1Q4, TENACITY OF DUCTILE METALS. 



Two observations, that offered themselves to the author 



in the course of his inquiry, led him to some researches, 



that form important sections in his paper. 



Density of lead The first is the diminution of the specific gravitv of lead 



diminished by , ., ,» a . ., , , 



flatting b y the process 01 Hatting, confirmed by numerous expert* 



ments of Muschenbroeck, und which Dr. Thomson has re- 

 lated, at the same time confessing, that the cause still re- 

 mains unknown. Mr. Morveau was particularly induced to 

 clear up this anomaly, as in a paper in the 2d part of the 

 Memoirs of the Institute for 1806 he had recorded a fact, 

 which appears contradictory to this: four men wer« unable 

 to ram home a cannon ball surrounded by a ring of lead. 



Having verified this diminution of the density of lead, 

 and determined with precision the circumstances accompa- 

 nying it, when extended under the hammer, passed between 

 rollers, drawn out as wire, and struck with the engine ; he 

 perceived, that this effect took place only in proportion to 

 the facility with which this metal softens, this occasioning 

 the metal to escape from the pressure, even when struck in 

 a collar ; as was clearly shown by the quantity of the metal 

 it is that rose at each stroke. He was resolved however to obtain 



compressed on a more direct proof, by stamping planchets of lead in a 

 very strong collar, in which they were completely confined 

 between two plates of iron. , In this way their density was 

 gradually increased from 11*358 to 11'3S8. Hence it is to 

 be concluded, that lead, when confined in a place from 

 which it cannot issue out as if it were fluid, is susceptible, 

 like other ductile metals, of a degree of compression, which 

 brings its particles nearer together, and increases its specific 

 gravity. 

 Lead readily The second phenomenon, to which the author's attention 

 dissolyed by wag c^ig^ wa s the very speedy action of water on lead ; 

 the distilled water, in which it was suspended from the hy- 

 drostatic balance, soon acquiring a milky aspect, and a 

 •white flocculent sediment being at length deposited in it. 

 He satisfied himself by a series of experiments, which he 

 • gives with their results, that distilled water acts on lead 

 spontaneously, and without the assistance of agitation : 

 that this action takes place even on. lead revived from the 

 muriate : that it occurs with water distilled in glass vessels, 



a circura- 



