Keating, Vanuxen, Seybert, Booth, Clemson, Litton, and Moss, would fill many volumes. In organic chemistry, the researches of Clark, Hare, and Boyé were rewarded by the discovery of a new ether, the most explosive compound known to man. Mitchell's experiments on the penetration of membranes by gases, and the ingenious extension of them by Dr. Rogers, are worthy of all praise. The softening of indiarubber, by Dr. Mitchell, renders it a most useful article. Dyer's discovery of soda ash yielded him a competence. Our countrymen have also made most valuable improvements in refining sugar, in the manufacture of lard oil and stearin candles, and the preservation of timber by Earle's process. Sugar and molasses have been extracted in our country from the cornstalk, but with what, if any profit, as to either, is not yet determined. No part of mechanics has produced such surprising results as the steam engine, and our countrymen have been among the foremost and most distinguished in this great and progressive branch. When Rumsey, of Pennsylvania, made a steamboat, which moved against the current of the James River four miles an hour, his achievement was so much in advance of the age, as to acquire no public confidence. When John Fitch's boat stemmed the current of the Delaware, contending successfully with sail boats, it was called, in derision, the _scheme boat_. So the New Yorkers, when the steamboat of their own truly great mechanic, Stevens, after making a trip from Hoboken, burnt accidentally one of its boiler tubes, it was proclaimed a failure. Fulton also encountered unbounded ridicule and opposition, as he advanced to confer the greatest benefits on mankind by the application of steam to navigation. So Oliver Evans, of Pennsylvania (who has made such useful improvements in the flour mill), was pronounced insane, when he applied to the Legislatures of Pennsylvania and Maryland for special privileges in regard to the application of steam to locomotion on common roads. In 1810 he was escorted by a mob of boys, when his amphibolas was moved on wheels by steam more than a mile through the streets of Philadelphia to the river Schuylkill, and there, taking to the water, was paddled by steam to the wharves of the Delaware, where it was to work as a dredging machine. Fulton's was the first successful steamboat, Stevens's the first that navigated the ocean, Oliver Evans's the first high-pressure engine applied to steam navigation. Stevens's boat, by an accident, did not precede Fulton's, and Stevens's engine was wholly American, and constructed entirely by himself, and his propeller resembled much that now introduced by Ericsson. Stevens united the highest mechanical skill with a bold, original, inventive genius. His sons (especially Mr. Robert L. Stevens, of New York) have inherited much of the extraordinary skill and talent of their distinguished father. The first steamboat that ever crossed the ocean was built by one of our countrymen, and their skill in