20 THE VEGETABLE WORLD. 
tion, the least dense liquid passing, however, more rapidly than the 
other ; and if we adapt a vertical tube to the vessel, B, we see it 
gradually rising in the tube. This curious result is called Endos- 
mose by chemists. This phenomenon, which has been carefully 
studied by chemists and botanists, is visibly in action in the vital 
functions of plants. The fibrous extremities of vegetables are 
filled with liquids and 
saccharine matter heavier 
than the water which sur- 
passage of water through 
the thin cellular exterior 
tissues takes place; thence 
the water rises up through 
the interior vessels of the 
plant, as we have seen it rise | 
in the tube of the Endos- 
mometer. In this manner 
the first movement of 
ascension is produced. 
But the mere power of 
endosmose would not force 
the foreign fluids very far 
up into the vessels of the 
plant. A second force 
a . which here intervenes sin- 
iANTL a . 
Vis: SL 2 tibet gularly accelerates their 
upward progress. When a 
liquid “has begun to penetrate, by means of endosmose, at the 
extremities of the root, the density of the liquid contained in 
these radicular extremities being thus diminished by dilution, 
there is a current formed for them in the interior of the root. 
After that the force known in physics by the name of capillarity 
promotes the ascent of the liquid in the more elevated part of the 
root. The internal walls of each cell of the root exercise on the 
liquid which it contains the force of capillarity ; in other words, an 
