The process, patented some time ago, for the removal of straw, burrs,
etc., from wool, by treatment with sulphuric acid, has been modified
by Lisc as follows: The stuff is worked for one to two hours in a bath
consisting of about 26 gallons sulphuric acid, of 3° to 6°, 1 lb.
alum, ½ lb. salt, and 750 grains borax. It is then treated in a
centrifugal machine, and afterward subjected to a temperature of 212°
to 248°. For removal of the acid it is first washed with pure water
for 1½ hours, then treated for two hours with fuller's earth, soda,
and lime, and finally washed for two hours with fresh water. As
sulphuric acid can only be employed with uncolored cloths, or such as
have been dyed with indigo, chloride of zinc and chloride of manganese
diluted to 6° are substituted with fabrics otherwise dyed.
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