Manuscript, 'Preliminary communication on the nature of the contagium of Rinderpest' by Alexander Edington Edington communicates the results of experiments made in South Africa on the infectivity of the blood of animals affected with Rinderpest. The experiments were all made on cattle kept under conditions in which accidental spontaneous infection could with certainty be excluded. These experiments had been concluded in 1896, before the arrival of [Robert] Koch in South Africa, and their results had been communicated to him on his arrival. Annotations in pencil and ink throughout. Includes two plates of figures of bacteria in petri dishes. Subject: Pathology Received 22 March 1897. Read 3 June 1897. Communicated by Sir James Crichton-Browne. A version of this paper was published in volume 61 of the Proceedings of the Royal Society as 'On the nature of the contagium of Rinderpest. Preliminary communication'. 22 February 1897