n 4 HERMANN VON HELMHOLTZ 



a jurist and distinguished physicist from London, Andrews, 

 Professor of Chemistry in Belfast, Stokes, a physicist from 

 Cambridge; there was no one who could properly be called 

 a physiologist. The clearest and most popular, as well as 

 most valuable communications, were those of the geologists 

 Phillips and Hopkins, and the ethnographer Dr. Latham, 

 but many of them were tedious, and many to my surprise 

 were mumbled, and so badly delivered that they were unin- 

 telligible. I joined in one discussion ex tempore, and explained 

 a point in the optics of the eye that had been worked out in 

 Germany. I got through all right, though I made plenty of 

 mistakes, but the English people praised me, and said it was 

 quite clear and easy to understand, although I used certain 

 words in a different sense from that which they usually 

 convey. I read my lecture on "The Mixture of Colours" 

 aloud to Dr. Francis, who corrected the mistakes, and was much 

 commended for it. The style of course was not entirely my 

 own, but they were pleased with the delivery, and I received 

 many compliments at the expense of Professor Plucker, who, 

 considering how often he comes to England, speaks very badly.' 



Helmholtz intended to visit Utrecht on the return journey, 

 to make acquaintance in person with Donders, but was sum- 

 moned home by his wife's illness. This time, however, she 

 soon recovered from the attack of the malady to which she 

 was becoming increasingly liable, and he was able to talk 

 over his travelling experiences with her, invigorated in mind 

 and body. This journey to England made a deep and abiding 

 impression upon him, and he took every subsequent oppor- 

 tunity of revisiting his scientific friends there. 



' England/ he writes to Ludwig, ' is a great country, and one 

 feels what a splendid thing civilization is, when it penetrates 

 into all the least relations of life. Berlin and Vienna are 

 mere villages in comparison with London. London is quite 

 indescribable; one must see its traffic with one's own eyes, 

 before one can realize it; it is an event in one's life to see 

 it; one learns to judge the ways of man by other standards/ 



At length, in the middle of October, 1853, Helmholtz received 

 Cramer's memoir for which he had been waiting so many 

 months, and was enabled to continue the work on accom- 

 modation that had been interrupted by Donders's letter. After 



