^66 



SIBTHORPIA. 



[class XIV. ORDER II. 



by oft repeated doses it accumulates in the system without producing 

 any apparent effect : when perhaps after its administration has been 

 discontinued it produces constitutional symptoms which are nausea 

 vomiting, giddiness, restlessness and a sensation of general heat in the 

 body, want of sleep, general depression, sometimes diarrhoea or saliva- 

 tion, and profuse perspiration, and the more urgent symptoms of 

 delirium, general convulsions, and insensibility follow ; the pupil is 

 dilated, the pulse slow and irregular, a perfect state of coma comes on, 

 and death terminates the scene in a few weeks, or perhaps hours. 

 Such are the general syujptoms and effects of Digitalis if incautiously 

 administered or accidentally taken; but in the hand of the careful 

 physician it is one of the most valuable of our medicines in diminishing 

 the action of the heart ; hence its value in certain stages of consumption, 

 diseases of the heart and inflammatory disorders, and almost all affec- 

 tions attended with increased vascular action, active haemorrhages, and 

 some cases of mania. Its use as a diuretic is also now well established, 

 and for its introduction to notice we are indebted to Dr. Withering, 

 who found it of the greatest use in certain stages of dropsical affec- 

 tions ; but in these cases also it requires the same cautious adminis- 

 tration, and the disease to be in a particular stage before its use will 

 be advantageous. 



The active properties of Digitalis appear to reside in a peculiar 

 alkaline salt, which has been named by Le Royer Digitalina. It is 

 soluble in water, alcohol, and ether. It exerts the same poisonous 

 action on the animal economy as the plant itself. From experiments 

 which have been made upon animals, it was found that from one half 

 to a grain and half of the Digitaline injected into their veins caused 

 speedy death without convulsions, but producing the same effect upon 

 the pulse as characterises the administration of Digitalis. 



The chemical investigation of vegetable productions is extremely 

 difficult, from the great number of their component parts. Digitalis 

 has been lately analyzed by Welding, and he obtained 



7. Volatile oil. 



8. A fixed flocky substance. 



9. Gum. 



10. A fatty substance. 



11. Extractive. 



Gallic acid. 

 Mucus. 



Red colouring matter soluble in 

 water, but not in ether or alcohol. 

 Chlorophylle. 

 Sugar. 

 Starch, a trace. 



12. Digitaline. 



13. Lignine. 



GENUS XXXIII. SIBTHORP'IA— Linn. Sihthorpia. 

 Nat. Ord. Scrophularia'ce^. Lind. 



Gen. Char. Calyx in five deep spreading segments. Corolla rotate, 

 five-cleft, two lower segments narrowest. Capsule sub-orbicular, 

 compressed, two celled, two valved. — Name given by Linnajus in 



