Manuscript, 'On the effects of increased arterial pressure on the mammalian heart' by J A [John Alexander] MacWilliam MacWilliam writes: 'The following is a short preliminary statement of some of the main facts elicited in the course of a recent investigation. The experiments were conducted on chloroformed cats.' Annotations in pencil and ink. Includes four diagrams showing the rhythm of the heartbeat. Subject: Physiology Received 30 May 1888. Read 7 June 1888. Communicated by Michael Foster A version of this paper was published in volume 44 of the Proceedings of the Royal Society as 'On the effects of increased arterial pressure on the mammalian heart'. 1888