^^S Acai^.cmy of Ufefttl Sciences at Erfurt, &c. 



when fet in motion with various velocities. He confiders 

 the refults as fully confirming Mr. Vince's principles, that 

 friftion is a uniformly retarding force ; although the refift- 

 ance of the air and other accidental circumftances introduced 

 great irregularities into the experiments. He found this force 

 equal to about i-40th of the weight: the ftcel fpindles run- 

 ning on brafs, with the interpofition of an unftuous fubftancc. 



The Society adjourned to Thurfdav the T4th of January, 

 when an algebraical paper was read, of which we can give no 

 idea in a fliort notice. 



A paper, by Smith Gibbs, Efq. on galvanifm, has alfo 

 been read before the Society ; but we have occupied fo large 

 a portion of our prefent Number with that fubjeA, that wc 

 cannot at prefent enter upon it. 



ACADEMY OF THE USEFUL SCIENCES AT ERFURT. 



The Academy of the Ufefa! Sciences at Erfurt, in confc- 

 quence of a prize of thirty ducats, offered by an anonymous 

 friend of chemiftry, have propofed the following queftion : 

 What ufeful application can be made in chemiUry and the 

 arts of the temperatures below zero of Reaumur ; and how 

 far is it poffible to lower the temperature by artificial means ? 

 The Society wiflies that thofe who undertake to anfwer this 

 queftion will repeat the experiments of Lowitz, Fourcroy, &c. 

 and examine whether a much greater degree of cold than anv 

 yet found may be produced by changing the proportions of 

 the mixtures, employing them in greater quantity, by new 

 mixtures, or by placing more refrigeratory veffels within 

 each other, and, where it can be done, by making experiments 

 in a rarefied atmofphere : alfo to examine the influence of 

 low temperatures on the different gafes flmt up with fpirit of 

 wine; and to obfcrve their mixture, where pofilble, in a 

 comprefl'ed ftate ; and their influence alfo on liquids, on 

 folid bodies, and on the galvanic phaenomena^ and, in the 

 laft place, to (how what employment may be made of the 

 low temperatures in the arts and manufailures. 



The papers on this fubjeft mufl be tranfmitted to profcflbr 

 Esllerman, the fecretarv of the academy, before the end of 

 April i8oa; three months after which the prize will be ad- 

 judged. 



FRENCH NATIONAL INSTITUTE. 



The National Inflitute of Fralice having been formed dur- 

 >nor the war, the nomination of the foreign alfociates, infli- 

 tuted by the fecond article of the law of 3d Bruma'tre 

 (061. 25.) year 4, was fufpended. As peace has removed 

 this fufpenfion, in the General Sitting, which brings to- 

 gether, on the 5th of each month, the three claffes of the 



Inftitute, 



