11 



Structures as Mutual Exponents," which was followed by another 

 on the same subject in 1856. In 1857 a paper " On the Functions 

 of the Tympanum " was also read before the Royal Society. These 

 three papers are published in the * Proceedings.' Among his other 

 medical papers, which are mostly inserted in the proceedings of 

 kindred societies, or in medical journals, the following titles will give 

 a good notion of Dr. Jago's original investigations. " The Eustachian 

 Tube : why opened in Deglutition ? " 1856 ; " Pains in the Abdo- 

 minal and Thoracic Walls," 1861; " Ophthalmoscopic Muscae Voli- 

 tantes in a very Myopic Eye," 1861; "Medicine as influenced by 

 Scientific Tendencies," 1861 ; " Entacoustics," 1868; and important 

 papers on " Entoptics," published in the ' British and Foreign 

 Chirurgical Review,' 1859. So much interest was taken in Dr. Jago's 

 papers on Entoptics that he was encouraged to continue his inves- 

 tigations on this subject, which resulted in a publication of a separate 

 treatise in 1864 under the title of ' Entoptics, with its Uses in 

 Physiology and Medicine,' giving not only his own views in some 

 detail, but also those of other writers. This work is an exposition of 

 a difficult subject, especially as the author has ventured on un- 

 trodden ground while investigating and suggesting explanations 

 of phenomena which had not hitherto been sufficiently accounted 

 for. Dr. Jago was also a contributor to the ' Journal of the Royal 

 Institution of Cornwall,' which contains his papers " On Observa- 

 tions of the Solar Phenomenon of April 5, 1871 ; " " Nangitha Cross," 

 with illustrations ; and " Ancient Cross at Trelanvean, St. Keverne." 

 During the last forty years or more, Dr. Jago took a considerable 

 interest in the proceedings of the Royal Institution of Cornwall at 

 Truro. He had served as Honorary Secretary for many years, and 

 in 1873 was elected President for two years. His presidential 

 addresses, delivered at the annual meetings of the Instjtntion, have 

 all been marked as giving the history and progress of Cornish 

 science, and even at the present time may be read with profit. As 

 a Vice-President he continued so long as he was able to take his 

 personal share of work, and his presence on all occasions was always 

 looked upon as certain. Lately, however, owing to his feeble health, 

 he was compelled to retire altogether from any active participation 

 in the management of the Institution. This forced retirement of 

 Dr. Jago from so many of his old associations was much regretted by 

 his friends. He, however, remained a Vice- President until his 

 death, and, though he was unable to attend the meetings, his interest 

 in the proceedings never abated. In 1856, Dr. Jago was appointed 

 Physician to the Royal Cornwall Infirmary, and he was also con- 

 nected with other medical institutions at Truro. On June 2, 1870, 

 he was elected a Fellow of the Royal Society. 



Dr. Jago was married in 1864 to Maria Jones, daughter of Mr. 



