Not only was the Roman most careful to expiate involuntary offences, and also to appease the wrath of the gods, if shown in any special active way, e.g. by lightning and many other prodigia[1338], but he also sought to avert evil influences _before-hand_, which might possibly emanate from hostile or offended _numina_. This religious object is well illustrated in the sacrifice of the _hostia praecidanea_, which was offered beforehand to make up for any involuntary errors in the ritual that followed[1339]. But it is also seen in numerous other rites of which we have had many examples; all those, for instance, which included a _lustratio_. We generally translate this word by ‘purification’; but it also involves the ideas of intercession, and of the removal of unseen hostile influences which may be likely to interfere with the health and prosperity of man, beast, or crop. At such rites special victims were sometimes offered, or the victim was treated in a peculiar manner; we find, perhaps, some part of it used as a charm or potent spell, as the strips of skin at the Lupercalia, or the ashes of the unborn calves at the Fordicidia, or the tail and blood of the October horse[1340]. To the first of these, at least, if not to the other two, the word _februum_ was applied, and we may assume it of the others: also to many other objects which had some magical power, and carry us back to a very remote religious antiquity. Ovid gives a catalogue of them[1341]: Februa Romani dixere piamina patres, Nunc quoque dant verbo plurima signa fidem. Pontifices ab rege petunt et flamine _lanas_, Quis veterum lingua februa nomen erat. Quaeque capit lictor domibus purgamina †ternis†[1342] Torrida cum mica farra, vocantur idem. Nomen idem _ramo_, qui caesus ab arbore pura Casta sacerdotum tempora fronde tegit. Ipse ego flaminicam poscentem februa vidi: Februa poscenti _pinea virga_ data est. Denique quodcunque est, quo corpora nostra piantur, Hoc apud intonsos nomen habebat avos. Objects such as these, called by a name which is explained by _piamen_, or _purgamentum_, must have been understood as charms potent to keep off evil influences, and so to enable nature to take its ordinary course unhindered. Only in this sense can we call them instruments of _purification_.