been popular in India, and soon became common after its introduction into Europe and this country. It is due to a volatile oil, of which the plant by distillation yields about 2 per cent.; this, as essence de patchouly, is also found in commerce. The odor is peculiar and remarkably persistent. Sachets of patchouli are small bags filled with cotton and the broken leaves, and used to perfume drawers and to put away with woollen clothing and furs to keep out moths; the essence is sometimes used alone, but more frequently employed in combination with other essences to make compound perfumes. India ink and India shawls owe their peculiar odor to this perfume, and in India it is used to scent smoking tobacco. Accounts are given of injurious effects resulting from an excessive use of patchouli as a perfume, such as nervous debility and loss of appetite and sleep.
PATÉ DE FOIE GRAS (Fr.), literally, a pie of fat liver, made generally of the liver of the goose, and in Nérac, France, of the liver of the musk duck. Strasburg and Toulouse are famous for goose-liver pasty tureens. The method of producing the abnormally large liver is to take a young bird in autumn, confine it in a close cage which permits but little movement, generally in a dark place, and feed the bird with beans, or more commonly with maize. During the last three or four weeks the bird is “crammed” twice or three times a day with parboiled maize seasoned with salt, the crammer forcing the food down its throat. Under this unnatural treatment the liver swells and attains a weight of from one to two pounds, and in exceptional cases even three pounds. The bird's throat is cut, and after being drawn the body is hung in a cold, airy place till the liver acquires sufficient firmness to be taken out. The pastry cook seasons and spices it, adds truffles and other ingredients, bakes the contents of the tureen, and pours over the mass a layer of fresh hog's lard to keep it from contact with the air. It is estimated that the trade of the Strasburg pastry cooks alone in these tureens amounts to $500,000 a year.
PATELLA (Lat., a kind of dish), the knee-pan, a chestnut-shaped bone placed in front of the knee joint, the cavity of which it protects from external violence. It is attached above to the tendon of the extensor muscles on the front of the thigh, and below, by means of a strong and broad ligament, to the tuberosity on the upper and front part of the tibia or leg bone. Its anterior surface is convex and rough, while its back part presents a double articular surface, invested with a thin layer of cartilage, corresponding with the articular surface of the front part of the lower extremity of the femur. The patella thus takes part in the formation of the knee joint. It is liable to fracture and to lateral dislocation; but neither of these accidents is very frequent.
PATENTS, Law of. Letters patent are granted by the governments of various countries to secure to inventors, their heirs and assigns, for a specified period, the exclusive right to new inventions and discoveries useful to industry. The system was not known to the ancients, and in many countries does not now exist. It is much favored in the United States, is common in Europe and the English colonies, and has been introduced into several South American countries. In England the authority to grant patents for useful inventions rests upon a proviso in the statute of monopolies passed in 1624. This act prohibited the granting of exclusive privileges in trade, but excepted “letters patent and grants of privilege for the term of one and twenty years or under, heretofore made, of the sole working or making of any manner of new manufacture within this realm, to the first and true inventor or inventors of such manufactures.” In France the earliest law in favor of new inventions was passed in 1791. The patent system of the United States has grown up under a positive grant in the federal constitution. The first act was passed in 1790. The grant of a patent is in the nature of a contract between the government and the inventor, the former giving to the latter the exclusive usufruct of the invention for a limited term in consideration of the benefit received from it by the public. This benefit results from the immediate practice of the invention under the patent, the privilege of practising it after the expiration of the patent, and the general encouragement given to industry. But it is disputed whether patent laws are for the public good. Neither Switzerland nor Holland has such laws. In Prussia the granting of patents is not regarded with favor by the government; and in England, Belgium, Saxony, and some other countries, the abolition of the system has been advocated.—The United States patent office in Washington is a bureau of the interior department; here are kept all records, books, models, drawings, specifications, and other things pertaining to patents. The officers are all paid, and comprise a commissioner, assistant commissioner, and three examiners in chief, appointed by the president with the consent of the senate; also one chief clerk, an examiner in charge of interferences, 24 principal, 24 first assistant, 24 second assistant, and 24 third assistant examiners, a librarian, a machinist, and a large clerical force. The examiners in chief must be persons of competent legal knowledge and scientific ability. The general law in force relating to patents is that of 1870.—Who may obtain a Patent. Any person, whether citizen or alien, whether resident in this or in a foreign country, being the original and first inventor or discoverer of anything patentable, may obtain letters patent therefor. A patent will issue to the assignee of the inventor, but the application must be made by the latter, and the assignment must be first recorded. In case of the death of the inventor, his legal representatives may apply for the patent. Joint inventors are entitled to a joint
