the evaporation in vacuo also to the drying and preserving fruit and vegetables. It may be easily conceived of what advantage this process may be, particularly in the army and navy, by preserving unchanged, alimentary substances, and also by diminishing their weight and bulk, when they are to be sent to distant parts of the world.

Mr. Leslie proposes to introduce the apparatus into hospitals. in sultry climates, and to various domestic purposes; among others, to coolers, so as to produce ice in large quantities.

From Tilloch's Philosophical Magazine, for April 1812.

Professor Leslie has succeeded in freezing quicksilver by his frigorific process. This remarkable experiment was performed in the shop of Mr. Adie, optician, with an air-pump of a new and improved construction. A wide thermometer tube, with a large bulb, was filled with mercury, and attached to a rod passing through a collar of leather, from the top of a cylindrical receiver. This receiver, which was seven inches wide, covered a deep flat bason of nearly the same width, and containing sulphuric acid, in the midst of which was placed an egg-cup half full of water. The inclosed air being reduced by the working of the pump to the 50th part, the bulb was repeatedly dipt in the water, and again exposed to evaporation, till it became incrusted with a coat of ice about the 20th of an inch thick. The cup, with its water still unfrozen, was then removed, and the apparatus replaced, the coated bulb being pushed down to less than an inch from the surface of the sulphuric acid. On exhausting the receiver again, and continuing the operation, the icy crust at length started into divided fissures, owing probably to its being more contracted by the intense cold, than the glass which it invested; and the mercury having gradually descended in the thermometer, till it reached the point of coagelation, suddenly sunk almost into the bulb, the gage standing at the 20th of an inch, and the included air being thus rarified about 600 times. After a few minutes, the apparatus being removed, and the bulb broken, the quicksilver appeared a solid mass, which bore the

stroke of a hammer. The temperature of the apartment was then 54° of Fahrenheit.

In another experiment, with a small spirit of wine thermometer, under the same circumstances, and the same degree of rarefaction, the cold produced was found to be 7010 below nothing, or more than 30° below the point usually assigned for the congelation of mercury.

Such a prodigious power of refrigeration, and which will no doubt be further improved, opens a wide field for philosophical investigation. Liquids which have hitherto resisted coagelation may yet be rendered solid, and gases converted into liquids.

From the following extract, it will appear, that in the application of the principle of Mr. Leslie, by the French, they have long since been anticipated. It is taken from page 8 of the Appendix to the "Mill-wright and Miller's Guide," by Oliver Evans, published in Philadelphia in 1795, containing "Rules for discovering new improvements.'

(6 EXAMPLE EIGHTH.

"Take the art of preserving fruits, liquors, &c. from putrefaction and fermentation. Step 1. What are the principles of putrefaction and fermentation? By experiments with the airpump, it has been discovered that apples, cherries, &c. put in a tight vessel, having the air pumped out, will keep their natural fresh bloom for a long time. Again, by repeated experiments, it is proved, that things frozen will neither putrefy nor ferment while in that state. Hence he may conclude that air and heat are the principles or moving causes of putrefactive fermentation. II. What plans in theory are most likely to succeed? By removing the causes we may expect to avoid the effect.

1. Suppose a cistern in a cellar on the side of a hill, and supplied by a spring of cold water running in at the top, that can be drawn off at the bottom at pleasure. If apples, &c. be put in tight vessels, and the air pumped out, and beer, cyder, &c. be put in this cistern, and immersed in water, will they putrefy or

ferment? May not the experiment succeed in an ice-house, and fruits be conveyed from one country to another in glass or metal vessels made for the purpose, with the air pumped out and hermetically sealed? In support of this hypothesis, a neighbour told me, he filled a rum-hogshead in the autumn with apples, at the bung; bunged it tight, and in the spring found them all sound. Another when a boy, I buried a hollow gum bee-hive full of apples, trampled the earth tight about them, opened them when the wheat began to ripen, and found them all sound; but leaving them, I returned in a day or two, and found them all rotten.

STEAM BOAT CONTROVERSY.

