Mk. Crum on a Peculiar Fibre of Cotton incapable of being Dyed. 61 



Having relinquished our intentions of going down the east side of Grlen- 

 luce Bay, we returned next morning (Thursday) to Ayr by the steamer, 

 and had an hour or two to examine the coast south of that town, before 

 returning to Glasgow by the train. We met with Juncus Gerardi, or 

 cmiosus of Bicheno, Atr'qylex Icbciniata, Polygonum Poberti, in abun- 

 dance, perhaps more so than on the coast of Galloway ; Borago officinalis, 

 Atriplex rosea, but nothing worthy of interest. 



The weather was excellent, except the single instance mentioned of a 

 cold drizzle when at the lighthouse ; and in this we were more fortunate 

 than if we had been at Glasgow or Ayr, for in these places, on the Wed- 

 nesday, there had been partial thunder and much rain. Indeed, while 

 walking from Port Float to Dunskey Castle, we saw, from the clouds, that 

 there was a thunder storm about the head of Glenluce Bay, and for some 

 time we were not without fear that we should not escape, as the wind 

 came from that quarter. It, however, dissipated before reaching us. 



I have only to regret that none other of the party has agreed to give 

 you this short account of our excursion, as I made no notes, and now 

 speak entirely from memory. I have to thank Dr. Thomson for bringing 

 some of the localities to my remembrance. 



Mr. Crum then read the following paper : — 

 Vm. — On a Peculiar Fibre of Cotton tohich is incapable of being Dyed. 

 By Walter Crdm, Esq., F.R.S., Vice-President. 



In the month of May last, Mr. Thomson of Primrose received from 

 Mr. Daniel Koechlin of Miilhausen some specimens of a purple ground 

 printed calico, each of them containing a portion of cotton which was 

 white, although subjected to the same treatment by which the rest of the 

 cloth, and even the threads which crossed the white one, was uniformly 

 dyed. The white part of the thread was usually thicker than the rest, 

 and little more than a quarter of an inch long. The whole fabric had 

 been thoroughly bleached before printing, so that it contained no grease 

 or other impurity that could resist the colouring matter. 



White specks like these are not unknown or undreaded among the 

 printers of calicoes in this country. Mr. Koechlin mentions that the 

 cotton of which they are formed is known by the name of colon mort, 

 and here also it is called dead cotton. Mr. Koechlin has been the first, 

 I believe, to suggest that it may consist of unripe cotton, and that its fibre 

 may be solid, wanting the hollow of the more perfect fibre. He adds, 

 that if such should prove to be the case, its behaviour with colouring 

 matters may afiect materially the question of the mechanical or chemical 

 nature of the union of cotton with its dye. Mr. Thomson did me the 

 honour to transmit me the specimens for examination. 



The ordinary cotton fibre, it will bo remembered, is described by Mr. 

 Thomson in the memoir where its form was first made known,* as a tube, 



* Annals of Philosophy, for June, 1834. Lately reprinted in the Classical 

 MuBeum, No. 20, and in Liebig's Annalen or January, 1849. 



