I feel as John does (though Lubbock's editors must have thought more like Gibb!). Especially since "The Happy Land of Canaan" was a minstrel song used for a number of soldiers' parodies during the Civil War.

Thus the phrase was "in the air" in completely secular contexts.

Hugill's treatment of the line shows that what he "camouflaged" can be far from "obvious" and didn't necessarily replace words that were crude in themselves.