For the purposes of § 43-34-2, that part is to be deemed the principal to which the other has been united only for the use, ornament, or completion of the former, unless the latter is the more valuable and has been united without the knowledge of its owner, who may in the latter case require it to be separated and returned to him although some injury should result to the thing to which it has been united.
SDCL 43-34-3