380 MEDICAL BOTANY. 



Quinia exists in all the Cinchona barks ; but most plentifully in the yel- 

 low varieties, in all of them in the form of Kinate of quinia. It is most 

 readily obtained by precipitating it from a solution of the disulphate, by means 

 of ammonia. It is in the form of a white powder, being crystallized with 

 much difficulty ; it is readily fused into a resinous mass ; it is little soluble in 

 water, but easily so in alcohol ; it forms crystallizable salts with acids, the 

 solutions of which are precipitated by tannin. It is usually employed in the 

 form of the Disulphate, which is the preparation generally known under the 

 name of Quinine. Comp. C 30 H 12 O- N. 



Cinchonia also is found in all the barks, but is in the largest proportions 

 in the pale varieties. It always occurs in the form of a Kinate. When 

 pure, it is in large, brilliant, four-sided prisms, nearly insoluble in cold water, 

 but readily so in alcohol. It forms crystallizable salts with the acids, and 

 the solutions of them are precipitated by tannin. Comp. C 20 H ia N O. 



Medical Uses, fyc.-r— Cinchona and its preparations are universally admitted 

 to be the most powerful and effective of all of the vegetable tonics. The 

 barks, in substance, decoction, or infusion, are somewhat astringent, but 

 eminently tonic and antiperiodic. When taken in a moderate dose, and re- 

 peated in a few hours, it causes increased force and frequency of the pulse, 

 augmented heat of the surface, and an improved tone of the system generally. 

 The digestive and assimilative functions are promoted, but the secretions of 

 the mucous membranes are usually diminished, and in most persons consti- 

 pation is induced, though occasionally an opposite condition ensues. Bark is 

 prescribed as a tonic where debility exists, but more especially to arrest the 

 attacks of periodic diseases, as Intermittent and Remittent fevers, Neuralgia, 

 &c. In what manner it acts, is not understood, though various hypo- 

 theses have been formed on the subject. Bark is given, in substance, decoc- 

 tion, infusion, and tincture. But since the discovery of Quinia, this alkaloid, 

 in the form of the sulphate, has nearly superseded all other preparations. 

 The numerous applications of Cinchona and Quinia to different forms of dis- 

 ease and conditions of the system, cannot be treated upon in a work of the 

 present character without exceeding all due limits.* 



The dose of Bark, in powder, is from 9j. to 3j., or more where the sto- 

 mach can bear it ; of the infusion, from f3j. to fjij. three times a day ; of the 

 decoction, about the same; of the tincture, from f3j. to f3iij. The sulphate 

 of Quinia is given in doses of gr. j. to grs. v. ; but of late years, in some parts 

 of our country, in much larger quantities, it having been exhibited in 9j. 

 doses, and it is said with good effects. Many other salts of Quinia have 

 been highly praised, a full account of which will be found in Professor Dun-, 

 glison's New Remedies. 



Uncaria. — Schreber. 



Calyx 5-cleft, urceolate, limb short. Corolla funnel-shaped, throat naked, lobes five, 

 spreading, oval-oblong, tube slender. Anthers included or protruded. Style filiform, ex- 

 serted ; stigma tumid, not cleft. Capsules pedicellated, clavate. Seeds numerous, wing- 

 ed, imbricated. 



A genus of climbing plants, principally found in the East Indian islands 

 and Malayan peninsula, having flowers in loose heads, the peduncles when 

 old, becoming axillary, compressed, hooked spines. 



* See on this subject, Percira, Elem. Mat. Med., ed. 2d, ii. 444, et seq. ; Dunglison, 

 New Remedies, ed. 5th, 524, et seq.; Dunglison, Therap. and Mat. Med., ed. 3d, ii. 76, et 

 seq., &c. 



