_Lignum Santalinum rubrum_, _Santalum rubrum_; _Red Sanders Wood_,
_Ruby Wood_; F. _Bois de Santal rouge_; G. _Rothes Sandelholz_,
_Caliaturholz_.
=Botanical Origin=—_Pterocarpus santalinus_ Linn. fil.—A small tree not
often exceeding 3½ to 4 feet in girth, and 20 to 25 feet in height;
it is closely related to _Pt. Marsupium_ Roxb., from which it differs
chiefly in having broader leaflets always in threes. It is a native
of the southern part of the Indian Peninsula, as Canara, Mysore,
Travancore and the Coromandel Coast, but also occurs in Mindanao, in
the southern Philippines. In India the districts in which the wood is
at present chiefly obtained are the forests of the southern portion of
the Kurnool Hills, Cuddapah and North Arcot (W. and N.W. of Madras).
The tree is now being raised in regular plantations.[780]
The wood is a staple article of produce, and the felling of the trees
is strictly controlled by the forest inspectors. The fine trunk-wood
is highly valued by the natives for pillars in their temples and other
buildings, as well as for turnery. The stumps and roots are exported to
Europe as a dye-stuff, mostly from Madras.
=History=—It is difficult to tell whether the appellation _Red_
Sandal-wood used in connexion with _Yellow_ and _White_ Sandal-wood
by some of the earlier writers on drugs, was intended to indicate
the inodorous dyewood under notice or the aromatic wood of a species
of _Santalum_. Yet when Marco Polo[781] alludes to the sandal-wood
imported into China, and to the _red_ sandal (“_Cendal vermeil_”) which
grows in the island of Necuveran (Nicobar), it is impossible to doubt
that he intended by this latter name some such substance as that under
notice.
Garcia de Orta, who wrote at Goa in the middle of the 16th century,
clearly distinguished the fragrant sandal of Timor from the red
inodorous wood of Tenasserim and the Coromandel Coast. It is remarkable
that the wood of _Pt. santalinus_ is distinguished to the present
day in all the languages of India by names signifying _red-coloured
sandal-wood_, though it has none whatever of the peculiarities of the
odorous wood of _Santalum_. Red Sanders Wood was formerly supposed to
possess medicinal powers: these are now disregarded, and it is retained
in use only as a colouring agent.
During the middle ages, it was used as well as alkanet for culinary
purposes, such as the colouring of sauces and other articles of food.
The price in England between 1326 and 1399 was very variable, but on an
average exceeded 3_s._ per lb.[782] Many entries for the purchase of
Red Sanders along with spices and groceries, occur in the accounts of
the Monastery of Durham, A.D. 1530-34.[783]
=Description=—The wood found in English commerce is mostly that of the
lower parts of the stem and that of the thickest roots. It appears
in the market in ponderous, irregular logs, rarely exceeding the
thickness of a man’s thigh and commonly much smaller, 3, 4 or 5 feet in
length; they are without bark or sapwood, and are externally of a dark
colour. The internal wood is of a deep, rich, blood-red, exhibiting in
transverse section zones of a lighter tint, and taking a fine polish.
At the present day, druggists generally buy the wood rasped into small
chips, which are of a deep reddish-brown hue, tasteless and nearly
without odour.
[780] (Beddome), _Report of the Conservator of Forests_, for 1869-70,
Madras, 1870, pp. 3. 39. 123; for figure of the tree, see _Flora
Sylvatica of Southern India_ of the same author, tab. xxii.
[781] Pauthier, _Livre de Marco Polo_, 580—_Pt. indicus_ Willd. grows
in the adjacent Andaman Islands.
[782] Rogers, _Agriculture and Prices in England_, 1866, i. 631, ii.
545, &c.—The average price of a sheep during the same period was about
1_s._ 6_d._
[783] _Durham Household Book_, Surtees Soc. 1844. 215; also Pegge,
_Form of Cury_, Lond. 1780. p. xv.
