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while it renders the uva urji entirely unfit for the pur-poses of making ink, may possibly be of some advantageto it for the black dye; as the largeness of the colouringparticles, which concrete in the pores of the cloth, mayrender them more fixed, so that less of the colouringmatter is wasted in the liquor, and less of it can be dis-charged from the cloth. To this cause may perhaps beascribed a quality of the uva ursi dye mentioned by theSwedish author, that the cloth is cleaner than after theother black dyes, or requires less washing to free it fromthe loose colour.

Among many astringents I have tried, oak wood camedie nearest to the uva urji in this concretion of thecolouring matter. A piece of white flannel was boiledfirst with oak faw-dust, and afterwards with an additionof vitriol as in the foregoing processes. The liquor, assoon as the vitriol was put in, became bluilh-black,though with much less bluenefs than the cold infusionof oak-dust and vitriol, page 383 : some of it beingpoured oft into a glass, it appeared full of powderymatter, which soon settled to the bottom, leaving theliquor of a pale bluish. From the blue colour of thismixture it was hoped, that a black dye might be obtainedfrom it without logwood or a blue ground; and in effectthe piece of flannel, though it did not acquire a trueblack, approached more to blackness than I rememberto have observed with other astringents : its colour was adark grey, without any mixture of blue or brown, likea pure black diluted with a little white. This woodseems therefore to deserve the attention of the dyers :there are grounds to believe that oak faw-dust, or theheart of oak reduced to powder in mills, will be foundan astringent of sufficient efficacy, and supply with ad-vantage the place of galls : the oak tree doubtless con-

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