Plate, 'Apparatus used in 1858, in experiments on the question whether plants assimilate free nitrogen' by unknown artist Diagram, published as plate XIV, showing the design and construction of an apparatus used by the authors to test whether plants assimilate free nitrogen. Subject: Botany Published in Philosophical Transactions as 'On the sources of the nitrogen of vegetation; with special reference to the question whether plants assimilate free or uncombined nitrogen'. Received and read by the Royal Society on 21 June 1860. [1860]