The water of the first boiling becomes red and thick, and when this is inspissated after the removal of the nuts it forms a catechu of high astringency and dark colour called in Bombay "Kossa."
The nuts are again boiled, and the inspissated juice of the second decoction yields a weaker catechu of a brown or reddish colour.
Garlic may also be prescribed as an extract consisting of the inspissated juice, in doses of 5-io grains, and as the syrupus allii aceticus, in doses of 1-4 drachms. This last preparation has recently been much extolled in the treatment of pulmonary tuberculosis or phthisis.
In a Chinese Herbal compiled before 1700 both the plant and its inspissated juice are described, together with the mode of collecting it, and in the General History of the Southern Provinces of Yunnan, revised and republished in 1736, opium is noticed as a common product.
Various other adulterants are sometimes used, such as the inspissated juice of the prickly pear, extracts from tobacco, stramonium and hemp, pulp of the tamarind and bael fruit, mahwah flowers and gums of different kinds.