intended to be claimed by the complete specification. must be foreshadowed in the preliminary instrument.

By the fifth and sixth subsections of the seventh section of the new Act it is provided that if after an application has been made, but before a patent has been sealed, another application is made, accompanied by a specification bearing the same or a similar title, it shall be the duty of the examiner to report to the Comptroller whether the second specification appears to him to comprise the same invention as that first specified; and if he reports in the affirmative, the Comptroller will give notice to the applicants that he has so reported. Where the examiner reports in the affirmative, the Comptroller may determine, subject to an appeal to the law officer, whether the invention. comprised in both applications is the same, and if so, he is empowered to refuse to seal a patent on the application of the second applicant.

By this provision an important change in the procedure was effected, as there had been previously no means of ascertaining whether an application conflicted with a prior unspecified patent or not. Under Rule 12 of the Patents Rules 1883 the second applicant must within a limited time notify to the Comptroller whether or not he intends to be heard upon the matter; and he may be required (Rule 13) to submit a statement in writing, or to attend before the Comptroller to make oral explanations. Under Rule 16 both the prior and second applicants may attend the hearing before the Comptroller, but neither will be at liberty to inspect the specification of the other. The report of the examiner will, in case of appeal from the Comptroller's decision, but not otherwise, be accessible to the second applicant (sect. 9, subsect. 5).

It sometimes happens that, after a provisional specification has been lodged, an inventor thinks it desirable

to abandon it, and lodge another in a different form. Under the old law it was at one time doubted whether a patent obtained upon the latter provisional specification was valid, but in the case of Oxley v. Holden (8 C. B. N. s. 666) it was held that a provisional specification did not become public by the mere fact of abandonment. It did not become public until published by the Patent Office. There appears to be nothing in the Act of 1883 to prevent an applicant from abandoning his first application, and lodging a new one before filing complete specification, and within nine months from the day of the first application.

In Stoner v. Todd (L. R. 4 Ch. D. 58) it was held that a patent was not invalidated by the fact that it was obtained for an invention which had been incompletely described in a prior provisional specification.

By the fourteenth section of the Patent Act of 1883, where an application for a patent in respect of an invention has been accepted, the invention may during the period between the date of the application and the date of sealing such patent be used and published without prejudice to the patent to be granted for the same; and such protection from the consequences of use and publication is termed provisional protection.

This protection, however, gives the applicant no rights against the public. He is only protected against the consequences of his own publication in case of his employing workmen, making experiments, or exercising the invention (Ex parte Bates & Redgate, L. R. 4 Ch. 577); that is to say, he will not thereby prejudice the patent afterwards granted to him. He must not forget, however, that as he cannot take any legal proceedings for infringements committed before the publication of the complete specification (sect. 13), his proceedings even under protection should be conducted with due caution.

Seeing that it was held by Lord Cranworth, C., in Mathers v. Green (L. R. 1 Ch. App. 29), that each of two joint patentees may use the invention without being liable to account to the other (joint patentees not being partners), it is desirable that joint applicants should consider their relative positions and come to an arrangement in good time as to the future working of the invention.

CHAPTER VII.

THE COMPLETE SPECIFICATION.

WHETHER there ever existed an implied compact between a patentee and the public with regard to a disclosure of the invention, as many lawyers formerly supposed and some doubted, is a question which it is unnecessary to discuss in these pages. It is sufficient for all practical purposes to say that the Patent Act of 1852 imposed upon every patentee the duty of particularly describing and ascertaining the nature of the invention, and in what manner it was to be performed; and that the Patent Act of 1883 has laid upon every applicant a like obligation in identical language (sect. 5, subs. 4). The instrument by which the applicant undertakes to satisfy the requirements of the law is known as the Complete Specification. It is by this instrument that the public are made acquainted with the inventor's secret, and he is bound to describe it clearly and fully, with the view of enabling others, when the proper time comes, to work the invention if they desire to do so. In the meantime the public are entitled to know what it is they are prohibited from using, that they may not unawares incur liability.

The reader will perceive before he arrives at the end of this chapter that the security of a patentee's privileges largely depends upon the shape given to this instrument. It is therefore necessary that he should exercise the greatest care and circumspection in its preparation.

As Sir George Jessel, then Master of the Rolls, once remarked in court, it is very difficult to draw a complete specification.' It may be conceived that, after the document has passed the ordeal of official examination, no further question can arise as to its sufficiency. An inventor, however, should not place too great reliance upon this, but should adopt every means in his power to make not only the complete but the provisional specification perfectly correct, and in accordance with both the letter and the spirit of the law, that they may, if at any time disputed, be held good upon their own merits.

After an account of the procedure has been given the greater part of this chapter will be devoted to a statement of the rules by which the inventor should be guided in preparing this important instrument. These rules will make him acquainted with the chief requirements of the law, and put him on his guard as to the faults which he is most likely to commit. Our remarks will be supported throughout by references to the reported cases.

PROCEDURE.

We have seen in the last chapter that, by the fifth section of the Patent Act of 1883, an application for a patent must be accompanied by either a provisional or a complete specification. Under the Act of 1852 the applicant had a similar liberty as regards the form of his specification. But it has never been a common practice to lodge a complete specification in the first instance, omitting the provisional specification altogether, because an inventor in the great majority of cases needs further time for making experiments and testing the invention with a view to its improvement and the working out of details, all which may be safely done under the protection of a provisional specification.