Baker Petrolite Corp. v. Canwell Enviro-Industries Ltd.

(2002), 17 C.P.R. (4th) 478 (Federal Court of Appeal per Strayer J.A., Rothstein and Evans JJ.A. concurring)

2002 FCA 158

April 29, 2002.

Facts

The patent claimed a process for removing hydrogen sulfide from natural gas. (Hydrogen sulphide at low concentrations smells like rotten eggs. At higher concentrations it is poisonous. It is corrosive.)

The patent claimed a method of using triazine to selectively reduce hydrogen sulphide in natural gas.

[4]The 946 patent is a process patent. It covers methods for removing hydrogen sulphide from natural gas. This is sometimes called sweetening or scavenging sour gas. Because hydrogen sulphide is corrosive in the presence of water and poisonous in very small concentrations, it must be removed almost completely from natural gas streams before use and before transport in a pipeline.

[5]Several methods for sweetening sour gas had been known. They involved bringing various chemicals into contact with natural gas at the wellhead or in a scrubber tower or absorber tower, or in other locations near the origin of the natural gas. However, use of these chemicals had undesirable side effects, e.g. health hazards, non-selective reaction resulting in removal of more than hydrogen sulphide, the production of precipitates that clog pipelines or poor performance at lower temperatures.

[6]The objective of the invention under the 946 patent is to reduce or eliminate these side effects by use of a reaction product of an alkanolamine with an aldehyde. The reaction product would be brought into contact with natural gas in a scrubber system, as a chemical solvent system, by injection into a pipeline or by other methods.

[7]The preferred embodiment of the invention is indicated to be monoethanolamine (MEA) as the alkanolamine and formaldehyde as the aldehyde. While the 946 patent claims cover a range of molar ratios of the alkanolamine and the aldehyde, from about 1:0.25 to 1:10, the preferable molar ratio is indicated to be from about 1:1 to about 1:1.5.

[8]The 946 patent states that the reaction product of MEA and formaldehyde is bisoxazolidine and triazine. However, the Trial Judge found that the expert testimony was unanimous that bisoxazolidine had never been conclusively identified as a reaction product of MEA and formaldehyde, and was equally unanimous that the predominant reaction product of MEA and formaldehyde was triazine.

[9]The triazine covered by the 946 patent had been known as a reaction product of MEA and formaldehyde. Accordingly, there is no product claim in the patent. The claims are limited to the reaction product used to selectively reduce the levels of hydrogen sulphide in natural gas.

…

[57]Claim 1 is not a product claim. Indeed no claim is a product claim. In other words, there is nothing novel about a composition that comprises a reaction product of a lower alkanolamine and a lower aldehyde. Nor is it a novel process to reduce hydrogen sulphide in natural gas by contacting gas streams with a chemical product. The invention that is the subject of claim 1 is the contacting of the known, but not previously used for the purpose, reaction product disclosed in the claim with sour natural gas streams to reduce the level of hydrogen sulphide in the streams.

…

THE LAW RELATING TO ANTICIPATION

The Relevant Statutory Provision

[28]The application for the 946 patent was filed December 19, 1989. According to paragraph 28.2(1)(a) [as enacted by section 33] of the 1996 Act, the subject- matter defined by the claims in the patent must not have been disclosed prior to December 19, 1988. Paragraph 28.2(1)(a) provides:

28.2 (1) The subject-matter defined by a claim in an application for a patent in Canada (the "pending application") must not have been disclosed

(a) more than one year before the filing date by the applicant, or by a person who obtained knowledge, directly or indirectly, from the applicant, in such a manner that the subject-matter became available to the public in Canada or elsewhere;

Anticipation by Publication

[29]In Beloit, supra, Hugessen J.A. (as he then was) set out the test for anticipation by publication, at page 214:

It will be recalled that anticipation, or lack of novelty, asserts that the invention has been made known to the public prior to the relevant time. The inquiry is directed to the very invention in suit and not, as in the case of obviousness, to the state of the art and to common general knowledge. Also, as appears from the passage of the statute quoted above, anticipation must be found in a specific patent or other published document; it is not enough to pick bits and pieces from a variety of prior publications and to meld them together so as to come up with the claimed invention. One must, in effect, be able to look at a prior, single publication and find in it all the information which, for practical purposes, is needed to produce the claimed invention without the exercise of any inventive skill. The prior publication must contain so clear a direction that a skilled person reading and following it would in every case and without the possibility of error be led to the claimed invention.

