Review of Recent Geological Literature. 427 
ites and (3) diabases; C. Monchiquites; L). Fourchites. All the strata of 
the shores of lake Champlain, up to and including the Utica slate, are 
cut by these dikes, and since their intrusion they have suffered practi- 
cally no deformation. From the fad thai camptonites, monchiquites 
aud fourchites .-in- almost invariably associated with eleolite syenite, 
the authors think that this rock may perhaps be found in the Adiron- 
dacks, or thai possibly these dikes represent the extreme southern 
manifestation of the eruptive action that produced the nepheline rocks 
near Montreal, whose time of intrusion was between the Trenton and 
I, owe]- Helderberg. < ;. 
Tin Qraniteat Mounts Adam and Eve, Wa/rwick, Orange Co., X. )'.. 
and its contact phenomena. By J. F. Kemp and Akthuk Hollick. An- 
nals N. Y. Acad. Sci.. vol. ;. pp. 638-654, pis. 2and 3, 1894. The granite 
is of a basic hornblendic type, almost a quartz diorite; it lias intruded 
the white limestone, and at the junction of the two is a well developed 
contact zone with minerals peculiar to granite-limestone contacts else- 
where. On approaching the limestone the granite becomes richer in 
pyroxene (malacolite) and at the contact is a distinct scapolite /.one. be- 
yond which the limestone is charged with aggregates of silicates. The 
i wo limestones (while and blue) are regarded by the au1 hors as probablj 
one. the former being a more metamorphosed phase of the latter. The 
same opinion is held by F. L. Nason. for the southward extenson of these 
limestones in New Jersey, where the blue is found to be of Cambrian 
age. Tin- paper is accompanied by a "List and Bibliography of the 
Minerals occurring in Warwick township."' by Beinrich Ries. G. 
On tin Crystallisation of Herderite. By S. L. Pknfiki.o. Amer. Jour. 
Sci.. 3, vol. 4T. pp. 329-339, pi. 8, May, 1894. An examination of some 
specimens from Paris. Me., which proved to be monoclinic, led to a 
study of specimens from other localities with the result that herderite 
was found to be always monoclinic and u< it orthorhombic as hitherto 
thought. In this mineral fluorine and hydroxy! are isomorphous and 
occur in different proporl ions; some of the physical properties of herder- 
ite vary as the amount of hydroxyl increases or diminishes. G. 
(In tin ( 'In miriil Composition and Related Physical Properties of Topaz. 
By S. L. PENFEELD and .1. C MINOR, .In. Amer. .lour. Sci.. :{. vol. 17, 
pp. 387-396, May, 1894. Topaz is found to contain a small and variable 
percentage of hydroxyl which is isomorphous with and partlj replaces 
the ilourine. As the proportion of these two substances vary there i-< 
found to lie a decided change in some of the physical properties of the 
mineral: thus, as the proportion of hydroxyl increases the specific grav- 
ity, the strength of the double refraction, the divergence of the optic 
axes and i he lengl h of t he crystallographic axes a and c decrease, while 
the indices of refraction increase. G 
Devon i*<- In l'< rxtrim m mji n von Lagoiriha in Matto Orosso (BrasiHen); bj 
Ludw. von Amnion. (Zeitschr. der Gesellsch. fur Erdkunde zu Berlin, 
vol. xxvin. 1894.) 
