Legend has it that the ancient art of fuming was discovered by a farmer who noticed that some raw oak planks he kept in a barn had turned beautiful shades of warm brown.
After enough investigation, it was also discovered that this odd yet beautiful occurrence was because the ammonia from the equine stables were reacting with the tannic acid in the oak.
After numerous 'fuming' tests with ammonia, it was noticed that although the fuming technique darkens the wood, it does not darken the unique light areas found in oak. The reason oak is quarter-sawn is to emphasize these beautiful areas (called "ray flecks"). This apparently means that any attempt to stain or dye oak will lessen the contrast between the dark and light areas, and therefore tend to mask the beautiful pattern, while fuming will tend to increase the contrast and beauty.