VOL. XLV.] i'HILOSOPHICAL TRANSACTIONS. 555 



enough to be measured, we then should be able to ascertain its velocity to the 

 distance equal to half the quantity of wire employed only, let the manner of the 

 electricity's discharging itself be what it would. 



To make the experiment, the same phial tilled with filings of iron, and coated 

 with sheet-lead, which was used last year, was placed in the window of the room 

 near the machine, and was connected to the prime conductor by a piece of wire* 

 To the coating of this phial a wire was fastened ; which being conducted on dry 

 sticks to the before-mentioned field, was carried in like manner to the bottom ; 

 and being conducted thus from the bottom of the field to the top, and from the 

 top to the bottom 7 other times, returned again into the room and was held in 

 one hand of an observer near the machine. From the other hand of this obser- 

 ver, another wire, of the same length with the former, was conducted in the 

 same manner, and returned into the room, and was fastened to the iron rod with 

 which the explosion was made. The whole length of the wires, allowing 10 

 yards for their turns round the sticks, amounted to 2 miles a quarter and 6 

 chains, or 12276 feet. 



WheTi all parts of the apparatus were properly disposed, several explosions of 

 the charged phial were made ; and it was invariably seen, that the observer hold- 

 ing in each hand one of the extremities of these wires was convulsed in both his 

 arms in the instant of making the explosions. 



Instead of one, 4 men were then placed, holding each other by the hand near 

 the machine, the first of which held in his right hand one extremity of the wire, 

 and the last man the other in his left. These also were all seen convulsed in 

 the instant of the explosion. Every one who felt it complained of the severity 

 of the shock. 



On these considerations we were fully satisfied, that through the whole length 

 of this wire, being 12276 feet, the velocity of electricity was instantaneous. 



Of Double Fetuses of Calves. By M. le Cat, M.D., F.R.S., i^c. Dated at 

 Rouen, August 20, 1748, N.s. N° 480, p. 497. 



M. le Cat had since the month of January 1735, been in possession of a child, 

 bom in the city of Rouen, which had 2 heads, 4 arms, 4 lower extremities, and 

 2 trunks united, and as it were blended together. About that time he published a 

 Description * of the internal parts of this monster, which had but one heart ; but 

 he did not cause drafts to be taken of those parts : and it was afterwards a diffi- 

 cult matter to have them drawn so as to exhibit a good representation of the 

 state in which they then were. This negligence, through which he was de- 

 prived of those curious and instructive figures, which this monstrous birth would 



* Journal de Verdun for March 1735, p. 19*. Orig. 

 4 B 2 



