J 02 TENACITY OF DUCTILE METALS. 



nickel in grains by bringing near them a magnet, which 

 would necessarily render these grains magnetic. It appear* 

 certain, that it is more difficult to deprive nickel of mag- 

 netism than iron. It would be interesting to science, to exa- 

 mine whether the variation and dip of a needle of nickel be 

 Its dip the the same with those of a needle of steel. I found the dip 



rsTe^needle/ of a needle ° f steel similar t0 tliat of a needle of nickel 

 touched by the magnet. They were both to the north. 



Abstract of a Paper on the Tenacity of ductile Metals, the 

 Changes of Density in Lead by the Operation of Pressure,, 

 and the Action of distilled Water on this Metal, read to 

 the Physical and Mathematical Class of the Institute, by 



GUYTON MoRVEAU*. 



Ti 



Tenacity of J|_ HE author of this paper having observed in modern 

 entiy stated/ works of the highest estimation expressions of the tenacity 

 of some metals very different from those he had deduced 

 from his experiments, published in the 25th volume of the 

 Ann. de Chim., deemed it of sufficient importance to insti- 

 tute a new examination, and to add at the same time the 

 observations he has since collected for completing the sy- 

 noptic table of the distinguishing properties of metals, 

 which he had drawn up for his course of lectins at the 

 imperial polytechnic school. Not that he thinks the maxi- 

 mum of this force of cohesion of metals should enter into 

 the calculations of artists who employ them ; for it is well 

 known, that the accidental imperfections, which always 

 more or less facilitate their rupture, oblige them to have re- 

 course to larger dimensions; but it is not the less true, that 

 the known ratios of their tenacity are of use to determine 

 which should be preferred, and afford an important test of 

 their purity, and the quality of the manufactured metal. 

 With regard to copper, platina, silver, gold, and iron, 



* Abridged from the Annales de Chimie, vol. LXXI, p, 189. 



thft 



