Concerning the Phoenician process of dyeing, the accounts which have come down to us are at once confused and incomplete.  Nothing is said with respect to their employment of mordants, either acid or alkali, and yet it is almost certain that they must have used one or the other, or both, to fix the colours, and render them permanent.  The gamins of Tyre employ to this day mordants of each sort;[821] and an alkali derived from seaweed is mentioned by Pliny as made use of for fixing some dyes,[822] though he does not distinctly tell us that it was known to the Phoenicians or employed in fixing the purple.  What we chiefly learn from this writer as to the dyeing process is[823]—­first, that sometimes the liquid derived from the murex only, sometimes that of the purpura or buccinum only, was applied to the material which it was wished to colour, while the most approved hue was produced by an application of both dyes separately.  Secondly, we are told that the material, whatever it might be, was steeped in the dye for a certain number of hours, then withdrawn for a while, and afterwards returned to the vat and steeped a second time.  The best Tyrian cloths were called Dibapha, i.e. “twice dipped;” and for the production of the true “Tyrian purple” it was necessary that the dye obtained from the Buccinum should be used after that from the Murex had been applied.  The Murex alone gave a dye that was firm, and reckoned moderately good; but the Buccinum alone was weak, and easily washed out.

The actual tints produced from the shell-fish appear to have ranged from blue, through violet and purple, to crimson and rose.[824] Scarlet could not be obtained, but was yielded by the cochineal insect.  Even for the brighter sorts of crimson some admixture of the cochineal dye was necessary.[825] The violet tint was not generally greatly prized, though there was a period in the reign of Augustus when it was the fashion;[826] redder hues were commonly preferred; and the choicest of all is described as “a rich, dark purple, the colour of coagulated blood."[827] A deep crimson was also in request, and seems frequently to be intended when the term purple ({porphureos}, purpureus) is used.

A third industry greatly affected by the Phoenicians was the manufacture of glass.  According to Pliny,[828] the first discovery of the substance was made upon the Phoenician coast by a body of sailors whom he no doubt regarded as Phoenicians.  These persons had brought a cargo of natrum, which is the subcarbonate of soda, to the Syrian coast in the vicinity of Acre, and had gone ashore at the mouth of the river Belus to cook their dinner.  Having lighted a fire upon the sand, they looked about for some stones to prop up their cooking utensils, but finding none, or none convenient for the purpose, they bethought themselves of utilising for the occasion some of the blocks of natrum with which their ship was laden.  These