etymology - When did the terms prescriptivism/prescriptivist enter the English language?

Though the issue of linguistic prescription is a few centuries old, the terms:

prescriptivism

• (language) the belief that there are correct and wrong ways to use language and that books about language should give rules to follow, rather than describing how language is really used.

and prescriptivist

• believing that there are correct and wrong ways to use language and that books about language should give rules to follow, rather than describing how language is really used.

( Cambridge Dictionary)

appear to be relatively recent, from the '50s according to Google Books.

There are a number of sources that deal with this issue, but I was not able to find information about:

• when the two terms were first used and by whom they were introduced.

Answer

OED's citations of the two words are somewhat confusing. Prescriptivist is cited in 1952:

He is likely not to see any reason why absolute uniformity, the desideratum of the prescriptivist, should be any particular concern of the student of language even if it were possible of attainment.

• Thomas Pyles · Words and ways of American English · 1952.

OED says, "compare with later prescriptivism, but provides an earlier attestation for linguistic prescriptivism from 1948.

Prescriptivism is the form of authoritarianism characteristic of the English, not Scottish, grammarians of the latter half of the 18th century.

• I. Poldauf · On Hist. Probl. English Grammar · 1948.

Regardless, the word prescriptive was used slightly earlier to refer to linguistics, so either way, the relevant etymons were forming in the context of grammatical prescriptivism in the 1930's.

Of greater value, however, than this prescriptive grammar is a purely descriptive grammar.

• Jens Otto Harry Jespersen · Essentials of English Grammar · 1933.

These dates seem to correspond as early precursors to the growth in use of the terms shown on Google Ngram.