668 
Proceedings of the Royal Irish Academy. 
R. Well, what does ferrugezi mean ? 
0. You must know that F and P are in Arabic closely akin (as I 
have before told you). Hence in the Arabic of Mesue the word is 
perugezi, which mean sturgueza, or turquoise. Por peruza in Arabic 
means turquoise, and of these there is an abundance in all parts of 
Persia.^ 
R, Truly I should have come to India for this matter alone, and if 
I had not found you perhaps they would not have told me about it 
there. Henceforward whenever I meet the word ferrugezi^ in Avicena 
or in any Arabic book I shall understand turquoise, and not consent 
to the apothecaries putting green smalt in the electuary of gemis, nor 
will I put faith in other green stones. I remember a few days ago 
someone came to you here to sell a jewel set with many small emeralds, 
and you told me that they were all false, and that in Balagate and 
Bisnager they were made from the glass of bottles, and that they were 
so common there they were not at all sought after. And therefore 
when I shall see the emerald I shall say sooner than put it in the 
electuary without exactly knowing what it is, viride vitro libera nos 
domine.^ And moreover the emeralds of Peru, says a modern writer, 
are very bad for use in medicine. 
0. I may tell you that these emeralds of Peru have been brought 
into this country and at first were very highly valued, but afterwards 
when they were found to be false no one would give money for them 
at all. Therefore you must be careful of these stones also. 
R. Tell me about the turquoise and whether it is used in medicine 
or not. 
0. Some say it is and others say it is not used by the natives ; yet 
all the Moors say it is used in medicine among them. 
R. Tell me of the amethyst, of the chrysolite, the beryl (for you 
say that it is not found in this country), of the alaqueca, and of the 
jasper. 
0. I will not speak of jasper, because there are more of these stones 
in your country than in this, and you know more about them than I. 
I may say, however, that there are small cups of jasper or of some green 
^ The chief source of turquoise is at Nishapur in Persia. 
2 Ferrugezi for Fencgezi = Turquoise, Firozaj is the Arabic form of the Persian 
Firoja. 
3 The art of making false emeralds of glass is of very great antiquity. Some 
years ago I identified some as such which were supposed to belong to the period of 
Asoka. See Froceedings As. Soc. Bengal, 1881, p. 89. 
