i^4 T&ytgT^s' Second Society at Haarlem, 



As it is of the greatell importance to every branch t)f 

 natural philofophy, that the prefcnt ftate of our knowledge 

 rcfpetfling them {hould be clearly explained, and^ that every 

 thing proved by experiment ihould be carefully feparated 

 from what is fupported only by hypothcfis, the fociety re- 

 quires to know : 



What is the prefent (late of our knowledge in regard to 

 aqueous phaenomena ?•— How far can we afccrtain from well 

 authenticated experiments the caufes by which water is re- 

 ceived into the atmofphere and retained there in the form of 

 vapour or in any other manner? — And to what caufes is it 

 to be afcribed that the water retained in the atmofphere is 

 fet at liberty and falls down under various forms? — Can the 

 aqueous phaenomena be afcribed to the liberation of the 

 water retained in the atmofphere alone? or are there any 

 obfervations which clearly fhow that^ during fome aqueous 

 phaenomena, water is produced in the atmofphere? 



The fociety renews alfo the following qucftion, to which 

 no fatisfadlory anfwers have been received, and offers a 

 gold medal of the value of 400 florins for the beft anfwer 

 tranfmitted to the fociety before the ifl of April 1802 : 



What do we know with certainty refpefting the nourifli- 

 ment and growth of plants? or how far can we determine, 

 from decifive and well-authenticated experiments, thofe fub- 

 ftances or matters which ferve in particular as the pabulum 

 of plants, and the manner in which they receive, fecretc, 

 and aiiimilate them? —How much of the information given 

 us on this head by eminent naturalifts is ftill to be confidcred 

 as doubtful ? — By what experiments might our knowledge 

 on this fubje£l be enlarged or confirmed ? and what in- 

 formation docs our aclual knowledge of the growth and 

 nourifliment of plants fupply us with to enable us to raife 

 and tranfpiaT:it with more fuccefs ufeful vegetables in different 

 kinds of foil ? 



The fociety requires, in particular in regard to the twq 

 fir ft members of this queftion, that the candidates will give 

 an accurate account of the prefent ftate of this part of the ' 

 natural hiftory of plants^ and at the fame time make a dif- 



• tin<5lioo 



