When I read period authors, i.e., Dickens, or Verne, or Hugo, etc., I always see things like:
My dear child/Child, come here/He is but a child!
But I don't see kid. In fact, I didn't see kid even in the contemporary work A Series of Unfortunate Events when I was reading it (unless I missed it). Children was still used there. So, my question is:
When did "kid" become used to mean "child"?
Is it less formal to use "kid" than "child"?