1893.] on Ancient Egyptian Pigments. 71 



to be the most likely way of identifying it. Naturally, madder, 

 which it is known has from the earliest times been used as a dye, was 

 the vegetable colouring substance first tried, and it answered perfectly, 

 giving under very simple treatment the exact shade of colour to the 

 sulphate of lime which the Egyptian pigment had. Essentially 

 the same colouring matter may have been obtained from another 

 source, viz. Munjeet. In the case of madder it is interesting to 

 note that the colour is not manifest in the plant — the Bubia 

 tinctorum — for it is obtained from the root, and is even not ready 

 formed there. In the root it exists as a glucoside, and this has to be 

 decomposed before the colour becomes manifest. In this root there 

 exists several colouring matters, which are known as madder-red, 

 madder-purple, madder-orange, and madder-yellow. On breaking up 

 the roots and steeping them in water for some length of time, the 

 colours come out, some sooner than others, so that the tints vary. 

 Again, changes of colour are easily obtained by the addition of very 

 small quantities of iron, lime, alumina, &c, so that in these different 

 ways a considerable range of colours could be obtained, but a delicate 

 pink colour was the one probably generally made. This colour is 

 easily obtained by simply stirring up sulphate of lime in a tolerably 

 strong solution of madder, and adding a little lime, taking care to 

 keep the colouring matter in excess; the colouring matter adheres 

 firmly to the lime salt, and this settles on to the bottom of the vessel ; 

 the liquid is then poured off and the solid matter, if necessary, dried, 

 or mixed — probably with a little gum, and used at once without other 

 preparation. That the colouring matter was really madder could 

 also be tested by another method, viz. by means of spectrum analysis. 

 Both the madder-red (alazarin) and the madder-purple (purpurin) 

 give, when the light which they transmit is analysed by the prism, 

 very characteristic absorption bands ; the purpurin bands are the ones 

 most easily seen, consequently it became a point of considerable 

 interest to ascertain whether from a specimen of this pigment, some 

 thousands of years old, these absorption bands could be obtained. 

 A small sample of this pink pigment was taken from a cartonage 

 which was exhibited, and by treating it with a solution of alum, the 

 colour was thus transferred to the liquid, and by throwing the 

 absorption spectrum which it gave on the screen, and comparing it 

 with the spectrum from a madder solution, it was clearly seen to be 

 identical. 



[W. J. E.] 



