form), with his remarks, at the end of a new Latin dialogue which he had meanwhile written in defence of another part of his philosophical doctrine. This was the _Dialogus physicus, sive De natura aeris_ (_L.W._ iv. 233-296), fulminated in 1661 against Boyle and other friends of Wallis who, as he fancied, under the influence of that malevolent spirit, were now in London, after the Restoration, forming themselves into a society (incorporated as the Royal Society in 1662) for experimental research, to the exclusion of himself personally, and in direct contravention of the method of physical inquiry enjoined in the _De corpore_.[17] All the laborious manipulation recorded in Boyle's _New Experiments touching the Spring of the Air_ (1660), which Hobbes chose, without the least warrant, to take as the manifesto of the new "academicians," seemed to him only to confirm the conclusions he had reasoned out years before from speculative principles, and he warned them that if they were not content to begin where he had left off their work would come to nought. To as much of this diatribe as concerned himself Boyle quickly replied with force and dignity, but it was from Hobbes's old enemy that retribution came, in the scathing satire _Hobbius heauton-timorumenos_ (1662). Wallis, who had deftly steered his course amid all the political changes of the previous years, managing ever to be on the side of the ruling power, was now apparently stung to fury by a wanton allusion in Hobbes's latest dialogue to a passage of his former life (his deciphering for the parliament the king's papers taken at Naseby), whereof he had once boasted but after the Restoration could not speak or hear too little. The revenge he took was crushing. Professing to be roused by the attack on his friend Boyle, when he had scorned to lift a finger in defence of himself against the earlier dialogues, he tore them all to shreds with an art of which no general description can give an idea. He got, however, upon more dangerous ground when, passing wholly by the political insinuation against himself, he roundly charged Hobbes with having written _Leviathan_ in support of Oliver's title, and deserted his royal master in distress. Hobbes seems to have been fairly bewildered by the rush and whirl of sarcasm with which Wallis drove him anew from every mathematical position he had ever taken up, and did not venture forth into the field of scientific controversy again for some years, when he had once followed up the physical dialogue of 1661 by seven shorter ones, with the inevitable appendix, entitled _Problemata physica, una cum magnitudine circuli_ (_L.W._ iv. 297-384), in 1662.[18] But all the more eagerly did he take advantage of Wallis's loose calumny to strike where he felt himself safe. His answer to the personal charges took the form of a letter about himself