A solution of 1 oz. of commercial alizarine in 20 ozs. of water, to which solution ammonia is very slowly added until the ammonia odor is perceptible, will give to oak, a yellow brown color, and to maple, a red brown. If the wood is then treated with a solution of barium chloride (2 drams to the pint of water), the first named wood becomes brown, and the latter dark brown. If calcium chloride is used in place of barium chloride, fir wood becomes brown, oak, red brown, and maple, dark brown.

If a solution of magnesium sulphat be used (4 drams to the pint of water), the fir and oak become dark brown and the maple, a dark violet brown.

Alum produces on fir a light red, and on maple, and oak, a blood red.

Chrome alum colors maple and fir reddish brown, and oak, a rich brown; manganese sulphate renders fir and maple a dark violet brown, and oak, a dark walnut brown.