six inches deep, for the purpose of making a large surface, to evaporate a part of the water contained in the acid more speedily by a slow heat. These vats are bedded on sand upon the top of a brick stove, where a gentle heat is applied; thus it may be got in a pretty strong state. This acid is used instead of acetate of lead (sugar of lead) by the calico printers, to make their acetate of iron or iron liquor; though it is not sufficiently pure, it does well enough for blacks, browns, drabs, &c. but for yellows or reds it is not so good, owing to the oil and tar which are in combination with it. However, some have attempted to depurate (purify it) and have in part succeeded, and I have no doubt but in time it will answer all the purposes of acetate of lead. It tastes of acetous acid mixed with oil, and smells a little of tar, in the same manner as the smoke of wood when burning does. In fact, it is merely acetous acid holding an empyreumatic oil in solution. In order to obtain this acid, Mr. De Morveau distilled small pieces of very dry beech wood in an iron retort, by a reverberatory furnace; he changed the receiver when the oil began to rise, and rectified the product by a second distillation. Fifty ounces of very dry chips, afforded 17oz. of rectified acid of an amber colour, not at all empyreumatic, whose specific gravity compared with that of distilled water, was 49 to 48. To cleanse the Pyroligneous acid, the following plan has been proposed. "I would propose that the filter should be made of wood, of a pyramidal form, well seasoned, and well put together. The inside should be stuck full of small wooden pegs, and then overlaid with a coating of calcined gypsum and sand, of about an inch thick; or of fresh burnt quarry lime and sand, brought to the proper consistence with water, and immediately after covered with pounded glass, of the fineness of sea sand, by sifting it through a wire sieve.Sand may answer the purpose well enough; but if it cannot be got, broken green glass will furnish an adequate substitute. The pegs are intended to secure the adherence of the lining, which should completely cover them. In this manner an artificial stone or glass funnel of any requisite size may be easily supplied, 1 through which the liquor may be strained without the hazard of receiving, or of being injured by any foreign metallic impregnation, to guard against which more effectually, the joinings should be all dove-tailed, and wooden pegs used instead of nails, whereever these are necessary. Let the bottom opening be closed with a piece of strong hair cloth, or coarse canvas to support a layer of flint, broken into pieces of the size of a walnut; this to be followed with two or three more layers of the same material, or of green grass, progressively smaller in size; the surface being made level, and the interstices filled up with a layer about the size of hempseed, sifted over it through a tin riddle. Cover this with fresh burnt charcoal, (the residum of the article from which the acid is distilled), to the thickness of three or four inches, which should not be smaller than peas, and this may be again covered with a layer of an inch thick as fine as sand, which may be occasionally removed as it becomes clogged with the impurities of the liquor filtering through it. It is obvious that the charcoal must be secured from floating, by a covering of sufficient weight of broken or fint glass. A cask, or large box, having its bottom bored full of holes, may be used instead of this trough funnel, being lined in the same manner." Iron liquor, or acetate of iron, was formerly made of vinegar and old iron; at present it is formed by the pyroligneous acid and copperas. To obtain this, as much chalk is thrown into the above mixture, as will destroy the acidity. The rationale is as follows: 1 The chalk saturates the pyroligneous acid; the sulphuric acid then unites with the lime, while the pyroligneous acid in consequence of double affinity, combines with the iron, forming the iron liquor, which remains in solution, and is taken for use. In preparing acetate of alumine, acetate of lead and alum are employed, and the same process pursued as for iron liquor. 409 FERTILITY OF AMERICAN GENIUS. By a report made to the House of Representatives, by the Secretary of state, in January last, it appears, that from the passage of the law for the protection of the rights of inventors, discoverers and authors, to the 1st of May 1805, five hundred and ninety-six patents had been issued. From that date to the 28th December 1810, eight hundred and two patents were ta ken out. The Editor intends to make an arrangement, in order to enable bim to publish in the ensuing numbers of this work, a regular statement of the patents which have been granted during the preceding quarter ; and he offers the " Archives" to the ingenious, as a proper channel to an nounce and describe their inventions and discoveries. 