Review of Recent Geological Literature. 315 
The large amount of hercynite reduces the erosive power and makes 
the mixture of no value as emerj'. w. 0. c. 
On the Constitution of Barytocclestitc. By C. W. Volney. /. Am. 
Chem. Soc, 21, 386-388. 
Although previous work had discredited the existence of a true 
bariumstrontium sulphate, showing only barites containing a trace of 
strontium or celestites containing a trace of barium, the author finds 
this mineral from eastern Ontario to yield : BaS04, 30.850 and SrSOj, 
70.010. A previous analysis by the author had given : BaSOi, 39.850 and 
SrSOi 58.200. These results correspond very closely to the formulas 
(BaSra) (504)3 and (BaSrs 804)4. These two types of baryto- 
celestites have distinct habits of crystallization which remain to be in- 
vestigated, w. 0. c. 
Examination of Sandstone from Augusta county, Virginia. By W. W. 
Miller, Jr. Am. Chem. Jour., 22, 216-217. 
This sandstone is a disintegrated quartzite, occurring in the vicinity of 
Basic City, and found to be valuable for ballast and road metal. The 
analysis shows large proportions of alumina and alkalies, indicating 
partially kaolinized feldspar which is regarded as explaining the pack- 
ing of the material in use. w. o. c. 
Analysis of Smithsonite from Arkansas. By W. W. Miller, Jr. Am. 
Chem. Jour., 22, 218-219. 
The smithsonite from the Morning Star mine in Searcy county, is 
the usual botryoidal variety, and encloses layers of zinc blende from 
which, probably, it has been derived. The analysis shows it to be 
nearly pure ; but with a little cadmium, copper and iron replacing zinc. 
\\ . 0. c. 
Some Principles of Rock Analysis. By Willi.\m F. Hillebrand. 
(Bull. No. 176, U. S. Geol. Surv.) 
While this is primarily a description of the analytical methods fol- 
lowed in making rock and mineral analyses by the chemists of the U. 
S. Geol. Survey at the Washington laboratory, the author has included 
so much that is valuable in the way of general discussion of the prob- 
lems involved that the bulletin practically amounts to a very com- 
plete treatise on the subject of rock analysis. Particular emphasis is 
laid on the importance of thoroughness of analytic work, especially as 
regards the detection and estimation of the rarer rock-forming elements. 
The value of many of the older analyses was greatly lessened and 
often wholly destroyed by failure in this respect, and many erroneous 
conclusions concerning mineral composition resulted. The introduc- 
tion of improved analytical methods has not only made greater accuracy 
possible but has brought to light many interesting facts about the oc- 
currence, relative distribution and associations of the rarer elements. 
In the descriptive parts we find the methods of procedure which experi- 
ence has shown to yield the most satisfactory results outlined in" such a 
manner as to be of service to any having occasion to make rock or min- 
eral analyses. Alternate methods are also given in many instances and 
their advantages and disadvantages considered. In a few cases ap- 
