[ 7°S ] 
explained. By a confonant fyftem was underftood 
a fyftem, whofe extreme or comprehending founds 
were confonant : of thefe, there were fix within the 
compafs of the immutable fyftem, viz. the diatefla- 
ron, diapente, diapafon, diapafon and diatefiaron, 
diapafon and diapente, and difdiapafon. Thefe con- 
fonant fyftems were considered as admitting each of 
a variety in the order of the intervals, of which it was 
compofed. A fyftem of a determined magnitude, 
compofed of the fame intervals, and of the fame 
number of them, might, if the component intervals 
were not equal, differ in refpedt to their order or 
fucceffion- Thefe variations of each fyftem they called 
eiS'os, its fpecies, or its figure, for thefe terms 
were fynonymous (6). The fpecies of diatefiaron 
were three ; thofe of the diapente four, and thofe 
of the diapafon feven, being the fum of the fpecies 
of the other two confonances, of which the diapafon 
itfelf was compofed: and here the dodtrine of the 
fpecies flopped; for, in the three larger confonant 
fyftems, they feem not to have conffdered the fpecies 
of the whole magnitude, but only thofe of the three 
fmaller fyftems, of which they were compofed, and 
which are called, by Ptolemey, the firft confonances 
(7). As the fpecies of diatefiaron and diapente do 
not immediately concern this dodtrine, the explaining 
them will be unneceflary ; and I fhall therefore pro- 
ceed to thofe of the diapafon. 
(6) Msra J'z tai net AiKTtov, T if sr/, kai tt'oia Tt< } >' kat" dt/of 
S'lafoyy. j J'’ vimv iS'iv, eiS'oi A lyeiV ij ^ 1/j.tv tp'igiyzv yog 
dypoTZ^y. 7 A ovoy. 0,7 A 70,1 iTA Wl TO AUTO. Ariftox. p. 74. V. 9. 
(7) n^S )S'lOSJ.7iOV 7 AS KATA 70 KAKvy.tl’OV ZlS'OS <T»V TZfWTUV 0 vy.^CO- 
yjcov diAptys. Ptol. lib. ii. c. 3. 
Concerning; 
3 
