66 
the same characters as in the case of the essexite, but the 
latter mineral is relatively more abundant than in that 
rock. 
An analysis of this pulaskite is given in the accom-. 
panying table together with analyses of the pulaskite and 
the nordmarkite of Shefford mountain described by 
Dresser. Analyses of three allied rocks from other local- 
ities are added for purposes of comparison. 
— I II III IV. Wi VI 
SIO; See 57°44 59°96} 65:43 56-45 59°01 60:03 
THOns see oe 1-97 0-66 0-16 0-29 ©: 81/223 
AV Ose esa: 19°43 19-12 16-96 20:08 18-18 20-76 
MesOs:2. 2 ac 1-69 1°85 1°55 I-31 -63 4:01 
MeO eas en 2-70 1-73 1-53 4°39 3°65} © 0°75 
Nn@:, An 0:25 0-49 0-40 0:09 0:03 trace 
MgO. I-16 0:65 0-22 0:63 1-05 0-80 
CAO. ees 2-66 2°24 1-36 2-14 2-40 2-62 
Ba). aeeece not det -12 MOMEs |. sae oe 08). oSkeeehee 
Na2O tire 6-48 6-98 5:95 5:61 7°03 5:96 
Iks@). eee 4:28 4:91 5°36 FouUg 5°34 5:48 
BeOsscaecea- 0-60 0-14) 0-02 0-13 trace 0:07 
SOs wae not det. 0:08, 0°06)... od. se oe ee 
Clee tas trace. O-14 0-04 0-43 O12). eee 
| alk © rials, oe I-03] I-10 0-82 1-51 0-50 0-59 
99:69) 100-17 99:86} 100-19 99:98} IOI-07— 
I.—Pulaskite (laurvikose), Mount Johnson, Quebec. 
I].—Pulaskite (laurvikose), Shefford mountain, Quebec. 
I1J].—Nordmarkite (nordmarkose), Shefford mountain, Quebec 
IV.—Sodalite syenite, Square Butte, Montana (differentiation 
product of shonkinite.) 
V.—Umptekite, Red Hill, Moltonboro, New Hampshire. ~ 
VI.—Pulaskite, Fourche mountain, Arkansas (original locality). 
The mineralogical composition (mode) of the Mount 
Johnson pulaskite (No. I), calculated from the analyses 
given above, is as follows :— 
