the hearing the parties may appear in person, or be represented by counsel, solicitors, or patent agents. Great delay frequently occurs in having oppositions at this stage finally disposed of, on account of the numerous other engagements of the Law Officers. They are naturally averse from stopping patents at this stage, because applicants have no power of appealing from their decision; and the only grounds upon which they decide not to allow an application to proceed, seem to be when there is proof of fraud on the part of the applicant; when previous public user of the invention is proved; or when the opponent is able to show that he is in possession of the identical invention. They do not consider the infringement of an existing patent to be a ground for refusing an application, because the invention for which a patent is sought may be a valuable improvement in respect of which the applicant may be well entitled to a new patent. This point has been frequently decided by many of the Law Officers. One of these cases was the opposition of Robertson to Hamilton's application, No. 474, 1872, before Jessell, S. G. However, if the Law Officer should report that part of the invention is covered by an existing patent, the Lord Chancellor may refuse the new patent for that part. (See p. 167.)

Oppositions at this stage are often entered in the dark, and upon mere suspicion. Since the provisional specification is not accessible to the opponent (see Re Tolson's Patent, 6 De G. M. & G. 422), he has no means of ascertaining exactly what the applicant's invention really is. Nor must the opponent look to the Law Officer for assistance in this respect. For example, there was a case of opposition before Baggallay, A. G., in June, 1875, where the applicant had referred to a model which had been made an exhibit to one of his declarations. The Attorney-General held that as the

model was used to elucidate the contents of the provisional specification, which the opponent had no right to see, neither was he entitled to see the exhibit.

The decisions of the Law Officers are not reported, and it is not unusual to find different Law Officers holding different views upon the same points.

The Law Officer will not grant his warrant for the seal if an opposer clearly proves a previous public use of the invention. Cairns, S. G., in the case of W. Pursall's application for a patent for percussion caps, heard before him 1st September, 1858 (P. M. J. vol. iii. 2nd series, 320), when it was proved that another manufacturer, who opposed, had obtained and used the improved percussion powder and sold caps made with it, prior to the application for Letters Patent, refused his warrant for sealing the patent.

It has, however, been held that an experimental use, even when the experiment was necessarily made with some degree of publicity, is not a sufficient reason to induce the Law Officer to withhold his warrant. (Adamson's Patent, 6 De G. M. and G. 420.)

In the case of Alexander's application (P. M. J. vol. iv. 2nd series, 73), an opposition was entered by Reed, who alleged that he invented apparatus identical with that sought to be patented in the year 1849, and that he exhibited, in Demerara, drawings and a description of the identical apparatus, and published a description of it in the Royal Gazette of George Town, Demerara, in the same year, Kelly, A. G., adjourned the hearing for a period sufficient to enable the opposer to obtain the necessary evidence from Demerara, conditionally on the opposer giving, within four days, an undertaking to pay whatever damages the Attorney-General should award to the applicant upon proof of loss by reason of the postponement; if no such undertaking was given within the speci

fied time, the patent to proceed. The opposer did not give the undertaking, and the patent was sealed. If the Law Officer is at all doubtful as to the effect of the evidence before him, he will allow the patent to proceed, that the question may be tried in a court of law. In the case of Dance's Patent (P. M. J. vol. vi. 2nd series, 298) opposition was entered on the part of James Stevens before Atherton, A. G., on the ground that the alleged invention was not a new invention, and that Dance was not the first and true inventor thereof. The opposer proved that crinoline fasteners similar to the alleged invention of Dance, were given to him by one Richardson, in the month of May, 1861, and that he exhibited the fastening publicly, and handed them to travellers for the purpose of taking orders for them. The travellers then proved their exhibition of the fasteners and their receipt of orders for them, prior to the 24th of June, 1861, the date of the application for the patent. There was no conflict of evidence on these heads, but the petitioner's declarations alleged that Dance had communicated the invention confidentially to Richardson. The Attorney-General finally gave his judgment as follows:-"I allow this patent to proceed, thinking that the question of fact, whether Mr. Dance or Mr. Stevens invented, and the mixed question of fact and law, whether the invention had been made public before Mr. Dance applied for protection, admit of too much doubt to justify a Law Officer in stopping the patent."

Where there are rival applications for a patent, it is the duty of the Law Officer to determine upon the evidence which patent ought to proceed; the question ought not to be remitted to the Lord Chancellor by issuing warrants for both patents. (Ex parte Henry, L. R. 8 Ch. 167.)

In cases where there are rival applicants, and the

Law Officer is satisfied that one of such applicants is entitled to one part of the invention, whilst the other can more fairly claim another part, he will issue his warrants to both, limiting the provisional specifications accordingly; this was done by Coleridge, S. G., in the matter of Craig and Macfarlane's applications (P. M. J. vol. iv. 3rd series, 366). The circumstances of the case were as follows:-Macfarlane applied for Letters Patent for "Improvements in rollers for paper-making machines," and obtained the usual provisional protection. The application was opposed by Craig, on the ground that he was the first inventor of an underpress roller, covered with vulcanite and vulcanized india-rubber which formed part of Macfarlane's provisional specification, and for which Craig had also applied and obtained the usual protection. The parties were heard, in accordance with the practice of the Law Officers, in the absence of each other. Craig contended that he was the first inventor and applier of the roller, which had worked satisfactorily at one of his mills; that Macfarlane, who had obtained the material for the covering of the rollers from the North British Rubber Company, simply acted as Craig's employé, and had not the merit of the invention; and that Macfarlane had only applied for his patent after the rollers had been experimented with by Craig, and had been found successful. In answer to declarations filed by Macfarlane, in proof of his having experimented at a paper-mill at Wandsworth, Craig submitted that such experiments, assuming them to have been successful, had only reference to the under coutch-roll of the machine, and that Macfarlane upon his own evidence had not proved that he had ever experimented on the under-press roll, and was not entitled to the sealing of his patent. Macfarlane contended that he was entitled to the patent for the

M

coutch and press-rolls. Coleridge, S. G., decided to grant his warrant for the sealing of Macfarlane's patent, for the coutch-roll alone, and to grant his warrant for the sealing of Craig's patent for the press-roll.

Where an employer opposed the application of a person who was or had been in his service, on the ground that the invention sought to be patented probably resulted from investigations or experiments directed and paid for by the employer, the Law Officer, being satisfied of the bona fides of the opposition, granted his warrant on condition that the applicant should submit his provisional specification to the inspection of the opponent, and should strike out such portions of it as contained matters of the kind referred to by the opponent. This was done by Coleridge, S. G., in the case of Healey's application, No. 85, 1872, and also in the case of Conniff's application, No. 3895, 1872, as to which there was a cross opposition, the opponent Jenner (in whose service Conniff had been employed) having already obtained provisional protection for an invention bearing a title similar to Conniff's. On an examination of the provisional specifications, it appeared that the inventions did not interfere with one another, and both patents were accordingly allowed.

An application of Mackay and Rae for Letters Patent was made 24th March, 1875, and opposed by West and Du Vallon on the ground that Mackay and Rae's invention was similar to that covered by Letters Patent already granted and sealed to West and Du Vallon, upon an application dated June 18, 1875. Baggallay, A. G., said, "These inventions appear to me to be substantially the same. If Messrs. Mackay and Rae desire to proceed, their Letters Patent must bear date after the sealing of Messrs. West and Du Vallon's ; and the Letters Patent were accordingly sealed on the 11th August, in place of the 24th March, 1875.