“ The black physicians of this country divide the diseases of mankind, as well as their medicines, into 
hot and cold ; to the cold disease they oppose a hot medicine, and to the hot disease a cooling medicine, 
among which last, this Extract is supposed to be very powerful. 
“ The extract is a principal ingredient in one of their ointments of great repute, composed of blue vitriol 
four drachms, Japan earth four ounces, alum nine drachms, white resin four ounces ; these are reduced to a 
fine powder, and mixed with the hand, adding olive oil ten ounces, and water sufficient to bring the mass to 
the proper consistence of an ointment., — This ointment is used in every sore, from a fresh wound. 
A gentleman (Mr. Robert Hunter, Surgeon to the Patna Factory) of great practice, told me, he used this 
ointment with success beyond expectation; and he remarks, that whether it is owing to the laxity of the 
solids in this hot climate, or to some other cause, he is clearly of opinion, that our greasy ointments have 
not the desired effect. Certain it is they avoid that empyreuma which our ointments often receive in boiling 
which cannot be a promising application to a tender sore. As to the virtues of this Extract in European 
practice, I must be silent; they are already better described than I can pretend to do.” 
Qualities and Chemical Properties. — There are two kinds of this extract; one is sent from 
Bombay, the other from Bengal; but they differ from each other more in their external appearance, than in 
their chemical composition. The extract from Bombay is of a uniform texture, and of a red brown tint ; 
its specific gravity being generally about 1.39. The extract from Bengal is more friable, and less consistent ; 
its colour is like that of chocolate externally, but when broken its fracture presents chocolate and red-brown 
streaks. Its specific gravity is about 1.28. Their tastes are precisely similar, being astringent, but leaving 
in the mouth a sensation of sweetness. They do not deliquesce, or apparently change, by exposure to the 
air. Solutions copiously precipitate gelatine, and speedily tan skins. The strongest infusions of the two 
kinds do not differ sensibly in their nature or composition. Their colour is deep red-brown, and they com- 
municate this tinge to paper ; they slightly redden litmus paper ; their taste is highly astringent, and they 
have no perceptible smell. The strongest infusions act upon the acids, in a manner analogous to the in- 
fusion of galls. Sulphuric and muriatic acids precipitate them. With strong nitrous acid they effervesce, 
and lose their power of precipitating solutions of isinglass and the salts of iron. The pure alkalies enter 
into union with their tannin, so as to prevent it from being acted upon by gelatine. Solutions of lime of 
strontia, and of barytes, poured into the infusions of catechu, produce copious precipitates. If carbonate 
of magnesia be added to the infusion, it loses its power of precipitating gelatine. The carbonates of potash, 
of soda, and of ammonia, also deprived them of their power of acting upon gelatine : though this power is 
restored by an acid. Solution of muriate of tin acts upon the infusion of catechu, in a manner similar to 
that in which it acts upon the infusion of galls. Both kinds of catechu are almost wholly soluble in large 
quantities of water; and to form a complete solution, about eighteen ounces of water, at 52°, are required 
to a hundred grains of extract. A considerable portion of both kinds of catechu is soluble in alcohol ; but, 
after the action of the alcohol upon it, a substance remains, of a gelatinous appearance, and a light brown 
colour, which is soluble in water, and is analogous in its properties to gum or mucilage. 
The peculiar extractive matter of the catechu, is much less soluble in water than the tanning principle ; 
and when a small quantity of water is used to a large quantity of catechu, the quantity of tannin taken up 
is much greater than that of the extractive matter. The extractive matter is much more soluble in warm 
water than in cold ; and when saturated, solutions of catechu are made in boiling water, a considerable 
quantity of extractive matter, in its pure state, falls down as the liquor cools. An aqueous solution of the 
extractive matter, when mixed with solutions of nitrate of alumine, and of muriate of tin, becomes slightly 
turbid. Nitrate of lead gives a dense brown precipitate. It is not precipitated by the mineral acids. Two 
hundred grains of Bombay Catechu, afforded 109 of tannin, 68 of extractive matter, 13 of mucilage, and 10 
of sand, calcareous earth, and other impurities. The variety from Bengal gave, by a similar analysis, 9 7 of 
tannin, 73 of extractive matter, 16 of mucilage, and 14 of residual matter, and sand, with a small quantity 
of calcareous and aluminous earth, in two hundred grains. 
Medical Properties and Uses. — Catechu is largely employed in the East, medicinally ; but es- 
pecially when used with the betel-nut, for chewing, a practice almost universal over the Indian continent. 
In this country it is extensively employed for all those disorders in which a mild, unirritating, power- 
ful astringent is required; such as chronic diarrhoea and dysentery; hoeinorrhoids, &c., and the Bom- 
bay catechu, as containing the greatest portion of tannin, is that which is best adapted for medicinal use. 
It is one of the most valuable medicines of the class, and may be advantageously used in all cases where we 
wish to restrain immoderate discharges, especially when not attended by inflammatory action, or produced 
by congestion. With this indication, it is usually combined with the bitter tonic and aromatic barks. It is 
also used in the form of troches, mixed with gum-arabic and sugar, to dissolve slowly in the mouth ; and 
in this form it often much assists the clearness of the voice in persons that have occasion to speak long in 
public. As a topical astringent it is used in scorbutic affections of the gums, and aphthous ulcerations of 
the mouth and fauces. Dr. Thompson has found the slow solution of a small piece in the mouth, “a cer- 
tain remedy for the troublesome cough induced by a relaxed uvula, hanging into, and irritating the glottis.” 
Dose. — Erom gr. x. to 3b of the powder ; or, 3 i. to 3iij. of the Tincture 
Off Prep. — Infusum Catechu, L. E. Tinctura Catechu, L. E. Electuarium Catechu compo- 
situm, E. D. 
“ The distilled water of the leaves of the Acacia contains prussic acid. The water has a strong smell of 
bitter almonds, and eight ounces of it, precipitated by nitrate of silver, yielded 4.15 grains of cyanide. The 
dried leaves gave no prussic acid on distillation.” — [Dr. Taylor on Poisons, p. 719.] 
