Reéramination of American Minerals. 369 
then the existence of a new earth in this mineral cannot be 
established, it is clear that it must be a saponite, with which min- 
eral it is identical in physical properties. 
30. Hudsonite, a Pyrorene. 
This species was described by Prof. L. C. Beck.* It has since 
been shown to be a pyroxene in which a portion of the silica is 
replaced by alumina. Beck and Brewer obtained for its composi- 
Ss Al Fe Mn Mg 
36-94 11:22 36°08 2°24 — 12°71 = 99°14. Brewer.+ 
37-90 1270 36:80 192 114010072. Beck, 
A recent examination of some specimens has shown the pres- 
ence of a considerable amount of alkalies. 'The mineral was re- 
ceived from Mr. Silas R. Horton, and is the same as was sent by 
him to Prof. Beck. The results ‘of two analyses are, 
ge 2. 
Silica, . P ‘i i 39°30 38°58 
Alumina, . : ; 9°78 11°05 
Protoxyd of iron, . i 30°40 80°57 
“ Manganese, . ‘ 0°67 0°52 
ime, 10°39 10°32 
Magnesia, 2°98 3:02 
Potash, 2:48 ai 
Soda, fe a ‘ 1°66 t ae 
Ignition, : ‘ : 1°95 1:95 
00° (00°17 
Considering the deans as replacing silica, these site the oxy- 
ts ratio of pyroxene and the formula RB? (Si, Al). 
31. Jenkinsite. 
e green mineral that occurs in velvety coatings on the mag- 
netite of O’Neil’s mine, in Orange County, N. Y., has been des- 
cribed by Prof. Shepard,t as a new species. Its intimate associa- 
tion with magnetite, renders it somewhat difficult to obtain it 
perfectly pure; but by placing the fine particles of Jenkinsite in a 
vessel of water, and stirring the mass withaclean rod of soft iron, 
that passes through an electro-magnetic. coil in connection with a 
attery, every particle of magnetic iron is removed. ‘Two differ- 
ent portions thus purified, procured at different times from Mr. 
Silas R. Horton and Mr. John Jenkins, gave 
F 2. 
Silic : 38°97 37-42 
Protoxyd of i iron, ‘ 19°30 20°60 
anganese, 4°36 J 405 4 
Maguest 22°87 22°75 
Alumi 0538 0-98 
Water, 13°36 : j 13-48 
99°39 99°28 
oe of N. York, p. 310. + From Dana’s Mineralogy, 3d ed., p. 267. 
t This Journal, [2] xiii, 392. 
Srconp Senizs, Vol. ol. XVI, No, 48.—Nov., 1853. 47 
