453 
Ink . 
ftsed. But if the impressions are not wanted to be very 
black, and the writing-ink is good, water itself may be 
used to moisten the thin paper, as herein first directed* 
It may be found necessary to add more or less water, in 
the preparation of the above liquor to be used for moist- 
ening the thin paper, or to vary the proportions of the 
other ingredients, according as they are more or less per- 
fect or strong, or as the impression is required to be more 
or less deep coloured. The writing ink which I use for 
letters or writings intended to be copied, is prepared as 
follows : take four quarts, ale measure, of spring water ; 
one pound and a half avoirdupoise weight, of Aleppo 
galls ; half a pound of green copperas or green vitriol % 
half a pound of gum arabic ; four ounces of roach allum ; 
pound the solid ingredients, and infuse them in the water 
six weeks or two months, during which time the liquor 
should be frequently shaken ; strain the liquor through a 
linen cloth, and keep it in bottles, closely corked fox 
yse.” Rep. Arts. 18. 
Common ink may be made fit for records by grinding 
up with it about one sixth part of the weight of the cop- 
peras employed of calcined lamp black (the calcining 
in a close vessel improving the colour and rendering it 
less oily.) Or indigo, or Frankfort black, or even a 
very finely powdered charcoal may be substituted ; or 
some common China or Indian ink may be dissolved in 
it. The liquid also should be half vinegar and half water, 
which sinks deeper, and the proportion of gum should be 
somewhat encreased. 
I do not find that the directions of Van Mons, Desor- 
maux, or Ribaucourt, offer any substantial improve- 
ment on the preceding recipe which is nearly Dr. Lewis’s. 
The blue vitriol I add to give a blue tinge with the log- 
wood : these two ingredients composing the false blue 
dye. 
3M 
