Unpublished paper, 'Preliminary communication on a theory of the suction-force of branches' by Sidney Howard Vines Vines presents brief observations on the 'suction-force of branches', beginning with [Henry Horatio] Dixon and [John] Joly's statement that 'Our theory is that this [the suction-force of the leaf] is the all-sufficient cause of the elevation of the sap, not however by establishing differences of gas-pressure, but by exerting a simple tensile stress on the liquid in the conduits.' Annotations in ink throughout. Subject: Botany Received 21 December 1896. 1896