Since the letter's readily available there, all I'll say about it here is that it's occasioned by the publication of MISTRESS MASHAM'S REPOSE, which delighted Lewis as much as White's earlier THE SWORD IN THE STONE (wh. I much prefer) had annoyed him. So much so that he wrote White a letter in mock-Swiftian prose -- not as good as the Johnsonian prose of his famous letter to Harwood, or the wonderful Malorian letter to Barfield (cf. MARK VS. TRISTRAM), or the pseudo-medieval letter(s) to E. R. E., but impressive nonetheless.
What really caught my attention, though, was the closing paragraph, wherein Lewis invited White to attend an Inklings meeting if ever he were passing through Oxford:
. . . If your occasions should lead you to these Academick Groves I shall beg leave to make you acquainted with half a dozen madcap fellowes* that have a freer and more masculine taste.** Till then, Sir, may you accept my Gratefull thanks for the Entertainment you have given me and believe me
your oblig'd obedient servant . . .
*this was my reading of the Ms. letter; Hooper in COLLECTED LETTERS prints instead 'Magdalen Fellows'. If I had the original in front of me I might be able to determine which is right; as it is, I give my reading as (a) being what I thought I saw and (b) making more sense, with the caveat that Hooper's certainly better at reading Lewis's handwriting than I am.
**i.e., than the woman mentioned two sentences before in the letter whose review of M.M.R. CSL thought insufficiently glowing.
The idea that T. H. White was invited to attend an Inklings meeting, much as CSL had invited Ch. Wms. eleven years before, tickles my fancy with what-ifs. So far as I know, White never took them up on this, and I'm sure that if he had one of the Inklings wd have mentioned it somewhere. In terms of his personal life, White would have been an uneasy fit for 'the Tolkien-Lewis seance', having been a minor second-generation associate of what people liked to call 'Bloomsbury' (though the same cd be said of Ld David Cecil, who seems to have fitted in well enough). But in terms of his love of the medieval -- translating the Bestiary, writing the most popular twentieth century Arthurian retelling -- he and Tolkien (who wrote four Bestiary poems and an unfinished retelling of the Arthurian myth himself) wd have had plenty to talk about.
Alas for the might-have-beens!