Key points are not available for this paper at this time.
Hadamard defines the “elementary solution” of the general linear partial differential equation of the second order, namely ( A ik , B i C being functions of the n variables x 1 , x 2 , .., x n , which may be regarded as coordinates in a space of n dimensions), to be one of those solutions which are infinite to as low an order as possible at a given point and on every bicharacteristic through that point.
H. S. Ruse (Thu,) studied this question.