void. Neither, however, can force the other to pay his quota. If both parties pay independently of each other, the Government will return the second payment on production of the first receipt. There are no means of knowing whether a tax has been paid or not during the current month, but information of all payments up to within a month of date can be obtained on application at the Ministry of Agriculture.

Certificates of Addition are null if for objects different from that of the principal patent. Thus, if the latter be for a product, and the certificate for a process of making that product, or vice versa, the certificate is invalid; but an addition to the process, or an alternative sub-process to form a part of that originally patented, provided it be operative to the same end, or an improvement on the product claimed in the first instance, can validly form the subject of a certificate of addition.

A certificate of addition granted to any shareholder or licensee of the original patent, becomes the joint property of all the proprietors in the same proportion as the original patent.

Amendment.-A patent invalid by reason of insufficiency or other defect in the description, cannot be made valid even by a "certificate of addition," though the added specification supplies the deficiencies of the original one, and makes it clear. Inexactitude is as bad as insufficiency of description, and equally nullifies a patent, even when unintentional.

Working. The patentee whose invention is not worked and who does not make bona fide efforts to work it within the realm, within two years, from date of grant (three years from date of application, if taken out under the convention of the Union for the Protection of Industrial Property), or who

abandons the working of it for two consecutive years, loses all right to his patent.

If any one "work" the invention during the two years, it suffices, it being immaterial to the question whether the inventor licensed him to do it or not.

Working invention in part has been held sufficient ; working a machine having a slight difference in design but the same in principle to that patented, will be sufficient working. Substantial efforts to get the trade to take it up, advertising the invention for sale, and exhibiting it in a public exhibition, all severally constitute sufficient working to satisfy the law.

Proof or working should be registered within the two years following the grant of patent, and if the inventor cannot arrange it in time the Patent Agent usually attends to it at a charge of from

8 to 10. Poverty, the fact of the patent being held an infringement of an existing patent, and that there was no demand for the invention at the time, have each been held sufficient excuses for not working a patent during the two years from date of grant.

Infringements.-Every interference with the rights of a patentee-either by manufacturing products or by using means forming the subject of his patent-constitutes the offence of an infringe

ment.

That offence is punishable by a fine of from one hundred to two thousand francs (£4 to £80). The patentee can also bring an action for and obtain damages from the infringer.

An imprisonment of from one to six months may also be inflicted whenever the infringer is a workman or person employed at the workshops or in the establishment of the patentee, or whenever the

infringer, after having gone into partnership with a workman or a person employed by the patentee, has become acquainted through the latter with the processes described in the patent.

In the latter case, the workman or person employed may be prosecuted as an accomplice.

It is an infringement of a patent for a new product to make that product by a different process from that set forth in the patent specification, or of different ingredients or materials.

It is an infringement the making of a product or the working of a process differing in unimportant details from that protected, but involving the principle of the patent. If an invention be for a combination of old parts, it is an infringement of the patent to manufacture or import those parts separately with a view to their being put together to form the invention.

It has been held an infringement of the patent to repair or renew, without license, worn-out parts of a machine originally purchased from the in

ventor.

Working the invention for one's own personal use is an infringement.

If a man infringes a patent while in the employ and at the command of another, the latter alone is liable for infringement.

A licensee who goes beyond his license is liable for infringement.

Articles seized from the inventor for debt can be sold and used without infringing.

If any one, prior to the date of the patent, possessed the patented article in France, he has the right to continue to use it throughout the duration of the patent without being accounted an infringer.

Actions cannot be maintained for infringements

made more than three years prior to the commencement of lawsuit; but if the infringements have been continuous, or repeated over a lengthened period, and a part of them have been committed within the three years, an action can be brought for the entire series. But an action must cover all the infringements up to the date of action; and after the suit at law no further action can be brought against the defendant for infringements made prior to said suit.

It is sufficient defence of an infringement that the part of the patent which is alleged to be infringed was, prior to the date of the patent, published in any country sufficient to enable any one to work it, or described in a prior patent which has fallen into the public domain, or of which the plaintiff has not acquired the rights, if still in force.

The patentee can obtain as damages in a civil action all profits that he could have made on the articles counterfeited, and satisfaction for injuries to his business that he can distinctly prove to be caused by the infringement.

The carriage of a patented article made abroad, in transit through France, is an infringement, even if destined for export to another country, thus the patented articles, made in Holland, where there is no Patent Law, if sent through France to a country where the invention is not patented, can be stopped and confiscated at the French Custom House.

Importation of Patented Articles.-A patent can be annulled if it be proved that the inventor, his agents, or any one with his or her connivance, has imported into the realm a specimen of the patented article manufactured abroad. France, has, however, joined the Union for the Protection of Industrial Property, and by so doing has agreed that this clause

shall be inoperative against patentees of the other nationalities of the Union (which includes Great Britain and the United States).

In a trial, where a man in Paris contracted with an American inventor to manufacture the American's invention in France, and supply it at a given price to the American's customers, and the contractor, instead of so doing, employed an agent in the United States, before that country joined the Union for the Protection of Industrial Property, to buy from the inventor and forward the machines to Paris, where they were regularly supplied, at sale price, by the contractor, it was held that this did not invalidate the patent, and that the patentee was not bound to interfere in the matter, but could, and, in fact, did, allow this singular trade to continue, to his own and the contractor's benefit.

The Minister of Agriculture can authorise an inventor, citizen of a state not in the Union, to introduce a single specimen of his invention by official permit; such permit can generally be easily obtained. During the régime of a late minister of agriculture they were, however, almost uniformly refused.

Importing the material for manufacture does not affect the patent. The article imported, to do any harm, must be in such a state of completeness that, if made in the realm, it would be held to be an infringement of the patent.

Nullification.-Any interested party can enter a suit to have a patent declared null. Any inventor in the same branch of industry is an interested party in the eye of the law.

A patentee can withdraw his application at any time within two months of the date of filing, when £4 will be returned.

Marking Articles.-Whoever, in his advertise