302 On preparing Ox-Gall for Painters, Sc. 
who colour prints, as many colours will not, without gall, 
work free on such paper, on account of the oil that is used 
in the printing-1nk, 
The artists who make drawings 1 in water-colours also use 
gall in the water which they mix their colour with, as it 
clears away that greasiness which arises from moist banda 
upon paper, and nakev the colour to work clear and bright. 
My preparation is ready for use in a few minutes; all that i is 
necessary being to dissolve about the size of a pea of it in 
a table-spoonful of water. 
It is also of great use to housekeepers, sailors, and others, 
to clean woollen clothes from grease, tar, &c. and will be 
found advantageous for many other purposes, 
If it should meet with the approbation of the Society, 1 
have no objection to prepare it for sale. 
] am, sir, your obedient servant, 
To C. Taylor, M.D. Sec. RicHarp CaTHERY, 
ae Botanical Colourer. 
Process for preparing Ox Gall in a concentrated State, by 
Mr. Cathery. 
Take a gall fresh from the ox and put it in a bason, let it. 
stand all night to settle, then pour it off from the sediment 
into a cleat earthen mug, and set it in a saucepan of boiling 
water over the fire, taking care that none of the water geis 
into the mug. Let it boil ull it is quite thick, then take it 
out and spread it on a plate or dish, and set it belies, the fire 
to evaporate; and when as dry as you can get it, put it 
into small pots, and tie papers over “their tops to keep the 
dust from it, and it will be good for years. 
Certificates were received from Mr. Gabriel Bayfield, 
No. 9, Park- place, eos and Mr. William Edwards, 
No. 9, Poplar-row 3; both Gtahiest colourers; stating, 
that they have nell the ox-gall prepared by Mr. Cathery, 
and find it to answer better than gall ina liquid state; that 
this preparation is free from disagreeable smell, and is much 
cheaper, as one ox-gall thus prepared will last one person 
for two years, and be as fresh as if just taken from the ox. 
A certificate was received from Mr. James Stewart, 
No.26, St. Martin’s- strecr, Leicester-square, stating, that he 
lately belonged to his Majesty’ s ship the Vestal frigate, ani 
that he took out with him, in a voyage to New founiland, 
a large pot of the prepared ox-gall, for the purpose of 
washinz his greasy clothes for two years; that he'found it very 
serviceable, and to keep its virtue as well as the first day. 
Lil. 4 
