238 Miscellaneous Intelligence, aaa 6 
these is the electro-chemical telegraph. ‘Two patents have been granted 
for inventions of this kind, one of which has already gqne into practical 
Bain, came into the contest for priority of inyention upon unequal 
grounds, the former be a citizen of the Ynit ted States, and the latter 
a foreigner. It was held by your predecessor in ‘office, that under the 
law a foreigner could not go behind his foreign patent or printed pub- 
lication for evidence of his invention, and upon meierenee. of this sub- 
ject to the Atiorney General, the opinion of the. commissioner was 
onfirmed, >It was also held that in a contest for alodieg of invention, 
the sealing of a foreign patent was not to be taken as proof of inven- 
and that proof of enrolment was alone adequate. On the appeal 
o Chief Justice Cranch, the parties ee by counsel, who occupied 
some days in elaborate argument. It was, I believe, the first trial of 
appeal from the office, had in open court, and the hole case ‘has 
been faithfully reported and printed at ee expense ye e of the par- 
ties. The — t will be read with much interest by ncn and 
professional m 
he pation: ‘of the electro- chemical telegraph depends upon the 
chemical re-agency of the galvanic current. Marks or stains are made 
ed at the time to give it sufficient conducting power. The advantage 
claimed for this over the electro-magnetic telegraph, is that it may 
worked with much greater rapidity. In the electro-magnetic welegie 
a — is ei by the development of ssinntacs -magnetism, and the c 
sequent movement of a small bar of iron, both of which operations 
require sinticaihe time. In the chemical telegraph the production of 
the stains or marks is commensurate with the passage of any portion 
of the galvanic current; for, according to the best authorities, the cur- 
rent could not pass through the salt without decomposition. The change 
of colors, as indicated to the eye, may not be so sudden as the transit 
= the — but if it should not a so in fact, it beeomes so practical- 
y, as 
ra ease not informed agree this point, but it is immaterial ; 
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raph being this, that as it sone res time to change a discharge a0 
electro-magnet, and also to overcome the inte of maton parts, 
aking signals, while in 
