A new system of Crystallographic Symbols. 261 
pose it to incline on the superior base, its symbol will be found to co- 
incide exactly with its situation. 15 expresses the decrement along 
the left basal edge, consequently it ought to be situated between the 
plane a? on the angle, and e? a plane on the edge ; where it really is. 
Fig. 3. Native Amalgam. Primitive form. Dodecahedron. 
Description. P e'|?|aa’|?|. 
Haiiy’s. PBBA‘?E! °E:. 
Dens) 1 
e = 150° a = 135° 
e2 = 160° 53/ 36” a? = 153° 26/ 6” 
a = 144° 44 Bh” 
6.3 
Description referred to the cube as nucleus, e a? 22 a P e®. 
Fig. 4. Idocrase. Prim. eet Right square Prism. 
Description. e|?|P Pa?|: la2|s I‘\e. 
2 (A 
Haiiy’s. 'G'?G:?: MPA AAA A (2A2 2A? ‘A! B? G?) B?. 
A NT oie aa 2 0tgo te! 
Pea q1580 3G! 6) a? = 133° 19! 
22 165° 51’ a? = 144° 44/ 
2) 4goma at = 1520 3/ 
A WE Or ioyteleay oP S10 527 
Reh ke La 44730. a0! 
Haiiy’s description has been made out on the supposition, that the 
plane a® instead of a, results from a decrement of a single row of par- 
ticles. ‘Thus he makes the planes a?|?|*|, intermediary, which ac- 
cording to the hypothesis adopted, are planes on the lateral angles. 
Fig. 5. Heavy Spar. Prim. form. Right rhombic Prism. PonP 
=101° 42’ 
xu Negi 
Description. eP e'|*|P aa'|?|* ae2 e?. 
1 2 
3 
Haiiy’s. 9G‘ M‘H' ‘Ht PEA A A (EB? B:)P. 
Cr tee i OF a? Set ALO ES 
= 140° 51’ adc == 15S) (oF 
6.3 
e# = 166° 53’ de2ni =) es h6, 
a = 127° 19 @2/ 4) A=) Mito) Any 
a == ene 487 
