300 Royal Institution of Great Britain. 
«© own Name will always stand conspicuous in the history of 
** these discoveries.” 
[The President afterwards presented the Medal, in a similar 
manner, to Mr. Herschel, as proxy for Professor Struve, and 
addressed him as follows:] ‘“‘ Assure M. Struve of the lively 
“ interest which we take in all that is passing at the Observa- 
“‘ tory of Dorpat: that we admire the patience, the exertions 
* and the address, with which he has overcome the difficul- 
‘© ties he has had to encounter, in the progress of his disco- 
“ veries: and that we look forward with confidence to a con- 
‘“ tinuance of the same brilliant career in the cause of astro- 
*nomy. Furnished, as he now is, with one of Fraunhofer’s 
* colossal telescopes, and thus armed with the most powerful 
‘‘ means, we anticipate the most successful results from his 
“ laborious exertions. Unconscious of what was going forward 
“in this country, he had opened for himself a vast field of 
s¢ inquiry, which he has pursued with the most splendid suc- 
«cess; and which places his name amongst the most cele- 
‘‘ brated of modern astronomers. The Paper which has been 
‘ yead to us, this evening, shows that his ardour is unabated : 
‘ since he there announces the important fact of the observa- 
* tion of 1000 double stars of the first four classes, (most of 
‘‘ which are entirely new,) and amongst which are 300 of the 
‘“‘ first class. ‘To a mind, formed like his for the pursuit of 
“ science, little need be said to animate him to a continuance 
“ of his labours: but, it may be pleasing to him to know that 
‘we are alive to the progress of his discoveries: and I am 
*¢ sure that you will convey to him, in much better terms than 
*‘ IT can do, the expressions of our esteem and admiration for 
‘‘ his services in the cause of science ;—services which assure 
*‘ us that the name of Struve will be imperishable in the an- 
“ nals of astronomy.” 
ROYAL INSTITUTION OF GREAT BRITAIN. 
April 7.—Mr. Faraday spoke in the Lecture-room on the 
subject of vapour of extreme tenuity, opposing the general © 
opinion that vapour may be diminished in its tension ad inji- 
nitum, and stating that there was reason to believe that a limit 
existed, varying with different bodies, but beneath which they 
gave off no vapour. He began from Dr. Wollaston’s argu- 
ment of the finite extension of the atmosphere, and then showed 
that either gravity or cohesion were sufficient to overcome a 
certain degree of elasticity, advancing experiments in illustra- 
tion of the power of cohesion over vapour. He.concluded 
that some bodies might have their limit of vaporization within - 
. the range of temperature which we can command, and even 
near 
