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instance the paper had absorbed the liberated soda, and the 
cloth in contact with it had almost entirely retained its 
original strength. 
The white portions of the patterns were in a further 
advanced state of decay than the blue ones, in most instances 
retaining only 10 per cent of their original strength. In the 
goods finished with starch only, the whites were equally as 
strong as the blues. In the goods finished Avith silicate of 
soda the whites Avere almost .as strong as the blues in all 
places where the before-mentioned decomposition of the 
silicate of soda had been accompanied by an abstraction 
of soda ; but in the interior of the goods, Avhere the silicate of 
soda had retained its original composition, the strength of the 
whites had decreased to about one-third of that of the blues. 
It Avas therefore evident that this excessive decay of the 
Avhites Avas due to some cause Avhicli had assisted the action 
of the alkali upon them, and we believe to have found an 
explanation of this in the action of the silicate of soda upon 
the sulphate of lead contained in them to the amount of 
about 10 per cent of the mineral ash. 
Sulphate of lead has been an ingredient of the resist paste 
printed upon the places intended to remain Avhite, and by 
the subsequent action of lime and sulphuric acid it has 
become fixed in the fibre. We have noticed that sulphate of 
lead decomposes solutions of silicate of soda very rapidly, Avith 
formation of sulphate of soda, free silicic acid, and silicate 
of lead. 
These changes give rise to the production of a crystallisable 
and strongly efflorescent salt, and to an increase in bulk ; 
and Ave think that the mechanical effect produced by the 
crystallisation of the sulphate of soda formed may have caused 
a further and final disintegration of the fibre already Aveakened 
by the action of the alkali. Under the microscope the 
fibre of the white portions of the pattern presented the 
appearance of cylindrical tubes, partially covered with 
