le ee eh eee ee ee A ee ee ule 
Dead Cotton. 125 
same is the case with cortical fibres before their ee so also 
hemp just obtained from the flax-plant resisted solution for more than 
six hours, and the portions not dissolved preserved Hide aie form. 
nerusting matter ; Dead cotton—All these questions have recalled 
attention to an old paper by Mitscherlich on the composition of vegetable 
cellules, cellules essentially formed of cellulose, and of a substance analo- 
gous to cork, a suberic material capable of yielding rep “_ and also 
succinic and nitric acids. e most delicate vegeta res are covered 
over with this slender coating of suberic matter ; it is on this account 
that fresh cotton is with difficulty moistened with wa ter, while it is at 
once ew if this coating of suberic matter is removed by the ac- 
tion of chlor 
Such at feast is the opinion of Mitscherlich. It seems however that an 
immersion in chlorine is not always sufficient to render this variety of 
cotton — of receiving color,—the variety perfectly well known 
among dyers, who have named it “dead cotton ;” it was first described 
by Daniel Keechlin of plioane: and has since bean carefully studied by 
Walter Crum of Glasgow, whose results are published in the = vol- 
ume of the Proceedings of the Philosophical Society of Glasgo 
In the opinion of Mr. Walter Crum the dyeing of cotton ph upon 
a purely mechanical action; chemistry is completely — to the sub- 
ject of fixing dyes upon stuffs; dead cotton the proof of this; the 
fibres of this — of cotton are flattened, while cotton which admits 
of being dyed is composed of cylindrical fibres; the coloring matter 
hence can penetrate within these and fix itself 
This is, as is seen, an opinion diametrically iptation to that of Runge, 
who is so strong an advocate of the _ eal theory that he considers 
r. Walter Crum faechates that the cabana’ of _— cotton has been 
entinaly bleached before becoming flattened; it con ns therefore, he 
ane neither fatty matter nor any impurity capable of hindering the fix- 
ing of the coloring matter. 
But let us return to the suberic matter whose presence Mitscherlich 
iz 
