by crumbs

English

(dated) Used as an intensifier; by God.
- 1925 July – 1926 May, A[rthur] Conan Doyle, “De Profundis”, in The Land of Mist (eBook no. 0601351h.html), Australia: Project Gutenberg Australia, published April 2019:
  He scratched his head. "Well, damn me," said he. "I never thought I would take orders from a Chink, but he says 'hist!' and by crums you've got to hist and no back talk either."
- 1895, A[rthur] Conan Doyle, The Stark Munro Letters: […], London: Longmans, Green, and Co., →OCLC:
  By Crums, they might get the salts and oxalic acid mixed up if they came to treat me, for there’s no love lost between us.