Review of Recent Geological Literature. 49 
This incorporation and absorption of basic material by an acid niaf?ma 
is not common and is of special interest. The present instance proves 
conclusivelj' that such a phenomenon does occur. The importance of 
this phenomenon was mentioned by the author and was further Vjrought 
out in the discussion which followed the reading of the paper, u. s. g. 
The Rubies of Burma and Associated Minerals. By J. W. Judd. In 
the Philosophical Transactions Prof. Judd, with C B. Brown, Esq., 
gives a detailed account of some minerals collected by the latter when 
carrying out, under orders from the Secretary of State for India, an in- 
vestigation into the long known ruVjy mines of Burma. Details are 
given, with maps, of the physical geography and geology of the region 
and the rude processes employed by the natives in mining the gems. 
They are for the most part washed out of alluvial material tilling hollow- 
basins and clefts in a limestone rock, but their original situation, as 
proved by Mr. Brown, is in the rock itself. This, is a hard, crystalline 
limestone interVjedded with gneiss, and by breaking some of it to frag- 
ments Mr. Brown obtained in ten days 14 rubies from one and a half 
cubic feet. These were of coui'se injured much by the jarring necessary 
to break up the stone, but they showed that by better methods the 
gems could be olitained in larger quantity. 
Prof. Judd says: ''The limestone which the rock in Burma most 
closely resembles is undoubtedly that of Orange Co., N. York and Sus- 
sex Co., N. Jersey, which is associated with the remarkable deposits of 
zinc ore at Franklin Furnace." "The general conclusion to which we 
have been led concerning the origin of the rubies of Burma is as fol- 
lows: Pyroxene gneisses abound with an unstable basic feldspar, which 
is easily converted by minute quantities of hydrochloric acid under 
pressure into a scapolite, this in turn breaking up into various hydra- 
ted aluminum silicates and calcite." While the limestones are being 
formed from Vjasie feldspars the aluminum silicates, taking up water, 
may be attacked by sulphuric, hydrochloric, boric or hydrofluoric acid 
at moderate temperature and decomposed, the aluminum oxide, in some 
cases anhydrous, being formed, which may as.sume the crystalline form. 
The presence of carbonic acid in the liquid state in .some of the cavities 
indicates formation under great pressure. e. w. c. 
Sobre la edad de Algunas formaciones Carboniferas de la Republica. 
Argentina. By Guil. Bodenbender. (Revista del Museo de la Plata, 
vol. vii, 1-20, 1895.) Accompanying an exposition of the Carboniferous 
formation in the Argentine is an important tal)ulation of the Paleozoic 
series of that country with its fo-ssils. Above uufossiliferous beds of the 
gierra de los Llanos and the Sierra de Cordoba, referred to the lower 
Cambrian are sandstones of the Olenus zone in the provinces of Jujuy 
and Salta, containing Agnosiiis, Olenus, Arionellus, Ortiiis, Lingula, 
and Obolus. To the Trenton horizon are referred the limestones and 
dolomites of the Antecordilleras of San Juan and the Sierra de Farna- 
tina, with MonticuUpora, Lituites, ]\[urch isonia, Maclii i-ea, Orthis calli- 
gramma, Orthisina adscendens, Lcpiacna sericea, etc. The Silurian 
