tried: the colour at first was an opake deep blue : afterthe liquor had stood for some days on a fresh quantity ofthe wood, it approached more to blackness; but still re-tained a very considerable blue tinge. Galls themselvesgive indeed a bluish colour when the liquor is diluted soas to be transparent; but in an opake state, so far as Ihave observed, they exhibit no blueness.

I made trial also of the juice of floes, which to thetaste is pretty strongly astringent, and which, as we haveformerly seen, page 332, gives of itself, to linen, a stainof remarkable durability. By mixing the juice, whether'of raw or of baked floes, with different proportions ofsolution of vitriol, 1 could not produce the least tendencyto blackness, the vitriol seeming to make little alterationin the colour. Some of the mixtures, however, havingbeen written with on paper, the characters, after standingfor several days exposed to the air, changed by degreesto a full black, which appeared to be more durable thanthat of any of the inks made with galls; their colour hav-ing stood well in the open air from the beginning of no-vember last, till the papers were destroyed by the weatherin the end of february. Writings with good commonink, exposed along with them as a standard, had fadedmuch.

As all the astringent vegetables communicate of them-selves some colour to water, galls a brownish, bistortroot a dark brown, logwood a purplish, tormentil root areddish, pomegranate peel a greenish yellow, &c. I en-deavoured to prepare a compound black from the astrin-gents alone, on the principles mentioned at the end ofthe fourth section, page 3 5.5 ; hoping that this additionalblack in the liquor might coincide with, and heighten, thatwhich the vitriol would produce with the direct astrin-gent matter. Accordingly, taking a decoction of galls

and