4. Unhead them and whitewash them with fresh milk of lime, made pretty
strong. This plan is commonly followed for brewers' vats.
5. Remove the heads, and char the insides of the staves by the aid of a
fire of shavings kindled within them.
6. A simpler, safer, and more effectual method of charring them than the
last is to wash the dry casks out with strong oil of vitriol (sp. gr.
1·854). This not only purifies the surfaces of the staves, but penetrates
into all the cracks, some of which might escape the action of the fire.
7. Steam has lately been applied to the insides of casks with great
advantage. High-pressure steam is driven in at the bung-hole, at the same
time that the cask is violently agitated (a heavy chain having been
previously put into it), until all the dirt and bad smell is removed.
8. A lye of pearlash or soda, mixed with milk of lime, as well as strong
hot brine, and other similar liquors, have been adopted by some persons,
and are highly spoken of.
9. The coopers boil the staves for gin casks in a strong lye of alum
before placing them together, to prevent their colouring the spirit, but
washing with oil of vitriol is a better plan.
10. Some persons fill musty casks with water and add 3 or 4 lbs. of
coarsely powdered fresh burnt charcoal, and agitate well for a few days.