chap, ii.] f Plants. De la Baisse. 483 



sap, namely the structure of the more delicate parts of the 

 plant, the knowledge of which had not advanced since the 

 days of Malpighi and Grew. Since most of them made no 

 phytotomical investigations of their own, and only partially 

 understood the descriptions of those writers, they had to be 

 content with misty and often quite inaccurate ideas of the 

 inner structure of wood and bark, and yet expected to obtain 

 an insight into the movement of the sap in them. In reading 

 the writings of Malpighi, Grew, Mariotte, Hales and even 

 Wolff, notwithstanding many mistakes in details we find a 

 pleasure in the connected reasoning, and in the sagacity which 

 knew how to distinguish between what was important and 

 what was not ; whereas the observers, whom we have now to 

 mention, give us only isolated statements, nor have we the 

 satisfaction of feeling that we are conversing with men of 

 superior understanding. 



We may pass over the unimportant writings of Friedrich 

 Walther (1740), Anton Wilhelm Platz (1751) and Rudolph 

 Bohmer (1753), as merely barren exercises; but some notice 

 should be taken of those of De la Baisse and Reichel, since 

 these authors at least endeavoured to bring to light something 

 new. But the method which they employed of making living 

 plants suck up coloured fluids was calculated to give rise 

 to serious errors both at the time and afterwards. Magnol 

 had mentioned experiments of the kind in 1709, and the 

 Jesuit father Sarrabat, known by the name of De la Baisse, 

 occupied himself with them and described them in a treatise, 

 1 Sur la circulation de la seve des plantes,' 1733, which received 

 a prize from the academy of Bordeaux \ He set the roots 

 of different plants in the red juice of the fruit of Phytolacca, 

 and found that in two or three days the whole of the bark of 

 the roots and especially the tips of the root-fibres were coloured 



1 See Sprengel, 'Geschichte der Botanik,' i. 229, and Reichel'a rod 

 Bonnet's works mentioned below. 



I i 2 



