CHEMICAL SCIENCE. 191 



with a modern pen ; where the marking fluid had flowed more copi- 

 ously than the characters required, the texture of the cloth had 

 become decomposed and small holes had resulted. I have no doubt 

 that the bandages were genuine, and had not been disturbed or 

 unfolded: the color of the marks were so similar to those of the pres- 

 ent " marking ink." that I was induced to try if they were produced 

 by silver. With the bloAvpipe I immediately obtained a button of that 

 metal ; the fibre of the linen I proved by the microscope, and by 

 chemical re-agents, to be linen ; it is therefore certain that the ancient 

 Egyptians were acquainted with the means of dissolving silver, and of 

 applying it as a permanent ink ; but what was their solvent ? I know 

 of none that would act on the metal and decompose flax fibre but 

 nitric acid, which we have been told was unknown until discovered 

 by the alchemists in the thirteenth century, which was about 2200 

 years after the date of this mummy, according as its superscription 

 was read. 



The yellow color of the fine linen cloths which had not been 

 stained by the embalming materials, I found to be the natural coloring 

 matter of the flax ; they therefore did not, if we judge from this spec- 

 imen, practise bleaching. There were, in some of the bandages near 

 the selvage, some twenty or thirty blue threads ; these were dyed by 

 indigo, but the tint was not so deep nor so equal as the work of the 

 modern dyers ; the color had been given it in the skein. 



" One of the outer bandages was of a reddish color, which dye I 

 found to be vegetable, but could not individualize it ; Mr. T. J. Hera- 

 path, analyzed it for tin and alumina, but could not find any. The 

 face and internal surfaces of the orbits, had been painted white, which 

 pigment I ascertained to be finely powdered chalk." 



CHEMICAL ACTION OF LIGHT. 



THE following account of experiments on the chemical action of 

 light have been published by J. W. Slater in the Chemical Gazette, 

 Sept., 1852. They were undertaken chiefly in order to examine the 

 law proposed by Grothuss, that substances are most readily de-color- 

 ized by rays of light of a color complementary to their own. The 

 solutions used for isolating the different rays were, bichromate of pot- 

 ash for yellow, mixed chlorides of copper and iron for green, ammonio- 

 sulphate of copper for blue, sulphuric tincture of roses for red, and 

 water with a little nitric acid for white. The vessels containing these 

 solutions stood on a shelf about 12 feet from the ground, and had free 

 sunshine through the day. In the first place, five test tubes contain- 

 ing a strong solution of permanganate of potash were placed 

 respectively in the five rays. The order of decomposition was blue, 

 red, white, green, yellow. The two first were nearly colorless on the 

 third day, and on the seventh, when opened and tested, contained no 

 manganese in solution. The white and green were not entirely 

 decomposed till the twenty-second day, and the yellow after eight 

 weeks still contained much permanganic acid. In order to determine 

 17* 



