_Catechu nigrum_; _Black Catechu_, _Pegu Catechu_, _Cutch_, _Terra
Japonica_; F. _Cachou_, _Cachou brun ou noir_; G. _Catechu_.
=Botanical Origin=—The trees from which this drug is manufactured are
of two species, namely:—
1. _Acacia Catechu_ Willd. (_Mimosa Catechu_ L. fil., _M. Sundra_
Roxb.[923]), a tree 30 to 40 feet high, with a short, not very straight
trunk4 to 6 feet in girth, straggling thorny branches, light feathery
foliage, and dark grey or brown bark, reddish and fibrous internally.
[922] Flückiger, _Pharm. Journ._ x. (1869). 641.
[923] Some Indian botanists, as Beddome, regard _Mimosa (Acacia)
Sundra_ as distinct from _A. Catechu._—Fig. in Bentley and Trimen, part
17.
It is common in most parts of India and Burma, where it is highly
valued for its wood, which is used for posts and for various domestic
purposes, as well as for making catechu and charcoal, while the
astringent bark serves for tanning. It also grows in the hotter and
drier parts of Ceylon. _A. Catechu_ abounds in the forests of Tropical
Eastern Africa; it is found in the Soudan, Sennaar, Abyssinia, the Noer
country, and Mozambique, but in none of these regions is any astringent
extract manufactured from its wood.
2. _A. Suma_ Kurz[924] (_Mimosa Suma_ Roxb.), a large tree with a red
heartwood, but a white bark, nearly related to the preceding but not
having so extensive a geographical range. It grows in the South of
India (Mysore), Bengal and Gujerat. The bark is used in tanning, and
catechu is made from the heartwood.
The extract of the wood of these two species of _Acacia_ is _Catechu_
in the true and original sense of the word, a substance not to be
confounded with _Gambier_, which, though very similar in composition,
is widely diverse in botanical origin, and always regarded in commerce
as a distinct article.
=History=—Barbosa in his description of the East Indies in 1514[925]
mentions a drug called _Cacho_ as an article of export from Cambay to
Malacca. This is the name for _Catechu_ in some of the languages of
Southern India.[926]
About fifty years later, Garcia de Orta gave a particular account of
the same drug[927] under its Hindustani name of _Kat_, first describing
the tree and then the method of preparing an extract from its wood.
This latter substance was at that period made up with the flour of
a cereal (_Eleusine coracana_ Gärtn.) into tablets or lozenges, and
apparently not sold in its simple state: compositions of this kind are
still met with in India. In the time of Garcia de Orta the drug was an
important article of traffic to Malacca and China, as well as to Arabia
and Persia.
Notwithstanding these accounts, catechu remained unknown in Europe
until the 17th century, when it began to be brought from Japan, or
at least said to be exported from that country. It was known about
1641 to Johannes Schröder,[928] and is quoted at nearly the same time
in several tariffs of German towns, being included in the samples of
mineral origin.[929]
[924] Brandis, _Forest Flora of North-Western and Central India_, Lond.
1874. 187, from which excellent work we also borrow the description of
_A. Catechu._
[925] Published by the Hakluyt Society, Lond. 1866. p. 191.
[926] As Tamil and Canarese, in which according to modern spelling
the word is written _Káshu_ or _Káchu_.—Moodeen Sheriff, _Suppl. to
Pharmacopœia of India_, 1879. 96.
[927] _Aromatum Historia_, ed. Clusius, 1574. 44.—He writes the word
_Cate_.
[928] _Pharmacopœia medico-physica_, Ulmæ, 1649. lib. iii. 516. “Est et
genus terræ exoticæ, colore purpureum, punctulis albis intertextum, ac
si situm contraxisset, sapore austeriusculum, masticatum liquescens,
subdulcemque post se relinquens saporem, _Catechu_ vocant, seu _Terram
japonicam_.... Particulam hujus obtinui a Pharmacopœo nostrate
curiosissimo Dn. Matthia Bansa.” The preface is dated Frankfurt A.D.
1641.
[929] _Pharm. Journ._ vi. (1876) 1022.
In 1671, catechu was noticed as a useful medicine by G. W. Wedel of
Jena,[930] who also called attention to the diversity of opinion as
to its mineral or vegetable nature. Schröck[931] in 1677 combated the
notion of its mineral origin, and gave reasons for considering it a
vegetable substance. A few years later, Cleyer,[932] who had a personal
knowledge of China, pointed out the enormous consumption of catechu for
mastication in the East,—that it is imported into Japan,—that the best
comes from Pegu, but some also from Surat, Malabar, Bengal, and Ceylon.
Catechu was received into the London Pharmacopœia of 1721, but was even
then placed among “_Terræ medicamentosæ_.”
The wholesale price in London in 1776 was £16 16_s._ per cwt.; in
1780 £20; in 1793 £14 14_s._, from which it is easy to infer that the
consumption could only have been very small.[933]
=Manufacture=—Cutch, commonly called in India _Kát_ or _Kut_, is
an aqueous extract made from the wood of the tree. The process for
preparing it varies slightly in different districts.
