166 



very act of fermentation, should discharge this spirit 

 through a small vent-hole in the f top of a vessel, and the 

 stoutest man should apply his nose to the hole, and at 

 once draw in this vapour, he would drop down dead 

 in an instant, without any apparent cause of it. It ex- 

 tinguishes flame instantaneously. If a lighted candle be 

 let slowly into it, the flame is borne up from the wick, 

 and the candle may be raised up again so as to receive 

 the flame." One put a mouse into it, which was kindled 

 in about a second of time, it kicked once or twice, and 

 then was quite dead. 



May we ascribe to a kind of damp, a sort of murrain, 

 which appeared in Italy, and made a great havoc among 

 the cattle ? It spread itself in the form of a blue mist, 

 over those pastures where they grazed, so that whole 

 herds came home sick, and most of them died in twenty- 

 four hours. Many who went among them were in- 

 fected, and died in the same manner. Some imputed 

 this contagion to noxioas vapours thrown out of the 

 earth by earthquakes preceding. It passed through 

 Germany to Poland, going without intermission eleven 

 or twelve miles in twenty-four hours, and suffering no 

 cattle in its way to escape, whether 'within doors or 

 without. Hence others imagined it was owing to some 

 volatile insect, which was able to make but short flights. 



9. Ignis Fatuus, vulgarly called Will with the Wisp, 

 is chiefly seen in dark nights, irregularly moving over 

 meadows, marshes, and other moist places. It seems 

 to be a viscous exhalation, which being kindled in the 

 air, reflects a kind of thin flame in the dark, though 

 without any sensible heat. It is often found to fly along 

 rivers or hedges, probably because it there meets with a 

 stream of air to direct if. In Italy there are luminous 

 appearances nearly resembling these. *"hich, on a close 

 inspectioB, have been found to be no other than swarms 

 of shining flies. 



In all the territories of Bologna these Jlery appear- 

 ances are common. There are some places where one 



