_Resina Elemi_; _Elemi_; F. _Résine Elemi_; G. _Elemiharz_.
=Botanical Origin=—The resin known in pharmacy as _Elemi_ is derived
from a tree growing in the Philippines, which Blanco,[586] a botanist
of Manila, described in 1845 under the name of _Icica Abilo_, but which
is completely unknown to the botanists of Europe. Blanco’s description
is such that, if correct, the plant cannot be placed in either of the
old genera _Icica_ or _Elaphrium_, comprehended by Bentham and Hooker
in that of _Bursera_, nor yet in the allied genus _Canarium_; in fact
even the order to which it belongs is somewhat doubtful.[587]
The tree grows in the province of Batangas in the island of Luzon
(south of Manila), where its name in the Tagala language is _ábilo_;
the Spaniards call it _Arbol a brea_, i.e. _pitch-tree_, from the
circumstance that its resin is used for the caulking of boats.
=History=—The explicit statements of Theophrastus in the 3rd century
B.C. relative to olibanum have already been mentioned. The same writer
narrates[588] that a little above Coptus on the Red Sea, no tree is
found except the acacia (ἀκάνθη) of the desert ... but that on the sea
there grow laurel (δάϕνη) and olive (ἐλαία), from the latter of which
exudes a substance much valued to make a medicine for the staunching of
blood.
This story appears again in Pliny[589] who says that in Arabia the
olive tree exudes tears which are an ingredient of the medicine called
by the Greeks _Enhæmon_, from its efficacy in healing wounds.
Dioscorides[590] briefly notices the _Gum of the Ethiopian olive_,
which he likens to scammony; and the same substance is named by
Scribonius Largus[591] who practised medicine at Rome during the 1st
century.
The writers who have commented on Dioscorides have generally adopted
the opinion that the exudation of the so-called olive tree of Arabia
and Ethiopia was none other than the substance known to them as
_Elemi_, though, as remarked by Mattioli,[592] the oriental drug thus
called by no means well accords with the description left by that
author.
[586] _Flora de Filipians_, segunda impression, Manila, 1845. 256.
[587] On consulting Mr. A. W. Bennett, who is now studying the
_Burseraceæ_ of India, as to the probable affinities of Blanco’s plant,
we received from him the following remarks: “I have little hesitation
in pronouncing that from the description, _Icica Abilo_ cannot be
a _Canarium_, but what it is, is more difficult to say. The leaves
having the lowest pair of leaflets smallest, seems at first sight
very characteristic of _Canarium_; but the following considerations
tend the other way. 1. The _opposite_ leaves which occur nowhere in
_Burseraceæ_ except in _Amyris_, with which the plant does not agree
in many ways. 2. The _stipellæ_ which are not found anywhere in the
order.—3. The _quinate_ flowers. In all species of _Canarium_ the parts
of the flowers are in threes, including _C. commune_, which according
to Miquel extends to the Philippines. The only exception is _C._
(_Scutinanthe_ Thwaites) _brunneum_, with which it does not agree in,
other respects.
“The foregoing reasons almost equally exclude _Icica_ (_Bursera_); yet
the fruit of Blanco’s plant seems so eminently that of a _Burseracea_,
that I think it must belong to that order, but with some error in the
description of the leaves.”
[588] _Hist. Plant_, lib. iv. c. 7.
[589] Lib. xii c. 38.
[590] Lib. i. c. 141.
[591] _Compositiones Medicament_. cap. 103.
[592] _Comm. in lib. i, Dioscoridis._
As to that name, the earliest mention of it appears in the middle of
the 15th century. Thus in a list of drugs sold at Frankfort about 1450,
we find _Gommi Elempnij_.[593] Saladinus,[594] who lived about this
period, enumerates _Gumi Elemi_ among the drugs kept by the Italian
apothecaries, but we have not met with the name in any other writer
of the school of Salerno. The _Arbolayre_,[595] a herbal supposed to
have been printed about 1485, gives some account of _Gomme Elempni_,
stating that it is the gum of the lemon tree and not of fennel as some
think,—that it resembles Male Incense,—and makes an excellent ointment
for wounds.
