In his editing for the 1837 edition, Joseph Smith not only removed the definite article the from this example of “in the which”, but he also changed the preposition from in to by. He may have been influenced by the earlier instance of “by the which means” in Ether 9:11 (the only instance of “by the which” in the original text). Joseph made the same change of “in the which” to “by which” three more times in the book of Ether:
(For one more case where Joseph appears to have intended to edit “in the which” to “by which”, see under Ether 11:15.)
There is also an instance of “in the which” near the end of this chapter where Joseph Smith changed the preposition to with:
In another case, he not only changed the preposition, to during, but he also added a noun, time:
(Interestingly, the word during never occurs in the original text of the Book of Mormon; Ether 10:32 is the only place where it has been introduced into the text.) The critical text will restore all these original instances of “in the which”. For an overview of Joseph Smith’s editing of “in the which”, see under 1 Nephi 3:2. For a complete listing, see under in the which in volume 3.
Summary: Restore each instance of original “in the which” that Joseph Smith edited for the 1837 edition, including those cases where he ended up changing the preposition (namely, to by in Ether 10:10, Ether 10:14, Ether 10:15, and Ether 11:10; to with in Ether 10:26; and to during in Ether 10:32); in the last case, he also added the noun time.