176 MATER i A MEDIC A AND THERAPEUTICS. 



B. Of the Root : 



1. Tinctura Aconiti. 1 in 8 of spirit. DOSP, 5 to 10 min. 



2. Linimentum Aconiti. 1, in 1 of spirit, with -fa camphor. 



3. Aconitia^ An alkaloid obtained from aconite root. Made 



(1) by dissolving the alcoholic extract of the powdered 

 root in water ; (2) Precipitating the impure aconitia by 

 ammonia ; (3) Extracting the dried precipitate with 

 ether, dissolving in diluted sulphuric acid, again precipi- 

 tating with ammonia, and purifying. 



Characters. See Composition. Not given internally. 

 Preparation. 



Unguentum Aconitia3. 1 in 60. 



ACTION AND USES. 

 1. IMMEDIATE LOCAL ACTION AND USES. 



Externally. Applied to the skin, or an exposed mucous 

 membrane, aconite affects the terminations of the sensory 

 nerves, causing tingling, followed by numbness, and lowering 

 the sensibility of touch and temperature. It is, therefore, 

 used to relieve pain due to disorder of the peripheral nerves, 

 especially certain forms of neuralgia, and acute and chronic 

 rheumatism. The aconitia ointment must be employed with 

 caution. 



Internally. Aconite and aconitia cause an intensely acrid 

 sensation on the tongue, followed by persistent tingling and 

 numbness. A sense of warmth, pain, and sickness follow its 

 admission to the stomach in full doses. 



2. ACTION ON THE BLOOD. 



Aconitia enters the blood, and thence finds its way to the 

 tissues. 



3. SPECIFIC ACTION AND USES. 



Medicinal doses of aconite, taken in close succession, 

 reduce the frequency, force, and tension of the pulse ; flush 

 and moisten the skin ; and increase the amount of urine. 

 Larger doses cause a sense of illness and muscular weakness ; 

 " creeping," " tingling," " numb " sensations generally, but 

 especially on' the lips, face, and extremities, ending in 

 anaesthesia ; and disturbances of vision, hearing, and conscious- 

 ness. On analysis, it is found that the heart is briefly acceler- 

 ated, and then reduced in frequency through the nerves; its 

 force is then reduced, by direct action on the nervo-muscular 



