Anthony Carlisle, William Nicholson 107 



work had earned for him the Fellowship of the Royal 



Society in 1791, and desirous of showing his appreciation 



of the honour, he not only contributed an important paper 



to the Philosophical Transactions in 1793, but announced 



his latest and greatest discovery in a letter addressed to 



the President of the Royal Society, Sir Joseph Banks. That 



letter bears the date March 20th, 1800, and appears to have 



been sent in two parts, the second of which was delayed 



in delivery, so that it could not be read before the meeting 



of the Society, held on June 26th of the same year. In 



the meantime, the first part of the letter had been privately 



communicated to Sir Anthony Carlisle, the celebrated 



surgeon of Westminster Hospital, and Professor of Anatomy 



to the Royal Academy. Carlisle was mainly interested in 



the physiological effects of electricity, and consulted William 



Nicholson, a man of varied interests, who was employed 



at different times as an official in the East India Company, 



a traveller for the firm of Wedgwood, a school teacher and 



a civil engineer. He had embarked on the publication of 



a scientific periodical Nicholson's Journal and relates in 



its fourth volume the important results he obtained by 



experimenting with the battery constructed according to 



Volta's directions. When two brass wires connected with 



the electric poles were immersed in a tube containing water, 



gas bubbles were seen to rise from one of the wires, while 



the other became corroded. The gas proved to be hydrogen. 



On replacing the brass wires by platinum, it was found that 



oxygen was set free as well as hydrogen ; the electrolytic 



decomposition of water was thus completely effected. This 



was the first step in the brilliant series of experiments by 



which English chemists and physicists traced the connexion 



between chemical and electric action. But we must here 



interrupt our account, and turn for a moment to another 



subject. 



The time had come when the correlation between the 

 various physical manifestations, such as light, heat and 

 power, forced itself into the foreground. The production of 

 heat by mechanical means was effected on a convincing scale 

 by Benjamin Thompson, better known as Count Rumford, 

 who had entered the service of Bavaria for the purpose of 



