1 40 PROCEEDINGS OF THE ACADEMY OF [1888. 



This furnislies the ratio 



P^O^ : (Fe, A1)'0' : H^O = 1 



= 2 

 = 2 



1-625 : 3-78 



3-23 : 7-56 



3 : 8 



hence the formula FeT*0^« + 8 H'O. This is the formula estab- 

 lished by A. Streug (Zeitschr. f Kryst. and Min. Vol. 7, p. 398). 

 Groth deduced from it the theoretical formula Fe' (HO)' (PO*)'. 

 2\ WO. (Tabell. Uebers. d. Mineral. Braunschweig 1882.) In 

 view of the fact tliat the whole of the water escapes at 250°C. with- 

 out change of color or structure, Groth's foi-mula, assuming three 

 molecules of hydroxyl, can not well be sustained. The water must 

 be considered wholly as water of crystallization. 



Eleonorite has heretofore been known but from one locality, the 

 " Eleonore " iron mine near Giessen, in Germany. Some specimens 

 are in Mr. C. S. Bement's collection, with which the author compared 

 the mineral from this new locality. It Avas first announced by A. 

 Nies in 1880 (Ber. d. Oberhess. Ges. fuer Natur. u. Heilk. No. 19.) 

 and subsequently studied by A. Streng, who determined the sym- 

 metry as monosymmetric and established the formula given above. 



April 24. 



Mr. John H. Redfield, in the chair. 



Twenty-nine persons present. 



Samuel H. Friend, M. D. was elected a member. 



The following were ordered to be printed : — 



