What is "to bolt to the bran"

Bolt \Bolt\, v. t. [imp. & p. p. Bolted; p. pr. & vb. n. Bolting.] [OE. bolten, boulten, OF. buleter, F. bluter, fr. Ll. buletare, buratare, cf. F. bure coarse woolen stuff; fr. L. burrus red. See Borrel, and cf. Bultel.]

1. To sift or separate the coarser from the finer particles of, as bran from flour, by means of a bolter; to separate, assort, refine, or purify by other means.

   He now had bolted all the flour.
   --Spenser.

   Ill schooled in bolted language.
   --Shak.

2. To separate, as if by sifting or bolting; -- with out.

   Time and nature will bolt out the truth of things.
   --L'Estrange.

3. (Law) To discuss or argue privately, and for practice, as cases at law.
   --Jacob.

   To bolt to the bran, to examine thoroughly, so as to separate or discover everything important.
   --Chaucer.

   This bolts the matter fairly to the bran.
   --Harte.

   The report of the committee was examined and sifted and bolted to the bran.
   --Burke.