
PROFESSOR KELLAND ON GENERAL DIFFERENTIATION. 
The symbolical form is 
c- /=D+1 gauge ts ag 
=D [=D 
or +(-DadgtaV—t Sees .e"’ y=0, by (D). 
This is reducible, 
1. When c=n—2; and it becomes, by dividing, by —D+n-—3, 


/—D+n 
or ; a =A ed y= Es s7=0 
or aVaTy-e $ DF BOA) 6 
a mh fives ae 0 
If yx——) =», this equation becomes 
av gt a4 =0, or 
aope-nte ee =0 
which is integrable when n=, 0, —3, —1, &c. (Class. 2.) 
2. When c=n, the equation becomes 
[/—-_Dint+t 4, 


2 7) = 
ytanv ies e 0 
or LZ eal aaa eg, 
[-D+n+% 
pee 4/—D+4 _ ane 
or a —ly—e fae 1 ore 0 
d® y 
or CL aoe re ere 
If = == this equation becomes 
Brean 
av+e@r cae =0; the same as before. 
dy 3d? y 3 4.— 
Ex. 9. adel a —2y=0. 

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