Miscellanies. 215 



that state of carbon which is called plumbago or graphite. To render 

 this hypothesis more probable, he adverts to the progressive debitumini- 

 zation of the coal of the United States, as we proceed from the horizontal 

 coal measures of the Ohio and the west, to the eastern and more dis- 

 turbed axes of the Apalachian mountains, where coal, occupying pre- 

 cisely the same geological position, and exhibiting the same species of 

 fossil plants, assumes the form of anthracite, as has been shown by 

 Prof. H. D. Rogers and others. 



The Rhode Island anthracite may be considered as representing a 

 further state of change, in which the volatile ingredients of the original 

 coal have been still more completely expelled ; and in the plumbago of 

 Worcester we have the last step in the series of transmutation, where 

 all traces of fossil plants and vegetable structure have been obliterated, 

 and where the lithological character of the sedimentary rocks has been 

 entirely altered. It is remarked that the Silurian formations, which 

 are so largely developed in the United States, yield no beds of coal or 

 anthracite which could by metamorphosis be supposed to become turn- 

 en into such a carbonaceous stratum as that of Worcester. 



The author concludes by observing that the difference of strike be- 

 ff een the mica schist containing plumbago at Worcester, and the near- 

 est carboniferous rocks of Rhode Island and Massachusetts, affords no 

 argument against the theory of both having belonged originally to the 

 same group of sedimentary strata. In New England and in Nova Sco- 

 a , the coal measures frequently deviate widely from the same strike 



contiguous districts, and the direction of continuous anticlinal axes 



e Alleghany Mountains, composed throughout of similar Silurian 



and I carboniferous rocks, has been shown by Professors W. B. and H. 



R °gers to vary more than 40° in different sections of that chain. 



• Hydrous Borate of Lime. — This mineral, first made known by A. A. 

 yes, has been analyzed by him with the following result : Boracic acid 



® ll h lime 18869, water 35, giving the formula CaB 2 -f 6H. The 



»ystals, figured on Mr. Hayes's authority in Dana's Mineralogy, p. 243, 



°een found on analysis to be glauberite. The borate of lime oc- 



: . ln lnt erlacing fibres of a snow-like whiteness. Besides glauberite, 



' ss ociated with gypsum, magnesian alum, and a native iodate of soda, 



g species first pointed out by Mr. Hayes. It comes from near Iquique, 



" A - (See this Journal, vol. xlvx, p. 377.) 



4 A 



obt ' natase - — This mineral has been lately examined by Damour. He 

 98"3p e ^ e com P° s 'tion of a specimen from Brazil, Titanic acid 



it i s f er0XJ,d of iron ll h ox y d of tin 0-20=99-67, according to which 

 Yrie * emical, y i(J entical with nttile. A specimen of rutile from St. 

 Specif, aff ° rded him Titanic acid 9760, peroxyd of iron 1*55=99- 1 5. 



gravity of the anatase 3857. Descloiseaux has measured crys- 



