Volume 1
Alle de brieven van Antoni van Leeuwenhoek / uitgegeven, geïllustreerd en van aanteekeningen voorzien door een Commissie van Nederlandsche geleerden.
- Antonie van Leeuwenhoek
- Date:
- 1939-
Licence: Public Domain Mark
Credit: Alle de brieven van Antoni van Leeuwenhoek / uitgegeven, geïllustreerd en van aanteekeningen voorzien door een Commissie van Nederlandsche geleerden. Source: Wellcome Collection.
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![are ejected and this is continued by the third, fourth and all following valves. In this manner a tree one hundred feet high does not require more force in order to propel its water or growth to its topmost part than a plant of one foot or less. I have likewise found two sorts of holes or pipes t,!), one larger than the other, in beech-, ash-, willow-, and vine-wood, as also in sugarcane and rotan. I have examined the bark of the root of the ash-tree and have found it to be so spongy as if we saw pores in it. I have made a transverse cut of the root of ashwood and examined it. Here I find also two sorts of holes, one larger than the other. I have also examined it lengthways, and find that the root also consists of ascending pipes, pierced transversely by numberless holes without any order, as if these had been forcibly bored in between the pipes1'), through which pipes the tree takes its food. Above I have told that I have found two kinds of holes or pipes in this wood, and I here suggest that the water in the plant or tree is pushed upwards through the large pipes, and that, when it is at the top and of no use to the tree or fruit, it would descend through the narrow pipes and thus cause growth and enlargement of the rootls), or else that part of this water, when it reaches the lower extremity, is mixed with the other water, is pushed upwards again and so forth19).] 16) The vessels. [Sch.] 17) The medullary rays. [Sch.] 18) See also the letters of April 5th and 7th 1676. 19) Already L. sees that the conduction of water is an important problem, but his attempts at its solution are fantastic. [Sch.] Movement of fluids in trees.](https://iiif.wellcomecollection.org/image/b31364962_0001_0059.jp2/full/800%2C/0/default.jpg)
