§ 21. STAINED GLASS. 29 



(Labarte, "Handbook of the Arts of the Middle Ages," p. 66), 

 and Pope Leo III., in 816, adorned those in the apse of 

 S. Giovanni Laterano, " with glass of various colours." It is 

 evident then, that stained glass windows were used during 

 the 300, in the age of Constantine, and they are even ad- 

 mitted to have been known in the previous century. 



That it was likely to be adopted for windows in hot climates 

 as soon as the art of applying it became known, is highly 

 probable ; as the direct transition of heat is less through 

 coloured, than through white, glass ; and for this reason the 

 Arabs in Egypt and elsewhere preferred the former, whenever 

 they glazed the windows of their mosks or dwellings. De- 

 barred as they always were from the representation of the 

 human figure *, they only introduced conventional forms ; and 

 their patterns, which frequently resemble, rather than imitate, 

 a flower rising from a fanciful root, or a vase, are composed 

 of various pieces of coloured glass (according to the earliest 

 method), each surrounded and separated from its neighbour by 

 a thin partition composed of egg and gypsum, in lieu of lead- 

 work. The windows are small, both in the mosks and 

 houses ; and the former are generally made up of geometrical 

 patterns and other devices. 



21. Colourless glass windows (" speculariorum usum, perlu- 

 cente testa, clarum transmittentium lumen,") were already used 

 in the age of the first Caesars, as shown by Seneca (Ep. 90, 

 p. 398), and perhaps also by Philo Judaeus (Leg. ad Ca.); and 

 Seneca says (Ep. 86, p. 373), " rusticitatis damnant Scipionem, 

 quod non in caldarium suum latis specularibus diem admise- 

 rat." And though talc or other translucid substances might pos- 

 sibly be implied, Seneca's speaking of the " multa luce" would 

 rather require them to be glass; " specular ia " was the name 



* The few instances where figures have been introduced by the Arabs in 

 Spain, and by the Moslems in Persia, are not sufficient to disprove the force of 

 the injunction. The same remark may apply to the cherubim of the Jews. 



