4i4 
Vdue. 
fceived less or more of the tanning,) was easily capable of 
being converted into glue, or boiled down into a jelly, 
which is adopted to various useful purposes without go- 
ing through the fuir process of glue making. What first 
engrossed my attention, was the vast quantities of scraps 
and parings of tanned leather thrown away from curriers^ 
work houses, and every shoemaker’s shop. What struck 
me was, that if any means could be fallen on to extract 
the tan, tliat all these which are at present thrown to the 
dunghill, might be converted to a valuable purpose. 
My first experiment was to steep a quantity of small 
pieces of tanned leather in water, renetving it regularly be- 
fore it came to a state of putrefaction, as whenever that 
takes place, the substance of the leather is rendered entire- 
ly unfit for the intended purpose ; but while any of die 
tan seemed to remain in the leather, the water kept fresh 
a very long time : how long I continued this, I cannot 
exactly say, but at least six or nine months. The water 
at last came oiF perfectly clear, and the leather seemed so 
soft and pliable, I had some hopes my object w^as obtain- 
ed ; but when boiled after the manner of dissolving other 
leather, I found that in place of dissolving into a soft or 
pulpy-like substance, it turned hard and brittle ; if the 
boiling was long continued, it separated into a kind of 
corney substance, or into small particles, but never dis- 
solved so as to intermix ivith the water. My next expe- 
riment was putting the leather into a weak solution of difi 
ferent acids : I thought it possible that some of these 
might either dissolve the tan, or at least be more powerful 
in extracting it than pure water ; this was very often re- 
peated, and at each renewal the leather was carefully wash- 
ed with water, to prevent its being in any degree corrod- 
ed by the acid. The same experiment was tried with a 
solution of alkali, but when the operation of boiling was 
again resorted to, the appearances were more unpromis- 
