123 
Mr. Charles O’Neill, F.C.S., made a communication 
“ Upon the Appearances of Cotton Fibre during Solution and 
Disintegration.” These experiments referred to the applica- 
tion of Schweizer’s solvent. Two strengths were used; the 
weaker contained oxide of copper, equal to 4 - 3 grs. metal per 
1,000, and 47 grs. dry ammonia ; the stronger contained 15'4 
grs. metal and 77 grs. dry ammonia per 1,000. The latter is 
about the most concentrated solution which can be made. Refer- 
ring to the researches of Payen,Fresny, Peligot,Schlossberger, 
and others who have employed this solvent, the author said 
the only experimenter who seemed to have worked in the 
same direction with himself, and that apparently only to a 
small extent, was Dr. Cramer, whose paper he had only been 
able to see in a translation appended as a note to a memoir of 
M. Payen in Comptes Rendus, p. 319, vol. xlviii. 
Mr. 0‘ Neill considers that cotton exhibits, under the 
action of this solvent, (1) an external membrane distinct from 
the true cell wall or cellulose matter; (2), spiral vessels 
situated either in or outside the external membrane ; (3), the 
true cell wall or cellulose ; and (4), an inner medullary matter. 
The external membrane is insoluble in the solvent, and may 
be obtained in short hollow cylinders by first acting upon the 
cotton with the dilute solvent so as to gradually remove the 
cellulose, and then dissolve all soluble matters by the strong 
solvent. If the strong solution is first applied, the extra- 
ordinary dilation of the cellulose bursts the external mem- 
brane, and reduces it to such a state of tenuity that it is 
invisible. This membrane is very elastic, appears to be quite 
impermeable to the solvent, and when free from fissures 
protects the enclosed matter from its action. It is not seen 
in cotton which has been submitted to the action of alkaline 
acids and bleaching powder, being either chemically altered, 
or, what is most probable, entirely removed. 
The spiral vessels are unmistakeably apparent, running 
round the fibre in more or less close spirals, sometimes single, 
