SECTION II. 
HISTORY. 
While the general history in a preceding section 
refers largely to this member of the class, it is found 
necessary now to treat the history of each tannin sep¬ 
arately, beginning with 1802, when Proust made the 
statement that there were many different kinds of 
tannin. 
Davy published in 1803 the results of two years’ 
labor on the subject, which was prefaced by some his¬ 
torical remarks, in which he, like Ivarsten, attributed 
the discovery of tannin to Seguin, although he called 
attention to the fact that Diz6 first noticed the precipi¬ 
tate caused by the addition of sulphuric acid to infusion 
of galls. He further reviewed the work of Deyeux 
and Proust, giving the former much credit for his 
“able memoir,” but to the claim of the latter, “that 
there exist different species of the-tanning principle, 
possessed of different properties and different powers 
of acting upon reagents, but all precipitable by gelatin,” 
he answered, that, while probable, it could “ not be 
considered settled until the tannin in the different vege¬ 
tables has been examined in its pure and isolated state.” 
He did not accept all of Seguin’s theories about the 
action of infusion of galls on animal membrane, and 
considered them unwarranted by facts. 
Thus far the papers quoted confined themselves to 
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