AS, the unit of value in the Roman and old Italian coinages, was made of copper, or of the mixed metal called AES. It was originally of the weight of a pound of twelve ounces, whence it was called _as libralis_ and _aes grave_. The oldest form of the _as_ is that which bears the figure of an animal (a bull, ram, boar, or sow). The next and most common form is that which has the two-faced head of Janus on one side, and the prow of a ship on the other (whence the expression used by Roman boys in tossing up, _Capita aut navim_.) Pliny informs us, that in the time of the first Punic war (B.C. 264-241), in order to meet the expenses of the state, this weight of a pound was diminished, and asses were struck of the same weight as the sextans (that is, two ounces, or one-sixth of the ancient weight); and that thus the republic paid off its debts, gaining five parts in six; that afterwards, in the second Punic war, in the dictatorship of Q. Fabius Maximus (B.C. 217), asses of one ounce were made, and the denarius was decreed to be equal to sixteen asses, the republic thus gaining one half; but that in military pay the denarius was always given for ten asses; and that soon after, by the Papirian law (about B.C. 191), asses of half an ounce were made. The value of the as, of course, varied with its weight. Before the reduction to two ounces, ten asses were equal to the denarius = about 8½ pence English [DENARIUS]. Therefore the as = 3·4 farthings. By the reduction the denarius was made equal to sixteen asses; therefore the as = 2⅛ farthings. The as was divided into parts, which were named according to the number of ounces they contained. They were the _deunx_, _dextans_, _dodrans_, _bes_, _septunx_, _semis_, _quincunx_, _triens_, _quadrans_ or _teruncius_, _sextans_, _sescunx_ or _sescuncia_, and uncia, consisting respectively of 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1½, and 1 ounces. Of these divisions the following were represented by coins; namely, the _semis_, _quincunx_, _triens_, _quadrans_, _sextans_, and _uncia_. After the reduction in the weight of the as, coins were struck of the value of 2, 3, 4, and even 10 asses, which were called respectively _dussis_ or _dupondius_, _tressis_, _quadrussis_, and _decussis_. Other multiples of the as were denoted by words of similar formation, up to _centussis_, 100 asses; but most of them do not exist as coins. In certain forms of expression, in which _aes_ is used for money without specifying the denomination, we must understand the as. Thus _deni aeris_, _mille aeris_, _decies aeris_, mean respectively 10, 1000, 1,000,000 _asses_. The word _as_ was used also for any whole which was to be divided into equal parts; and those parts were called _unciae_. Thus these words were applied not only to weight and money, but to measures of length, surface, and capacity, to inheritances, interest, houses, farms, and many other things. Hence the phrases _haeres ex asse_, the heir to a whole