CLASS IV. 2. 2. 8. OF ASSOCIATION. 4 1 7 



which prevents the evaporation of the perfpirable matter, and 

 thence diminifhes one caufe of external cold. 



M. M. Valerian in powder two drams three or four times 

 a day is recommended. The bark. Chalybeates. A grain of 

 opium twice a day for a long time. From five to ten drops of 

 the faturated folution of arfenic two or three times a day. See 

 Clafs I. 2. 4. 1 1. A lady once aflured me, that when her head- 

 ach was coming on, me drank three pints (pounds) of hot water, 

 as hailily as me could ; which prevented the progrefs of the dif- 

 eafe. A folution of arfenic is recomnaended by Dr. Fowler of 

 York. Very ftrong errhines are faid fometimes to cure head- 

 achs taken at the times ih~ pain recurs, till a few drops of blood 

 ifiue from the noftrils. As one grain of tupeth mineral (vitriol- 

 ic calx of mercury) mixed with ten grains of fine fugar, Eu- 

 phorbium or cayenne pepper mixed with fugar, and ufed with 

 caution as an errhine. See the M. M. of the next Species. 



8. Hemicraniafympathetica. Sympathetic pain on one fide of 

 the head. This difeafe is attended with cold Ikin, and hence 

 whatever may be the remote caufe, the immediate one feems 

 to be want of ftimulus, either of heat or diftention, or of fome 

 other unknown ftimulus in the painful part ; or in thofe, with 

 which it is ailbciated. The membranes in their natural (late 

 are only irritable by diftention ; in their difeafed ftate, they are 

 fenfible like mufcular fibres. Hence a difeafed tooth may ren* 

 der the neighbouring membranes fenfible, and is frequently the 

 caufe of this difeafe. 



Sometimes the ftomach is torpid along with the pained mem- 

 brane of the head j and then ficknefs and inappetency attend 

 either as caufes or confequences. The natural cure of hemi- 

 crania is the accumulation of fenforial power during the reft or 



ficknefs of the patient. Mrs. is frequently liable to hem- 



icrania with ficknefs, which is probably owing to a difeafed 

 tooth ; the paroxyfm occurs irregularly, but always after fome 

 previous fatigue, or other caufe of debility. She lies in bed, 

 lick, and without taking any folid food, and very little of fluids, 

 and thofe of the aqueous kind, and, after about 48 or 50 hours, 

 rifes free from complaint. Similar to this is the recovery from 

 cold paroxyfms of fever, from the torpor occafioried by fear, 

 and from fyncope ; which are all owing to the accumulation of 

 fenforial power during the inactivity of the fyftem. Hence it ap- 

 pears, that, though when the fenforial power of volition is much 

 cxhaufted by fatigue, it can be reftored by eight or ten hours of 

 deep; yet, when the fenforial power of irritation is exhaufted 

 by fatigue, that it requires two whole folar or lunar days of refh, 

 before it can be reftored. 



VOL. IL F F f Th 



