And Hermeas replied: It is said that Mercury was the first God that discovered letters in Egypt; and therefore the Egyptians make the figure of an Ibis, a bird dedicated to Mercury, for the first letter. But it is not fit, in my opinion, to place an animal that makes no noise at the head of the letters. Amongst all the numbers, the fourth is peculiarly dedicated to Mercury, because, as some say, the God was born on the fourth day of the month. The first letters called Phoenician from Cadmus are four times four, or sixteen; and of those that were afterward added, Palamedes found four, and Simonides four more. Now amongst numbers, three is the first perfect, as consisting of a first, a middle, and a last; and after that six, as being equal the sum of its own divisors (1+2+3). Of these, six multiplied by four makes twenty-four; and also the first perfect number, three, multiplied by the first cube, eight.