694 ST. LOUIS ACAI)E3I¥ OF SCIENCES. 



Barytcs is often found in Missouri, sTiowing pipe iron ore traversing it ; 

 "but in this chhc the iron ore is stalactitic, it being formed first and after- 

 wards surrounded by baryte. 



Minerals are often seen occupying drusy cavities — attracted to the sides 

 of the cavity — the points of crystals directed towards a central place.* These 

 have evidently crystallized from mineral solutions as can be proven in a 

 chemical laboratory. Loaf sugar can be crystalized, bjit no organic growth 

 can be detected. I collected at Oronago, Jasper county, many specimens of 

 chert, all showing that they had been blasted out within a few years past 

 by the miners, but at that time this locality was abandoned. Many had 

 small, waxy looking globules adhering to their surface, some attached to the 

 evidently recent fractxired rock. Analysis proved them to be carbonate of 

 zinc. This I think is a proof that minerals are forming; that is, being 

 crystallized noiv as well as long since. 



I have before me a stalactitic form from a cave in Galena, Kansas, show- 

 ing a central nucleus of claystone ; next to and nearly surrounding it is the 

 white aggregation of small stalactites, about f of an inch long and termin- 

 ating in hollow-rounded points — the deposit of the last drop of solution. 

 JSText to this aggregation, and apparently a continuation of and adhering to 

 the stalactitic mass and radiating beyond for a ^ inch to 1 inch, is a collec- 

 tion of numerous minute white hair-like calriite crystals. At one side the 

 stalactites we know have been formed by regular dripping in water holding 

 calcareous matter in solution, and the whole stalactitic mass presents the 

 phenomena of stalactites attached to each with crystals apparently emana- 

 ting from them. The presence ot the crystals can most probably be ex- 

 plained by the cave becoming filled with water containing much calcari- 

 ous matter, since the period when the stalactite was formed. 



Geologists are familiar with the fact that minerals often crystallize 

 around fossils, or some hard substance in turn forming a concretion. — Mines, 

 Metals, Arts and Railroad Journal. 



ST. LOUIS ACADEMY OF SCIENCES. 



The Academy of Sciences held its twenty-second annual session January 

 7, 1878, at the Polytechnic Hall, with tv\renty-three members present. In 

 the absence of Prof C. V. Rile}-, I)r. Forbes was called to -the chair. 



Judge N. Holmes, the <Jorresponding Secretary, submitted a number of 

 letters from various points. Under the call for donations, Judge Terry pre- 

 sented to the Society the original draft of Mr. Ira Stout's air ship. Mr^ 

 Stout had promised to be present at the meeting and give the members his 

 views on aerostation, but having received an urgent call from Indianapolis,, 

 had been obliged to leave the city. J udge Terry also laid before the Society 

 a fine specimen of septarium formation, found by him at the Hot Springs. 



Prof. liile}^, who had in the meantime arrived, laid before the body a 

 paper on mite transformacions, which was referred to the Publication Com- 

 mittee; also a note on ocean gulls. 



