540 PROCEEDINGS OF THE ACADEMY OF [Oct., 



Scolecite. — The specimen analyzed consisted of a mass of radiating 

 needles in which were mixed small, but distinct, crystals of calcite, 

 particularly at the base of the tufts of needles. The crystals showed 

 a silky lustre. They gave out much water when heated in a closed 

 tube and curled up like a worm. Thej^ were readily gelatinized 

 by means of hydrochloric acid. The specific gravity was found to 

 be 2.27. The analysis showed: 



Si0 2 47.04 per cent. 



AL0 3 25.42 



CaO 9.S6 



Na,0 4.77 



Ign 13.60 



So far as the writer is aware, this represents the first notice of the 

 occurrence of this particular mineral in the State of Pennsylvania. 

 All the others have been obtained at various points in Berks County, 

 which has proved to be a most fruitful field for many mineral varieties. 



