308 Clarke and Schneider — Experiments upon the 



A. Dull-green serpentine from Montville, New Jersey, de- 

 rived from pyroxene by alteration. 



B. Dark-green serpentine from the well-known locality at 

 Newburyport, Massachusetts. 



C. Silky, fibrous chrysotile from Montville. 



D. Grayish-green picrolite from Buck Creek, North Caro- 

 lina. 



E. A grayish green mineral from Corundum Hill, North 

 Carolina, which was supposed at first to be deweylite. It is 

 an ordinary, massive serpentine. 



Analyses as follows, with the itemized water determinations 

 subjoined. 



ABODE 



SiO„ 42-05 41-47 42-42 42-94 41-90 



H„0" 14-66 15-06 15-64 13-21 16-16 



MgO 42-57 41-70 41-01 36"53 40-16 



FeO -10 -09 undet. 1-88 undet. 



CaO "05 none trace 



NiO -23 -61 -10 



Fe„0 3 -30 } ,_' -62 3-33 -91 



AL'O. -.. X L ' 6 -63 1-72 -71 



99-73 



100-05 100-£ 



»5 100 



•22 



99-94 



H 2 at 105° 



•96 1-20 



2-04 



1-53 



2-26 



H o at 250° 



"55 "55 



•71 



•44 



1-01 



H 2 at 383°-412° .. 



•27 ( 



•27 



•62 



•98 



H 2 at 498°-527° .. 



•23 ..._ 



•56 







•42 



H„0 at red heat 



12-37 ( 13-01 



11-81 



10-58 



11-32 



H„0 at white heat.. 



•28 -30 



•25 



•04 



•17 



From these data it is clear that practically all the water in 

 serpentine is constitutional, and that none of it can be fairly re- 

 garded as crystalline. The small, variable amount lost below 

 250° is mainly hygroscopic and enclosed water, since the anal- 

 yses refer to air-dried material. It is hardly necessary to state 

 that in each fractional determination the material was heated 

 to constant weight. 



Upon heating in dry, gaseous, hydrochloric acid all of these 

 serpentines were strongly attacked ; differing essentially in this 

 particular from olivine and talc. The bases thus taken out as 

 chlorides at 383°-412° were as follows : 



No. of hours heated _. 



A 

 .. 54 



B 



68 



C 

 54 



9-98 



D 



78 



E 

 41 



MgO extracted 



R.O. extracted 



10-14 



16-73 

 •43 



11-38 

 •66 



15-25 

 •51 



