=OLEUM CACAO.=
_Butyrum Cacao_, _Oleum Theobromatis_; _Cacao Butter_, _Oil of
Theobroma_; F. _Beurre de Cacao_; G. _Cacaobutter_, _Cacaotalg_.
=Botanical Origin=—Cacao seeds (from which Cacao Butter is extracted)
are furnished by _Theobroma Cacao_ L., and apparently also by _Th.
leiocarpum_ Bernoulli, _Th. pentagonum_ Bern., and _Th. Salzmannianum_
Bern.[382] These trees are found in the northern parts of South America
and in Central America as far as Mexico, both in a wild state and in
cultivation.
=History=—Cacao seeds were first noticed by Capitan Gonzalo Fernandez
de Oviedo y Valdés (1514-1523), who stated[383] that they had been
met with by Columbus, being used among the inhabitants of Yucatan
instead of money. They were likewise pointed out to Charles V., by
Cortes in one of his letters to the Emperor, dated Temixtitan, Sept.
3rd 1526.[384] The tree as well as the seeds and their uses, were at
length described by Benzoni,[385] who lived in the new world from 1541
to 1555. Clusius figured the seeds in his “Notæ in Garciæ Aromatum
historiam,” Antwerpiæ, 1582.
[379] _Journ. de Pharm._ 22 (1875) 278.
[380] _Archiv der Pharmacie_, cxcv. (1871) 142.
[381] Della Sudda, _Rép. de Pharm._, Janvier, 1860. 229.
[382] Bernoulli, _Uebersicht der bis jetzt bekannten Arten von
Theobroma_.—Reprinted from _Denkschriften der Schweizerischen
Gesellschaft für Naturwissenschaften_, xxiv. (Zürich, 1869) 4°. 376.
[383] _Historia general y naturel de las Indias islas y terra firme del
mar oceano_, iii. (Madrid, 1853) 253.
[384] Vedia, _Cartas de relacion enviadas al emperador Carlos V. desde
Nueva España_. Madrid, 1852. T. 1.
[385] Chavveton (Urbain) _Hist. nouv. du Nouveau Monde ... extraite
del’ italien de M. Hierosme Benzoni Milanais_. 1579. p. 504.
Cacao butter was prepared and described by Homberg[386] as early as
1695, at which time it appears to have had no particular application,
but in 1719 it was recommended by D. de Quelus[387] both for ointments
and as an aliment.
An essay published at Tübingen in 1735[388] called attention to it
as “_novum atque commendatissimum medicamentum_.” A little later it
is mentioned by Geoffroy[389] who says that it is obtained either by
boiling or by expressing the seeds, that it is recommended as the basis
of cosmetic pomades and as an application to chapped lips and nipples,
and to hæmorrhoids.
=Production=—Cacao butter is procured for use in pharmacy from the
manufacturers of chocolate, who obtain it by pressing the warmed seeds.
These in the shelled state yield from 45 to 50 per cent. of oil. The
natural seeds consist of about 12 per cent. of shell (testa) and 88 of
kernels (cotyledons).
=Description=—At ordinary temperatures cacao butter is a light
yellowish, opaque, dry substance, usually supplied in the form of
oblong tablets having somewhat the aspect of white Windsor soap. Though
unctuous to touch, it is brittle enough to break into fragments when
struck, exhibiting a dull waxy fracture. It has a pleasant odour of
chocolate, and melts in the mouth with a bland agreeable taste. Its sp.
gr. is 0·961; its fusing point 20° to 30° C.
Examined under the microscope by polarized light, cacao butter is seen
to consist of minute crystals. It is dissolved by 20 parts of boiling
absolute alcohol, but on cooling separates to such an extent that the
liquid retains not more than 1 per cent. in solution. The fat separated
after refrigeration is found to have lost most of its chocolate
flavour. Litmus is not altered by the hot alcoholic solution.
Cacao butter in small fragments is slowly dissolved by double its
weight of benzol in the cold (10° C.), but by keeping partially
separates in crystalline warts.
=Chemical Composition=—The fat under notice is composed, in common with
others, of several bodies which by saponification furnish glycerin and
fatty acids. Among the latter occurs also oleic acid,[390] contained in
that part of the cacao butter which remains dissolved in cold alcohol
as above stated. In fact by evaporating that solution a soft fat is
obtained. But the chief constituents of cacao butter appear to be
stearin, palmitin, and another compound of glycerin containing probably
an acid of the same series richer in carbon,—perhaps arachic acid,
C₂₀H₄₀O₂, or “_theobromic acid_” C₆₄H₁₂₈O₂, as suggested in 1877 by
Kingzett.
[386] _Hist. d. l’Acad. Roy. des Sciences_, tome ii. depuis 1686
jusqu’à 1699, Paris, 1733. p. 248.
[387] _Hist. nat. du Cacao et du Sucre_, Paris, 1719. (According to
Haller, _Bibl. Bot._ ii. 158.)
[388] B. D. Mauchart præside—dissertation _Butyrum Cacao_. Resp.
Theoph. Hoffmann.
[389] _Tract. de Mat. Med._ ii. (1741) 409.
[390] See article _Amygdalæ dulces_.
=Uses=—Cacao butter, which is remarkable for having but little tendency
to rancidity, has long been used in continental pharmacy; it was
introduced into England a few years ago as a convenient basis for
suppositories and pessaries.
=Adulteration=—The description given of the drug sufficiently indicates
the means of ascertaining its purity.