That quote doesn't explain why the abbreviation was used about a hundred years before stabndard oil introduced the blue barrel, as claimed by the wikipedia quote in the comment you ansered to. In fact, your quote just reiterates the claim that wikipedia said was probably false, so to make your argument you should instead show that the citations from the late 1700s are wrong.

EDIT: This will be difficult, as it is quite easy to find citations for "bbl oil" from before 1850 using google books, the first I found was on p. 239 of a book called "Railway engines and cars" from 1832. So the blue barrel legend can be firmly laid to rest in peas.