Unpublished paper, 'Researches into the structure of the spinal cord' by Jacob Augustus Lockhart Clarke Clarke shares a series of observations with the view of determining the relationship between the spinal nerves and the respiratory nervous centres. After stating that the observations were made, by means of a microscope of the best construction, upon many thousand preparations of the spinal cord of a man, a calf, a sheep, a pig, a dog, a cat, a rabbit, a guinea-pig and a frog, he describes the methods adopted in making these preparations. Marked on title page as 'Not to be printed - see other copy'. Subject: Neuroscience Received 15 October 1850. Read 5 December 1850. Communicated by Samuel Solly. Whilst the Royal Society declined to publish this paper in full, an abstract of the paper was published in volume 6 of Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London [later Proceedings of the Royal Society] as 'Researches into the structure of the spinal cord''. 1850