VOL. XXXIX.] PHILOSOPHICAL TRANSACTIONS. 5 



of the plate ; then the tube being applied to the other end of the rod, and after 

 going to the plate, on striking it gently with the finger on the backside, a light 

 appeared on the plate, and at the same time the pencil of light issued from the 

 point of the rod ; and when the hand or cheek was held near any of the angles 

 of the plate, a light issued from thence, with a small hissing noise, and the 

 pricking was felt, as when the experiments were made with the pointed rods. 



A pewter plate being laid on the stand, which had been set on a glass cylin- 

 der, applying first the tube, and then the finger, a light appeared on the plate, 

 and the end of the finger was pushed ; and when the cheek was held near the 

 edge of the plate, a snapping was heard, but not so loud as when the iron rods 

 were used. On filling the plate with water, and applying the tube and finger as 

 before, there was the same light, with the pushing of the finger and snapping, 

 as when the experiment was made with the empty plate. When the experi- 

 ment is made with water by day-light ; by applying the end of the finger near 

 the surface of the water, it appears to rise in a little hill, but on the snapping 

 noise it falls down again, putting the water into a waving motion, near the place 

 where the water had risen. 



He then took a wooden dish, and placed it on the stand, first empty ; then 

 applying the tube and the finger near the dish, a light appeared, but no pushing 

 of the finger, nor snapping. He then filled the dish with water, and the tube 

 being held over the surface of it, there appeared a greater light than when the 

 finger had been applied to the empty dish, but no snapping ; till by holding the 

 tube, after it had been well rubbed, within 2 or 3 inches of the finger that was 

 held near the surface of the water ; for then the finger was pushed, and a snap- 

 ping noise wafe heard, as when the experiment was made with the pewter 

 plate. 



By these experiments we see, that an actual flame of fire, with an explosion, 

 and an ebullition of cold water, may be produced by communicative electricity; 

 and though these effects are at present but in minimis, it is probable that in 

 time there may be found out a way to collect a greater quantity of it ; and con- 

 sequently to increase the force of this electric fire ; which, by several of these 

 experiments, seems to be of the same nature with that of thunder and 

 lightning. 



A General Method of describing Curves, by the Intersection of Right Lines, 

 moving round Points in a Given Plane. By the Rev. IVm. Braikenridge. 

 N° 436, p. 25. Translated from the Latin. 



The following general method of describing lines of any order, by the inter- 



