COUNTERFEITING. 331 



842. THE SILVER SOLUTIONS. To prepare 



How is the sil- 

 ver solution the silver solution, above required, put a 



prepai three cent piece into a test-tube, having a 



diameter a little larger than the coin itself. Then fill the 

 tube to the depth of an inch, with a mixture of equal 

 parts of nitric acid and water. The solution of the coin 

 commences immediately. When it is completed, fill 

 up the tube with water, mix well by shaking, and the 

 solution is ready for use. For the same quantity of 

 salt solution, enough common salt to fill about two- 

 thirds of an inch of the tube, may be used. 



843. ANASTATIC PRINTING. This name 



Describe 



briefly the is given to a process by which any kind 

 astatic print- ^ Panted matter, may itself be converted 

 ill O ? into a plate, from which new copies may be 



printed. It consists, essentially, in the transfer of the 

 letters, or other design, to zinc, by pressure, the paper 

 having been previously moistened by dilute acid. 

 The oil of the ink remains, and the paper is re- 

 moved. The zinc plate is then used, like an ordi- 

 nary lithographic stone. When the inked roller is 

 passed over it, the ink only adheres to the design, from 

 which an impression may then be taken by the ordi- 

 nary process. 



What is said of 844 COUNTERFEITING. Bank notes may 

 counterfeiting fa counterfeited by either of the above 



by the above 



process? processes. Great apprehension has been 



felt, test they should render the use of paper money en- 

 tirely insecure. An effectual means of protection 

 against such counterfeiting, has recently been devised.* 



* Serop van's patent. 



