PROCEEDINGS OF SOCIETIES. 299 
March 20th, 1865. 
J. StpEpoTHAM, Exq., President of the Section, in the Chair. 
A paper entitled “ Remarks on the Microscopical Appearance 
of Cotton Hair during Dissolution in the Ammoniacal Solution 
of Copper,” was read by J. B. Dancer, F.R.A.S. 
The structure of cotton hairs has occasionally furnished an 
interesting topic of conversation at the meetings of our micro- 
scopical section. 
Two of our members, Mr. Charles O’Neill and Mr. Heys, have 
given considerable time and attention to this subject. Mr. 
Walter Crum, F.R.S., communicated to the Chemical Society a 
memoir “On the Cotton Fibre,’ and the manner in which it 
unites with colouring matter. His paper is illustrated with some 
beautifully executed drawings of the microscopical appearances 
of cotton in the natural state, and when mordanted, mercerised, 
and treated with various dyes; the paper is well worthy the 
attention of those interested in this branch of inquiry. Mr. Crum 
has presented a copy of his memoir to this society. His deserip- 
tion of the ordinary appearance of the cotton fibre agrees so 
nearly with what I believe it to be, that I will take the liberty of 
referring to his printed paper at page 5. To Mr. Crum’s descrip- 
tion I may add, that many specimens of cotton, especially on the 
cylindrical portions of the hairs, show transverse markings. At 
times these appear at tolerably regular intervals ; they have been 
claimed as evidences of spiral structure ; when, however, they 
are examined with magnifying powers of 1000 to 1200 diameters 
they proved to be cracks in the external membrane. Other por- 
tions of cotton exhibit longitudinal furrows, irregular in length and 
direction—having a shrivelled appearance something like the bark 
ofan aged tree. In gun-cotton the transverse cracks are very 
numerous. From an examination of transverse sections of cotton 
T‘incline to the opimion that there is an external membrane 
distinct from the true cell-wall or cellulose matter ;* inside the 
cellulose there is an irregular cavity ; this, in some specimens 
(when viewed longitudinally), appears to contain granules, pro- 
bably the remains of the organizing fluid contents of the cell, the 
mucous matter which is seen in growing cotton as mentioned by 
Captain Mitchell, in his letter to Mr. Hurst, read at this society, 
March 22nd, 1864. 
On the 21st of April, 1863, Mr. Charles O’Neill made a com- 
munication to this section, “ On the Appearance of Cotton Fibre 
during Solution and Disintegration ;” these experiments referred 
to the application of Schweizer’s solution of copper and ammonia. 
Under the action of this solvent Mr. O’ Neill considers that cotton 
exhibits spiral vessels situated either inside or outside the 
external membrane. In a paper read by the same gentleman, on 
the 18th of May, 1863, it is stated that spiral vessels are seen 
* See Mr. O’Neill’s paper, April 25th, 1863. 
