VOL. LXXVI.] PHILOSOPHICAL TKANSACTIONS. 135 



with red, green, and white spots, the white ones particularly bright ; the eyes 

 large, the iris red, its outer edge tinged with yellow. 



The island of Johanna is situated in latitude 12° 13' south. The coast is 

 wholly composed of coral rocks, which are in many places hollowed by the sea. 

 In these cavities Mr. P. found several of the electrical fishes. The water is 

 about 5d^ or 6o° of heat of Fahrenheit's thermometer. He caught 2 of them 

 in a linen bag, closed up at one end, and open at the other. In attempting 

 to take one of them in his hand, it gave him so severe an electrical shock, that 

 he was obliged to quit his hold. He however secured them both in the linen 

 bag, and carried them to the camp, which was about 2 miles distant. On his 

 arrival there, one of them was found to be dead, and the other in a very weak 

 state, which made him anxious to prove, by the evidence of others, that it 

 possessed the powers of electricity, while it was yet alive. He had it put into a 

 tub of water, and desired the surgeon of the regiment to lay hold of it between 

 his hands ; on doing which he received an evident electrical stroke. Afterwards 

 the adjutant touched it with his finger on the back, and felt a very slight shock, 

 but sufficiently strong to ascertain the fact. 



XX. Observation of the Transit of Mercury over the Suns Disc, made at Lou- 

 vain, in the Netherlands, May 3, 1786. By Nathaniel Pigot, Esq., F.R.S. 

 p. 384. 



About 6 o'clock, when Mr. P. attended for the observation, there beino- a 

 great number of solar spots, Mercury might easily have been mistaken for one ; 

 but his motion soon removed every doubt in that respect. Flying clouds ob- 

 scured the sun at intervals ; but during the last half hour, the weather was 

 fine, the sky clear, the limb of the sun well defined ; Mercury round and very 

 black. There seems to have been some mistake, in respect of this phenomenon, 

 either in the calculation or the printing of the Connoissance des Temps of this 

 year : the emersion of the centre of Mercury is there set down at ig^ 45™ appa- 

 rent time at Paris ; whereas, by his observation, the egress of the centre at Lou- 

 vain was at 20^ 47™ 28* or 20* apparent time. Taking here no other equation into 

 consideration, besides the difference of meridians between Paris and Louvain, 

 which by a great number of observations, he determined in 1775 to be 9™ 37* 

 in time, the emersion of the centre at Paris must have been at 20^ 37™ 51* or 

 52% which differs nearly 53™ from the computed time. 



By observation, the internal contact at the egress 20^ 45™ 41% and the ex- 

 ternal contact at ,20*^ 49™ 16*. 



XXI. Observation of the late Transit of Mercury ever the Sun, observed by 



Edward Pigott, Esq., at Louvain, in the Netherlands, p. 389. 

 We have been fortunate here in seeing Mercury's egress. I observed it thusr 



