In the latter half of the eighteenth century, many other suggestions of telegraphs based on the known properties of the electric fire were published; for example, by Joseph Bozolus, a Jesuit lecturer of Rome, in 1767; by Odier, a Geneva physicist, in 1773, who states in a letter to a lady, that he conceived the idea on hearing a casual remark, while dining at Sir John Pringle's, with Franklin, Priestley, and other great geniuses. 'I shall amuse you, perhaps, in telling you,' he says,'that I have in my head certain experiments by which to enter into conversation with the Emperor of Mogol or of China, the English, the French, or any other people of Europe... You may intercommunicate all that you wish at a distance of four or five thousands leagues in less than half an hour. Will that suffice you for glory?' George Louis Lesage, in 1782, proposed a plan similar to 'C. M.'s,' using underground wires. An anonymous correspondent of the JOURNAL DE PARIS for May 30, 1782, suggested an alarm bell to call attention to the message. Lomond, of Paris, devised a telegraph with only one wire; the signals to be read by the peculiar movements of an attracted pith-ball, and Arthur Young witnessed his plan in action, as recorded in his diary. M. Chappe, the inventor of the semaphore, tried about the year 1790 to introduce a synchronous electric telegraph, and failed. Don Francisco Salva y Campillo, of Barcelona, in 1795, proposed to make a telegraph between Barcelona and Mataro, either overhead or underground, and he remarks of the wires, 'at the bottom of the sea their bed would be ready made, and it would be an extraordinary casualty that should disturb them.' In Salva's telegraph, the signals were to be made by illuminating letters of tinfoil with the spark. Volta's great invention of the pile in 1800 furnished a new source of electricity, better adapted for the telegraph, and Salva was apparently the first to recognise this, for, in the same year, he proposed to use it and interpret the signals by the twitching of a frog's limb, or the decomposition of water.