Now is the time for Christmas presents, and the search for them can be arduous and unnerving, to say the least. In fact, I gave up on the Christmas Chase quite a few years ago. Fortunately Google has found its own solution and presents us lovers of language with a wonderful toy, the Ngram Viewer. Being on holiday, I'm in no mood to explain it and refer you guys to good old Wiki : http://en.wikipedia.org/wiki/Google_Ngram_Viewer
I've tried a number of words and expressions (separated by commas) and it's doing a good job, as far as I can tell. Here is the graph that tells us all about the word that in a way stands for the whole of Jack's oeuvre. Amazing : Since Ngram Viewer only includes words or expressions that were found in at least forty books in a given year, it means that the N-word was being used far more frequently than we thought. If I remember well, the word was originally used in English county law for describing a last will that was not confirmed by any written document. That use apparently sharply declined in the beginning of the 20th century and stopped around 1940. However, we see that its frequency increases again, although modestly, in the late forties and early fifties. Could that be Jack's influence?
Oops. For some reason the Ngram Viewer graph cannot be copied. You'll have to look for yourselves then. Arduous and unnerving, just as I said.