034 PHILOSOPHICAL TRANSACTIONS. [aNNO 1754. 



silk, between two chairs placed back to back, at the distance of about 3 feet, a 

 tin tube with a fine sewing needle at one end of it; and rubbed sulphur, sealing- 

 wax, or the rough glass tube, as near as can be to the other end, for 3 or 4 

 minutes. Then will the air be found to be negatively electrical; and will con- 

 tinue so a considerable time after the apparatus is removed into another room. 



The air without-doors is sometimes found to be electrical in clear weather ; but 

 never at night, except when there has appeared an aurora borealis, and then but 

 to a small degree. How far positive and negative electricity in the air. with a 

 proper quantity of moisture between, to serve as a conductor, will account for 

 this, and other meteors sometimes seen in a serene sky, he leaves to the curious 

 in this part of natural philosophy to determine. That dry air at a great distance 

 from the earth, if in an electric state, will continue so till it meets with such a 

 conductor, seems probable from this experiment: an excited glass tube with its 

 natural polish, being placed upright in the middle of a room, by putting one 

 end of it in a hole made for that purpose in a block of wood, will generally lose 

 its electricity in less than 6 minutes, by attracting to it a sufficient quantity of 

 moisture, to conduct the electric fluid from all parts of its surface to the floor. 

 But if, immediately after it is excited, it be placed in the same manner before a 

 good fire, at the distance of about 2 feet, where no moisture will adhere to its 

 surface, it will continue electrical a whole day, and how much longer he knows 

 not. It may not be improper to mention here, that if a solid cylinder of glass 

 be set before the fire till quite dry, it may as easily be excited as a glass tube, and 

 will act like one in every respect; the first stroke will make it strongly electrical. 



XCIV. On the Ejects of Electricity in the County Hospital at Shrewsbury. By 



Cheney Hart, M.D. p. 786. 



They tried the effects of electricity in many different cases, though with little 

 success, except in the case of one woman, whose left arm had been paralytic 

 some years, and remained so, notwithstanding all the endeavours used to remedy 

 it, so that it was absolutely motionless, and senseless of heat, cold, or pain. This 

 patient had her arm electrized frequently, and the sparks were drawn from it, and 

 the greatest blows given to it, for many days successively, by which in about 8 

 or 9 days time her arm grew sensible of pain and warmth, &c. and she had some 

 little motion of her fingers, being able to grasp any thing with her arm down, 

 or before her ; but she could not lift it up to her head any better. This encou- 

 raged them to continue the electrizing 3 or 4 weeks longer; in which time she 

 had got some little strength in her arm, could open and shut her fingers, and 

 lift it half way to her head : but the pain she had from the electrizing, and the 

 fear that increased continually of new shocks, made her obstinately resist using 

 it any longer; and she chose, she said, rather to remain paralytic, than undergo 



