160 On the Preparation of Writing Ink. 
be particular in their manufecripts, the rule I have here baid 
down will be found fully to anfwer their expectations at @ 
cheaper rate than they are in general furni{hed with it, The 
beft veftel, in my opinion, in which to make ink, ts a come 
mon ftone bottle, which will contain half as much more as 
is propofed to be made, and which fhould be agitated twice 
a day, and be left uncorked, in order to expofe frefh furfaces 
of the liquor to the action of the air, without which it can- 
not be expected to write very black when firft ufed, but with 
this precaution may be fit for ufe in about 14 days; when 
it may be poured from its dregs, and soem up, to preferve it 
from duft, as well as wafle by evaporatidn. In cold weather 
it fhould never be fuffered to freeze, which is found to caule 
a difunion of its parts, nor does it ever afterwards recover 11s 
former intenfity of colour, luftre, or durability. Many per- 
fons, I am aware, difapprove, and therefore omit the ufe of 
Joewood, from an apprehenfion that it induces a tendency in 
the ink to fade; this however, from the ftricteft attention, I 
can affert' to be fallacious, at leaft where it is not had recourfe 
to by way of fubftitute for the other more expenfive articles ; 
indeed its effets are quite the reverfe, where all the ingredi-: 
ents are properly proportioned. As to the beautiful complexion 
which is given by it to the entire mafs of fluid, it would be 
needlefs to infift, unlefs for the fake of thofe who are unac- 
quainted how a mixture of the acetite of copper and logwood 
liquor work together, and by which, in this inftance, a rich- 
nefs and bloom is given, which can in no other way be got 
with equal economy and fuccefs; independent of which, the 
colouring matter of the wood, by its affinity with the oxyde 
of ivon, has a very powerful effect to blacken the ink, and 
to render it lefs capable of change from any unfaturated acid 
in the fulphat of iron, or from the operation of the air, I 
am aware, too, that the introduétion of cupreous matter has 
been objeéted to, on the fcore of its mjuring the penknife by 
a portion of copper attaching itfelf thereto in confequence of 
fuperior elective attraétion, whereby it has been remarked 
that a part of the knife’s edge is diflolved, and a quantity of 
copper aniwering thereto is exchanged and depofited in its 
place, which is always faid to happen when the pen retains 
a little 
