212 Reéxamination of: American Minerals. 
_Of the water 1:04 per cent. were lost by 24 hours’ desiccation 
over sulphuric acid, 8:81 per cent. by heating to 212°, and the 
remainder at a red heat. wee 
In chemical composition it is near halloysite. It is an imper 
fectly formed mineral, and consequently is not homogeneous; it 
passes into euphyllite and felspar. 
6. Bowenite, identical with Serpentine. 
This mineral occurs at Smithfield, R. I., and was described by 
Bowen* as a variety of nephrite. His analysis gave: 
i Mg a Fe Al Mn sit 
44°69 34°63 425 175 0°56 trace 13°42 
eS its surface ; it first gives way, but ultimately scratches the 
ass, 
Highly translucent. Structure granular, and exceedingly toug 
We give analyses of three specimens. No. 1 was from the cabr 
net of Prof. Silliman, Jr., No. 2 from the mineralogical collectiou 
of Harvard University, received from Prof. Cook, No. 3 from the 
Lederer collection in Yale College. 
} Mg e Ca 
1 42°20 trace 42°50 156 trace 13 apne 
z. 2-56 trace 43-15 0-9 12 ht 
3. 42°10 trace 41-23 V1 1-90 12-77 9F 
_ These analyses give the oxygen ratio 4: 3: 2, and the formula 
2Mg* Sit+3Mg H*, which calculated, is : 
Si Mg H 
43°5 43°8 tA ieee he 
This is the composition, and formula of serpentine, and t 
fact of its identity with that species is also borne out by its phY* 
ical characters. tless 
_ The large amount of lime obtained by Bowen, was doubties 
due to the limestone and tremolite with which it is often very 
intimately associated; much care is required to separate 
substances entirely from the Bowenite, but the mineral so pe 
fied, contains no lime. 2 
7. Williamsite, identical with Serpentine. 
We notice that this species is considered distinct by P. rof. ag 
ard in the last edition of his mineralogy, notwithstanding ? 
been shown to be serpentine by Hermann ;{ and previously 
* This Journal, [1], vi, 346, os Mines | 3d ed, p- 265: 
+ Jf pe Chom, Bh Seton mrs 
