hal ia io 
430 Scientific Intelligence. 
phate of iron may perhaps be applied in calico-printing as a discharge for : 
indigo and also in bleaching blue rags for paper making.— Répertoire de 
Chimie Appliquée, Oct. 1859, p. 429. 
12, Critical and Experimental Contribution to the Theory of Dycing— 
Under this title a somewhat extended treatise by Prof. Bouter of Zurich 
Ro tee a 
Two questions have long been agitated among chemists intetested in 
the theory of dyeing. (1.) In what part of the colored fibre is the 
coloring matter situated? Does it merely adhere to the surface, or does 
it penetrate the entire substance of the cell-walls of such fibres as caee? let 
and flax? Or lastly, in the case of such fibres is it stored up in the 
, h . - 
with colors in a mere state of suspension* seem to be impregnat ym 
the dye throughout their entire mass; while in the case of cotton, by fat 
the larger portion of the coloring matter adheres to the surface of ies 
re, the penetration of the cell-walls by the dye being either very slight 
or altogether wanting, 
That the theory of W. Crum (L. E. and D. Phil. Mag, 
compare this Journal, [2], xxviii, 125), in accordance with which t 
lar form of the cotton fibres is an essential condition to thei 
In like 
* : : surface of the 
* In which case the coloring matter only adheres as a crust to the 
ieee from its solution in cuprate of ammonia (see this 
2], xxvii, 118) may be mordanted and dyed like ordinary cotton. 