1 t The following publication of Mr. Thornton, will prove highly serviceable to those persons who intend to apply for patents from the general govern ment. (From the National Intelligencer.) TO THE CITIZENS OF THE U. STATES. Patent Office, March 5th, 1811. HAVING the honour of directing or superintending the important duties of issuing patents for arts and inventions, which formerly were thought worthy of the labours of a council, composed of the secretary of state, the secretary of war, and the attorney general of the United States, I have thought it a duty to my fellow citizens to publish a few lines of information to facilitate the mode of acquiring patents, by which many will be enabled to dispense with long journies to the seat of government, or with troubling their friends by a tedious correspondence. Before an application be made for a patent I would advise the inventor to examine well the dictionaries of the arts, and sciencies, the Repertory of Arts and other publications that treat of the mechanic arts, to endeavour to ascertain if the invention be new; also to make inquiry of scientific characters whether or not the invention or discovery be practicable. These previous inquiries will sometimes prevent great trouble, and save the expense of much time, labour, and money; for a patent does not confer fights, where just claims do not exist; and as there is at present no discretionary power to refuse a patent, even where no just claim exists, it may be proper to caution the purchaser of patent rights against the supposition that the invention patented is always valuable, or new, or that it interferes with no previous patent. The respectable names of the president, the secretary of state, and attorney general are requisite to give validity to a patent; but ought never to be considered in any degree as evidence of the originality or utility of invention. The issuing of patents is grounded not only on a desire to promote the progress of useful arts, but also to prevent the loss of valuable secrets; for many have been buried with the inventors previous to the or ganization of this system of protection for the property of talent, mind, and genius. Formerly the arcana of any profession were withheld from the tyro; his initiation was gradual and secret, and the caution with which inventors worked to prevent the infringement of unprotected rights, confined many important inventions to limits too narrow to materially benefit either the inventors or the world: at present the law grants a monopoly to the inventor, for a limited time, provided the art, invention, discovery or machine, be duly explained, deposited, and recorded, for the benefit of mankind as soon as the time limited has expired-and the patent is not only an evidence that the inventor has formally confided his secret to the public, but some declaration of the protection of the right from infringement; hevertheless, of the right, by others, a jury of the country is only competent to decide. The general law concerning the issuing of patents will be found, in the 2d vol. of the Laws of the United States, page 200. This law provides for citizens only; but a subsequent law, vol. 5th, page 88, provides also for applicants who have resided two years or upwards in the United States, and who are not citizens. In applying for a patent it is necessary to attend to every legal form, for in consequence of inattention to* forms only, some of the patents issuing formerly, have in the course of law been declared null and void. * Oliver Evan's, among the number. MODE OF APPLICATION "Every inventor before he presents his petition to the secr secretary of state, signifying his desire of obtaining a patent, shall pay into the treasury of the United States, † thirty dollars, for which he will be furnished with duplicate receipts; one of which he shall deliver to the secretary of state when he presents his petition : and the money thus paid, shall be in full, for the sundry services, to be performed in the office of the secretary of state, consequent to such petition. This petition must be addressed to the secretary of state, and may be in the following or in a similar style, TO THE HON. ROBERT SMITH, SECRETARY OF STATE OF THE UNITED STATES. The petition of A. B.-of—in the county of ་ and state of-respectfully represents— That your petitioner has invented a new and useful improvement "[ or art, machine, manufacture or composition of matter, or any new and useful improvement in any art, machine, manufacture, or composition of matter] in-not known or used before his application," the advantages of which he is desirous of securing to himself and his legal representatives: he therefore prays that letters patent of the United States may be issued, granting unto your petitioner his heirs, administrators or assigns, the full and exclusive right of making, constructing, using, and vending to others to be used, his said improvement, [art, invention, machine, manufacture or composition of matter, &c.] agreeably to the acts of congress in such case made and provided; your petitioner having paid thirty dollars into the treasury of the United States, and complied with the other provisions of the said acts. [Date.] A. B. See laws of the United States, vol. 2d, chap. XII. § 11, p. 205: † Notes on any of the banks of the United States. James Munroe is now secretary of state-Editor. |