The tree is reckoned to be of proper age when its trunk is about a foot
in diameter. It is then cut down, and the whole of the woody part,
with the exception of the smaller branches and the bark, is chopped
into chips. Some accounts state that only the darker heartwood is thus
used. The chips are then placed with water in earthen jars, a series
of which is arranged over a mud-built fireplace, usually in the open
air. Here the water is made to boil, the liquor as it becomes thick and
strong being decanted into another vessel, in which the evaporation is
continued until the extract is sufficiently inspissated, when it is
poured into moulds made of clay, or of leaves pinned together in the
shape of cups, or in some districts on to a mat covered with the ashes
of cow-dung, the drying in each case being completed by exposure to the
sun and air. The product is a dark brown extract, which is the usual
form in which cutch is known in Europe.
In Kumaon in the north of India,[934] a slight modification of
the process affords a drug of very different appearance. Instead
of evaporating the decoction to the condition of an extract, the
inspissation is stopped at a certain point and the liquor allowed to
cool, “coagulate,” and crystallize over twigs and leaves thrown into
the pots for the purpose. How this drug is finished off we do not
exactly know, but we are told that by this process there is obtained
from each pot about 2 lb. of “_Kath_” or catechu, of an ashy whitish
appearance, which is quite in accordance with the specimens we have
received and of which we shall speak further on.
In Burma the manufacture and export of cutch form, next to the sale
of timber, the most important item of forest revenue. According to a
report by the Commissioner of the Prome Division, the trade returns
of 1869-70 show that the quantity of cutch exported from the province
during the year was 10,782 tons, valued at £193,602, of which nearly
one-half was the produce of manufactories situated in the British
territory. Vast quantities of the wood are consumed as fuel, especially
for the steamers on the Irrawadi.[935]
[930] _Usus novus Catechu seu Terræ Japonicæ,—Ephemerides Nat. Cur._
Dec. i. ann. 2 (1671) 209.
[931] _Ibid._ Dec. i. ann. 8 (1677) 88.
[932] _Ibid._ Dec. ii. ann. 4 (1685) 6.
[933] Pegu Cutch is quoted in a London price current, March 1879, £1.
2_s._ per cwt.
[934] Madden in _Journ. of Asiat. Soc. of Bengal_, xvii. part i. (1848)
565; also private communication accompanied by specimens of tree, wood,
and extract from Mr. F. E. G. Matthews, of the Kumaon Iron Works, Nynee
Tal.
[935] Pearson (G. F.) _Report of the Administration of the Forest
Department in the several provinces under the Government of India_,
1871-72, Calcutta, 1872, part 5. p. 22.
=Description=—Cutch is imported in mats, bags, or boxes. It is a dark
brown, extractiform substance, hard and brittle on the surface of the
mass, but soft and tenacious within, at least when newly imported. The
large leaf of _Dipterocarpus tuberculatus_ Roxb., the _Ein_ or _Engben_
of the Burmese, is often placed outside the blocks of extract.
Cutch when dry breaks easily, showing a shining but bubbly and slightly
granular fracture. When it is soft and is pulled out into a thin film,
it is seen to be translucent, granular and of a bright orange-brown.
When further moistened and examined under the microscope, it exhibits
an abundance of minute acicular crystals, precisely as seen in gambier.
We have observed the same in numerous samples of the dry drug when
rendered pulpy by the addition of water, or moistened with glycerin and
viewed by polarized light.
The pale cutch referred to as manufactured in the north of India, is
in the form of irregular fragments of a cake an inch or more thick,
which has a laminated structure and appears to have been deposited
in a round-bottomed vessel. It is a porous, opaque, earthly-looking
substance of a pale pinkish-brown, light, and easily broken. Under the
microscope it is seen to be a mass of needle-shaped crystals exactly
like gambier, with which in all essential points it corresponds. We
have received from India the same kind of cutch made into little
round cakes like lozenges, with apparently no addition. The taste of
cutch is astringent, followed by a sensation of sweetness by no means
disagreeable.
=Chemical Composition=—Extractiform cutch, such as that of Pegu, which
is the only sort common in Europe, when immersed in cold water turns
whitish, softens and disintegrates, a small proportion of it dissolving
and forming a deep brown solution. The insoluble part is _Catechin_
in minute acicular crystals. If a little of the thick chocolate-like
liquid made by macerating cutch in water, is heated to the boiling
point, it is rendered quite transparent (mechanical impurities being
absent), but becomes turbid on cooling. Ferric chloride forms with this
solution a dark green precipitate, immediately changing to purple if
common water or a trace of free alkali be used.
Ether extracts from cutch, catechin. This substance has been
investigated by many chemists, but as yet with discrepant results. It
agrees, according to Etti (1877), with the formula C₁₉H₁₈O₈, when dried
at 80° C. By gently heating catechin, _Catechu-tannic acid_, C₃₈H₃₄O₁₅,
is produced: