104 OP PROGNOSTICS CHAP. 4. 7- 



violent effects when they occur near to the 

 conjunction or opposition of the Moon. 



That the Lunar influence which I have de- 

 scribed exercises its power over the animal 

 machine, by means of some changes effected in 

 it by the Electricity of the Atmosphere, is to 

 me more than probable. Occasionally I have 

 observed that similar headaches, shiverings, and 

 other nervous disorders, which occur about the 

 time of the novilunar and plenilunar changes, 

 also happen at other times when from the 

 occurrence of Thunderstorms and other the like 

 phaenomena,the electricity of the air is disturbed. 

 It may be observed that the approach of Storms, 

 particularly those which are highly electrified, 

 is generally anticipated by certain nervous 

 people by the occurrence of those disorders 

 which they are predisposed to incur ; a parti- 

 cular kind of headache, occuring in the forehead, 

 but distinguished from a headache of indiges- 

 tion, by its taking place even during a cathartic 

 operation, affords a familiar proof of my obser- 

 vation. These cephalalgias begin by slight 

 symptoms, observe a climax, and then rapidly 

 decline. The period of their greatest exacer- 

 bation, though commonly about III in the 



