men, who frequently take it to excess, in order to prolong their studies unconquered by sleep, the mind 
seeming to be enlivened by its use, and the body invigorated and calmed. It appears likewise to induce far 
less depression and nervous irritability than are known sometimes to follow too free indulgence in the use of 
tea. The Turks and other Asiatic nations, to whom indolence is enjoyment, moderate the effects of coffee 
by mixing opium with it. ( Burnett’s Outlines .) 
Brute animals appear likewise to be subject to its influence, for it has been affirmed that the goats, 
which in Arabia browse on the leaves and eat the fruit of the coffee, are remarkable for their liveliness and 
gamboling. Coffee is a more fit drink for persons of a lymphatic and sluggish temperament than for those of 
a lively sanguineous habit, more wholesome, according to the French writers, for the old than for the young, 
and more required by men than women. 
Qualities and Chemical Properties. — When the berries of coffee are roasted, a portion is con- 
verted into tannin by the action of the heat, and an agreeable aromatic substance is developed, the nature 
of which has not been ascertained. The same principle is also developed by roasting barley, beans, and 
many other vegetables, which, on that account, are occasionally employed as substitutes for coffee, and suit 
some stomachs better. The infusion of unroasted coffee in boiling water, is of a yellowish green colour; 
but the decoction, by continuing the boiling, becomes brown. It becomes turbid on cooling. The alkalies 
render it more brown. It strikes a black with sulphate of iron, but does not precipitate with gelatin. 
Chlorine nearly destroys the colour ; but if an alkali be added, the liquid becomes red. When water was 
distilled from coffee, what came over had an aromatic odour, and a few drops of a substance, similar to 
myrtle wash, swam on the surface of it; the residual liquid became milky when mixed with alcohol, and let 
fall a substance possessing the properties of gum. From experiments made, chiefly by Cadet, 3 it appears 
that coffee contains an aromatic principle, a little oil, gallic acid, mucilage, extractive and bitter principle. — 
The result of Cadet’s experiments on sixty-four parts of coffee, was as follows : — 
Gum 8*0 
Resin 1*0 
Extract and bitter principle l'O 
Gallic acid 3*05 
Albumen O' 14 
Fibrous and insoluble matter .... 45*05 
Loss 6.86 
From 1920 parts of Levant and Martinique coffee, Hermann obtained the following proportions re- 
spectively : — 
Levant 
Martinique 
Gum . . . 
.... 130 . 
... 144 
Resin . . . 
.... 74 . 
... 68 
Extractive 
.... 320 . 
... 310 
Fibrous matter 
.... 1335 . 
. . . 1386 
Loss . . . 
.... 61 . 
. . . 12 b 
Other analyses have been made by chemists. M. Grindel c found it contain kinic acid; and M. Payss£ 
has discovered what he has endeavoured to show as a peculiar acid, to which he has given the name of 
coffee-acid. / 
As a general palliative, strong coffee is often serviceable in various kinds of head-ache, and where its 
own sedative power is unavailing, it forms one of the best vehicles for the administration of laudanum. It 
diminishes in some degree the narcotic power of the latter, but counteracts its distressing secondary effects. 
When laudanum is intermixed with strong coffee for the cure of many modifications of head-ache, tranquil- 
lity and ease are produced, though there may be no sleep: when laudanum, on the contrary, is taken alone, 
sleep will, perhaps, follow, but is mostly succeeded by nausea, and a return of pain. Hence, the Turks and 
Arabians make strong coffee their common vehicle for opium, from its tendency to counteract the narcotic 
principle of the latter ; and on the same account, it is plentifully administered after the stomach has been 
evacuated of its contents, in cases of poisoning by opium. 
For common purposes, infusion of coffee is the most agreeable method of preparing it, as the aromatic 
and volatile principles are dissipated by boiling. 
In Arabia and other parts of the East, that called Mocha is considered the best. 
a Ann. de Chim. lviii. 226. b Crell’s Ann. 1800, ii. 108. c Hist. Paris, iv. 545. 
