G-enth.] *0-± tSep 19) 



The oxygen ratio of RO : R.O., : SiO, : H,0 = 1 : 3.75 : 3.01 : 

 1.8, or very nearly 4 • 15 : 12 : 7, which gives the formula : 

 2 (2 RO, Si0 2 ) + (5 R 2 : j> 4 SiO.,) -f 7 H,0. 



Although the material was not quite pure, containing a very minute 

 quantity of margarite, I wish to put this analysis on record, believing 

 the mineral to be new, and wishing that it may be found in a state of 

 greater purity. 



29. Dudleyite (a new species). 



At the Cullakenee Mine, but in larger quantity with the margarite of 

 Dudleyville, Alabama, a soft bronze or brownish-yellow mineral is found, 

 which is probably the result of the alteration of margarite and still 

 retains its form ; lustre pearly. When heated, it exfoliates very slightly 

 and then melts with difficulty into a brownish-yellow plebby mass. 



With chlorhydric acid decomposed easily with separation of silicic acid 

 in pearly scales. It is named after the locality, Dudleyville, Alabama. 



The analysis gave : 

 SiO, = 



Al,< ) :i 

 Fe.A 

 Feb 

 MgO 

 Li,0 

 Na,0 

 KoO 

 Ignition 



The oxygen ratio for 

 2.24 : 1.55, which is vei 



2 (3 RO, 2 SiO,) + (4 R,0 :; , 3 SiO,) + 10 H,0. 



30. Lazuli te. 



In mentioning the alteration of the corundum of Crowder's and Clubb's 

 Mountains, Gaston County, North Carolina, I observed that in all these 

 localites, and others which I considered as analogous, lazulite was one of 

 the results of alteration. 



I have seen specimens from the Gaston County localities which were 

 mixtures of lazulite and damoui'ite, and, what is very significant, lazulite, 

 which inclosed crystals of rutile, the constant associate of the corundum 

 at these localities. 



Although not in accordance with the views of modern chemistry, I 

 hope that I will be justified in having attempted to give the composition 

 of these minerals in formulae, which, as we once thought, would express 

 an idea of the rational composition of the species. I do not intend to 

 discuss their merits, I will even admit that such formuhe state a great 



