. the different Cryftalline Forins. 369 
fuch anvangle or edge tmdergoes, and of which the refult is 
this orthat fecondary form. | I have endeavoured'to fubje@ 
the arrangement of the letters to a regular progrefs in’ rela+ 
tion with the order of the alphabet; fo that this arrange- 
ment might appear as if occurring naturally of itfelf. 
a. Let us fuppofe that fig. 1. reprefents an oblique angled 
parallélopipedon, the faces of which have angles different in 
meéafure, andwhich are the primitive form of a particular 
kind of mineral fuch as feld {par *. Having adopted the 
vowels to denote, im general, the folid angles, place the four 
firft AE LQ-at the four angles of the upper balis, following 
the order of ;the:alphabet, and atthe fame time.the com 
mon mode, ofwritting, whichiis to begin at the tep and to 
proceed from night to left. (See jg. 2: where the arrange? 
ment of the letters in lines is rendered, fenfible toithe: eye.)! 
_2ydiaving adopted. the confonants to denotd the edees, in 
general place, according tothe fame ralé, the fir fix 
BCDEGH on the middle of the fides of theupper bafe; 
(figi,t-) andvou the two longitudinal edges of the ‘lateral 
face; which firlt prefents itfelf from) left to right. 
- 3s Laftly,,place.on the middie of the upper bafe and the 
tivo, laigral faces, fituated ia front,, the, three letters P.M T; 
ashich are the firft,of the. fyllabics that.form, the cna pri- 
a SAMI isco ni sha; 
44» Each of, the four folid rep or af “ti fix. Ace de> 
noted by letters, ,is fufceptible, in the sg TB ac- 
count of the. irregular form of the. parallelopipedon,, of 
undergoing peculiar laws of decrement;, but,as thefe laws 
act sith the greateft poflible fymmetry, at leaft in common, 
every thing that takes place on one, of the, angles or edges; 
pointed out, is repeated on the angle or edge diametrically 
oppefite among thofe, which remained unoccupied ;, fo that 
we latter is fuppoted to perform »the, fame,,function jas the 
sy The parallilopipe -don i is fuppofed to ‘be! reprefented in fuc h a By ner 
fet the angle BAC, fartheft from the ee 1s one of the "angles of 
the tates a 4 
fornler? 
