928 General Notes. [November, 



Minerals from Pike's Peak. — Pike's Peak has already become 

 famous for the number and beauty of the mineral species in its 

 vicinity. Besides the extraordinary specimens of amazon-stone 

 (microcline) from that locality, there have been found smoky 

 quartz, albite, fiuorite, biotite, siderophyllite, columbite, gothite, 

 arfvedsonite, astrophyllite, zircon, limonite pseudomorphs, etc. 

 Most of these occur in cavities in granite. Recently Messrs. W. 

 Cross and W. F. Hillebrand have added several species, new to 

 this locality. Several crystals of colorless or pale greenish topaz 

 were found, one specimen being a fragment, which must have be- 

 longed to a crystal a foot in diameter. Two imperfect crystals of 

 phenacite were found, this being the first locality known in the 

 United States. Cryolite, thomsenolite and several undetermined 

 species were also found. 



Mineralogical Notes. — The volcanic ash ejected from Vesuvius 

 during the eruption of February 25, 1882, has been analyzed by 

 Ricciardi. The ash was black and magnetic. Whenheated.it 

 gave off hydrochloric acid. It contained particles of magnetite 

 and awgite, and numerous crystals of leucite. As shown by 

 analysis, it also contained a small percentage of apatite. Sulphate 

 and chloride of ammonium were also present, and could be dis- 

 solved out by water. 



Mountain cork has been recently used in Germany as a substi- 

 tute for animal charcoal for the removal of color from molasses. 

 The mountain cork, a variety of amphibole, is dried, ignited and 

 soaked in molasses, then again dried and ignited. This process is 

 repeated several times until some 3.5 per cent, of carbon has be- 

 come fixed in the mineral, which is then ready for use. It is 

 more efficient than charcoal in removing the alkalies from 

 molasses. 



GEOGRAPHY AND TRAVELS. 1 



De Brazza's Explorations on the Ogowe and the Congo. 

 At a recent meeting of the Geographical Society of Paris, M. 

 Savorgnan de Brazza described his recent journeys in the terri- 

 tory between the Ogowe and Congo Rivers, of which, previously, 

 few details had been known. He was directed by the French 

 Government to trace the Alima River, discovered by him on his 

 first expedition (1875-8), to its junction with the Congo and to 

 establish stations on the Ogowe and the Congo. 



M. de Brazza left France in December, 1879, ascended the 

 Ogowe, and succeeded in negotiating with tin; tribes on its banks 

 and establishing a regular system of transport on the river, r c 

 founded his first station, Franceville, at the confluence of the 

 Passa with the Ogowe. From here in June, 1880, he dispatched 

 770 natives in 44 canoes to meet his coadjutor, Dr. Ballay, at tie 

 coast, and then started alone, with a small party of natives, for the 

 Congo. 

 1 Edited by Ei.lis II. Yarnall, Philadelphia. 



