C8H10N4O2+H2O=211.68. Synonyms. - Theine. Guaranine. A feebly basic, proximate principle, obtained from the dried leaves of Thea sinensis Linne (nat. ord. Ternstroemiaceae), or from the dried seed of Coffea arabica Linne (nat ord. Rubiaceae), and found also in other plants.


Tropical Africa; cultivated in tropical countries.


Exhaust bruised coffee by successive portions of boiling water, precipitate with Lead Acetate, decompose the excess of Lead Acetate in the filtrate by Hydrogen Sulphide, concentrate by evaporation, neutralize with Ammonia. The Caffeine crystallizes on cooling, and is purified by re-dissolving in water, treating with Animal Charcoal, and evaporation.


Fleecy masses of long, flexible, white crystals, possessing a silky lustre, without odor, having a bitter taste, and permanent in the air.


In 80 parts of water, 33 parts of Alcohol, 555 parts of Ether, or

7 parts of Chloroform. Tea contains 3 to 5 per cent. (hence the name Theine), Coffee, 1.3 per cent. (coffee leaves contain much more). Guarana (the seeds of Paullinia Cupana), 4 to 5 per cent. (hence the name Guaranine). Mate (Paraguay tea, the leaves of Ilex paraguayensis), 1.2 per cent. Kola nut (which is used as a beverage in Africa), 3 per cent.; this is the fruit of Sler-culia acuminata. Caffeine is trimethyl-xanthine, theobromine is dimethyl-xanthine, and both can be prepared synthetically from xanthine.

Strictly speaking, Theine is the alkaloid of tea-leaves. It differs from caffeine in that it is analgesic and constipates. Much of the caffeine in the market is really theine and is made from the sweepings of tea warehouses.

Incompatibles. - Potassium iodide, mercury salts, and tannic acid.

Dose, 1 to 5 gr.; .06 to .30 gm.


1. Caffeina Citrata. - Citrated Caffeine. Dissolve Citric Acid, 50, in hot Distilled Water, 100; add the Caffeine, 50, and evaporate the resulting solution on a water-bath to dryness, constantly stirring towards the end of the operation. Reduce the product to a fine powder.


A white powder, odorless, having a purely acid taste and an acid reaction.


One part of Citrated Caffeine forms a clear, syrupy solution with about 3 parts of water.

Dose, 2 to 8 gr.; .12 to .50 gm.

2. Caffeina Citrata Effervescens. - Effervescent Citrated Caffeine. Caffeine, 10; Citric Acid, 10; Sodium Bicarbonate, 330; Tartaric Acid, 300; Sugar, 350; Alcohol, to make 1000. Triturate the solid ingredients, separately well dried, to a fine uniform powder. Mix this with Alcohol to a soft paste and rub it through a sieve. Then dry it, and reduce it to a coarse, granular powder.

Dose, 1 to 4 dr.; 4. to 15. gm.