

-*, ^ 



3ed 



' *• n» Si'nfl 



a% 



1-) 



I 



'^^ch k 



«bd 



T 



els of 



■*» of the Aflti. 



■ ■ • -r bv a tiiiii 



li^bjbTOB 



•re fra?iLu;j 





British '^^ 



3 



ft 



eonsistmg of 



itiqne 



GiwiaD 



t of the sea, 



ofC 



rades- 



of lime. H^ 

 ^ and ^b^'* 



^ with sp^* 



: amy ^^'^ 







b^p^ 



■,i]i 



t 



Ch. XLVIL] 



HIS WOllKS IN SUBAQUEOUS STEATA. 



551 



some places considerably corroded, in others very slightly. 

 It proves, on analysis, to be copper alloyed with 18-5 per 

 cent, of tin. Its colour is that of our 



common 



possesses a considerable degree of flexibility. 



' It is a curious question,' he adds, ' how the crystals were 



helmet 



from 



mineral 



ising process depends on a small motion and separation of 



the particles of the original compound ? 



motion may 



have been due to the operation of electro-chemical powers 

 whicli may have separated the different metals of the alloy/^" 



¥ 



Millions of silver dollars and other coins have been some- 

 times submerged in a single ship, and on these, when they 

 happen to be enveloped in a matrix capable of protecting 

 them from chemical changes, mnch information of historical 

 interest will remain inscribed, and endure for periods as inde- 

 finite as have the delicate markings of zoophytes or lapidified 

 plants in some of the ancient secondary rocks. In almost 

 every large ship, moreover, there are some precious stones set 

 in seals, and other articles of use and ornament composed of 

 the hardest substances in nature, on which letters and various 

 images are carved — engravings which they may retain when 

 included in subaqueous strata, as long as a crystal preserves 



its natural form. 



It was, therefore, a splendid boast, that the deeds of the 

 English chivalry at Agincourt made Henry's chronicle 



as rich with praise 



As is the ooze and bottom of the deep 

 With sunken wreck and siimless treasuries ; 



number of monuments of 



the skill and industry of man will, in the course of ages, be 

 collected together in the bed of the ocean, than will exist at 



time 



* Phil. Trans., 1826, part ii. p. 55. 



