Final answer:
In Bertrand Russell's paper on existential import, the null-class refers to a class that has no members. Russell contends that the null-class does not exist as an actual entity. This concept is different from the empty set in mathematics.
Step-by-step explanation:
Bertrand Russell's statement about the null-class in his paper on existential import refers to the concept of a class that has no members. Russell argues that this class, which he calls the null-class, does not exist. This means that there is no actual entity that corresponds to the null-class. It is important to note that this concept is distinct from the empty set in mathematics, which does exist. The null-class is a philosophical concept used to illustrate the idea that there can be entities that have no members or instances.