126 



the sides to the height often inches. Yet this Heycr m- 



, -creases so as to form any drops. While you stand up- 

 right, you remark nothing more, than a slight cart by 

 smell, common in ail .subterraneous places \vhi<; 

 kept shut. But if you put down vour hand, within ten 



..inches of the ground, it feels as if you put it into the 

 Gteam of boiling water; yet your hand contracts nei 

 ther smell nor taste. A vapour similar to that fn the 

 grotto, rises also from the grown d without ; but it & 



weaker, and does not rise so high. .This partly spreads 

 itself from the cavern, partly exhales from the earth. 



Alighted flauibeau thrust. into the vapour, presently 

 goes out; yet without any noise or hissing. The thick 

 smoke which appears immediately after its extinction^ 

 remains floating on the vapour, and being lighter than! 

 it, but heavier than the air . above it, spreads between 

 both. Indeed common smoke is lighter than .air: 

 that impregnated with the vapour is heavier. 



If a young vigorous dog be held dowji within 

 -vapour, lie at first struggles, pants, snorts, and rattles in 

 .Ihe throat; but in three. minutes he lies as dead. Cany 

 him into the open air, and he draws in long draughts, <u 

 one recovering, from a fit, and in two minutes gets upoo. 

 liis legs, and seems, to ail nothing. A cock having his 

 head plunged into the vapour, was suffocated all at 

 once beyond recovery. Frogs are stupified by it in three 

 r or four minutes-', yet though they have laid in it a quar- 

 ter of an hour, soon recover when placed in the open 

 air. Large flies, beetles, .and butterflies, : were longer 

 without giving signs of their suffering, and longer in're- 



* .covering. .A toad resisted the vapour near half an hour, 

 a lizard above an hour and, a quarter; and a large grass- 

 hopper stirred in the .-vapour., after being more than two 

 hours in it. 



An English gentleman kneeled down in the grotto, 

 and leaning on his hands, bowed his face to vyithin two 

 or three inches of the ground, holding his breath, keep 

 ing his eyes open, and his tongue a .little out of hh. 

 ~xuouth. He remained thus three or four seconds, with- 

 out any painful impression, or any..sort of taste on his 



