236 
could only have been obtained, if at all, by an incredible 
amount of labour. 
Effect of bleaching upon strength of cotton. These experi- 
ments were made upon printing cloth of 18 threads to the 
quarter inch, American cotton, and bleached for printing by 
the low pressure process. The process included, among 
other treatments, — 
(1) Passing three times over a red hot copper plate. 
(2) Boiling 16 hours with milk of lime. 
(8) Boiling 16 hours with soda and rosin. 
(4) Steeping in solution of bleaching powder for several 
hours. 
(5) Steeping in dilute hydrochloric acid for several hours. 
Strength of threads in the grey cloth 
WAEP. 
WEFT. 
S.V. (mean of 30 experiments) ... 
Ditto in the bleached cloth S.V. 
3140 grs. 
1714 grs. 
(mean of 30 experiments) 
2920 grs. 
2785 grs. 
The warp threads from two other pieces of cloth give as 
follow, being the means of 40 experiments : — 
A. B. 
In the grey state 
3407 grs. 
3512 grs. 
In the bleached state 
3708 grs. 
4025 grs. 
The cloth S.V. became elongated in the bleachin process, 
and contracted in width. The contraction in width, owing 
to the fulling up of the weft, will explain the increase of its 
strength, while the elongation may explain the diminution 
of strength in the warp. The cloth A., and also B., were 
chemically treated exactly as S.V., but were washed and 
dried loose, and not being fulled so much by the mechanical 
processes did not sensibly alter in length. The increased 
