208 



PROPERTIES OF AIR 



and smashed under the pressure of two cubic 

 inches of lead, will remain in the sea, at the 

 depth of thirty fathoms, as entire and per- 

 fect as the most solid body. The finest fi- 

 bril of the finest blade of grass, which grows 

 at the bottom of the ocean, is found to wave 

 and to float, erect and rigid, under this im- 

 mense column of water, without suffering 

 more pressure from it, than the grass of the 

 field does from the medium of air in which it is 

 involved. This fact is more especially illus- 

 trated, by the perfect and entire manner in 

 which the leaves of corals, and of coral- 

 lines, are preserved at the greatest depths. 

 Immense forests of these vegetables are to be 

 seen, in the Indian seas; and, although the 

 fibres of which their foliage is composed, be- 

 come hard and firm, by exposure to the air ; 

 they break by the slightest touch, when they 

 are first taken out of the water; and yet they re- 

 main in it, without Isesion, or violence, at the 

 depth of 10 and 15 fathoms from the surface. 



If the assertion, which is so universally re- 

 ceived were true, that the pressure of water, 

 was in proportion to its perpendicular height 

 is it possible, I would ask, for any human be- 

 ing, to support the pressure to which lie is often 

 exposed, in consequence of .being immersed 

 in it. The facts are so numerous and common, 