THE question on appeal, between Messrs. Livingston and Fulton, and a combination at Albany relative to the exclusive right of the appellants to run steam boats on the waters that were within the jurisdiction, and were the property of the state of New York, having been determined in favour of the appellants by the unanimous vote of the court of appeals in that state; a short account of the controversy may be interesting to those who wish to encourage talents and enterprize. It is communicated by an eminent legal character, in New York, at the request of the Editor.

By the laws of the state of New York, a contract was entered into by that state, with Robert R. Livingston, Esq. for the building of steam boats. The laws recited that the state, in consideration of the advantages that would result to it from this enterprize, if successful, and the expense, and hazard, with which the experiments would be attended, grant to the said Robert R. Livingston, Esq. the exclusive right to navigate the waters of the state for twenty years with boats moved by steam or fire, upon condition that the said Robert should build a boat that should not be less than twenty tons burden, that should go four miles an hour; and should keep such boat in constant operation on Hudson's river. Mr. Livingston in pursuance of the law

built in the year 1800, a boat; but from the small size and imperfection of the engine he used, and perhaps from a defect in his plan (which was a horizontal wheel receiving the water at its centre, and propelling it by the centrifugal force from the stern) the boat went but little more than three miles an hour. As this was not a compliance with his contract, he founded no claim upon it: but broke up his boat and sold the engine, sustaining a loss of about $ 8000. Being shortly after sent as minister plenipotentiary to France, he, in conjunction with Mr. Fulton, whom he met at Paris, tried a variety of experiments on the different modes of propelling a boat by steam, and was convinced by them of the expediency of preferring that suggested by Mr. Fulton, and was in use in the state of New York. That nothing might be wanting to reduce their principles to practice, they built a large boat on the Seine, upon which they expended $ 8000, beyond what the materials sold for when taken to pieces. Encouraged by this experiment, they obtained from the state of New York, a law renewing their former contract, and extending it to Robert R. Livingston and Robert Fulton. In pursuance of this encouragement, they built three large vessels, the united tonnage of which amounted to upwards of 800 tons, (besides others built under their patent, and upon their models) and finished, furnished, and navigated them in such a style of expense and elegance, as renders the mode of travelling in them unequalled by any that Europe can boast of. We have been credibly informed, that they have expended on those boats and on one on the Ohio, and previous experiments, upwards of $ 150,000. Three years after these, or some of them were in operation, when every difficulty was removed and they began to reap some remuneration for their bold and expensive enterprize, a number of wealthy persons in Albany, (about 24) by no means distinguished for mechanical talents, combined to make two boats upon the model of the patentees, with very trifling variations to colour their usurpation, and actually built such boats, and run them the last summer (1811) in competition with the boats of Messrs. Livingston & Fulton. These gentlemen brought suits against the intruders,

265861B

and applied to the court of chancery for injunction to stop their boats; this the chancellor refused to grant. From the chancellor's decree, they appealed to the court for the trial of impeachments and the correction of errors; which is the highest court of judicature in the state of New York; and is composed, in case of appeals, of the five judges of the supreme court, and members of the senate, many of whom are always professional lawyers.

The ground taken by the defendants was, ist, that congress having a right to grant patents, the state had no right to make any contract which might interfere with that right.

2d. That congress having a right to regulate trade, the waters of the state were subject to their control, and no exclusive privilege would be granted upon them.

3d. That an injunction should not issue till the right was tried at law.

every

The appellants insisted, first, That congress had no power but to secure to inventors the right to their invention. That the right must therefore be such as could and did exist before it was secured. That no right ever existed or could exist in inventors to control that of a state to prohibit the use of an invention that they might find injurious, or to encourage enterprize by exclusive privileges. That these powers were of the essence of independent government; and as congress could not give exclusive privileges, the right to give them must rest in the state. That the most dangerous consequences would result from a contrary doctrine.-It was asked, cannot the legislature of Carolina prohibit the sale of a book upon the right of slaves to recover their liberty by force, or could they not give an exclusive right to one who imported, though he was not the inventor of a useful machine? and that as no power exists in congress to do these acts, such power must reside in the state. It was alleged that every power vested in congress not in its nature exclusive, or prohibited to the states, might be exercised by them in concurrence with congress. That the securing a natural right, had nothing exclusive in its nature, and might therefore be încreased