=Microscopic Structure=—The wood is built up for the greater part
of long pointed cells, having thick walls (libriform). Through this
ligneous tissue, there are scattered small groups of very large
vessels. In a direction parallel to the circumference of the stem,
there are less coloured small parenchymatous layers, running from one
vascular bundle to another. The whole tissue is finally traversed by
very narrow medullary rays, which are scarcely perceptible to the
unaided eye. The parenchymatous cells are each loaded with one crystal
of oxalate of calcium, which are so large that, in a piece of the wood
broken longitudinally, they may be distinguished without a lens. The
colouring matter is contained especially in the walls of the vessels
and the ligneous cells.
=Chemical Composition=—Cold water or fatty oil (almond or olive)
abstracts scarcely anything from the wood, and hot water but very
little. On the other hand, ether, spirit of wine, alkaline solutions,
or concentrated acetic acid, readily dissolves out the colouring
matter. Essential oils of bitter almond or clove take up a good deal
of the red substance; that of turpentine none at all. This resinoid
substance, termed _Santalic Acid_ or _Santalin_,[784] is said to form
microscopic prismatic crystals of a fine ruby colour, devoid of odour
and taste, fusing at 104° C., insoluble in water but neutralizing
alkalis and forming with them uncrystallizable salts.
Weidel (1870) exhausted the wood with boiling water, containing a
little potash, and obtained by means of hydrochloric acid a red
precipitate, which was redissolved in boiling alcohol and then
furnished _colourless_ crystals of _Santal_, C₈H₆O₃. They are devoid of
odour or taste, not soluble in water, benzol, chloroform, bisulphide of
carbon, and but sparingly in ether. Santal yields with potash a faintly
yellow solution which soon turns red and green. The wood afforded
Weidel not more than 3 per mille of santal.
Cazeneuve (1874)[785] mixed 4 parts of the wood with 1 part of slaked
lime, and exhausted the dried powder with ether containing a little
alcohol. After the evaporation of the ether, a small amount of
colourless crystals of _Pterocarpin_ was obtained, which were purified
by recrystallization from boiling alcohol. They melt at 83° C., and are
abundantly soluble in chloroform, in bisulphide of carbon, very little
in cold alcohol, not at all in water. Pterocarpin agrees with the
formula C₁₇H₁₆O₅. It yields a red solution with concentrated sulphuric
acid, and a green with nitric acid 1·4 sp. gr. By submitting it to
destructive distillation pyrocatechin appears to be formed.
Franchimont (1879) assigns the formula C₁₇H₁₆O₆ to another principle
of Red Sanders Wood, which he isolated by means of alcohol. It is
an amorphous substance, melting at 105°. By extracting the wood
with a solution of carbonate of sodium, Hagenbach (1872) obtained a
fluorescent solution. Red Sanders Wood yielded us of ash only 0·8 per
cent.
=Commerce=—In the official year 1869-70, Red Sanders Wood produced to
the Madras Government a revenue of 26,015 rupees (£2,601). The quantity
taken from the forests was reported as 1,161,799 lb.
[784] Gmelin, _Chemistry_, xvi. (1864) 259; the formula assigned to
santalic acid (C₁₅H₁₄O₅) appears to be doubtful. Weidel in proposing
the formula C₁₄H₁₂O₄ points out that it may be allied to alizarin,
C₁₄H₈O₄.
[785] See _Dictionnaire de Chimie_, art. _Santaline_, p. 1434, and for
particulars: Cazeneuve, _Recherche et extraction des alcaloïdes_, etc.
Paris, 1875. 66. It would appear that the author obtained about 4 per
_mille_ of pterocarpin from the wood.
=Uses=—Red Sanders Wood is scarcely employed in pharmacy except for
colouring the Compound Tincture of Lavender; but it has numerous uses
in the arts. The latter applies also to the wood of _Pterocarpus
angolensis_ DC., which is largely exported from the French colony of
Gaboon; it is the “Santal rouge d’Afrique of the French,” or Barwood of
the English commerce.