Jacobs spends some time reflecting on the eucharistic rites of the Prayer Book, and it was here that I found one intriguing tidbit. On reaction to Cranmer's Prayer Book, and especially that it was in English rather than Latin, Jacobs writes:
The Cornish rebels [who spoke Cornish rather than English] said that the new rite was "but a Christmas game," and frankly thought that a Mass celebrated in English simply wouldn't work--would not achieve any reconciliation between a wrathful God and sinful men. Many native English speakers felt the same: they perceived the rite as something like a magical incantation, depending for its efficacy on the precise recitation of strange words. (Throughout much of the Middle Ages, when people were allowed to receive Communion only once a year, the[y] focused their attention in the Mass on the moment when the consecrated Host was elevated, accompanied by the words Hoc est corpus meum--"This is my body"--a phrase easily and naturally corrupted to Hocus Pocus.) (p. 11).
Ah, so that's where hocus pocus came from. Well, maybe. In such matters, one should always consult Wikipedia, and here it does not dissapoint. In the article "Hocus Pocus (magic)," the derivation of the words is explored. There is some suggestive additional evidence in favor of the etymological connection to the celebration of the Eucharist, but other suggestions are also discussed, with no apparent consensus opinion emerging. But, in fact, the Wikipedia article cites the OED as favoring an interpretation other than the one connected to the Lord's Supper.