758 General Notes. [September, 



impregnated with crystals of native sulphur. As shown by 

 Daubree, there is no doubt but that a chemical action has taken 

 place between the organic matter and the plaster to produce these 

 crystals of sulphur. A similar reaction may explain the forma- 

 tion of sulphur in stratified rocks. 



Mineralogical Notes.— The amethysts of the Saxon Ober- 

 gebirge are found frequently to have become soft and friable. 

 They are often reduced to a fine powder, in which state they are 



known as mealy quartz. An asbestos from Silesia, made up of 



short bundles of white interwoven fibers, has been found to con- 

 tain more than three per cent, of soda. Gilbercite, a mineral 



from the Saxo-Bohemian tin veins is, according to Frenzel, not a 

 distinct species, but a transition product of the alteration of topaz 

 into potash-mica. The topaz becoming white or greenish-gray, 

 is then called gilbertite, while the latter afterwards becoming 

 laminated and paler in color, finally becomes a potash-mica. Such 



changes of mineral species are of great interest. E. F. Smith m 



and N. W. Thomas announce new localities for corundum and 

 tvavellite in Lehigh county, Penna. The former occurs in well 

 defined and often large hexagonal crystals near Shimersville. One 

 crystal was eight inches long and four and a-half inches wide. 

 The locality has been leased for technical purposes. Wavellite 

 was found in white, radiating nodules upon limonite, near Macun- 

 zie, in the same county It has the composition A1 2 3 36.66, 



P-A 34-14. H 2 28.32, Fl. trace, limonite 0.00 = 99.72. 



At a recent meeting of the Microscopical Society of Belgium, 

 M. Prinz read a paper upon the microscopic inclusions in sapphire, 

 ruby and spinel. The paper is accompanied by a plate giving 

 drawings of the remarkable liquid and solid enclosures, the crys- 

 tals and the microlites which occur in these gems. The minute, 

 hair-like crystals which produce the beautiful asterism of some 



rubies, are probably rutile. Cerite has recently been shown to 



contain a new element, to which the provisional name of Beta- 

 Didymium has been given. Ordinarv didymium is supposed to 

 be a mixture of at least three- different elements, one being true 

 didymium, another being a more basic element of lower atomic 

 weight (Di-<3f) and the third a less basic element with higher atomic 

 weight. 



GEOGRAPHY AND TRAVELS. 1 



African- Exploration.— Dr. Stecker has left Abyssinia for 

 Kaffa in company with an embassy which has recently visited 

 Abyssinia to offer the allegiance of the Sultan of Kaffa to King 

 Johannes. He, therefore, has good reason to hope for a favora- 

 ble reception in that country. 



Some of the results of the six years' exploration of Shoa and 



1 Edited by Ellis H. Yarnall, Philadelphia. 



