In a vat holding 120 gallons provided with good agitating apparatus, dissolve 8 pounds potash alum in 10 gallons hot water and add 50 gallons cold water. Prepare a solution of

2  pounds ammonia soda and add slowly to the alum solution, stirring all the time. In a second vessel dissolve 5 pounds of brilliant scarlet aniline, by first making it into a paste with cold water and afterwards pouring boiling water over it; now let out steam into the vat until a temperature of 150° to 165° P. is obtained. Next dissolve 10 pounds barium chloride in 10 gallons hot water in a separate vessel, add this very slowly, stir at least

3  hours, keeping up temperature to the same figures. Fill up vat with cold water and leave the preparation for the night. Next morning the liquor (which should be of a bright red color) is drawn off, and cold water again added. Wash by decantation 3 times, filter, press gently, and make into pulp.

It is very important to precipitate the aluminum cold, and heat up before adding the dyestuff. The chemicals used for precipitating must be added very slowly and while constantly stirring. The quantity used for the three washings is required each time to be double the quantity originally used.

I

Madder Lakes.—Prepare from the root 1 pound best madder, alum water (1 pound alum with 1.5 gallons of water), saturated solution of carbonate of potash (| pound carbonate of potash to 0.5 gallon of water).

The madder root is inclosed in a linen bag of fine texture, and bruised with a pestle in a large mortar with 2 gallons of water (free from lime) added in small quantities at a time, until all the coloring matter is extracted. Make this liquor boil, and gradually pour into the boiling water solution. Add the carbonate of potash solution gradually, stirring all the time. Let the mixture stand for 12 hours and drop and dry as required.

II

Garancine Process.—This is the method usually employed in preference to that from the root. Garancine is prepared by steeping madder root in sulphate of soda and washing.

Garancine.......... 2 pounds

Alum (dissolved in a

little water)....... 2 pounds

Chloride of tin...... J ounce

Sufficient carbonate of potash or soda to precipitate the alum. " Boil the garancine in 4 gallons of pure water; add the alum, and continue boiling from 1 to 2 hours. Allow the product to partially settle and filter through flannel before cooling. Add to the filtrate the chloride of tin, and sufficient of the potash or soda solution to precipitate the alum; filter through flannel and wash well. The first filtrate may be used for lake of an inferior quality, and the garancine originally employed may also be treated as above, when a lake slightly inferior to the first may be obtained.