MR. RICHMOND'S letter appears to be written under a misapprehension. My objection to such phrases as “non-singular cubic curve,” “non-singular curve of the nth order,” arises from the fact that a ...

MR. BASSET'S objection to the term “non-singular” (see NATURE, Oct. 11, p. 572), arises from a misunderstanding. The ordinary use ot the term by English-speaking mathematicians is natural and ...