60 Howard and Davison — Estacado Aerolite. 



Of the S found 0*82 per cent came from the metallic and 

 the portion soluble in HC1, and 0*55 per cent from the insolu- 

 ble portion fused with Na 2 C0 3 . In this fusion the crucible 

 was screened by a close fitting asbestos board, and a blank 

 experiment showed that there was no contamination from the 

 gas flame. This distribution of the S would indicate that 

 nearly half of the troilite was embedded in the enstatite pro- 

 tected from action of acids. 



From 3*9597 grams of the aerolite 0*025 gm. of chromite 

 was separated by repeated treatment with HF1 and other acids. 

 With the chromite were a few minute particles of a transparent 

 colorless mineral that had survived this usage, though evidently 

 attacked. 



Search was made for Zr0 2 , with negative result. 



