180 THE ELECTRIC TELEGRAPH. 



chemical telegraph with which he proposed to supersede the 

 Morse recorder. Instead of the style at the end of the 

 printing beam moved by the electro-magnet, Pouget takes 

 a simple fixed style, and records the messages by chemical 

 decomposition instead of by embossing, thus dispensing with 

 the printing magnet and beam : he, however, retains the 

 relay and other arrangements of the Morse system. 



His paper is prepared by being soaked in a mixture of 



150 parts crystallised nitrate ammonia ; 



5 ferro-cyan. potassium ; and 

 10 water. 



Before being used, the paper is moistened with dilute 

 sulphuric acid sufficiently strong to make it conduct, but not 

 to attack, the metal of the style. This paper is said to be 

 cheap and easily prepared ; the salts are easily decomposed 

 and the traces permanent. 



Gintl,* a German, in his method, dispenses with the relay, 

 and records the messages on the prepared paper by the line 

 current direct, in the same way as Bain. 



His paper is prepared with a solution of 



1 part iodide of potassium and 

 20 starch paste, in 

 40 water. 



The results of this process are very satisfactory, and recom- 

 mend the apparatus as more convenient, in some respects, for 

 long lines than Morse's. An experiment, on a line between 

 Amsterdam and Berlin, made in 1853, with six Daniell's 

 elements, gave very legible signals ; and even with four ele- 

 ments the marks, although weak, were readable when no 

 reliable signals could be read with a Morse. 



The noiseless operation of the electro-chemical telegraphs 

 may have assisted in keeping this method of recording out 

 of more general use. It is always indispensably necessary to 

 combine an alarm with the system, to call the attention of 

 the manipulator ; not so necessary with the Morse, which is, 



* Brix's Journal, vol. i. p. 4. 



