TITLES AND ABSTRACTS OF PAPERS 91, 



Prof. F. R. Van Horn : We are indebted to Doctor Kraus for a new view- 

 point on the composition of complex sulphosalts. Doctor Kraus quoted analysis 

 of pearceite and polybasite, discussed by Penfield, and later by Van Horn. 

 I do not think that I am willing to admit that such a series exists here as 

 might be drawn from the two formulae proposed, but that the older formulae 

 suggested by Heinrich Rose for polybasite and by Penfield for pearceite are 

 not correct; ^ 



Doctor Kkaus answered Dr. Pogue's questions and was also inclined to' 

 believe that two formulae did not exist for polybasite and peaceite instead of 

 6n^, as contended by Van Horn. 



Prof. James F. Kemp participated in the discussion. 



GENE 81 S OF GLAtlCO^ITE 

 BY CHASE PALMER ^^ 



(Abstract) 



A dense cloudy substance brought to the surface along with the water of 

 a well 2,000 feet deep, newly sunk at Charleston, South Carolina, was studied. 

 The composition of this substance corresponds very closely with that of 

 glauconite. 



The qualities of the water in the well are compared with the qualities of 

 the river waters of the Piedmont Plateau and Coastal Plain. 



The coprecipitation of ferric hydrate, potassium oxide, and silicic acid, all 

 of which are essential constituents of glauconite, may take place in the ab- 

 sence of organic matter. An explanation is offered of the mode of formation 

 of glauconite in marine glauconitic shells. 



Presented by title in the absence of the author. 



CRYSTALLIZATION OF CERTAIN PYROXENE-BEARING ARTIFICIAL MELTS 



EY N. L. BOWEN '" 



(Abstract) 



The melts dealt with contain lime-magnesian pyroxenes, and certain of them 

 show the crystallization of olivine (forsterite) at relatively high temperatures 

 and its later resoi-ption or reaction with the melt at lower temperatures. 

 There is therefore an interesting analogy with some recorded natural occur- 

 rences. 



Presented in abstract without notes. 



29 Introduced by T. Wayland Vaughan. 

 80 Introduced by C. N. Fanner. 



