356 



With vain ambition emulate her eyes. 



At thee the Ruby lights its deepening glow, 



And with a waving radiance inward flames. 



From thee the Sapphire, solid ether, takes 



Its hues coerulean; and, of ev'ning tinct, 



The purple streaming Amethyst is thine. 



With thy own smile the yellow Topaz burns: 



Nor deeper verdure dyes the robe of Spring, 



When first she gives it to the southern gale, 



Than the green Emerald shows: but ALL 



Thick through the whitening OPAL play thy beams, 



Or, flying several from its surface, form 



A trembling variance of revolving hues, 



As the site varies in the gazer's hand. 



SEASONS, Summer, 1. 140. 



Cto 



Mr. Klaproth, having subjected the noble opal, both in its ordi- 

 nary, and in its hydrophanous state, to the test of his accurate 

 examinations, is induced to conclude", that the difference bet\yeen it, 

 common flint, and rock crystal, is only that which depends on a 

 difference in the state of aggregation*. From this same examina- 

 tion, I am led to make a widely different inference ; and to con- 

 clude, that the same bituminous matter, which has been assumed 

 to be present in the other stones of a waxy lustre, is also present 

 in J:he opal; and that it is by its admixture with the simple, pure, 

 silicious earth, that the opal is produced. In two of Mr. Klaproth's 

 experiments, which being made merely to ascertain the nature of 

 the earth existing in this stone, prove the quantity only of its vola- 

 tile parts, the real constituent parts of the opal are shown to be, 



Gr. 



Silex ....... 90 



Water, and other volatile matters ... 10 



100 



* Analytical Essays, p. 44O. 



