Paper · 1808 · Philosophical Transactions of the Royal Society of London

XX. On the origin and office of the alburnum of trees

Thomas Andrew Knight

5
claims
9
verbatim quotes
1
citations
1
research areas
—
Not open access

Abstract

My Dear Sir, In my last communication 1 endeavoured to prove that the bark of trees is not subsequently transmuted into alburnum; and if the statements that I have there given be correct, they are, I conceive, decisive on the point for which I contended: and if the bark be not converted into alburnum, the experiments of Duhamel, and subsequent naturalists, and those of which I have given an account in former memoirs, afford sufficient evidence that the bark deposits the alburnous matter. If the succulent shoot of a horse chesnut, or other tree, be examined, at successive periods in the spring, it will be seen that the alburnum is deposited, and its tubes arranged, in ridges beneath the cortical vessels ; and the number of these ridges, at the base of each leaf, will be found to correspond accurately with the number of apertures through which the vessels pass from the leaf-stalks into the interior bark, the alburnous matter being apparently deposited (as I have endeavoured to prove in former memoirs) by a fluid which descends from the leaves, and subsequently secretes through the bark. I shall therefore venture to conclude that it is thus deposited, and shall proceed to enquire into the origin and office of the alburnous tubes. The position and direction of these tubes have induced almost all naturalists to consider them as the passages through which the sap ascends ; and at their first formation, when the substance which surrounds them is still soft and succulent, they are always filled with the fluid, which has apparently secreted from the bark. They appear to be formed in the soft cellular mass, which becomes the future alburnum, as receptacles of this fluid, to which they may either afford a passage upwards, or simply retain it as reservoirs, till absorbed, and carried off, by the surrounding cellular substance. The former supposition is, at first view, the most probable; but the latter is much more consistent with the circumstances that I shall proceed to state.

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Claims 5

Observationobservedoriginal resultmeasured

Claim · model-written summary

In succulent horse chestnut shoots, alburnum is deposited in ridges beneath the cortical vessels.

Taxon
horse chesnute1
Organ / stage
succulent shoote1
Outcome
alburnum is depositede1

Verbatim

e1

“If the succulent shoot of a horse chesnut, or other tree, be examined, at successive periods in the spring, it will be seen that the alburnum is deposited, and its tubes arranged, in ridges beneath the cortical vessels”

✓ located verbatim in the source · abstract, characters 493–711 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

The number of alburnum ridges at the base of each leaf corresponds accurately to the number of leaf-trace apertures through which vessels pass into the bark.

Taxon
horse chesnute1
Outcome
number of these ridgese2
Qualifier
correspond accuratelye2
Comparator
number of aperturese2

Verbatim

e1

“If the succulent shoot of a horse chesnut, or other tree, be examined, at successive periods in the spring, it will be seen that the alburnum is deposited, and its tubes arranged, in ridges beneath the cortical vessels”

✓ located verbatim in the source · abstract, characters 493–711 · show in text ↑
e2

“the number of these ridges, at the base of each leaf, will be found to correspond accurately with the number of apertures through which the vessels pass from the leaf-stalks into the interior bark”

✓ located verbatim in the source · abstract, characters 718–914 · show in text ↑
Mechanismauthor interpretationoriginal resultbasis n/a

Claim · model-written summary

Alburnous matter is apparently deposited by a fluid descending from the leaves that secretes through the bark.

Taxon
treest0
Outcome
alburnous mattere3
Qualifier
by a fluid which descends from the leavese3

Verbatim

t0

“the alburnum of trees”

✓ located verbatim in the source · title, characters 32–53 · show in text ↑
e3

“the alburnous matter being apparently deposited (as I have endeavoured to prove in former memoirs) by a fluid which descends from the leaves, and subsequently secretes through the bark”

✓ located verbatim in the source · abstract, characters 916–1100 · show in text ↑
Mechanismauthor interpretationoriginal resultbasis n/a

Claim · model-written summary

The bark deposits the alburnous matter, according to the earlier experiments the author cites.

Taxon
treest0
Organ / stage
barke4
Outcome
alburnous mattere4

Verbatim

t0

“the alburnum of trees”

✓ located verbatim in the source · title, characters 32–53 · show in text ↑
e4

“afford sufficient evidence that the bark deposits the alburnous matter”

✓ located verbatim in the source · abstract, characters 421–491 · show in text ↑
Mechanismhypothesisoriginal resultbasis n/a

Claim · model-written summary

The alburnous tubes more probably retain fluid as reservoirs than afford a passage upwards.

Taxon
treest0
Outcome
receptacles of this fluide5
Qualifier
simply retain it as reservoirse5

Verbatim

t0

“the alburnum of trees”

✓ located verbatim in the source · title, characters 32–53 · show in text ↑
e5

“as receptacles of this fluid, to which they may either afford a passage upwards, or simply retain it as reservoirs”

✓ located verbatim in the source · abstract, characters 1660–1774 · show in text ↑