ce a pickling effect, and secondly, the alum at the same time is hydrolysed, and its dissociation components partly adsorbed by the hide, thereby effecting true tannage. This double effect is still more pronounced in the synthetic tannins which contain colloidal bodies of pronounced tanning intensity on the one hand, inorganic and organic salts on the other, which then act as described above. Their real mode of action can only be explained with the aid of experimental data. The following chapters will deal with the different behaviour of the various groups of synthetic tannins.
THE SYNTHESIS OF VEGETABLE TANNINS
The first investigations of gall-tannin date from the year 1770, at which time, however, no exact differentiation between tannin and gallic acid was made. The first step in this direction was made when Scheele,[Footnote: Grell's _Chem. Ann._, 1787, 3, I.] in 1787, discovered gallic acid in fermented gall extract, and in
VOLUME ONE in the WOOD COW CHRONICLES series. <... Read more
Fans of paranormal and urban fantasy will enjoy... Read more
2013 SFR GALAXY AWARD WINNER
"Heroism and... Read more
Set in the late Georgian era, Elizabeth Bailey’... Read more
There are six secret clans across the world–Afr... Read more
"Tim Hurtletuta has forgotten something. He can... Read more
12th century England: Two men vie for the thron... Read more
Dr. Gabe Allen has a rule about dating colleagues... Read more
See it as donating a moment of your social media time, every little thing helps us improve and stay online.
The list of books below is based on the weekly downloads by our users regardless of eReader device or file format.
See more popular titles from this genre.