Titus Livius (Livy), The History of Rome, Book 32
Cyrus Evans, Ed.

26. In Gaul, the consul Sextus Aelius did nothing worth mention, though he had two armies in the province: [2] one, which he had retained under their standards, although it ought to have been disbanded; and of this, which had served under Lucius Cornelius, proconsul, he had given the command to Caius Helvius, the praetor: the other he had brought with him into the province. [3] He spent nearly the whole summer in compelling the people of Cremona and Placentia to return to their colonies, from whence they had been driven to various places by the calamities of war. [4] While Gaul, beyond expectation, remained quiet through the whole year, an insurrection of the slaves was very near taking place in the neighbourhood of the city. [5] The hostages, given by the Carthaginians, were kept in custody at Setia: [6] as they were the children of the principal families, they were attended by a great multitude of slaves; to this number many were added, in consequence of the late African war, and by the Setians themselves having bought, from among the spoil, several of those which had been captured. [7] Having conspired together, they sent some of their number to engage in the cause the slaves of the country round Setia, and then those at Norba and Circeii. When every thing was fully prepared, they determined, during the games which were soon to be solemnized at the first-mentioned place, to attack the people while intent on the show, and when Setia had been taken in the midst of the slaughter and unexpected turmoil, then to seize on Norba and Circeii. [8] Information of this atrocious plot was brought to Rome, to Lucius Cornelius Merula, the city praetor. Two slaves came to him before daylight, and disclosed to him in order the whole proceedings and intentions of the conspirators. [9] The praetor, ordering them to be guarded in his own house, summoned a meeting of the senate; [10] and having laid before them the information of the discoverers, he was ordered to go himself to the spot, and examine into and crush the conspiracy. [11] Setting out, accordingly, with five lieutenant-generals, he compelled such as he found in the country to take the military oath, to arm, and follow him. [12] Having by this tumultuary kind of levy armed about two [p. 1426]thousand men, while all were ignorant of his destination, he came to Setia. [13] There the leaders of the conspiracy were instantly apprehended; on which, the remainder fled from the city; but parties were sent through the country to search them out. The services of the two who made the discovery, and of one free person employed, were highly meritorious. [14] The senate ordered a present to the latter of a hundred thousand asses;¹ to the slaves, twenty-five thousand asses² each, and their freedom. The price was paid to their owners out of the treasury. [15] Not long after, intelligence was received, that other slaves, belonging to the remains of the conspiracy, had formed a design of seizing Praeneste. The praetor, Lucius Cornelius, went thither, and inflicted punishment on near five hundred persons concerned in that wicked scheme. [16] The public were under apprehensions that the Carthaginian hostages and prisoners fomented these plots: watches were, therefore, kept at Rome in all the streets, which the inferior magistrates were ordered to go round and inspect; while the triumvirs of the prison, called the Quarry, were to keep a stricter guard than usual. [17] Circular letters were also sent by the praetor to all the Latin states, directing that the hostages should be confined within doors, and not at any time allowed the liberty of going into public; [18] and that the prisoners should be kept bound with fetters, of not less than ten pounds weight, and confined in no other place of custody than the common jail.