[a. late L. cambium exchange (found in the Laws of the Lombards); the physiological sense, 2, occurs in 14th c. in Arnold de Villa Nova (‘cambium humiditas manifeste alterata membri continentis complexione’).]
† 1. a. Exchange, barter. b. A place of exchange, an exchange. Obs.
1708. Kersey, Cambium, the exchanging or bartering of Commodities; also an Exchange, or Place where Merchants meet.
1721–1800. in Bailey; and in mod. Dicts.
† 2. One of the ‘alimentary humours’ formerly supposed to nourish the bodily organs. Obs.
1643. T. Johnson, trans. Parey’s Wks., I. vi. (1678), 9. The Arabians have mentioned four other humors, which they term Alimentary…. The third [humor] they call by a barbarous name, Cambium, which, already put to the part to be nourished, is there fastned.
1708. Kersey, Cambium, one of the three Humours sometime thought to nourish the Body, the other two being call’d Gluten and Ros.
1721–1800. in Bailey; and in mod. Dicts.
3. Bot. A viscid substance, consisting of cellular tissue, lying immediately under the bark of exogens, in which the annual growth of the wood and bark takes place. ‘The cells are inactive during winter, but very succulent in spring. This name was formerly given to the fluid contents only of the cells.’ Syd. Soc. Lex.
(Quot. 1671 illustrates the origin of this sense from 2.)
1671. Grew, Anat. Plants, I. ii. § 23. The said sap … becomes (as they speak of that of an Animal) the Vegetative Ros or Cambium: the noblest part whereof is at last … assimilated to the like substance with the said Lignous Body.
1813. Sir H. Davy, Agric. Chem., iii. 147. The Cambium which is the mucilaginous fluid found in trees between the wood and the bark.
1877. W. Dall, Tribes N. W., 86. A species of red … derived from pine bark or the cambium of the ground-willow.
b. attrib., as in cambium-layer, -ring.
1842. Gray, Struct. Bot., iii. § 3 (1880), 78. There is always a zone of delicate young cells interposed between the wood and the bark. This is called the Cambium, or better, the Cambium-layer.
1882. Vines, Sachs’ Bot., 654. The primary bundles … are united by a cambium-ring.
