46 Professor Hamitton’s Third Supplement 
sa £20 8) 807, gy, 82) Y? 
ood 5 (arte 82) P(e 8S) 
2 § 6Q f cQy, 8a i 
= $2(y-¥y ~ 739) (553018 oe 
exe) x 6a ie) , , 62 
so oS Gage ees, 5) (br -82— 8 =e 
dae o¢ 9 ' 
™ (-2( yay vse (=22( a2 —ar— 77 52) 
8a sumer 2 8a sa 
vote | ~ epi, 45 = i aaa: 
~(se—20 79 2)) (SC ar—av' — V8) 
sa , 6a sa , 6Q 
9 ea Boe ots =, (82-82 — Ve ; 
+ 2 : D’) 
ads ) 80 Sy JOR se 8a iS ante oa, 
: —5 (ar—a - V3) -5,(y-W-735) 
in which the symbol 8’ has the same meaning as before, so that as 2’ y' 2’ do not enter 
into the composition of the function Q, & refers here to the variation of colour only. 
This equation (D°) may be put under the following simpler form, 
+2 
= (8 + 782 + 28V8Q) 
="! (ara Vy 
+5 y-y Vee) 
(wv 9 BY 
+255 (e- Awe 2) (y- a a any 
2 Y- a — 792) (82-8 V3 2) 
a" (a8 $9) (ar—ar 792), (E*) 
if we attend to the equations already established, in the second number, 
a_ sO B_& y_8Q 1a _ 8a 
ooo? 0 fers 0 Oeeee OBE Tey” 
