S. L. Penfield— Chemical Composition of Triphylite. 425 



In this connection the following analyses may not prove un- 

 interesting, showing as they do that, in some cases at least, the 

 chromium does ''appear in the finished steel." 



Sulphur, 0-005 per cent, trace trace 



Phosphorus, ....'... 0-021 " 0-020 per cent. 0-005 per cent 



Silicon,... 0-129 " 0-189 " 0-279 " 



Total carbon*, 0*825 " 0-935 " 1-199 " 



Comb, carbon, .0*811 " 0*920 " 1-186 " 



Graphitic carbon, _. 0*014 " 0-015 " 0-013 " 



Manganese, 0-245 " 0-062 " 0-039 



Copper, 0-007 " 0*010 " 0*005 " 



Nickel, trace 0-023 " 0*021 u 



Cobalt,.!. ...0*016 " trace 0*018 •' 



Aluminium, 0*034 " 0*029 u 0*026 " 



* Chromium,. .0*651 " 0*223 " 0-916 " 



Chromium, soluble,. 0-615 " 0-212 " 0-899 " 

 Chromium in residue, 0-021 " trace trace 



Slag,... ... o-320 " 



The determinations of Cr marked * were made by the first 

 method without the separation of Al, and consequently are a 

 little higher than the sum of the " chromium soluble in dilute 

 HC1," and " chromium in residue," which were determined in 

 the portion and by the method taken for estimation of Al. 



The " slag" in the first analysis given above, was determined 

 by the "iodine" method and contained bv analysis Fe 2 O s 

 0*110 per cent, Cr 2 3 0*160 percent, undetermined 0*50 per cent, 

 total 0*320 per cent. 



Laboratory of U. S. Board appointed to test Iron, Steel etc. ) 

 Watertown Arsenal, Mass, April 14, 1 877. f 



Art. XLVI. — On //■■ i ■ THj^yKte, irom 



Grafton, New Hampshire; by Samuel L. Penfield. Con- 



Lvbomtoro <>l Y<i'l-. iolhye. No. 



XLYII. 



The rare mineral species, triphylite, is found at Grafton in a 

 granite vein which has been extensively worked for mica It 

 occurs imbedded in the granite in masses of varying size, and 

 occasionally of fifty or more pounds in weight The exterior 

 of the masses in some instances shows evidences of the decom- 

 position to which the mineral is peculiarly liable, but a large 

 portion of the material is fresh and unaltered. It has a light 

 blue color, a greasy to resinous luster and a perfect cleavage. 

 Specific gravity =3%52. Analvses of the finely i : 

 pure mineral, dried over sulphuric acid, show the following 

 composition : 



