aE 
Miscellaneous Intelligence. 145 
ance of moisture is removed. The acid being an aqueous solution, 
will not have attached itself to the ink on the paper, printers’ ink being 
of an oily nature ; and if the paper thus prepared be placed on a pol- 
ished sheet of zinc and subjected to pressure, two results follow :—In 
first place, the printed portion will leave a set-off or impression on 
the zinc; and secondly, the nitric acid attached to the non-printed parts 
of the paper will eat away and corrode the zinc, converting the whole, 
in fact, into a very shallow stereotype. The original being removed 
(perfectly uninjured), the whole zinc plate should next be smeared with 
gum-water, which will not stick to the printed or oily part, but will 
attach itself to every other portion of the plate. A charge of printers? 
ink being now applied, this in its turn only attaches itself io the set-off 
obtained from the print. The final process consists in pouring over the 
plate a solution of phosphorous acid, which etches or corrodes more 
deeply the hon-printed portion of the zinc, and produces a surface to 
which printers? ink will not attach. he process is now complete, and 
fom such a prepared zinc plate any number of impressions may be 
Struck off. 
pig by the patent paper invented by Messrs. Glynn & Appel. Itis 
88 beautiful from its simplicity as it is efficacious in its operation. It 
ble salt, the phosphate of copper. Besides this, a very small portion 
- 4 ~.HOte so unlawfully used. Hitherto, elaborate engraving, beauty 
°f design, and executio <e P 
Stomp Suns, Vol. XV, No. 43,—Jan, 1853. 