The name _Enhæmon_[596] of Pliny, also written _Enhæmi_, is probably
the original form of the word _Animi_, another designation for the same
drug, though also applied as at the present day to a sort of copal. It
is even possible that the word _Elemi_ has the same origin.[597]
This primitive Elemi is in our opinion identical with a peculiar
sort of olibanum known as _Luban Meyeti_, afforded by _Boswellia
Frereana_ Birdwood (p. 135). It has a remarkable resemblance both
in external appearance and in odour to the substance in after-times
imported from America, and which were likened to the elemi and animi
of the Old World. The description of “gummi elemnia” given by Valerius
Cordus,[598] the most careful observer of his period, could in our
opinion well apply to _Luban Meyeti_. (See p. 153 further on.)
The first reference to Elemi as a production of America comes from
the pen of Monardes[599] who has a chapter on _Animi and Copal_.
He describes animi as of a more oily nature than copal, of a very
agreeable odour, and in grains resembling olibanum but of larger size,
and adds that it differs from the animi of the Old World in being less
white and clear.
At a somewhat later period this resin and some similar substances began
to be substituted for _Elemi_ which had become scarce.[600] Pomet,[601]
who as a dealer in drugs was a man of practical knowledge, laments that
this American drug was being sold by some as Elemi, and by others as
Animi or as Tacamaca. It was however introduced in great plenty, and
at length took the place of the original elemi which became completely
forgotten.
American Elemi was in turn discarded in favour of another sort imported
from the Philippines. The first mention of this substance is to be
found among the descriptions accompanied by drawings sent by Father
Camellus to Petiver of London, of the shrubs and trees of Luzon,[602]
in the year 1701. Camellus states that the tree, which from his drawing
preserved in the British Museum appears to us to be a species of
_Canarium_, is very tall and large, that it is called by the Spaniards
_Arbol de la brea_, and that it yields an abundance of odorous resin
which is commonly used for pitching boats. Living specimens of the tree
together with samples of the resin were brought to Paris from Manila by
the traveller Perrottet about the year 1820. For the last twenty years
the resin has been common, and is now imported in large quantities[603]
for use in the arts, so displacing all other kinds. It has been adopted
as the _Elemi_ of the _British Pharmacopœia_ (1867), and is in fact the
only variety of elemi now found in English commerce.
[593] Flückiger, _Die Frankfurter Liste_, Halle, 1873. 7. 16.—“Gumi
elemi” is also found in a similar list of the year 1480, compiled in
the town of Nördlingen, Bavaria. See _Archiv der Pharm._ 211 (1877) 103.
[594] _Compendium Aromatariorum_, Bonon. 1488.
[595] This very rare volume is one of the treasures of the National
Library of Paris.
[596] From the Greek ἔνιμον, signifying _blood-stopping_.
[597] Brassavola observes—“quandoque inclinavimus ut gummi oleæ
Æthiopicæ esset gummi _elemi_ dicti, quasi _enhæmi_.”—_Examen
simplicium_, Lugd. 1537. 386.
[598] _Hist. Stirp. libri iv._, edition of Gesner, Argentorati, 1561.
209.
[599] _Libro de las cosas que se traen de nuestras Indias
Occidentales_, Sevilla, 1565.
[600] Thus Piso in 1658 describes the resin of an _Icica_ as exactly
resembling _Elemi_ and quite as good for wounds.—_Hist. nat. et med.
Ind. Occ._ 122.
[601] _Histoire des Drogues_, 1694, 261.
[602] Ray, _Hist. Plant._ iii (1704), appendix, p. 67. No. 13.—Compare
also p. 60, No. 10.
[603] Thus in a drug sale, May 8, 1873, there were offered 275 cases,
equal to about 480 cwt.
=Description=—Manila elemi is a soft, resinous substance, of granular
consistence not unlike old honey, and when recent and quite pure is
colourless; more often it is found contaminated with carbonaceous
matter which renders it grey or blackish, and it is besides mixed
with chips and similar impurities. By exposure to the air it becomes
harder and acquires a yellow tint. It has a strong and pleasant odour
suggestive of fennel and lemon, yet withal somewhat terebinthinous.
