SECTION OF COVKRKD-EYKl) MEDUSAE. 



Normal wiitor 



Six secmiils after trans- 

 ference to chloroform 



Six seconds later 



Six seconds later 



S i X seconds later 



Six seconds later 



One second 



In such experiniL^nts, the recovery of the normal 

 rate in unpoisoned water is gradual. Taking, for 

 instance, the case of a spiral strip in morphia 

 (Fig. 19), it will be seen that the original rate 

 did not fully return. Some substances, however, 

 exert a more marked permanent effect of this kind 

 than do weak solutions of morphia. Here, for 

 instance, is an experiment with alcohol (see Fig. 20). 



In normal water 



yuart?r of an hour after 

 exposure to mopliia ... 



One iniiiuieaft'.T strength- 

 ening dose 



Four uiiiiut'-s later, and 

 just bel'on- blocking of 

 wave 



Fifteen seconds lat r,wave 

 cimtinuing blocked 



Innned lately alter pa-s.ige 

 of wave on r- toation 

 to nui inal sea-water . . . 



Four minutes later 



Quarter of an hour later... 



An hour later 



One second ... .,. ^^^--—^^—^■■■i™ 



Fig. la. 



