M. Dutrochefs Discoveries in Vegetable Physiology. 105 



third day, when it began to sink. On the fourth day the fluid in 

 the ccecum was found to be putrid. The same results were ob- 

 tained with the inflated bladder of the Colutea arborescens, or 

 bladder senna, and also with the swimming-bladder of the carp. 



M. Dutrochet likewise found, that when an alkaline solution 

 was placed in the ccecum, endosmose took place, and exosmose 

 when the fluid contents were acid. He now placed the nega- 

 tive wire of a galvanic battery in the ccecum containing water, 

 and the positive wire in the water in which the ccecum was im- 

 mersed. Endosmose took place, and the fluid rose in the tube 

 and flowed over as before when fluids of different densities 

 were employed. But when the wires were reversed, and the 

 ccecum filled with water, exosmose took place, and the ccecum 

 was emptied. Hence our author regards such membranes as 

 minute Leyden phials, negatively electrified within, and posi- 

 tively without. This conclusion was countenanced by the fol- 

 lowing experiment. A ccecum, nearly filled with the white of 

 an egg, was closed and plunged in water. Turgidity ensued, 

 and in a few hours its inner surface was lined with coagulated 

 albumen, which is one of the effects of galvanic action. 



The upward flow of the sap, produced by the elasticity of 

 the sides of the lymphatic vessels called into action by the tur- 

 gidity of endosmose, is greatly aided by another operation which 

 M. Dutrochet calls adfluxion. 



The loss occasioned by the copious transpiration of water 

 from the leaves of plants, is supplied by endosmose in the leaves, 

 in virtue of which there is an adfluxion or motion of the sap 

 from the lymphatic vessels to the leaves. A plant of Dogs' 

 Mercury, for example, with four leaves only, continued fresh 

 four days when placed in a vessel filled with quicksilver. In 

 this experiment, " the plant," says M. Dutrochet, ?' lived at 

 the expence of the liquids which the roots contained, and which 

 were drawn up into the leaves by adfluxion only, for there could 

 be no impulse communicated in the roots, as nothing entered 

 into them from without." 



When the sap is thus drawn to the leaves, it is changed by 

 the action of light into a nutritious fluid, which is the proper 

 juice of the plant, and which descends by the alburnum and 

 liber until these parts are changed into hard wood and old bark. 