When moistened with spirit of wine, it disintegrates, and examined
under the microscope is seen to consist partly of acicular crystals. At
the heat of boiling water the hardened drug softens, and at a somewhat
higher temperature fuses into a clear resin.
=Chemical Composition=—Manila elemi is rich in essential oil. On
submitting 28 lb. of it to distillation with water, we obtained 2 lb.
13 oz. (equivalent to 10 per cent.) of a fragrant, colourless, neutral
oil, of sp. gr. 0·861 at 15° C. Observed in Wild’s polaristrobometer we
found it to be strongly dextrogyre.[604] H. Sainte Claire Deville[605]
on the other hand has examined an oil of elemi that was strongly
levogyre. This discrepancy shows that there are among the oils of
various kinds of elemi, differences similar to those existing in the
oils of turpentine and copaiba. By the action of dry hydrochloric
acid gas, Deville obtained from his oil of elemi a solid crystalline
substance, C₁₀H₁₆ + 2 HCl. We failed to produce any such compound from
the oil of Manila elemi. Our oil of elemi dissolves in bisulphide of
carbon; when mixed with concentrated sulphuric acid, it becomes thick
and assumes a deep orange colour.
By submitting the crude oil to fractional distillation, we separated it
into six portions, of which the first five were dextrogyre in gradually
diminishing degree, while the sixth displayed a weak deviation to the
left.[606] The first portion having been dissolved in four times its
weight of strong sulphuric acid, washed and again distilled, exhibit a
deviation to the left.[607]
[604] I observed the following deviations:—
In a column of 25 mm from 47°·5 to 70°·5 (deviation 23°).
” ” 50 ” ” 93°·6 ( ” 46·1).
” ” 100 ” ” 49°·6 (2·1 + 90 = 92°·1).
—F. A. F.
[605] _Comptes Rendus_, xii (1841) 184.
[606] The following deviations were observed, in a column of 25
millimetres:—
Oil
distilled
at
1. 172°-180° C. from 47°·6 to 74°·5; deviation 26°·9 _right_.
2. 180°-183° ” 71°·2 ” 23°·6 ”
3. 183°-184°·5 ” 68°·8 ” 21°·2 ”
4. 184°-195° ” 65°·8 ” 18°·2 ”
5. 200°-230° ” 61°·0 ” 13°·4 ”
6. Thickish yellow ” 46°·2 ” 1°·4 _left_.
residue
[607] From 47°·6 to 46°.
If the essential oil of elemi (8 parts) is shaken with alcohol,
0·816 sp. gr. (2 parts), nitric acid, 1·2 sp. gr. (1 part) and
water (5 parts), the mixture, on exposure to air in a shallow
capsule soon yields large crystals, which were found to agree
crystallographically[608] perfectly with terpin, C₁₀H₂₀O₂ + OH₂ from
oil of turpentine.
Maujean,[609] a French pharmacien, examined Manila elemi as long
ago as 1821 and proved it to contain two resins, the one soluble in
cold, the other only in hot spirit of wine. The former, which appears
to constitute by far the prevailing part of all varieties of elemi,
has not yet been satisfactorily examined. Bonastre[610] a little
latter made a more complete analysis, showing that the less soluble
resin which he obtained to the extent of 25 per cent. is easily
crystallizable, and apparently identical with a substance obtainable
in a similar manner from what he regarded as true elemi, which the
Manila resin was not then held to be. Baup (1851) gave it the name of
_Amyrin_. According to our experiments, it is readily isolated to the
extent of 20 per cent. when Manila elemi is treated with cold spirit of
wine, in which the crystals of amyrin are but slightly soluble. If the
elemi is pure, the amyrin may be thus obtained (by washing with spirit
and pressure between bibulous paper) in a cake of snowy whiteness,
which may be further purified by crystallization from boiling alcohol.
