460 Proceedings of Philosophical Societies. {Dec, 



5. Two also, and equally unsatisfactory ones, respecting the 

 Draining of the Wyker-meer. It was, therefore, determined, 

 that the time assigned for the first of these questions should be 

 extended to Jan. 1, 1822, and that of the second to Jan. 1, 1821, 



6. " By what artificial methods can the arms of the sea at the 

 Texel be improved, either entirely or more particularly at the 

 Schulpen-gat, and how can they be rendered deeper ? " The 

 plan proposed in the memoir sent in was found to be so expen- 

 siveas to be judged altogether impracticable : it was, therefore, 

 determined to repeat the question, which is to be answered by 

 Jan. 1, 1822. 



7. " What knowledge do we possess of those insects which 

 are destructive to objects deposited in cabinets of natural history, 

 and likewise to furs and skins of animals ; and what are the 

 most eflicacious means of securing them against, or protecting 

 them from, the attacks of such insects ? " 



Two papers received on the subject, neither of which obtained 

 the prize; one was rejected with indignation as a despicable pla- 

 giarism, being little more than a transcript from the second 

 volume of " Ohvier sur les Coleopteres." The question is, 

 therefore, repeated, and the answer to be sent in by Jan. 1, 1822. 



8. " What is known concerning the circulation of the sap in 

 certain trees and shrubs during the spring ; for instance, in the 

 vine, poplar, ash, &c. ; what is fikely to be learnt in this respect 

 from further experiments ; what deductions are to be derived 

 from them as to the cause of the saps rising in plants ; and 

 what practical information can be expected to be obtained on 

 this head which may conduce to an improved cultivation of use- 

 ful trees ? " Two answers, one in French, and the other in 

 Dutch, had been received, but neither of them satisfactory. It 

 ■was, therefore, agreed, that the question should be again pro- 

 posed ; the answer to be dehvered by Jan. 1, 1822. 



9. " It having been proved by practical agriculture that, dur- 

 ing the first vegetation of wheat and other grain, the earth does 

 not diminish in fertility, but that after fructification, and during 

 maturation, the same soil is considerably exhausted, and deprived 

 of its fecundity ; it is inquired, what is the cause of this pheno- 

 menon, and how far is it likely that the solution of this problem 

 could supply certain rules for ameliorating the cultivation of 

 lands ? " A French paper had been received on this subject, but 

 as it contained nothing important or satisfactory, it was deter- 

 mined that the question should be repeated without assigning 

 any limited time for a reply. 



10. " What are the principal causes of the degeneration of 

 plants to which we are indebted for varieties of them; and what 

 information can be obtained on this head that may tend to 

 improve the culture of useful plants ? " The memoir sent in was 

 deemed unsatisfactory, and it was, therefore, agreed to extend 



