KINO.

49i

from the fruit of the areca palm, Areca catechu , a tree widely spread over thetropic portion of Asia. This kind of cutch is met with in commerce in theshape of cubical blocks, each side measuring from 3 to 4 centimetres.The colour of this substance is brighter than that of the cutch which isshipped at Bombay (the mixed produce of the Acacia catechu and areca nut),the colour being chocolate-brown, with deeper and lighter coloured bandsalternating. This substance exhibits a dull appearance when broken, and isvery dry and sandy, although sand is not necessarily present; the sp. gr. is i ’28.

Yellow cutch, cubical cutch, or gambir, is the extradt obtained from theleaves of the Uncaria gambir and Uncaria acida shrubs, belonging to thefamily of the Rubiaceae, tribe of the Cinchonas (Roxburg), abundantly metwith in Sumatra, Malacca, Pulo-Penang, Singapore, the Moluccas, and theSunda Islands. This kind of cutch, known very generally as gambir, occursin commerce in the shape of thick flat cakes, externally brown, internallybright yellow, fradture dull, taste bitter and astringent.

Kino or gum kino, the produce of the Butea frondosa (Leguminoste) andthe Ptcricarpus marsuf>ium, also of some other plants, is a deep blackish brown,glossy-looking substance, of an astringent and bitter taste, only used inmedicine. The following preparation of kino might be worthy of pradticalinvestigation : —Boil powdered kino for some time in water. On cooling theconcentrated solution a substance separates out, and is colledted upon a filter.It is then boiled in concentrated hydrochloric acid, when it dissolves with anintense violet colour. This is allowed to cool, and then diluted with water,when a rich dark brown powder is deposited, and carefully washed. It issoluble in alcohol with a violet-red, and in hot acetic acid with a poppy-red.The latter solution is said to give a pale rose shade on stuffs mordanted withsalts of iron. It dyes wool and cotton moderately, and silk very finely.With tin mordants it yields rich cherry and scarlet shades; alumina com-pounds are unfavourable to the colour.

As regards their chemical composition, the above-named substances do notdiffer much from each other. By qualitative tests there have been found inthese substances the following matters:—

1. A peculiar kind of tannin, soluble in cold water, precipitated by gelatin,

and also by salts of the peroxide of iron with a greyish-green colour; notprecipitated by a solution of tartar emetic. This rather ill-definedbody, whose properties and composition are not very well known, istermed catechutannic acid.

2. A colourless, crystallisable principle, called catechuin or catechuic acid,

which is the main cause of the tindtorial properties of catechu.

3. Brown so-called extractive substance, present in greater or less quantity,

and due to the alteration of the two foregoing matters.

Catechutannic acid is an amorphous, colourless substance, soluble in coldwater, as well as in alcohol and ether; its taste is astringent. It may beprepared in an impure state by adding to a cold-made and concentratedaqueous solution of catechu concentrated sulphuric acid; the precipitate thusproduced is washed with water slightly acidulated with sulphuric acid, andnext re-dissolved in water; this solution is treated with carbonate of lead,filtered, and concentrated in vacuo. Another mode of preparation consists intreating catechu, coarsely powdered and put in a displacement apparatus,