The fabulous wealth accumulated by the Fatimi caliphs of Egypt (908-1171 A.D.) became proverbial in later days. Makrisi, writing about the year 1400, quotes from an older writer the description of the treasure-house of the Khalifah Mustansir Billah. This building was sacked and burned with all its contents during a military riot between Turkish and Soudanese troops in 1062. Here among the vast accumulation of Oriental wealth were, it is stated, many thousand vases of rock crystal and others of sardonyx. We hear also at this time (but not in the list of these treasures) of glass mirrors in filigree frames, and of vessels of glass ornamented with figures and foliage. How the decoration in this last case was given we are not told, but the reference is probably to carvings in relief: at any rate it would, I think, be an anachronism to look for enamelled glass in this connection. There is, however, one application of glass that we can definitely associate with these heretic caliphs, but this is scarcely an artistic one. The little coin-like discs of glass stamped with an inscription in Arabic had their prototypes in Roman times; a few rare examples have been found with the heads of Roman emperors and letterings in Latin. Among the Saracens these coin-like discs continued in use as late as the fifteenth century. In all cases, I think, they come from Egypt. The glass discs of the Fatimi period are, however, the most abundant and these are of special interest, as they bear the name of the ruler, while those of the later Memlook times have only private inscriptions. The glass varies from an amber tone to a dark bottle-green, but many are quite opaque and of a purplish black. As these little discs are of uniform weights, corresponding to parts and multiples of the gold _dinar_ and the silver _dirhem_, they were at one time regarded as coins; they are now, however, recognised as weights, but essentially weights for weighing coins. Indeed a contemporary Arab writer (985 A.D.) distinctly states that in his day in Egypt they used money weights of glass; and an Arab traveller of the time mentions incidentally that such weights have this advantage, that they cannot be readily increased or decreased. The inscription occupies generally the whole surface, but a few of them bear a rough design—a ‘seal of Solomon’ or a rosette. Larger weights of glass are rare, but some of a cylindrical form weighing more than a pound may be seen in the British Museum. In Dr. Petrie’s Egyptian collection at University College is a large mass of black glass with a solid ring handle, the whole some four inches in height. This is probably a weight, but its date is uncertain.