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, 'Sur la circulation de la seve des plantes,' 1733, which received a prize from the academy of Bordeaux[1]. 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
- ↑ See Sprengel, 'Geschichte der Botanik,' i. 229, and Reichel's and Bonnet's works mentioned below.
