The telegraph manual: a complete history and description of the semaphoric, electric and magnetic telegraphs of Europe, Asia, Africa, and America, ancient and modern.

366 THE ELECTRO-CIIEMICAL TELEGRAPH.
case, these form the received communications, substantially, in
the manner and with the effects described and shown, including any merely practical variations in the means employed and
the effects produced thereby.
MORSE'S ELECTRO-CHEMICAL TELEGRAPH.
In order that the chemical telegraph invented by Prof. Morse
may be understood, I have taken the following extracts from
his patent. This chemical telegraph has never been put into
operation. The right is held by the companies owning the other
Morse patents, and, whether better or worse, there is a disinclination to change the systems.
Whetreas, among any earliest conceptions of the telegraph, in
Octob3r of the year 1832, on board the packet-ship, Sully, on
her voyage from France to New-York, I conceived the idea of
marking the telegraphic signs I had invented (being dots and
spaces to signify numerals), by electrical decomposition of certain salts and chemical compounds; and whereas, the application of the proper means for producing a successful result of
this thought was soon after superseded in my mind by another
method, at the same time conceived, of marking the said signs,
to wit, by magnetism, produced by electricity, which is the
successful method now in use, and having recently recurred to
my original thought of applying decomposition by electricity
through a single circuit of conductors, and discovered a means
of successfully applying the same, as then conceived, to the
rnarking of the aforesaid signs for numerals and letters, and of
any desired characters, I will here describe the nature of my
invention, and the method by which I obtain my results.
The nature of my invention consists: 1st. In the application
of the decomposing effects of electricity produced from any
known generator of electricity, to the marking of the signs for
numerals or letters, or words, or sentences, invented and arranged by me, and secured by patent, bearing date June 20th, 1840,
reissued January 15th, 1846, and again reissued June 13th,
1848, or their equivalents, through a single circuit of electrical
conductors.
2d. In the mode of applying this decomposition, and the machinery for that purpose.
3d. In the application of the bleaching qualities of electricity
to the printing of any desired characters.
In applying the decomposing effects of electricity upon any
known salts that leave a mark, as the result of the said decomposition, I use