S. L. Penfield — Chemical Composition of Triphjlite. 



MnO 



CaO 





The phosphoric acid was separated from the iron and man- 

 ganese by fusion with sodium carbonate, except a small amount 

 retained with the iron, which was separated afterward by 

 means of molybdic acid. 



The alkalies were separated from the iron and phosphoric 

 acid by adding a small amount of ferric chloride to a nearly 

 neutral, oxidized solution of the mineral and precipitating the 

 iron and phosphoric acid together by means of barium carbon- 

 ate. Care was taken to use platinum vessels in conducting the 

 •ns. The torn I amount of water was expelled by 

 ignition and determined by absorption in a chloride of calcium 

 tube. Water amounting to 0'50 per cent was driven off at 

 100° C. These results show the Grafton mineral to be richer 

 in manganese and lithia than that from Bodenmais. 



The relative number of atoms calculated from analysis 1 are 

 the following : 



The above gives the ratio of the phosphorus to the bases 

 = •622: -945 or 1:1-52, which shows the composition of the 

 mineral to be that of a normal phosphate. The ratio of the 

 atoms of the univalent elements to those of the bivalent is 

 •594: -648 = 1 : 1-09 which gives the formula lORjPC^+llRsPA- 

 Rammelsberg * deduces the formula 4RgP0 4 -f 5K 3 P 2 8 from 



the most trustworthy analysis of the Bodenm 



ais mineral 



. but 



suggests EgPC^-fR^-A as pos: 



sibly the true 



formula. 



The 



* Mineralchemie, : 



1875, page 307. 







