154 Dr. A. Schuster on 



"Experiments" page 323. 



"Nov. 7, 1749. Electrical fluid agrees with lightning in 

 " these particulars : 1. Giving light. 2. Colour of the light. 

 " 3. Crooked direction. 4. Swift motion. 5. Being con- 

 " ducted by metals. 6. Crack or noise in exploding. 7. Sub- 

 " sisting in ice or water. 8. Rending bodies it passes 

 '' through. 9. Destroying animals. 10. Melting metals. 

 "11. Firing inflammable substances. 12. Sulphureous 

 " smell. — The electric fluid is attracted by points. — We do 

 "not know whether this property is in lightning. — But 

 " since they agree in all the particulars wherein we can 

 " already compare them, is it not probable they agree 

 " likewise in this ? Let the experiment be made." 



During the succeeding year he formulates more clearly 

 how the observations may be carried out, and in an article 

 forwarded to Peter Collinson on July 29, 1750 {Experiments, 

 p. 54, Works, Vol. I., p. 216), writes as follows : — 



" To determine the question whether the clouds that 

 " contain lightning are electrified or not, I would propose an 

 " experiment to be try'd when it may be done conveniently. 

 " On the top of some high tower or steeple, place a kind of 

 " sentry box big enough to contain a man and electrical 

 " stand. From the middle of the stand let an iron rod rise 

 " and pass bending out of the door and then upright 20 or 

 " 30 feet, pointed very sharp at the end. If the electrical 

 " stand be kept clean and dry, a man standing on it when 

 " such clouds are passing low, might be electrified and afford 

 " sparks, the rod drawing fire to him from a cloud. If any 

 " danger to the man should be apprehended (though I think 

 " there would be none) let him stand on the floor of his box 

 " and now and then bring near the rod the loop of a wire 

 " that has one end fastened to the leads, he holding it by a 

 " wax handle ; so the sparks, if the rod is electrified, will 

 4< strike from the rod to the wire, and not affect him." 



The experiment was first performed by d'Alcibard, at 



