1900. No.5. ON PARTIAL DIFFERENTIAL EQUATIONS, ETC. 17 
3 -G)81- +16) 0 ee 
ee Clan 
Er - BEE skje mn 
ov %u ov au du ov av ou 
2 = 
SF EF Sp = of) os | ls EE TE | (ad — By) + 
er oa: 
It is seen, that as regards the mode in which the quantities @, B, y, 0 
are involved in this equation, this is of the same form as in the given equa- 
tion (I). That it may be equivalent, its coefficients must stand to those 
of (I) in a common ratio u. This gives 
(5) > a) 7 =ud (a) 
Er.) 2 
AA sla =e 
ea @ 
Ou Ov ou ov 
as ar) or os I 
9A Å 
As we have here eight equations which are homogeneous with respect 
to the five differential coefficients of v, and to w, it is clear that we can, 
Vid.-Selsk. Skrifter. M.-N. KL 1900. No. 5. 2 
