348 JH. EVOGH 
examples’ of orbicular structure, the orbs chiefly consisting of 
quartz, and in addition some sillimanite and tourmaline (!). The 
intervening mass between the orbs here contains less SiO, (and 
less quartz) than the orbs, therefore reckoned from the acid pole 
there here appears a displacement of the residual magma in the 
direction of the eutectic, quartz:feldspar. In these cases we 
have, however, the complication that the orbs contain much 
tourmaline and sillimanite, the latter being very little soluble in 
acid magma. 
Finally we compile a series of analyses of glass bases (Gl.), 
respectively groundmasses (Grm.), and spherulites (Sph.) from 
porphyritic rocks, and intervening masses from granites with 
basic concretions, etc. These analyses represent approximately the 
composition of the residual magmas resulting from far-advanced 
TABLE VIII 
ANALYSES OF THE FINAL PRODUCT OF THE CRYSTALLIZATION OF ACID ROCKS—THE 
GRANITIC EUTECTIC 
SiO; 
No. Without SiO. Al.0; Fe.0; FeO MgO CaO Na20 K.0 H.0 Total 
FO 
GISiSpheeeeee 30 oft W72eOl\o 5 ooo 15.04|....] tr. jo. 25/1. 75/8. 8510.94] 99.52 
TMM Se eevee Bir HbeY W7i2bo@) lao dgocllacanc easieles sls oe «lOOOl7n5(7]| eres | ene 
32 AQ oas Ou oc oc 16.28]... ./0. 20l0. 59/2.12/6.40|/1.35| 99-47 
: 23 Tok 73037 2Bo8Ollc ooo 1.54|0. 26/0. 99/3 .00]/5. 74/1 .08/100. 07 
Glass basis... .| 434 73-3 |72-35|13-97| I-20 0.46\0. 72/3. 58/5.38!1.37| 99.12 
35 | 73-7 |73-05|14.67| 0.89 0. 26/0.97/3-99/5.11]0.91| 99.85 
9c | 75.3 |74-59|12.88] 0.80 0. 30/0. 76/3. 30/5. 35|1.03| 99-01 
Intervening 2562| 74.0 |73.69|12.46] I.21|1.75]0.17/0.3614.47/4.92/0. 38/100. 09 
mass of 23€ | 74.9 |74.40|13.91| 1.39]... .|0.28)0.61/4.65/4.36|0. 65/100. 25 
granites....| |26¢ | 74.1 |73.70|14.40| 0.43|1.40] tr. |r.08]4. 21/4. 43/0. 61|100. 39 
36 74.0 |73.21|12.90| 2.10]....]0.27/0.88/4.8314.75|1.04] 99.98 
Spherulites...| 437¢r | 75-1 |74.52|12.97| 2.02]... .]0.2510.92I4. 26/4. 53/0. 83/100. 30 
38 74.7 |173.72|12.91| 1.37]....]0.25|1.37/4.0214.45/1.30] 99-45 
Ge rere 30 73.5 |72.70|13-79| I.01],...|0.65|2.07/4.93|4. 33/1. 10|/100. 48 
Sph {3762 | 74.0 |73.42|14.20] 1.01]... .]o.43/1.00/5.61/3.19]0.84] 99.79 
Pataseest er \40 74.8 |74.36/14.46] 1.62]....]0.44/1.49/6.11|1.490/0.57|100.54 
t From Krageré and Modum in Norway and from Pine Lake in Ontario (lecture. 
by W. C. Brégger on the Krageré locality, in Kristiania Vidensk. Seisk, 1901, and 
Frank D. Adams, Bull. Geol. Soc. Amer. No. 9, 1898, see résumé in my treatise in 
Tscherm. Mitt., Vol. XXV [1906]). 
