316 Learned Societies. 



tiofts been made which clearly {hew that water fomctimes i* 



produced in the atmofphere ? 



The Society will reward the author of that paper which 

 fhall treat this lubjecl in the cleareft manner, and throw moil 

 light upon it, with a gold medal of the value of 400 florins. 



The anfwers muft be written in the Dutch, Latin, French, 

 Englifli or German (but not with German charafters) in 

 the ufual manner, and tranfmitted with a fealed note con- 

 taining the name of the author, to the houfe of the Teylerian 

 foundation at Haarlem, before the ift of April 1800, that the 

 prize may be adjudged before the ift of November the fame 

 year. 



As no anfwer was tranfmitted before the fixed period to 

 the phyfical prize queftion for 1797, the Society have thought 

 proper to propofe it a fecond time. The prize is a gold 

 medal of the fame value as the above. The queftion is as 

 follows : 



What certain knowledge have we refpecling the nourifh- 

 Kient and growth of plants ; or how far can we at prefent 

 conclude, from certain and decifive experiments and obferva- 

 tions, what the fubftances or principles are which chiefly af» 

 ford nouriflimcnt to plants, and how they receive, fecrete, 

 and athmilate them? — What circumftances relating to this 

 fubjeft, aflertcd by reipcctable philofophers, are ftill to be 

 considered as doubtful ? — By what experiments might our 

 knowledge in this refpec! be with probability enlarged and 

 confirmed? — And laftly, What can be deduced from the. 

 knowledge here required refpecting the nourifhment and 

 growth of plants, which might be practically applied in order 

 to cultivate ufeful plants in many kinds of foil with more 

 fuccefs ? 



The chief object of the Socictv, in both the firft divifions 

 of this queftion, is, that the prefent ftate of this part of our 

 knowledge reflecting plants may be accuratelv afcertained, 

 And that what is fully proved may be clearlv diftinguiflied 



from 



