THE VEGETABLE KINGDOJI. 405 



celebrated Hales made a very curious experiment on this 

 subject. Having fitted a long tube to the stem of a young 

 vine which he had severed, he saw this fluid rise forty-four 

 feet high. These results appearing very extraordinary to 

 the French physiologists, they soon repeated the experi- 

 ments of the foreign philosopher, but they were greatly 

 astonished to see that they were within the mark. In fact, 

 De CandoUe, who was one of the last to move in the matter, 

 noticed that the force with which the sap rises in the 

 vessels of the plant is equal to the pressiu^e of two atmos- 

 pheres and a half— a force which enormously exceeds, and 

 indeed almost doubles, the results obtained by the Canon 

 of Windsor, since it is equal to the weight of a column 

 of water eighty feet in height. 



Thus in an occult function, which is performed so mys- 

 teriously in the vegetable kingdom, experiment reveals a 

 powerful energy — an energy which surpasses the visible 

 and tumultuous circulation in the largest animals. Many 

 authorities have stated, not without some foundation, that 

 the sap rises in the vessels of the vine with at least five 

 times as much force as the blood circulates in the crural 

 artery of the horse — the most important blood-vessel of the 

 thigh — and with seven times as much force as in the same 

 vessel in the dog. 



It is certain that the blood which the heart projects so 

 violently into the vessels of large animals is not driven 

 with so much power as imjDels the sap in its ascending 

 movement. Indeed, experiments made on the ox and 

 horse have shown that the impulse given to the arterial 

 blood would only raise a column of blood about two 

 metres (6 feet 6f inches) ; the advantage is therefore not 

 at all on the side where it was supposed to be, since, 

 according to what has been already stated, the vegetable 



