In the civil law. An act which has been executed before a notary or other public officer authorized to execute such functions, or which is testified by a public seal, or has been rendered public by the authority of a competent magistrate, or which is certified as being a copy of a public register. Nov. 73, c. 2; Cod. 7, 52, 6, 4, 21; Dig. 22, 4. The authentic act, as relates to contracts, is that which has been executed before a notary public or other officer authorized to execute such functions, in presence of two witnesses, free, male, and aged at least fourteen years, or of three witnesses, if the party be blind. If the party does not know how to sign, the notary must cause him to affix his mark to the instrument. All proc&s verbals of sales of succession property, signed by the sheriff or other person making the same, by the purchaser and two witnesses, are authentic acts. Civil Code La. art. 2234.