The fusing point of the crystals is 177° C.; their composition has been
ascertained by Buri[611] to agree with the formula C₂₅H₄₂O, which may
be written thus: (C₅H₈)₅ OH₂. Amyrin at 16° C. dissolves in 27·5 parts
of alcohol 0·816 sp. gr., being readily soluble also in all the usual
solvents for resins. The alcoholic solution is slightly dextrogyre.
Amyrin is a neutral substance, and may be sublimed in small quantities
by very carefully heating it.
By heating amyrin with zinc dust Ciamician[612] obtained chiefly
toluol, methyl-ethyl-benzol and ethyl-naphtalin.
By allowing an alcoholic solution of the amorphous resin of Manila
elemi[613] to evaporate, Baup obtained in very small quantity crystals
of _Bréine_, a substance fusing at 187° C., which he considered to
be distinct from amyrin. In our opinion it was impure amyrin; it is
extremely difficult, or rather practically impossible to extract all
the crystallizable resin from the amorphous. If the latter, perfectly
transparent, is kept for several years, an elegant crystallization at
last begins to make its appearance throughout the bulk of the resin.
Baup further extracted from Manila elemi a crystallizable substance
soluble in water to which he gave the name of _Bryoidin_,[614] and
in smaller quantity a second also soluble in water which he called
_Bréidine_. From the experiments of Baup it appears that bryoidin is
soluble in 360 parts of water at 10° C., and melts at 135° C.; whereas
bréidine requires for solution 260 parts of water and fuses at a
temperature not much over 100° C.
[608] Examined at my request by Prof. Groth.—F. A. F..
[609] _Journ. de Pharm._ ix. (1823) 45. 47.
[610] _Id._ x. (1824) 199.
[611] _Pharm. Journ._ vii. (1876) 157, also _Yearbook of Ph._ 1877. 21.
[612] _Berichte der deutschen chemischen Gesellschaft_, 1878. 1347.
[613] I am indebted for a specimen of the material that Baup worked
upon and which he called _Resin of Arbol a brea_, to M. Roux,
pharmacien of Nyon, Switzerland—F. A. F.
[614] From the Greek βρύον, in allusion to the moss-like aspect
sometimes assumed by the crystals.
We have also obtained _Bryoidin_[615] by operating in the following
manner: the watery liquid left in the still after the distillation of
28 lb. of Manila elemi was poured off from the mass of hard resin,
and having been duly concentrated, it deposited together with a
dark extractiform matter, colourless acicular crystals of bryoidin.
The deposit in question having been drained and allowed to dry, the
bryoidin may be separated by boiling water or by cold ether. We found
the latter the more convenient; it readily takes up the bryoidin
contaminated only with a little resin. The ethereal solution should
be allowed to evaporate and the residual crystalline mass boiled in
water, when the solution (which is colourless), poured off from the
resin, will deposit upon cooling brilliant tufts of acicular crystals
of bryoidin. The boiling in water requires to be several times
repeated before the whole of the bryoidin can be removed; the latter
sometimes crystallizes as a mossy arborescent growth. Bryoidin is a
neutral substance, of bitter taste, scarcely soluble in cold water,
but dissolving easily in boiling water, or in alcohol or ether. When
a little is placed in a watch-glass, covered with a plate of glass,
and then gently heated over a lamp, it sublimes in delicate needles.
To obtain it perfectly pure, it is best to sublime it in a current
of dry carbonic acid. Thus purified its fusing point is 133·5 C.;
after fusion it concretes as a transparent, amorphous mass, which if
immersed in glycerin and raised to the temperature of 135° C., suddenly
crystallizes.
