1816.] Scientific Intelligence. 163 
Armiger. I merely notice this, as it gives me the opportunity of 
saying that a similar idea was maintained in a thesis three years ago 
by a Graduate of the University of Pennsylvania. 
I have, however, contemplated this important agent as a probable 
means of establishing telegraphic communication with as much 
rapidity, and perhaps less expense, than any hitherto employed. I do 
’ not know how far experiment has determined galvanic action to be 
communicated by means of wires; but there is no reason to suppose 
it confined as to limits, certainly not as to time. Now by means of 
apparatus fixed at certain distances, as telegraphic stations; by 
tubes for the decomposition of water and of metallic salts, &c. regu- 
larly ranged ; such a key might be adopted as would be requisite to 
communicate words, sentences, or figures, from one station to 
another, and so on to the end of the line. 1 will take another 
opportunity to enlarge upon this, as 1 think it might serve many 
useful purposes; but, like all others, it requires time to mature. 
As it takes up little room, and may be fixed in private, it might in 
mauy cases, of besieged towns, &c. convey useful intelligence, 
with scarcely a chance of detection by the enemy. However fan- 
ciful in speculation, I have no doubt that sooner or later it will be 
rendered useful in practice. 
I have thus, my dear Sir, ventured to encroach upon your time 
with some crude ideas, that may serve perhaps to elicit some useful 
experiments in the hands of others. When we consider what won- 
derful results have arisen from the first trifling experiments of the 
junction of a small piece of silver and zinc, in so short a period, 
what may not be expected from the further extension of galvanic 
electricity! I have no doubt of its being the chiefest agent in the 
hands of nature, in the mighty changes that occur around us. If 
metals are compound bodies, which I doubt not, will not this active 
principle combine those constituents in numerous places, so as to 
explain their metallic formation: and if such constituents are in 
themselves aeriform, may not galvanism reasonably tend to explain 
the existence of metals in situations to which their specific gravities 
certainly do not entitle us to look for them. 
X. Royal Institute of France. 
Class of Mathematical and Physical Sciences.—Prizes pro- 
posed at the meeting of the 8th of January, 1816. 
Theorem vf Fermat.—Though the successive labours of different 
mathematicians have advanced the science of numbers far beyond 
what it was in the time of Fermat, yet two of the principal theorems 
of that philosopher remained still without demonstration, or at 
Jeast were demonstrated only in the two first of the general cases 
which they embrace. 
One of these theorems, that which concerns polygonal numbers, 
has been just demonstrated by M. Couchy, in.a memoir which 
obtained the approbation of the Class, and which will be likewise 
approved of by all mathematicians. 
