wish to direct special attention to the instances of 

 abnormal behaviour, which I believe to be entirely due to the 

 solubility of the salts produced in the reaction. When these 

 get rapidly into solution and diffuse through the acid, the 

 electrification due to the gas passing through acid cannot be 

 obtained. There are two cases with £LN0 3 and two with 

 acetic acid where this happens, and we know that the salts 

 derived from these acids are very soluble. On the other hand, 

 there are two cases where H 2 S0 4 takes part in the reaction, 

 in neither of which could the electrification due to the 

 passage of the gas through the solution of salt be obtained. 

 In both instances sulphate of calcium is formed, and we know 

 that this is rather insoluble. The ejected gas therefore never 

 passed through a solution of salt. My contention here 

 derives great support from the fact that when Na 2 C0 3 is used 

 with H 2 S0 4 to give C0 2 , both deflexions are obtained. The 



