Here gold and sulphur are compared together as similar, at all events in colour, for colour is the only possible _tertium comparationis_ between them; and in fact we also find in Arabic the expression ‘yellow sulphur, as if it were gold’ (kibrît aṣfar kaʾannahu ḏahab).[400] I lay particular stress upon this, because a common phrase among the Arabs is, al-kibrît al-aḥmar ‘red sulphur,’ to denote a peculiar person, one without his equal, inasmuch as there is no red sulphur. Now gold, of all things, is commonly used both in the later literature and in popular speech with the epithet _red_ (al-ḏahab al-aḥmar). This phrase, as Osiander has proved,[401] occurs also in Himyaric, and passed from Arabic into Persian and Turkish (in Persian zeri surch; in Turkish ḳizil altyn), and is used especially when minted gold is opposed to silver coins. The former is _red_ money, the latter _white_: e.g. wa-malaʾtum aydîkum min al-ḏahab al-aḥmar wal-fiḍḍâ al-beyḍâ ‘you have filled your hands with _red gold_ and _white silver_;’[402] dihhezâr dînâr zeri surch, ‘ten thousand dînârs of _red gold_.’[403] In a very noteworthy essay, Belin has shown with reference to Turkish that in the Ottoman Empire the metal money is divided into _white_, ‘aḳ,’ and _red_, ‘ḳizil’;[404] and in Egypt at the present day the silver piaster is called abyaḍ ‘white,’ to distinguish it from the copper money _chorde_. Muʿâwiyyâ said to Ṣaʿṣaʿâ, ‘Thou Red one;’ and he answered, ‘Gold is red.’[405] Thus we see that _red_ has become the constant designation of the colour of gold. Now in what harmony does this stand with the above-quoted designation, ‘sulphur-coloured gold,’ when we consider at the same time the proverbial kibrît aḥmar ‘red sulphur’?