We have observed that if the filtered mother-liquor of bryoidin after
complete cooling and standing for a day or two is warmed, it becomes
turbid and that in a few minutes there separate from it long white
flocks like bits of paper or wool, which do not disappear either by
warming or by cooling the liquid; under the microscope they are seen
to consist partly of thread-like, partly of acicular crystals. It is
possible this substance is Baup’s _Bréidine_; we found it to fuse at
135° C., to be neutral, and to crystallize from weak alcohol exactly
like bryoidin. Both it and bryoidin look very voluminous in water, but
are extremely small in weight, and are present in the drug in but a
very small amount. The composition of bryoidin agrees with the formula
C₂₀H₃₈O₃, which might be written thus (C₅H₈)₄+3OH₂. But it contains
no water of crystallization. In the vapour of dry hydrochloric gas,
bryoidin assumes a fine red colour, turning violet, then blue, and
lastly green. This behaviour is not at all displayed by amyrin.
The liquids from which bryoidin is obtained contain an amorphous
brown substance of intensely bitter taste, at the same time somewhat
aromatic. It is decomposed by dilute mineral acids, evolving a very
peculiar strong odour.
Buri[616] isolated from Manila Elemi an extremely small amount of
_Elemic acid_, C₃₅H₅₆O₄. It is in very brilliant crystals, much larger
than those of the other constituents of elemi. Although we have before
us some prisms of the acids several millimetres long, it has been found
impossible to ascertain their crystallographic character, each of the
prisms being formed of very intimately aggregated crystals. Elemic acid
melts at 215° C.; its alcoholic solution decidedly reddens litmus.
Elemate of potassium is a crystalline salt.
[615] Flückiger, _Pharm. Journ._ v. (1874) 142.
[616] _Pharm. Journ._ viii. (1878) 601.
The relations of the substances hitherto isolated from elemi may
perhaps be given thus:—
Essential oil, C₅H₈.
Amyrin, (C₅H₈)₅ + OH₂
Amorphous resin (?) (C₅H₈)₂ + OH₂
Bryoidin, (C₅H₈)₄ + 3OH₂
Elemic acid, (C₅H₈)₇ + O₄
=Uses=—Elemi is scarcely used in British medicine except in the form of
an ointment, sometimes prescribed as a stimulating application to old
wounds.
=Other sorts of Elemi=—1. _Mexican Elemi_, _Vera Cruz Elemi_—This drug,
which used to be imported into London about thirty years ago, but which
has now disappeared from commerce, is the produce of a tree named by
Royle _Amyris elemifera_ growing at Oaxaca in Mexico.[617] It is a
light yellow, or whitish, brittle resin occurring in semi-cylindrical
scraped pieces, or in irregular fragments which are sometimes
translucent but more often dull and opaque. It easily softens in the
mouth so that it may be masticated, and has an agreeable terebinthinous
odour. Treated with cold spirit of wine (·828), it breaks down into a
white magma of acicular crystals (_Amyrin_?).
2. _Brazilian Elemi_—Was described as long ago as 1658 by the traveller
Piso, as a substance completely resembling the elemi of the Old World
and applicable to the same purposes. It is the produce of several
trees described as species of _Icica_, as _I. Icicariba_ DC.,[618] _I.
heterophylla_ DC., _I. heptaphylla_ Aublet, _I. guianensis_ Aubl., _I.
altissima_ Aubl.—In New Granada a similar exudation[619] is furnished
by _I. Caranna_ H.B.K.
A specimen in our possession from Pernambuco[620] is a translucent,
greenish yellow, fragrant, terebinthinous resin, which by cold spirit
of wine may be separated into two portions, the one soluble, the other
a mass of colourless acicular crystals. The resin spontaneously exuded
and collected from the trunks, is often opaque and white, grey, or
yellowish, looking not unlike fragments of old mortar. The microscope
shows it to be made up of minute acicular crystals.[621]
3. _Mauritius Elemi_—Fine specimens of this substance and of
_Colophonia Mauritiana_ DC. the tree affording it, were sent to one of
us (H.) in 1855 by Mr. Emile Fleurot of Mauritius. The resin accords in
its general characters with Manila elemi, like which it leaves after
treatment with cold spirit of wine, an abundance of crystals resembling
amyrin.
[617] Royle’s very imperfect specimens of this plant are in the British
Museum.
[618] Now _Protium Icicariba_ Marchand, in _Flora Brasiliensis_,
fascicul. 65 (1874) tab. liii.
