JANUARY 29, 1914] 
NATURE 
619 
T. N. Dale and H. E. Gregory (Bull. 484) describe 
the granites of Connecticut, with remarks (p. 17) 
on the composite origin of some of the associated 
gneisses. As is usual in such memoirs, examples are 
given of the monumental use of the quarried stones. 
T. N. Dale also reports on the marbles of Vermont 
.(Bull. 521), in which graphitic bands are ascribed to 
marine alge of Ordovician age. ; 
Bull. 492, by G. F. Loughlin (1912), contains some 
interesting examples of the 
effects of dynamic meta- 
morphism upon gabbro in 
Connecticut, well illustrated 
in plates x. and xi. 
C. W. Hayes and W. 
Lindgren edit the report 
on the developments in 
economic geology during 
1910 (Bull. 470, 1911). Con- 
siderable attention is given 
(pp. 371-483) to the oolitic 
phosphate beds of Idaho, 
Montana, and Wyoming. 
R. W. Richards and G. R. 
Mansfield (p. 377) hope to 
show later that the Upper 
Carboniferous phosphatic 
deposits of Idaho were 
formed at a time of ab- 
normal enrichment of the 
sea-water with phosphoric 
acid or its salts, and not by 
subsequent infiltration. In 
Bulletin 471, M. R. Camp- 
bell continues this report by 
an extensive review of 
mineral oils, coals. and lig- 
nites in many districts now 
under exploration. W. T. 
Lee (Bull. 510) has explored 
the area of Cretaceous coals 
in north-west Colorado. 
These coals have been im- 
proved in calorific value by 
the influence of quartz- 
monzonite laccolitic intru- 
sions, which are clearly 
shown in the published sec- 
tions. 
H. S. Gale (Bull. 523) re- 
views the nitrate deposits of 
the United States, none of 
which seem at present to be 
of commercial value. The 
sketch of the origin of 
nitrates in soils (pp. 31-5) 
is just what teachers of 
mineralogy and agriculture 
require. 
The demands of agricul- 
turists are further  con- 
sidered in Bulletins 511 and 
512. The former, by B. S. 
Butler and H. S. Gale, Ric: 
deals with a newly found 
deposit of alunite in Utah, which is believed (p. 36) 
to result from the uprising of solutions from below. 
The mineral occurs in veins in andesite, the main one 
being 20°ft. thick. The purity of the mass is shown 
by analyses which yield respectively 10-46 and 9-71 per 
cent. of potash. Alunite may be converted into a soluble 
sulphate by calcination, anda useful review is given of 
its commercial use in Australia and other places. In 
Bulletin 512, A. R. Schultz and Whitman Cross, with 
NO. 2309, VOL. 92] 
1.—Rock-glacier on McCarthy Creek, Nizina district, Alaska. 
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a somewhat prophetic outlook, consider the future ot 
the potash-bearing rocks of the leucite hills in 
Wyoming. The percentage of potash in these lavas 
is about the same as that in alunite, and may reach 
even 12 per cent. The greater portion of the potash 
occurs in the two minerals leucite and phlogopite, 
and the authors look forward to the possibility of the 
separation of these minerals and the extraction of 
potash and alumina from them, or even from the lavas 
From Bull. 448, U.S. Geol. Survey. 
as a whole. The estimate of the alumina availab‘e in 
millions of tons (p. 35) premature, and any 
commercial process that may be devised will probably, 
so far as this substance is concerned, be applied also to 
common clay. 
Petrographers as well as miners will find much of 
interest in Professional Paper 77, on the Park City 
District, Utah, by J. M. novel and 
seems 
We Boutwell. <A 
effective feature is the illustration of the ores and 
