Historia Augusta, Macrinus (12)
“Macrinus was arrogant, bloodthirsty, and eager to rule like a general, complaining about the discipline of earlier times and praising Severus alone above all other emperors. For he often crucified his soldiers and afflicted them with the punishments reserved for slaves. When he experienced mutinies of the soldiers, he often subjected them to decimation*, and sometimes to centimation. This latter word was his own invention, which he used to demonstrate his clemency, since he was only centimating the soldiers who were really worth of decimation or vicesimation.
It would be tedious to relate all of his cruelties, yet I will record one which, though it was not (as he thought) the greatest, was yet sadder than all of his other tyrannical evils. When some soldiers had violated the slavemaiden of their host who had long been of dubious moral character, Macrinus learned of it through one of his secret spies. He had the men brought before him and asked whether they had committed the crime. When it had been proven, Macrinus ordered two live bulls of immense size to be cut open, and for these two soldiers to be inserted into them with their heads poking out so that they could speak with each other. And so he afflicted them with this punishment because such punishments had not been established for adulterers either in the pastor even in his own time.”
*decimation = killing of every tenth man; centimation (perhaps centesimation?) = killing of every hundredth man; vicesimation = killing of every twentieth man
Fuit igitur superbus et sanguinarius et volens militariter imperare, incusans quin etiam superiorum temporum disciplinam ac solum Severum prae ceteris laudans. Nam et in crucem milites tulit et servilibus suppliccis semper adfecit et, cum seditiones militares pateretur, milites saepius decumavit, aliquando etiam centesimavit, quod verbum proprium ipsius est, cum se clementem diceret, quando eos centesimaret, qui digni essent decimatione atque vicensimatione. Longum est eius crudelitates omnes aperire, attamen unam ostendam non magnam, ut ipse credebat, sed omnibus tyrannicis inmanitatibus tristiorem. Cum quidam milites ancillam hospitis iam diu pravi pudoris affectassent atque per quendam frumentarium ille didicisset, adduci eos iussit interrogavitque, utrum esset factum. Quod cum constitisset, duos boves mirae magnitudinis vivos subito aperiri iussit atque his singulos milites inseri capitibus, ut secum conloqui possent, exertis; itaque poena eos affecit, cum ne adulteris quidem talia apud maiores vel sui temporis essent constituta supplicia.