70 Mr. William J. Russell [March 17, 



arisen from imperfect mixing, or from some parts of the furnace being 

 hotter than others. It hardly appears to be intentional, possibly- 

 some of the dark, purplish-coloured frits were produced by accident ; 

 large pieces of it have as yet, I believe, not been found. By means of 

 comparatively small alterations these frits could be obtained of a 

 green colour, One way was by introducing iron. If, for instance, 

 the silica used was a reddish coloured sand, it gave a greenish tinge 

 to the frit ; and frit made with some of the ordinary yellowish desert 

 sand was found to give a frit undistinguishable from the most com- 

 mon of the old Egyptian frits. Again, a rather strong green colour is 

 obtained by stopping the heating process at an early stage, this green 

 frit, simply on heating for a longer time, becoming blue. Another 

 way in which even the strong-coloured blue frits have been con- 

 verted into apparently green pigments is by their being coated over with 

 a transparent but yellowish coloured varnish which has to a remarkable 

 extent retained its transparency, but no doubt become with age more 

 yellow, and although strongly green now, may very likely originally 

 have been nearly colourless, and consequently the frit was then seen 

 in its original blue colour. Even as early as the twelfth dynasty the 

 green frits used were dull in colour, and if by chance a brighter green 

 was required, then they used the mineral malachite. No doubt by 

 far the most brilliant blue used at any time was selected and powdered 

 chessylite, and even down to the twenty-first dynasty they seem to have 

 made use generally of somewhat brilliant coloured frits ; but after 

 that time more subdued colours appear to have been used, and 

 even the scarabs were made of a much duller colour than formerly. 

 All these blue frits form a perfectly unfadeable and unchangeable 

 pigment. Neither the sun nor acids are able to destroy or alter their 

 colour. 



The only other pigment to which I can refer this evening is the 

 pink colour which, in different shades, was much used. This is 

 again an artificial pigment, and belongs to an entirely different 

 class from any of the foregoing ones, for it is one of vegetable 

 origin. On simply heating it, fumes are given off and the colour is 

 destroyed, but a large white residue remains ; this is sulphate of lime. 

 It may here be stated that the white pigments used sometimes were 

 carbonate of lime, but more generally sulphate of lime in form of 

 gypsum, alabaster, &c. This substance is often very white in colour, 

 is very slightly soluble in water, and has a singular smoothness of 

 texture, which makes it work well under the brush ; and in addition 

 to these qualities, it is a neutral and very stable compound, so is well 

 fitted for the purpose to which it was applied. It w 7 as easily obtained, 

 being found native in many parts of Egypt. It is also interesting 

 to note that there is an efflorescence consisting of this substance 

 which frequently occurs in Egypt, and is of a remarkably pure white 

 colour ; probably this w r as used as a superior white pigment. It was 

 easy to prove then that the pink colour was gypsum stained with 

 organic colouring matter, and to try and imitate the colour appeared 





