Reéramination of American Minerals. * 209 
had not at that time sufficient of the mineral to complete the 
Investigation as desired. {n the mean time Hermann* reanalyzed 
It, found a different composition from any previous one, and con- 
curring with the one that had been made by us, as well as with 
_ those more recently made which are here given. 
Si Al Fe Ca Mg Na kK H 
1. 2847 50°24 165 = =11°50 070 187 trace 5:00 99:26 
2. 28°64 516 1225 0-68 201+ 4°76=100°00 
These correspond to the formula 
RSi+3A1?Si+3H. 
Atoms. At. weight. Per ct. Oxygen ratio. 
Silica, A 2309-24 30°58 4 
Alumina, 6 3850°8 50-99 6 
Lime, 3 10545 13:96 1 
Water, 3 337-5 A-A7 1 
The specimen of margarite examined was received from Dr. 
tantz of Bonn, and came from Sterzing in the Tyrol, the origi- 
nal locality, 
By these analyses it will be seen that margarite and emerylite 
ate identical, and the former name having priority of date (al- 
though the composition of the mineral was not made out until 
lately,) it must doubtless replace the latter, unless its geological 
4ppropriateness can sustain it. 
: 2. Euphyllite of Silliman. 
‘his mineral was first analyzed by Crooke, but the analysis 
having been made by a fusion with carbonate of baryta, 
sund to be incorrect. It was reanalyzed by Erni and Garrett.t 
found no Water, his analyses give the same formula as Erni’s, 
minus the water, : 
_ Our results differ essentially from those heretofore obtained, as 
seen by the following analyses: 
2, 3. 4, 
Silica, 4099 3964 4021 40-96 
Alumina, 43:00 4240 4150 41-40 
Peroxyd of iron, 1:30 160 150 130 
Lime, - 1-01 1:00 1:88 1-11 
gignesia, 62 70 78 70 
a, 304 394 325 325 
Potash, 5-16 5-16 4-26 4:26 
Water, 500 508 591 623 
100-32 99°52 99:29 99-21 
SCSI at ieee aie atta” 
* J. £. pr. Chem., liii, 1, + By the difference. 
+ This Journal, [2], viii, $82 ; Dana’s Mineralogy, 3d ed, p. 362. 
