covery soon engaged the attention of the physicists of all countries; that it was extended by zealous inquiry and repeated experiments, and proved itself to be fruitful by a rapid succession of new discoveries; so that now it forms the basis of one of the principal divisions in books of instruction. Renown and honourable testimonials streamed in upon him from every side; many learned societies selected him as their member; the Royal Society in London sent him the Copley medal, and the French Institute, as an extraordinary acknowledgment, presented him with one of the mathematical class-prizes, worth 3000 francs.
We must bear in mind, when speaking of this great event of Oersted's life, that his services in experimental physics were by no means confined to this single phenomenon, although it may have cast the others into shade. In the following years his labours in a new edition of his work on Physics led to very important experiments on the compression of water, and when engaged in these researches, he invented an instrument by which a more certain method was attained of compressing liquids. By repeated experiments he succeeded at a later period to point out the hitherto doubted validity of the so-called law of Mariotti (for the compression of the air), even for a greater amount of pressure, up to the point where the gases become liquid. He proved the existence of a metal in alumina, and invented a method of separating it; farther, a new method to make chlorides out of oxides.
Assisted by the Government, Oersted undertook a third journey to Germany, France, and England, in 1822–23; he was chiefly occupied with the latest discoveries on light, and he brought back a number of important instruments. On his return home, he founded the Society for the Distrbution of Natural Science, which, among other things, was the occasion of public lectures being delivered by its pupils
