390 Allen and Comstock—Bastndsite and Tysonite. 
marbled structure of the coating of some of them, and also the 
pulverulent variety of meteorites, or, as it is sometimes called, 
meteoric dust, ete. 
I have thus given a statement of some of the prominent fea- 
tures of this most admirable work on the mineral and geologi- 
cal study of meteorites, embracing not merely descriptions, but 
also the results of well directed experiments, and comprehen- 
sive philosophical conclusions. We have nothing like it in 
our scientific literature; and being the result of the labors of 
so distinguished a geologist as Professor Daubrée, one who 
has devoted much thought and labor to the subjects of which 
he treats, it deserves the closest study. The first part of the 
work I have not referred to, for it has been made known to us 
briefly in a former notice in this Journal, and quite fully in 
Professor Dana’s recent edition of his Manual of Geology, which 
work cites many of the facts and conclusions, and some of its 
excellent illustrations. : 
In the preparation of both parts of this volume, the publisher 
has done his part most thoroughly, the paper and typography 
being such as are rarely equalled in scientific publications, and 
the illustrations in the text, which are very numerous, being © 
unusual beauty. The work is one that should find its way to 
the library of every geologist. 
Art. LIIL—Bastniisite and Tysonite from Colorado ; b 
y O. D. 
ALLEN and W. J..Comstock. ‘(Contributions from the 
Laboratory of the Sheffield Scientific School. No. LX.) 
THE material for the investigation, the results of which are 
here given, was received from Messrs. S. T’. Tyson and H. KE. 
ood, to whom our thanks are due. so hy 
The first mineral examined was found by careful qualitative 
analysis to contain only the metals of the cerium group, uo 
and carbonic acid, with a trace of iron. Its characters are a 
Ss 18, : 
to resinous. Color reddish brown. Streak light Bhi 
gray. Infusible. Is very slightly attacked by hy rochlori¢ 
acid, without perceptible evolution of carbonic acid. * oA 
“ha ini acid dissolves it with evolution of carbonic an 
hydrofluoric acids. Strongly heated in a closed tube shows 
scarcely a trace of moisture. The direct results obtained by 
analysis are : 
ish bastnasite 
I. I. Mean. ns ‘Nordenskidld. 
Ce.05 40°88 41°21 41°04 } ap .29 28°49 {14-26 
(La, Di)sO; 34°95 34°56 34-76 ; 45°77 
OO, 20°09 20°20 20°15 19°50 