[619] G. Planchon, _Bulletin de la Soc. Bot. de France_, xv. (1868) 16.
[620] Given me by Mr. Manley, late of Pernambuco. I have also an
authentic specimen of the resin of _I. heterophylla_ collected at
Santarem, Pará, by Mr. H. W. Bates in 1853.—D. H.
[621] For some experiments on the resin of _Icica_, see Gmelin,
_Chemistry_, xvi. (1866) 421.—Also Stenhouse and Groves, in Liebig’s
_Annalen der Chemie_, 180 (1876) 253, on resin and oil of _Icica
heptaphylla_. The former would appear to agree with the formula
(C₅H₈)₉OH₂.
4. _Luban Meyeti_[622] or _Luban Mati._—This substance, which we claim
to be the _Oriental_ or _African Elemi_ of the older writers, and also
one of the resins anciently designated _Animi_,[623] is the exudation
of _Boswellia Frereana_ Birdwood, a remarkable tree gregarious on the
bare limestone hills near Bunder Murayah to the west of Cape Gardafui.
The tree which is called _Yegaar_ by the natives, is of small stature,
and differs from the other species of _Boswellia_ growing on the same
coast in having glabrous, glaucous leaves with obtuse leaflets, crisped
at the margin.[624] The bark is smooth, papery, and translucent, and
easily stripped off in thin sheets which are used for writing on.
Though growing wild, the trees are said by Capt. Miles[625] to be
carefully watched and even sometimes propagated. The resin exudes after
incision in great plenty, soon hardens, and is collected by the Somali
tribes who dispose of it to traders for shipment to Jidda and ports of
Yemen: occasionally a package reaches London among the shipments of
olibanum. It is used in the East for chewing like mastich.
In modern times Luban Mati has been mentioned by Wellsted in his
“Travels in Arabia” (1838).
_Luban Meyeti_ occurs in the form of detached droppy tears and
fragments, occasionally in stalactitic masses several ounces in weight.
It breaks very easily with a brilliant conchoidal fracture, showing an
internal substance of a pale amber yellow and perfectly transparent.
Externally it is more or less coated with a thin opaque white crust,
which seen under the microscope appears non-crystalline. Many of the
tears have pieces of the thin, brown, papery bark adhering to them.
The resin has an agreeable odour of lemon and turpentine, and a mild
terebinthinous taste.
Treated with alcohol (·838) it is almost entirely dissolved; the very
small undissolved portion is not crystalline. The former agrees with
the formula C₂₀H₃₀O₂. 20 lb. of Luban Mati yielded us 10 ounces of
a volatile oil (= 3·1 per cent.) having a fragrant odour suggestive
of elemi and sp. gr. 0·856 at 17° C. The oil examined in a column
50 millim. long, deviates the ray 2°·5 to the left. By fractional
distillation we found it to consist of dextrogyre hydrocarbon, C₁₀H₁₆,
mixed with an oxygenated oil which we did not succeed in isolating;
the latter is evidently lævogyre, and exists in proportion more than
sufficient to overcome the weak dextrogyre power of the hydrocarbon.
There is no gum in this exudation; it is therefore essentially
different from olibanum, the product of closely allied species of
_Boswellia_.[626]
[622] _Lubán_ is the general Arabic name for olibanum: _meyeti_ perhaps
from Jebel Meyet, a mountain of 1200 feet on the Somali Coast in long.
47° 10′.
[623] By the assistance of Professor G. Planchon we have ascertained
that it is identically the same substance as described by Guibourt
under the name _Tacamaque jaune huileuse_ A.—_Hist. des Drogues_, iii.
(1850) 483.
[624] Figured in Birdwood’s paper, _Trans. Linn. Soc._ xxvii. (1870)
tab. 32; also, (reduced) in Cooke’s report on the _Gums, Resins, etc.,
of the India Museum_, 1874, plate iv.
[625] _Journ. Geograph. Soc._ xlii. (1872) 61.
[626] Flückiger, on Luban Mati and Olibanum, _Pharm. Journ._ viii
(1878) 805, with sketch map of the Somali Coast.