Rather more difficult than relating the facts concerning Mossotti's escape is to understand the reasons that stand behind it. Was Mossotti lucky enough to get ill just a few days before the order to question him came to Brera, or is there more to it? Why did Mossotti decide not to go to the police (after all it was not an official arrest but an interrogation) but to fly from the state, thus giving the impression of being guilty? How did he manage to pass the borders with an expired passport? Why did he come back again to pick up a few books and clothes, thus risking being caught? All these questions could be explained if Mossotti was a member of the Adelphi Society, but even today it is uncertain whether he was or not.
There is evidence for and against his affiliation to the society. The fact that the above questions would be easily answered if Mossotti had been a member of the society is one. Furthermore in M8 and M9 it is reported that Pecchio actually admitted him to the Society. The Government had this information from Castiglia, inquired by the Austrian Police, who told them that Ambrogio Berchet (who escaped to England) had spoken to him about Pecchio accepting Mossotti into the Society. On the other hand, in his Memoirs of a prisoner of state Andryane reports that, as far as he knew, Mossotti was perfectly innocent of such an accusation. Moreover, the obituaries depict him as man who was interested in science more than politics, and who lacked the aggressiveness and the strong faith in ideals that are necessary to make up a conspirator. As after his escape Mossotti did not concern himself with political matters until very much later (he was nominated senator of the Kingdom after the unification), and given also that Andryane would presumably not have had any reason to lie in his Memoirs, which were written nearly 15 years after this affair, one could suppose that Mossotti was not a member of the society. One more evidence of this can be found in M11, where the ambassador of Lombardy in Piedmont writes to the Government of Milan saying that Mossotti is known as an honest man, and there is no rumour about any political crime. It is therefore necessary to justify the pieces of evidence that stand against his innocence.
First of all, even assuming that Mossotti was not actually a member of the Perfect Masters, he certainly simpathised with some of their ideas and had friendly relationships with some of them. It is certain, by confession of Andryane himself, that he had talked to Mossotti at least in three different occasions: once in the restaurant Viellard, once in the salotto of Didina Calderara, and once in the observatory, where Mossotti had shown Andryane the instruments. Andryane denied, however, to have talked about politics with Mossotti. As Andryane arrived in Milan on 26 December 1822 and was arrested on 18 January 1823, Mossotti had evidently become a friend of Andryane. Even though it may seem unlikely that Mossotti's illness came in the nick of time for him not to get caught, it is not impossible altogether: he fell ill, he took some time off in order to recover his health in his family house near Novara, and when he came back to the observatory he found the letter inviting him to go to the tribunal. As Andryane had been arrested two months before, it is more probable that the news of his arrest had reached Mossotti. During the Austrian occupation in Lombardy, a delation was sometimes all it was needed to be condemned, so he quickly (and perhaps wisely) decided that it would have been safer to quit his job rather than getting tangled in the police's affairs (the Spielberg prison was then infamous only a little less than concentration camps were during World War II). He left Milan hoping that his passport, although only valid for the Christmas period, would gain him freedom in Piedmont. From Novara he then sent letters to Brera saying that he would take some more time off. The friend of Mossotti that went to Brera to speak with the astronomers towards the end of March had probably been sent to see whether it was safe for Mossotti to return. De Cesaris must have told him it would have been better if he did not come back, and so Mossotti decided to leave Italy altogether.
The astronomers of Brera helped Mossotti as much as it was possible without appearing guilty of treason. Carlini and Oriani seemingly advised Mossotti to stay out of Milan, while de Cesaris, who as the director of the observatory had the duty to correspond with the Government, did not write in his reports any more than it was strictly necessary to let the Government understand that the astronomers were completely ignorant of what Mossotti had done, where he was, or what he was up to. In the library of Brera observatory I found the rough copies of some official letters that de Cesaris sent to the Government concerning this matter, and the letters that had finally been sent to the Government contain less details than the rough copies.
It is also necessary to explain the infamous piece of paper referred to in M8, M9 and M14 that Andryane had among his papers when they were seized, on which there were written the names of Mossotti and of other Italian people. This paper was perhaps the main cause of the Government's interest towards Mossotti: the delation of Castiglia that Mossotti was affiliated to the society, mentioned in M8, had been considered indicial but not decisive by the Government, on the basis that Castiglia was referring informations about which he was highly uncertain.
Andryane had met Buonarroti in Geneva at the beginning of 1821, and immediately felt a strong admiration for him. From his memoirs of the time it is possible to infer that Buonarroti must have had a very dominant personality, and a very strong wish for power. Andryane was initiated to the Adelphi Society on 10 October 1821. Andryane's first missions were in South-Eastern France, and they all went astray. Coming back from those missions, Andryane began to feel that the secret societies did not represent the way to democracy and freedom, and although he did not leave the Adelphia, he stopped being an activist and told his views to Buonarroti. At length Buonarroti felt that Andryane was a disadvantage to the society, so he gave him leave to quit it, begging him to make him a last favour in accepting a last mission in Italy. In order to convince him, Buonarroti introduced to Andryane some Italian exiles just escaped from Italy. Seeing the conditions of these people, Andryane decided to take the mission. This was organized in a series of meetings with Buonarroti, Andryane and the Italian exiles at the end of 1822. The mission began, as it has already been said, on 26 December 1822, and ended miserably on 18 January 1823, because the Governor of Milan had inexplicably developed a suspicion against Andryane. He was searched and an unusual (for the kind of mission he was taking) amount of compromising papers were found in his bag. From Andryane's memoirs, we know that Andryane was definitely against bringing so many compromising papers with him, but that time and time again Buonarroti replied to him that they were absolutely essential. Also, it is worth considering that even after the seizing all those papers, which consisted in professions of faith, statutes of the society, secret codes and keys to break them, and letters to a number of people, the Adelphi society was not destroyed, and seemingly not even weakened; of the compromised people, some were innocent, some were only suspected but not proven guilty (like Mossotti), and the guilty ones did not have high rank in the Adelphia. In my opinion, the whole business had been set up by Buonarroti in order to frame Andryane (he was of the opinion that secret societies had extinguished their role in history) and put him in a position where he could not have harmed the Adelphia. He sent him on an impossible mission, his bags full of compromising papers, and then he made sure the authorities knew what he was up to. Unfortunately this meant that a few innocent people had to suffer some of the consequences of this, in particular Mossotti. In fact Andryane says in his Memoirs of a prisoner of state that the piece of paper with the name of Mossotti written on had been put in his bag by one of the Italian exiles with whom he organized his mission.