Review of Rixcftt Geological Litei^atiire. 319 
tourmaline acid,Al5(Si04)6(B02)2.B03H3. H12, in which H may be 
replaced by Ca, Mg, Na, and Al. Numerous examples of mixtures of 
isomorphous molecules of this tourmaline acid are given. The formulae 
advanced by the author as covering all established variations in com- 
position, and rendering intelligible the various isomorphous mixtures, 
are as follows: 
/ SiO* = R'3 / SiO* = R"H 
Al— SiO* = Al Al— Si04 = R"H 
xSi04 = AlB02 \Si04 = AlB0= 
i 
Al— B03=R'2(R") Al— B03 = R" 
I I 
/ SiO. = Al BO2 / 5164 = Al BO2 
Al— Si04 = Al Al— Si04 = R"H 
\ SiOi^AUR'o) \ Si04=R"H 
The objection to these formulae, and also to that of Penfield and 
Foote as well, is that the end products contain no alkalies, while in 
reality an alkali-free tourmaline is unknown. Under these formulae, 
the variations from the supposed ratio of silicon and boron of 2:1 are 
accounted for by the supposition that part of the bivalent group of 
atoms=Al-BO.. is replaced by the similar groups ^Al-OH and — A1- 
F. Room for alternatives still exists, and future investigation may 
prove a derivation from a complex boro-silicic acid as yet unknown. 
M. L. F. 
Note on a New Meteoric Iron Found near Toinbigbee River, in 
Ckoctaini and Sumter Counties, Alabama, U. S. A. By Warren M. 
Foote. (Am. J. Sci., 158, 153-156.) 
Detailed descriptions are given of the appearance, structure, and 
occurrence of six masses with an aggregate weight of nearly a hun- 
dred pounds. An analysis made by Mr. J. E. Whitfield showed 95 
per cent, iron, 4 per cent, nickel, with small amounts of Co, P, C, 
and S. M. L. F. 
An Albertite-likc Asphalt in the Choctaw Nation, Indian Terri- 
tory. By Jos. A. Taff. (Am. J. Sci., 158, 219-224.) 
This asphalt, which is found at several localities in the vicinity of 
McAlister in the southeastern portion of the territory, occurs as string- 
ers in veins filling fissures along zones of thrust faulting in shales of 
unknown age. Although an analysis showed that in composition it 
was very similar to certain bituminous coals of the same region, its 
brittleness, easy fusibility, and more especially its distillation products, 
show that it should be placed among the asphalts. Of these it most 
clearly resembles albertite, the only important variation being the 
greater solubility of the latter in terpentine. .m. l. f. 
On the Separation of Alumina from Molten Magmas, and the for- 
mation of Corundum. By J. H. Pratt. (Am. J. Sci., 158, 227-231.) 
The evidences bearing upon the separation of alumina from molten 
magmas as presented in the field by the various types of peridotytes of 
North Carolina are 'discussed, and an account given of the experi- 
ments of Morozewicz and their results. The conclusions are as fol- 
