On the Preparation of Writing Ink. 16 
a hittle ink at the time of its being mended. This, I think, 
is {pinning out .the effet of chemical affinity too far; for 
although, with refpet to tke reafoning, the truth mutt be 
admitted, I contend, notwithftanding, that its confequences 
to the edge are net apparent te the eye; nor is any fenfible 
detrimental change thereby produced upon the knife, more 
than what is induced by any other ank into which neither 
the fulphat or the acetite of copper is introduced. As to 
miyfelf, however, I have never yet feen a receipt for the form~- 
ation. of ink, where each of the principles were fo.completely 
proportioned and faturated with each other as to be inert 
when applied to the furface of a piece of polithed metal, 
fuch as iron, for example; nay, even the frequent contact of 
water only, if allowed to remain, would {poil any inftrament 
made of that material. I fhall not enlarge on this particular, 
conceiving the moft powerful objection I can offer in oppofi- 
tion to that opinion, is, that I have now lying by me a 
penknife, which has been in conftant ufe between two and 
three years, and which even yet retains almoft as good an 
edge as it had at firft, by the mere affiftance of an unprepared 
leather ftrap, although in the ink with which I write the 
acetite of copper has always been ufed. But even admitting, 
for argument’s fake, that what I have attempted to difprove is 
true, how many hundred pens might be made and mended 
ere it would be requifite to beftow twopence to the-cutler for 
the exercife of his art? In fhort, if the introduétion of the 
fubftance alluded to into ink be a fault, I confider it as one of 
no confequence when put in competition with the advantages 
of beauty, durability, and intenfity of colour imparted by it. 
I fhall intrude no“longer on the time or patience of your 
readers, than by requefting, if any of them are pofleffed of a 
cheap and efficacious method whereby the mouldinefs of ink 
may be prevented, that they will communicate the fame 
through the medium of your Magazine, in doing which 2 
very confiderable fervice will be rendered towards its perfeét- 
ability. The admixture either of a {mall quantity of the 
-muriate of foda, of the’ nitrate of pot-afh, of alcohol, or of 
cloves, have been feverally recommended for this purpofe; 
; t by experience I know that of thefe oily alcohol will 
‘a, Vou. V. ® avail, 
