Learned Societies. 4 J 



A fatisfaaory anfwer to thisqueftion will entitle the author 

 to a prize of 6000 florins. In the anfwer care muft be taken, 

 1ft, That the means be not too expenfive, or attended with 

 too much trouble ; that they do not occafion too great a con- 

 fumption of fuel ; and that they can be employed at fea, on 

 board veffels heavily laden, and often expofed to violent agita- 

 tion.— 2d, That the means do not require too much art, and 

 may be eafily applied, even by feamen.— 3d, That they 

 be proved by experiments capable of producing the fame ef- 

 fects in every temperature.— 4 th, That they be not hurtful, 

 by corroding the copper veffels in which {hip's provifions are 

 boiled, or in any other manner. 



If the inventor of fuch means, after afcertaining their ef- 

 fect, will communicate his fecret, without concealing any 

 part of it, to the commiffioner of the Society, fo that it may 

 be fubjeaed to trial in any determined place or fhip, and if 

 it mall be found to anfwer after feveral experiments, he will 

 receive a third part of the premium. The reft of the fum 

 will be paid as foon as the Society have been convinced of 

 the certainty of the refult of thefe means, by experiments made 

 in different climates, and by the opinion of competent judges. 

 The Society, however, retains to itfelf a right of dividing 

 the prize among feveral competitors, fhould the means pro- 

 pofed by each be equally efficacious. 



The papers are to be tranfmitted, with the ufual formali- 

 ties, addreffed to C. J. J. Deflbut at Harlem, Secretary Ge- 

 neral to the Batavian Society, before the 28th of February 

 1800. 



SWISSERLAND. 



The Economical Society of Berne, having received no 

 fatisfaaory paper on the means of extirpating a deitruaive 

 kind of moth, common there, which not only attacks woollen 

 hutalfofilk, and is particularly deitruaive to furniture (lulled 

 with horfe-hair, for which they offered a prize of 20 ducats 

 in the years 1796 and 1797, again repeat the fame queftion, 

 and extend the time for receiving anfwers to three years. 



E <: 4 Tllt 



