1884] Mineralogy. 1261 
_ was not homogeneous, being traversed by rutile and by other un- 
_ determined substances. 
MINERALOGICAL Notes—Professor Bonney’ publishes an ac- 
count of a case of the replacement of quartz by fluor spar. The 
rock in which it occurs is a mixture of red felspar, fluor spar and 
tourmaline, and has been named “ Trowlesworthite”* by Mr. 
orth. It is believed that the rock has been formed from granite 
_ through the replacement of quartz by fluor spar. This is an un-. 
= usual substitution. 
_ One mass of columbite was two feet long by twenty inches wide, 
and must have weighed a ton. In the cavities in the columbite 
he found a beautiful yellow powder in pellets and pill-like balls, 
_ consisting of nearly pure hydrous uranium oxide. 
À _ Garnet is reported by H. Louis‘ as occurring in the form of an 
_ igneous dyke in the province of Catalonia in the Pyrenees. The 
7 dyke varies in thickness from two to five and a half feet and is 
_ Vertical. It is made of pure garnet free from admixture of other 
- Minerals, 
E The discovery of herderite at Stoneham, Maine, described by 
Mr. W. E. Hidden’ about a year ago, and analyzed by J. B. 
_ Mackintosh, was of considerable interest. It had previously been 
_ lound only at Ehrenfriedersdorf, Saxony, where it was very rare. 
Na recent note ê Professor A. Wiesbach gives the results of a 
xon and Maine her- 
| Mineralog. Magazine, 1884, VI, P. 48. 
: Trans, Royal Geolog. Soc. of Cornwall, Vol. xX, p. !77- 
Amer. Jour. Sc. and Arts, November, 1884, P. 349- 
» Neues Jahrb. d. Miner., 1884, II, 134+ 
. Amer. Philos. Soc, Oct. 17, 1884- 
