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minute crystals (soluble in water) ; in some places these 
tubes appeared to be split longitudinally. 
A paper on the same subject was lately read before the 
Chemical Society of London by Dr. F. Crace Calvert, 
F.R.S. 
A paper, entitled “ Remarks on the Microscopical 
Appearances 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 for conversation at the meetings of our 
Microscopical Section. 
Two of our members, Mr, Chas. 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 u 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 ; 
this 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 description 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 description I may 
add, that many specimens of cotton, especially on the cylin- 
drical portion of the hairs, shew 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 1,000 to 1,200 
diameters they proved to be cracks in the external membrane. 
Other portions of cotton exhibit longitudinal furrows, irregular 
