VOL XXXVII.] I'HILOSOPHICAL TKANSACTIONS. 45Q 



leaf-brass being laid on a stand under it, and the tube rubbed, the brass was at- 

 tracted by the bubble, when the tube was held near the hair-line. He then re- 

 peated the experiment with another bubble, holding the tube near the small end 

 of the pipe ; and the attraction was now much greater, the leaf-brass being at- 

 tracted to the height of near 2 inches. 



March 25, he repeated this experiment after a somewhat different manner : 

 the pipe was now suspended by 2 lines of white sewing silk, of about 5^ feet 

 long : these were hung on 2 nails, driven into the beam of his chamber, about 

 a foot distant from each other, by loops at the other ends of the lines, by which 

 the pipe was suspended : then the bubble being blown, by holding the tube to 

 the small end of the pipe, the bubble attracted the leaf-brass to the height of 

 near 4 inches. This experiment was made to see whether fluid bodies would 

 not have an electricity communicated to them. 



April 8, Mr. Gray made the following experiment on a boy between 8 and Q 

 years of age. His weight, with his clothes on, was 47 lb. 10 oz. He suspended 

 him in a horizontal position, by 2 hair-lines, such as clothes are dried on : they 

 were about 13 feet long, with loops at each end. There was driven into the 

 beam of his chamber, a pair of hooks opposite to each other ; and 2 feet from 

 these another pair in the same manner. 



On these hooks the lines were suspended by their loops, so as to be in the 

 manner of two swings, the lower parts hanging within about 2 feet from the floor 

 of the room: then the boy was laid on these lines with his face downwards; one 

 of the lines being put under his breast; the other under his thighs. Then the 

 leaf-brass was laid on a stand, which was a round board of a foot diameter, with 

 white paper pasted on it, supported on a pedestal a foot high, which Mr. Gray 

 had frequently used in his experiments. The tube being rubbed, and held near 

 his feet, without touching them, the leaf-brass was very vigorously attracted by 

 the boy's face; so as to rise to the height of 8, and sometimes 10 inches. 

 Mr. Gray put a great many pieces of leaf-brass on the board together, and 

 almost all of them rose up together at the same time. Then the boy was laid 

 with his face upwards ; and the hinder part of his head, which had short hair 

 on, attracted, but not at quite so great a height as his face did. Then the 

 leaf-brass was placed under the boy's feet, his shoes and stockings being on, and 

 the tube held near his head ; his feet attracted, but not at so great a height as 

 his head ; then leaf-brass was again laid under his head, and the tube over it ; 

 but there was then no attraction ; nor was there any, when the leaf-brass was 

 laid under his feet, and the tube held over them. 



April l6, Mr. Gray repeated the experiment with the boy : but now the at- 

 traction was not quite so strong as at the first, the leaf-brass not rising higher 

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