﻿416 Sir W. Ramsay and Dr. Spencer on Chemical and 



be noticed that, whereas the Curve I. only shows a discharge 

 rate o£ 20 seconds after ten hours exposure, Curves II., III., 

 and IV. show rates of 38, 270, and 290 seconds respectively. 

 The same phenomenon was observed for tin, aluminium, and 

 zinc (Table XI.; Curves VII., VIII., IX = , X., PL VIL). 



Table XI. 



Aluminium. 



Zinc. 



Tin. 



X. 



IX. 



VII. 



VIII. 



21 : 



May. 



14 June. 



24 



May. 



15 June. 



: Leak in 



Exposure 



Leak in 



Exposure 



Leak in 



1 

 Exposure 



Leak in 



Exposure 



sees. 

 , 1*2 



in mins. 

 02 



sees. 



in in ins. 



sees. 



in mins. 



sees. 



in mins. 











64 







9-6 



1-6 



1-8 



20 



2-0 



0-4 



8-6 



1-8 



11*2 



2-6 



1-8 



3-0 



2-2 



1-6 



105 



3-5 



124 



4-4 



2-1 



6-0 



2-5 



3-2 



110 



5-4 



13-1 



6-2 



2-7 



7-2 



26 



5-0 



11*5 



7-8 



150 



9-2 



2-7 



90 



2-7 



7-0 



122 



10-2 



166 



12-6 



26 



11-2 



2-6 



9-6 



132 



13-1 



170 



160 



3-0 



14-8 



2-8 



120 



13-8 



17-8 



18-8 



19-8 



2-9 



17-6 



3-2 



15-0 



150 



23-4 



20-8 



24-2 



3-8 



21-6 



2-8 



18-8 



166 



32-6 



21-5 



30-2 



4-0 



28-4 



3-4 



23-0 



17-8 



45-6 



22-7 



36-4 



3-8 



340 



3-4 



28'0 



18-8 



650 



22-8 



43'4 



4-0 



38-3 



3-4 



32-2 



30-2 



90-0 



25-7 



58-0 



4-5 



44-0 



37 



36-4 



62-6 



156 



29-8 



72-8 



4-5 



50-0 



4-2 



432 



66-8 



181 



324 



87-6 



4-5 



56 



4-8 



61-0 



71-0 



225 



396 



115-6 



49 



67 



5-4 



77-2 



79-2 



284 



41-4 



161 



56 



73 



64 



94-2 



104 



368 



49 



224 



60 



86 



7'4 



115-6 



102 



450 



45-8 



271 



6-4 



99 



8-6 



155 



115-4 



522 



57-4 



332 



6-7 



117 



10-0 



190 



134 



626 



706 



387 



7-2 



140 



103 



216 



139 



730 



78-2 



468 



7-8 



163 



120 



256 



166 



1420 



850 



538 



8-8 



193 



13-8 



307 







100 



630 



9-0 



244 



140 



361 







104 



747 



94 



275 



160 



477 







98 



821 



10-0 



327 



18-0 



572 







146 



1554 



11-8 



384 



186 



630 







152 



1634 



11-8 



438 



18-6 



747 











120 



506 



18-8 



821 











14-3 



569 



230 



1421 











147 



681 















162 



768 















Magnesium which has once been subjected to ultraviolet light 

 does not seem to regain its first rate of tiring, even after standing 

 for several days. A second piece of magnesium, which had been 



