SCIENTIFIC SEWS. 



143 



Experiments to prove that all Bodies, whatever may he tJieir Nature, 

 are obedient to the Action of Magnetifm, and that this Aclion is 

 fufficiently powerful to admit of being meafured. By Citizen 

 Coulomb *. 



It has long ago been remarked, that platina, nickel, and feve- Magnetifm of 

 ral other bodies, acquire a fenfible degree of magnetifm : but n!ck f'» & c. fup- 

 r u-i r u \±\ .u- .i * J r Pofed to be acci- 



iome philolophers attribute this property only to a portion of dental. 



iron not eafy to be feparated, and conclude, that by obtaining 

 a greater degree of purity, we might fucceed in rendering 

 them perfectly indifferent to the action of the magnetic bar. 



The new experiments which Citizen Coulomb has made All bodies are 

 and repeated before the Inftitute, lead us on the contrary to ma gneticaJ. 

 think, that the action of magnetifm extends through all nature ; 

 for none of the bodies he has yet tried was found to refill this 

 power. 



But however real this action may be, it is not alike in all bo- 

 dies, and in mod of them it muft be neceffarily very fmall, to 

 have efcaped the attention of philofophers to this time. In 

 order^ therefore, to exhibit and to meafure thefe remits, we 

 muft begin by placing the bodies in a fituation which fhall 

 allow them to yield to the weakeft action. 



For this purpofe, Citizen Coulomb fafhioned his fubjects into Experiments 

 the form of a cylinder or fmall bar, andin thisftate he fufpended madewitnbod fes 

 them to a filken thread, fuch as is drawn from the filk worms* f lng i e g bre f 

 cone, and in this ftate he placed them between the oppofite"Ik. 

 poles of two magnetic bars of fteel. The fingle thread of (ilk 

 could hardly bear the weight of a quarter of an ounce without 

 breaking, confequently it became neceffary to form fmall bars 

 very light and thin. Citizen Coulomb made them about feven 

 or eight millemetres in length (or lefs than half an inch), with 

 three quarters of a millemetre (or about an hundredth part of an 

 inch) in thicknefs, and he gave the metals about one-third of 

 this thicknefs. 



In his experiments he placed the fteel bars in the fame right All bodies af- 

 line, their oppofite poles being five or fix millemetres farther ^"ned the direc- 

 afunder than the length of the needle intended to ofcillate be- nets which were 

 tween them. The refult of the experiment fhewed, that what- a PP lied » 

 ever might be the fubftance of the needle, it always difpofed 



* Communicated to the French National Inftitute, and inferted 

 in the Magazin Encyclopedique, No. 22, an 10, 



4 . itfelf 



