20 History of physical Science from [July, 



Second specimen. Common brass of commerce. 



Copper 61-59 



Zinc 35-30 



Lead 2-86 



Tin 0-25 



100-00 



Third specimen. Stolberg brass. 



Copper 65-80 



Zinc 31-80 



Lead 2-15 



Tin 0-25 



100-00 

 (Ann. de Chim. et de Phys. v. 321.) 



I had occasion some years ago to make the same observation. 

 A friend of mine in London, who excels, in the construction of 

 time-pieces, showed me a piece of brass which he valued very 

 highly. He gave it the name of old Dutch brass, and informed 

 me that he was in the habit of buying it up whenever he could 

 find it, and paying for it much higher prices than were demanded 

 for modern brass. He was one of those persons who have a 

 much greater veneration for former ages than for that in which 

 they happen to live ; and he stated this circumstance as a deci- 

 sive proof of the deterioration of the arts in Europe. This in- 

 formation piqued my curiosity, and induced me to make a 

 comparative analysis of these two varieties of brass. The old 

 Dutch brass was much more ductile than Bristol brass, with 

 which I compared it. I found the old Dutch brass composed in 

 round numbers of 



1 atom zinc = 4*125 



2 atoms copper = 16-000 



Bristol brass was composed of 



1 atom zinc = 4-125 

 1 atom copper = 8-0Q0 



The first specimen, analysed by Chaudet, approached some- 

 what to the old Dutch brass ; though it contained much less 

 copper. The last two specimens examined were obviously 

 similar to Bristol copper. 



9. Alloy of Tin and Antimony. — M. Chaudet has ascertained 

 by experiment that when tin is alloyed with the 20th part of its 

 weight of antimony, muriatic acid is capable of dissolving the 

 whole of the tin without touching the antimony. He proposes," 

 therefore, as an easy method of analyzing an alloy of tin and 

 antimony, to fuse the allay with a quantity of tin such as will 



