1820.] Harlein Philosophical Society. 45^ 



expected, from the matured labours of this Institution. Let it 

 not then be forgotten that success is the prize of exertion — not 

 of the few, but by a general concurrence in the spirit of our com- 

 prehensive Cornish motto " One and All." Then will the 

 memorial of these our days go down to posterity, adorned with, 

 the imperishable trophies of science. But if we supinely neglect 

 the auspicious opportunity, instead of living in the grateful 

 recollection of future times, posterity will mourn over our apathy,^ 

 over the unimproved talents thus buried, 



" And heap the pile with each Inglorious name. 

 On thefall'n altar of their country's fame!" 



At this meeting, being the first general one since the acces- 

 sion of his present Majesty to the throne, an address of congra- 

 tulation was voted to the King as Patron of the Society. 



HARLEM PHILOSOPHICAL SOCIETY, 1820. 



The Society held its Sixty-seventh Anniversary on May 27 

 and 28, when the President, M. J. P. Van Wickevoort Crom- 

 raelin, called upon the Secretary to report the papers which had 

 been sent in since their last sittino; in 1819. 



& 



Physics. 



1. The author of the German memoir, in reply to the question, 

 " What are the general rules according to which it may be 

 judged without actual experience, what exotic plants may he 

 most usefully cultivated in Holland ? is Johann Karl Leuchs, of 

 !Nuremburg. 



2. " What is the cause of the tarnishing {het weer) with which 

 glass is affected, after being exposed for some time to the air 

 and sun? and what are the most effectual means of preventing 

 it ? " The paper on this question to which the medal has been 

 adjudged is by G. W. Muncke, Professor of Physics at Heidel- 

 berg. It was resolved to print also another answer (in German) 

 having for its motto, La Nature park par les Experiences, and to 

 present the author, whenever he chooses to avow himself, with 

 the silver medal, 



3. " What uncultivated lands are there in the southern dis- 

 tricts of the kingdom that, judging from experiments on similar 

 soils, appear capable of being tilled with success, and of repay- 

 ing the expense of cultivation : and what would be the most 

 judicious method of undertaking such enclosures with hope of 

 their answering; the whole to be grounded on sure experiments?" 

 Three papers were sent in on this subject, but being unsatisfactory, 

 it was resolved to let it continue for answer till Jan. 1821. 



4. Two memoirs on the Draining of the Great Lake at Har- 

 lem had been received^ but both of them were deemed unsatis- 

 factory. 



