Balavlan Society at Haarlsm. C^t 



atid, \\'Tiat confequences can be deduced from our knowledge 

 oil this fubjctSl in regard to the choice of manure, and the 

 improvement of wade and barren lands ? 



" III. Is the ftudy of natural hiflory of fo much import- 

 ance to youth that it deferves to be confide red as an ellential 

 part of a well regulated education ? And if this be the cafe, 

 what part of this fcience deferves the preference ? and what 

 is the pi-opereft method of exciting young perfons to ftudy it, 

 and of making it as ufeful to them as poflible ? 



" IV. As it appears, from the experiments of Dr. Chladnl, 

 that, when a plate of metal or glafs has been llrened over 

 with light fand or duft, if a violiri bow be rubbed againft it 

 fo as to produce a tone, the fand aflTumcs various figures : the 

 Society requires a theory of this phenomenon, which (liall be 

 the refult only of obfervation ; and in particular : 



" lit. As complete an account as poffible of all tlie figures 

 which each tone produces, and a claflification of thci'e figures 

 according to their different kinds. 



" 2d, A phyfical explanation of the reafon why the faud 

 alTumes ihefe figures, and of their relation to the refpeclivs 

 tones." 



The anfwers to the three firft queftions muft be tranfmittect 

 lo the Society before the firft of November 1801 j that t(* 

 the laft, before the firft of November i8oa. 



The following queftions propofed laft year, to be anfwercd 

 before the firft of November j 800, remain to be anhvered : 



•' I. What light has been thrown by the new cheniifirw 

 on the' phyfiology of the human body ? 



*' II. How far has the light thrown by the new chemifirv 

 ©n the phyfiology of the human body contributed to make 

 us better acquainted with the nature and caui'es of certain 

 tlifcafes? and, \Vhat ufeful confequences, more or lefs con- 

 firmed by experience, can be thence deduced for the pradlics 

 of medicine ? 



" III. How far has the new chemiftry ferved to cive u? 

 more accurate ideas of the efficacy of external or iriternai 

 fncdicines long ufed or recently recommended ? and of whac 

 advantage may a more accurate knowledge in this fubjccl bje 

 in live treatment of certain difeafcs i" 



