A handbook of local therapeutics / edited by Harrison Allen.

Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: A handbook of local therapeutics / edited by Harrison Allen. Source: Wellcome Collection.

    236/554 (page 224)
    DUBOISIA. A small tree {Duboisia myoporoides), a native of Australia, The leaves are medicinal They contain the alkaloid duboisine, which is chemically identical with hyoscyamine, but physiologically is much stronger. (See Belladonna.) The sulphate is the salt most frequently used. Diseases of the Eye.—Duboisine has recently come into quite general use as a mydriatic. Its physiological action on the iris and ciliary muscle is the same as that of atropine, except that it is more prompt and energetic and of shorter duration. The latter peculiarity recommends it particularly where it is desired to paralyze the accommodation for the estimation of refraction. A solution of two grains to the ounce of the sulphate or salicylate of duboisine paralyzes the accommodation as com- pletely as a four-grain solution of atropine, and more quickly, while its effects last only about half as long as those of atropine. Recovery takes place in from five to seven days. The objection to its use is its greater tendency to produce constitu- tional disturbance. Alarming symptoms have frequently been produced by the instillation of four-grain solutions and occasionally by the use of much weaker ones. It is exceptional, however, for unpleasant results to follow the use of a two-grain solution, and this proportion is quite suffi- cient to insure the full effect of the drug. This, used three times the day before and once on the day of the examination, may be relied upon to produce complete paralysis of accommodation for testing the refraction. Duboisine is said to act well in some cases in which the irritating effect of atropine upon the conjunctiva precludes the use of the latter, but the greater danger of constitutional poisoning and the shorter duration of its effects upon the eye prevent it from competing with atropine as a thera- peutic agent. Like the other mydriatics, it must be used with caution where there is suspicion of increased intraocular tension. Duboisine is generally considered to be identical with hyoscyamine. Wood, in the recent edition of his Therapeutics, states that the most recent chemical researches seem to show that there are three mydriatic alkaloids—atro- pine, hyoscyamine, and hyoscine—daturine and duboisine being mix- tures of these. ERGOTA. Ergot of Rye. Ergot is the sclerotium of Claviceps purpurea, replacing the grain oi Secale cereale. (U. S. P.) Ergot is not the altered grain of the rye, as is usually believed, but is a parasitic fungus growing in the rye head. It contains a large proportion of fixed oil {oil of ergot), which is procured by percolating the ergot, either with ether or benzin, and evaporating the solvent. Ergot contains ecboline and ergotine, which exist in it combined with ergotic acid. Ergoiinine, a colorless, crystallized alkaloid, has also been separated, and sclerohc acid, or sclerotinic acid, has been separated by Dragendorff.