+ 
1887] eo l Mineralogy and Petrography. 571 
- José A. y Bouilla, secie of the Astronomical Observatory at 
Zacatecas, this meteor represents part of the comet Biela-Gam- 
bert, lost since 1852. It is characterized by the freshness of its 
pact graphite. For some time after its fall it remained red-hot. 
discovery by inca of little globules of a stony matter in 
the ashes of Krakat Upon examination they are found to be 
made up = little ues of augite and plagioclase in a vitreous 
ground-mass. The author calls attention to the similarity be- 
tween diese bodies and the chondra of certain meteorites. 
ent Publications.—lIt is unfortunate that a treatise written 
Trea for the use of students should contain so many inac- 
curacies as are noted in the recent “ Elements of Geology” 
are, to say the least, misleading, and the definitions of the vari- 
ous rock types are unsatisfactory. An excellent text-book of 
Mineralogy, by Max Bauer, appeared about a year ago. It is 
by far the best book for general use in the class-room that has 
yet been published. The chapters on the development of the 
principles of crystallography are to be recommended as es- 
pecially well adapted n the use of those beginning the study 
of the subject.—Ferdinand Henrich’s® text-book of Mathe- 
matical SUNETE will fill a long-felt want of those who 
_ constants, twinning planes, etc. The work is well written, and 
the directions given in it are all clearly and concisely expressed. 
Wherever it can aid the explanation oF a difficult point examples 
1 Amer. Jour. Sci., xxxiii., 1887, p. 115. °? Cf Amer. Naturalist, Jan. 1887, p. 73. . 
3 Comptes Re ndus, civ., 1887, p. 95. 
4 Geological Studies, or "Elements of Geo logy. Chicago: Griggs, I 
s Lehrbuch der Mineralogie. Berlin und Leipzig, 1886, F Gaeta (D: Collin). 
§ Lehrbuch der Krystallberechnung. Stuttgart, 1886. 
