LECTURE II 



The Prospect Demonstration of Retinal Currents The Initial Current 

 The Principal Fact ; Subordinate Features Three Types of Response 

 Two Opposed Processes Effects of Complementary Colours- 

 Cause : Effect Anaesthetics Retino-motor Effects. 



n. Prospective. It is my intention in the eight days' 

 laboratory excursion which I hope some at least of my present 

 hearers will complete to visit several apparently disconnected 

 points of physiology. And while I shall not attempt to show 

 you at once that these points are in fact intimately connected, 

 I will name them to you now, and promise that their uniting 

 bonds shall become evident to you in due season by your 

 own thinking, rather than by my talking. " The Excitability 

 of the Retina " " The Excitability of Vegetable Protoplasm " 

 "Skin Currents "" The Development of a Hen's Egg" 

 " Secreto-motor Action " " The Action of Anaesthetics." These 

 are some of the topics that are at present linked together in my 

 mind, as on a thread of intention, towards the next few lectures. 



And before I commence to tell the first bead of my chaplet, 

 let me make further confession of faith, and outline to you the 

 sort of purpose and intention by which scientific research may 

 be animated. There are two chief moments in the life of every 

 explorer the moment of discovery, and the moment of dis- 

 closure, when the first pleasure is shared with others. But before 

 this second moment may be enjoyed, a language not necessarily 

 of words alone must be common to talker and to hearer. The 

 talker must in a measure generalise his language, the hearer 

 must in a measure specialise his understanding, and learn the 

 meaning of terms and formulae and labour-saving symbols that 



are current coin in the daily dealings of every specialist, 

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