Qualities and Chemical Properties. — Gentian roots are long, and contain so large a propor- 
tion of water, that when dried, they are much wrinkled. Externally they are brown, internally spongy, 
and of a deep yellow colour. The best roots are of a middling size, of a lively yellow colour, 
tough, and almost free from fibres. The older and larger roots are more porous ; the 
younger and tender more compact. Neuman obtained from § xvj. of the root, by means of 
rectified spirit, jviiss. of resinous extract: and from water 3ix. of a gummy one. Sometimes the Thora 
valdensis of Ray, or the Aconitum pardalianches of Bauhin, is sold for the Gentian. It is known from the 
true Gentian by its paler colour externally, having longitudinal wrinkles; its texture is closer than that of 
Gentian, whitish within, and not bitter; but when chewed, only mucilaginous. It is the Ranunculus Thora, 
*Lin. Sp. PI. 775. Gentian yields its virtues to ether, alcohol, and water. A singular circumstance is con- 
nected with the analysis of this root : M. Henry and M. Caventou being employed at the same time in this 
pursuit, without being aware of each other’s proceedings, both discovered the substance termed gentianine, 
the principle on which the bitter and medicinal properties of the Gentian seem to depend ; and so little did 
they differ in the results of their investigations, that they resolved to publish their labours together. 
Preparation of Gentianine. — The powder of gentian is to be exposed to cold ether, which at the end of 
forty-eight hours furnishes a greenish tincture; this being filtered, poured into an open vessel, and exposed 
to heat, if the liquor be sufficiently concentrated upon cooling, settles into a yellowish crystalline mass, 
possessing a decided smell and taste of gentian. This mass is then to be treated with alcohol until it ceases 
to yield a citron colour. The washings are to be mixed, and exposed to a strong heat, and the yellow crys- 
talline substance begins to re-appear, assuming at the close of the evaporating process a solid form, and 
being extremely bitter. Taken up again by weak alcohol, it is partially dissolved, a certain portion of oily 
matter remaining separate. This last spirituous solution, besides the bitter • principle of the gentian, con- 
tains an acid substance, and the odorous principle also. 
Upon evaporating this liquid to dryness, washing the residue in water, adding a little calcined and well 
washed magnesia, boiling and evaporating in a water bath, the greater part of the odorous matter of the 
gentian is driven off ; the acidity is removed by the magnesia, and the bitter principle remains, partly free, 
and partly in a state of combination with magnesia, to which it imparts a beautiful yellow colour. Then 
upon boiling this magnesia with ether, the greater part of the bitter principle is obtained pure, and is insu- 
lated by evaporation. If it be wished to separate the bitter principle which remains in the magnesia, in a 
fixed state, and which could not be taken up by the ether, we may treat it with oxalic acid, in a quantity 
sufficient to produce slight acidity. This acid unites with the magnesia, and sets the bitter principle at 
liberty, which may be obtained in the manner already pointed out. 
Properties of Gentianine. — This substance is yellow, and inodorous, possessing very strongly the aro- 
matic bitter taste of the gentian, which is much increased by solution in an acid. It is highly soluble in 
ether and in alcohol, and separates by spontaneous evaporation in the form of very small yellow crystalline 
needles. It is much less soluble in cold water, which nevertheless it renders exceedingly bitter : in boiling 
water it is more readily dissolved. Diluted alkalis deepen its colour very much and dissolve rather more of 
it than water will alone. 
Action of Gentianine on the Animal and Human System. — M. Magendie has ascertained by experiment 
that this substance is not possessed of any poisonous qualities ; several grains injected into the veins pro- 
duced no effect. He himself swallowed two grains dissolved in alcohol, and was merely sensible of the ex- 
treme bitter taste, and a slight sensation of heat in the stomach. 
Medicinal Employment. — The tincture seems to be the preferable form for administration ; and it may 
be made in the following manner : — 
Take of Alcohol at 24° ... 1 ounce. Gentianine ... 5 grains. Mix. 
This may be substituted for the tincture of gentian, and employed in the same circumstances. 
Syrup of Gentianine. — Take of Simple syrup . . 1 pound. Gentianine . . . 16 grains. 
Make a syrup. 
This is one of the best bitters that can be employed in scrofulous affections. 
Medical Properties and Uses. — The root of this plant has been used from time immemorial as a 
valuable tonic, and occupied the first place as a febrifuge before the discovery of the Cinchonas. In large 
doses it is somewhat aperient ; but in smaller ones is found highly beneficial in dyspepsia, gout, hysteria, 
and jaundice ; and in all those cases of debility in which tonics are administered. The infusion, as ordered 
by the London College, is the most elegant and proper mode of administering it, and forms an excellent 
medium for the exhibition of chalybeates, mineral acids, and neutral salts, with which it is often necessary 
to combine it. The following is the form : — 
Take of. Gentian root, sliced, orange peel bruised, coriander seeds bruised, of each a drachm,. 
Fresh lemon peel two drachms, boiling water twelve fluid ounces. 
