ON THE FRUIT OP DIOSPYROS VIRGINIANA. 163 
baryta precipitated a solution of these crystals, and as 
neither nitric nor muriatic acids decomposed the precipitate, 
the salt was inferred to be a sulphate, and from the taste, and 
the fact of its decrepitating in the flame of a lamp, it was 
supposed to be a sulphate of potassa. 
From 600 grs. of green persimmon, freshly gathered, there 
was obtained : 
Of insoluble resinous matter - - - - 119 grs. 
" saccharine matter, slightly acid - - 64 " 
" ligneous matter 22 " 
" green coloring matter 1 " 
206 " 
leaving a loss of 394 grs., which was no doubt water, for 
the persimmons were very juicy. A portion of the saccha- 
rine matter was exposed to the air for a few days, when it 
became quite acid, and lost its sweetness in a great mea- 
sure ; a solution was made, and sub-acetate of lead added; a 
precipitate was formed, which after standing for some time 
lost its amorphous character, and was converted into groups 
of crystalline needles; a solution of sulphate of iron changed 
the solution to a brown colour. These experiments indicated 
malic acid, which may have been derived from the sugar ; 
which, if true, is an interesting metamorphosis, and de- 
serves a more attentive examination than I have been able 
to give it at this time. 
In the first of these experiments, we find the infusion of 
persimmons precipitated by solutions of sub-acetate of lead, 
sulphate of quinia, gelatin, and sulphuric and nitric acids. 
Solution of sub-acetate of lead yields precipitates with al- 
most all the organic acids, with gum, albumen, and caseous 
matter. Solution of sulphate of quinia causes a precipi- 
tate with tannin. Sulphuric acid forms a white sulphate, 
and nitric acid a dirty orange coloured nitrate of tannin. 
Sulphate of iron gives a purplish black colour to a solution 
