Unpublished letter, 'Further observations upon the descending fluids in plants, more especially the cambium' from George Rainey to the Royal Society

Description

Rainey relates an experiment in proof of the sap descending from the upper to the lower part of an exogenous tree, through vessels which are continuous from the leaves to the roots. The course of these vessels is shown by the addition of a solution of iodide of potassium after they had taken up by absorption a quantity of a solution of acetate of lead. The fluids in these vessels are, he conceives, separated from the sap, which is ascending from the roots, only by the membrane of which they are composed. When the leaf-buds of a tree are vegetating, large separations are observable between the cells of the bark, and also between the bark and the wood: while no such separations are apparent when the leaf-buds are entirely inactive. These separations are various in size, and irregular in form; their parietes consist of rows of cells, piled up one above another, like the bricks of a wall: and their cavities all communicate with one another. From these and other anatomical facts, which are given in detail by the author, he concludes that the propulsion of the sap along the vessels, resulting from the opera­tion of endosmose, will explain the descent of the cambium, which, being the nutritious portion of the vegetable fluids, corresponds in its nature to the chyle in animals.

Subject: Botany / Phytomorphology

Received 9 March 1843. Communicated by P M [Peter Mark] Roget.

Written by Rainey at 1 Maze Pond, Borough [London].

Whilst the Royal Society declined to publish this paper in full, an abstract of the paper was published in volume 4 of Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London [later Proceedings of the Royal Society] as 'Further observations on the descending fluids of plants, and more especially the cambium'.

Reference number

AP/26/13

Earliest possible date

09 March 1843

Physical description

Ink on paper

Page extent

10 pages

Format

Manuscript