60 



Proceedings of the Royal Irish Academy. 

 Table I. 



Time (minutes) 



N X 10-3 



JV-' X 10» 







1045 



96 



7 



767 



130 



17 



585 



171 



27 



469 



213 



38 



411 



243 



50 



380 



263 



63 



271 



369 



SO 



240 



416 



83 



240 



416 



105 



199 



502 



107 



200 



500 



127 



169 



692 



130 



169 



592 



154 



138 



725 



167 



130 



769 



169 



122 



820 



172 



118 



847 



and is represented graphically in fig. 3. It will be seen that the rate of 



IIUU 









1000 









900 









eoo 



\ 







1 700 



o 



\ 







X 600 



\ 







z 



\ 







500 



\ 







400 



* 



\ ° 





300 





o^^^^ 





200 







■~-°<'-~-. 



roc 









20 40 60 80 100 



Minutes 



Fio. 3. 



120 



140 160 



rao 



