46 G. Hinrichs on Planetology. 
angles J: J and 1: 72, along with the inclination of O tow 
117° 15’, and that of the edge 1:1 (or 12) to 7 = 95° 18’, 
as follows: 
(= 0: i) = 117° 15’ and 62° 45’ 
a (vertical axis) : b (clinodiagonal) : ¢ = 0°5396 : 1: 2°614 
1:1 ihe" 40° ~1:-1 (unobserved planes) = 164° 22’ 
The species is related in form to Vivianite, in which 
62} +¢== 1009 : 1.2 1:3843; 
for, if we double the a of Brushite, and halve the c, we have 
the ratio of its axes— 
: 2a: b: $¢ = 10792 : 1: 1-307. 
The two species are also alike in the perfect and pearly clin 
diagonal cleavage. 
Art. VII.—ZJntroduction to the Mathematical Principles of the Nebw 
lar Theory, or Planetology ; by Gustavus Hinricus, Profe 
of Physics and Chemistry, lowa State University. 
THe nebular hypothesis—the boldest thought that ever eleva 
the human mind, by bringing us, as it wee, in sight of the mys 
terious fiat of the Almighty—was, in its great general features, 
vault; for Copernicus and Kepler made us behold the found 
anastronomer, = 
2 Arago, Astronomie Populaire, ii, 7. Paris and Lei ee 
* 
