MADDER.

minimum of ash found in this substance. In some low-priced madders, con-taminated with the earth and sand in which the roots have grown, the ashamounts occasionally to 50 per cent. Dried Zealand madder, very carefullyincinerated, gave 7-20 to 9-5 ash on an average of some 50 estimations. Thecomposition of the ash of madder varies. Schlumberger found in 100 parts—

Salts of potassium.4-06

Silica.0-15

Phosphate of lime and alumina .o-8o

Carbonate of lime .3-60

Loss .0-15

Total ash. .. 876

The same chemist found in 100 parts of Alsace madder—

Salts soluble in water .4-23

Silica.0-65

Alumina and phosphate of lime . 1-33

Carbonate of lime .0-87

Loss .0-12

. Total ash.7-20

100 parts of Avignon madder yield 572 parts carbonate of lime, of which27 pre-exist as bicarbonate, while the rest is formed by the ignition of organicsalts of lime, from which latter source the small quantity of carbonate of limemet with in the ash of the Alsace madder is exclusively derived.

The results of the researches made by Kuhlmann, Bucholz, and John, allprevious to the year 1826, are in some respedts noteworthy, and may be brieflysummarised here. Madder, according to Kuhlmann, contains—

1. A yellowish-brown colouring matter soluble in cold water.

2. A red colouring matter soluble in hot water.

3. Woody fibre.

4. Vegetable acid.

5. Mucilage.

6. Vegeto-animal matter.

7. Gum.

8. Sugar.

9. Bitter principle.

10. Odoriferous resin.

11. Ash, viz.—

Carbonate of potassa .0-008

Sulphate of potassa.0-032

Phosphate of potassa .0-037

Chloride of potassium.0703

Carbonate of lime.0-467

Phosphate of lime.0-082

Silica.0-020

Loss

0-031

1-380