﻿380 Penfield and Harper — Composition of Ralstonite. 



work of centuries. It may be that the composition of the 

 alloy, german silver, had something to do with the comparative 

 rapidity of production, aided perhaps by the salt water of the 

 sea. 



Crystallized Lead carbonate (Cerussite). 



On the sand near the same locality at which the crystallized 

 cuprous oxide was found, Morris Island, S. C, among the metal- 

 lic remains of ammunition boxes, wagons, pieces of shell, the 

 debris of a battle-field, a dozen Minie balls were picked up. 



The greater number of the balls had, upon various parts of 

 the surface patches, of lead carbonate, sometimes amorphous, 

 sometimes acicular, crystalline and transparent, in some places 

 l mm thick. It was seen, however, that more was present in the 

 cup and about the base of the ball than elsewhere. The balls 

 had not been fired, and were probably dropped attached to the 

 cartridge, and it is possible that the formation of the carbonate 

 was hastened by the rapid oxidation of the lead by the nitre of 

 the gunpowder of the cartridge in the presence of moisture. 



The Citadel, S. C. M. A., Charleston, S. 0., Aug. 11, 1886. 



Art. XLVI. — On the chemical composition of Ralstonite ; by 

 S. L. Penfield and D. N. Harper. 



A number of years ago Professor Geo. J. Brush generously 

 gave one of us a specimen containing a large amount of the rare 

 mineral ralstonite associated with thomsenolite from Arksut 

 Fiord, Greenland. Considerable time was spent in picking out 

 the octahedral crystals free from thomsenolite and only a 

 partial analysis was made which was never published ; difficulty 

 was found in determining the fluorine, and the material was 

 exhausted before a complete analysis was made. The results 

 were essentially the same as those of Nordenskiold.* Since 

 then J. Brand If has analyzed the mineral, using material which 

 was selected by Professor P, Groth. The results of the three 

 analyses are as follows: 





Nordenskiold. 



Penfield. 



Brandl. 



Mg 



5*52 



4-29 



3-56 



Na 



5 66 



4-12 



5-50 



K 



tr. 



•11 







Ca 



199 



1-67 



1-53 



Al 



22-94 



22-33 



22-14 



H 2 



14-84 



18-41 



10*00 



F 











57*12 



49-95 99-85 



* Geol. Foren. i Stockholm. Forhandl., 1874, ii, 81. 

 f Annalen der Chemie, ccxiii, V. 



