91 
Ordinary Meeting, February 4th, 1868, 
Edward Schunck, Ph.D., F.R.S., &c., President, in the 
Chair. 
Among the donations announced were several bottles of 
Chemical Products for the Society’s collection, from Dr. 
F. Crace Calvert, F.R.S., &c. 
The thanks of the Society were voted to Dr. Calvert for 
his valuable donation, 
“ On Some Constituents of Cotton Fibre,” by E. Schunck, 
Ph.D., F.RS., & c., President. 
It is generally supposed that cotton, when quite pure, 
consists entirely of woody fibre or cellulose, and that its 
composition is consequently represented by the formula 
C 12 H 10 O 10 . It is certain, however, that in the raw state, as 
furnished by commerce, it contains a number of other ingre- 
dients, some of which occur so constantly that they may be 
considered essential constituents of cotton, viewed as a vege- 
table product. The object of the bleaching process to which 
most cotton fabrics are subjected is to deprive the fibre of 
these other ingredients and leave the cellulose behind in a 
state of purity. Notwithstanding the importance of an 
accurate knowledge of everything relating to cotton from an 
industrial point of view, the substances contained in it along 
with cellulose have never been subjected to a special chemical 
examination, and very little is consequently known about 
them. Persoz, in his Traite de V Impression des Tissus, 
Pbooeedings — Lit. & Phil. Society— Yol. VII. — No. 9. — Session, 1867-8, 
