IV. Experiments on Dying Black , by Mr . 
James Clegg, of Redivales, near Bury. In 
a Letter to Dr. Percival. 
DEAR SIR, 
Rcdde, Nov. t^TT I M E having been proved to in- 
*773- J j creafe the folvent power of 
water, upon allringent vegetables, for medical 
purpofes, I was defirous of knowing if it would 
be equally ufeful in the art of dying black; to 
this end 1 made the following experiments. 
EXPERIMENT I. 
Four penny-weights of each of the following 
afhingents ; videlicet, Galls, Sumach, Oak Bark, 
Biflort Root, and Logwood, were boiled during 
ten minutes, in half a pint of pure river water; 
upon mixing the decoflions with a faturated folu- 
tion of martial vitriol, in the proportion of i. 
of the folution to q of the decodton, they 
ftruck colours differently inclining to blacknefs, 
in the following order ; videlicet, Oak Bark, 
Biftort Root, Sumach, Galls. I then boiled the 
lame weight of all the aftringents, in the fame 
quantity of lime water ; and upon mixing them 
as 
