356 Mr. Thomson on the Mummy Cloth of Egypt ; 



the mummy cloth of Egypt was cotton ; and this opinion, on 

 their authority, was adopted by the learned of Europe. It is 

 singular that neither in the memoir of Rouelle, nor in the 

 notes of Larcher, nor in the dissertation of Dr. Forster, in 

 which this opinion is expressed, are any grounds assigned 

 for, or any proofs given of, this opinion. The amount of 

 their assertion is, that having examined the bandages of va- 

 rious mummies, which are designated by them, and some of 

 which I have myself since carefully examined, they found all 

 those which were free from resinous matter to be cotton. I 

 am forced to confess that with all the attention I could be- 

 stow upon them, and with the assistance of various intelli- 

 gent manufacturers, I was unable to arrive at such a conclu- 

 sion. Some were of opinion that the cloth was cotton ; others 

 that it was linen ; and some, again, that there were in the col- 

 lection specimens of both, — a proof that our means of judging 

 were unworthy of confidence. 



The great difference in the specific gravities as well as in 

 the conducting power of linen and cotton is sufficient to enable 

 us, by careful experiments, to discriminate accurately between 

 them ; and there are few individuals who have been accustomed 

 to the use of both cotton and linen who cannot readily di- 

 stinguish, by that delicate sense of touch diffused over the whole 

 body, between the two fabrics: but such tests require much 

 larger portions of the material than I had at my disposal, 

 many of the specimens submitted to my examination not be- 

 ing larger than a shilling. I found the difference of smell in 

 the burnt fibres, and the degree of polish which each kind 

 of cloth took on being rubbed with a glass stopper, as well as 

 other empirical modes suggested to me, liable to great uncer- 

 tainty, and I sought in vain for any chemical test. It occurred 

 to me that the supposed unfitness of cotton lint, compared 

 with linen, for dressing wounds, had been accounted for by 

 the different form of their fibres, the one being sharp and 

 angular, and the other round and smooth ; and, in fact, I found 

 in the 12th volume of the Philosophical Transactions, for the 

 year 1678, this structure ascribed to them by that early mi- 

 croscopic observer Mr. Leuwenhoek. It seemed to me, there- 

 fore, that the most simple mode of distinguishing between 

 cotton and linen would be to subject the fibres to examination 

 under a powerful microscope. Not being possessed of such 

 an instrument, nor accustomed to its management, my friend 

 Mr. Children undertook, through Sir Everard Home, to so- 

 licit the assistance of Mr. Bauer, whose labours are well known 

 to the scientific world, and whose microscopic drawings have 

 for a series of years enriched the Transactions of the Royal 



