Unpublished letter, 'An account of the water of the well Zem Zem with a qualitative analysis of the same by Professor [Michael] Faraday' from John Davidson to the Secretary of the Royal Society Davidson analyses a sample of water collected from the well Zem-Zem at Jedda [Jeddah, Saudi Arabia]. Includes a letter from Faraday dated 3 April 1835. Written by Davidson at St James Street [London]. Subject: Hydrology Received and read 14 May 1835. Whilst the Royal Society declined to publish this paper in full, an abstract of the paper was published in volume 3 of Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London [later Proceedings of the Royal Society] as 'An account of the water of the well Zem-zem, with a qualitative analysis of the same by Professor Faraday; in a letter from John Davidson, Esq., to the Secretaries, and communicated by them'. 1835