GLASS IV. 2. 2. 8. OF ASSOCIATION. 417 



which prevents the evaporation of the perspirable matter, and 

 thence diminishes one cause of external cold. 



M. M. Valerian in powder two drachms 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 

 saturated solution of arsenic two or three times a day. See Class 

 I. 2. 4. 11. A lady once assured me, that when her head-ach 

 was coming on, she drank three pints (pounds) of hot water, as 

 hastily as she could; which prevented the progress of the disease. 

 A solution of arsenic is recommended by Dr. Fowler of York. 

 Very strong errhines are said sometimes to cure head-achs, taken 

 at the times the pain recurs, till a few drops of blood issue from 

 the nostrils. As one grain of turpeth mineral (vitriolic calx of 

 mercury) mixed with ten grains of fine sugar. Euphorbium, or 

 cayenne pepper, mixed with sugar, and used with caution as an 

 errhine. See the M. M. of the next Species. 



8. Hemicrania sympathetica. Sympathetic pain on one side 

 of the head. This disease is attended with cold skin, and hence 

 whatever may be the remote cause, the immediate one seems to 

 be want of stimulus, either of heat or distention, or of some other 

 unknown stimulus in the painful part; or in those with which it 

 is associated. The membranes in their natural state are only 

 irritable by distention; in their diseased state, they are sensible 

 like muscular fibres. Hence a diseased tooth may render the 

 neighbouring membranes sensible, and is frequently the cause of 

 this disease. 



Sometimes the stomach is torpid along with the pained mem- 

 brane of the head; and then sickness and inappetency attend 

 either as causes or consequences. The natural cure of hemicrania 

 is the accumulation of sensorial power during the rest or sickness 



of the patient. Mrs. is frequently liable to hemicrania with 



sickness, which is probably owing to a diseased tooth; the pa- 

 roxysm occurs irregularly, but always after some previous fatigue, 

 or other cause of debility. She lies in bed, sick, and without 

 taking any solid food, and very little of fluids, and those of the 

 aqueous kind, and, after about 48 or 50 hours, rises free from 

 complaint. Similar to this is the recovery from cold paroxysms 

 of fever, from the torpor occasioned by fear, and from syncope; 

 which are all owing to the accumulation of sensorial power dur- 

 ing the inactivity of the system. Hence it appears, that, though 

 when the sensorial power of volition is much exhausted by fa- 

 tigue, it can be restored by eight or ten hours of sleep; yet, when 

 the sensorial power of irritation is exhausted by fatigue, that it 

 requires two whole solar or lunar days of rest, before it can be 

 restored. 



VOL. n, 3 H 