The test for anticipation by publication in Beloit, supra, was cited with approval by the Supreme Court of Canada in Free World Trust v. Électro Santé Inc., [2000] 2 S.C.R. 1024, at paragraph 26. In Free World Trust, supra, Binnie J. explains, at paragraph 25, that anticipation by publication is a difficult test to meet because, after an invention has been disclosed, it is all too easy to find its antecedents in bits and pieces of earlier learning:

Anticipation by publication is a difficult defence to establish because courts recognize that it is all too easy after an invention has been disclosed to find its antecedents in bits and pieces of earlier learning. It takes little ingenuity to assemble a dossier of prior art with the benefit of 20-20 hindsight.

Anticipation by Prior Use or Sale

[30]The anticipation in the appeal at bar is about anticipation arising, not from prior publications or patents, but from the prior sale of Petrolite's W-3053 product. Anticipation by prior patents is also argued by Canwell, but it will not be necessary to deal with that argument.

[31]The Patent Act in force in 1986, when Beloit, supra, was decided, provided that anticipation could be proven by the public use or sale of the invention in Canada more than two years prior to the filing of a patent application. Before October 1, 1989, paragraph 27(1)(c) provided:

27. (1) Subject to this section, any inventor or legal representative of an inventor of an invention that was

. . .

(c) not in public use or on sale in Canada for more than two years prior to his application in Canada

may, on presentation to the Commissioner of a petition setting out the facts, in this Act termed the filing of the application, and on compliance with all other requirements of this Act, obtain a patent granting to him an exclusive property in the invention.

Under paragraph 27(1)(c), it appears that public use or sale of the invention was sufficient to prove anticipation even if the invention was not thereby disclosed; that is, even if it was not possible to determine the claimed invention, the invention would be anticipated simply by its use or sale. It was, therefore, not necessary, at that time, to prove more than use or sale of the invention in the relevant time period in order to prove anticipation.

[32]As a result of amendments made effective on October 1, 1989, and continued in the 1996 Act, evidence of use or sale of the invention was no longer sufficient in itself to prove anticipation. With the enactment of paragraph 27(1)(d) on October 1, 1989 [R.S.C., 1985 (3rd Supp.), c. 33, s. 8], which was replaced by paragraph 28.2(1)(a) on October 1, 1996 [S.C. 1996, c. 15, s. 33], the test for anticipation by any means became disclosure of "the subject-matter defined by a claim"(the invention) "in such a manner that the subject-matter became available to the public in Canada or elsewhere". The change to the legislation, inter alia:

1. reduced the relevant grace period prior to the filing of the patent application;

2. made disclosure anywhere, and not just in Canada, relevant;

3. eliminated use or sale of the invention per se as sufficient evidence of anticipation;

4. as proof of anticipation, required disclosure in such a manner that the invention became available to the public in Canada or elsewhere.

DMC’s comment: UK and EPC jurisprudence is useful because of the similarities in the statutes.

[34]I agree with the learned Trial Judge that the United Kingdom authorities are not of assistance to the extent that they are contrary to the principles relating to anticipation articulated in Beloit, supra, and Free World Trust, supra. This Court is bound by Free World Trust and, to the extent it approved of Beloit, by Beloit. However, the U.K. authorities are useful to give content to the analysis of anticipation by prior use or sale and, to the extent they do not contradict the Canadian jurisprudence, guidance may be sought from such decisions for that purpose.

[35]I accept that, at a broad level, the principles in Beloit, supra, and Free World Trust, supra, relating to anticipation by prior publication are also applicable to anticipation by prior use or sale. For example, the evidence of anticipation by prior public use or sale, as well as by prior publication, should be subjected to close scrutiny. However, below a certain level of generality, the principles governing anticipation by prior publication may need to be tailored to fit the particular characteristics of anticipation by prior public use or sale. For example, the principle that the prior publication must contain so clear a direction that a skilled person reading and following it would be led, without error, to the invention claimed, applies to the specific context of prior publication. In the case of prior publication, the skilled person will read the publication. In the case of prior use or sale, reading may not be relevant. When faced with having to decide whether there has been anticipation by disclosure through prior use or sale under paragraph 28.2(1)(a), it is necessary for the Court to have regard to the circumstances of prior use or sale, in order to determine how a person skilled in the art might be led, without error, to the invention claimed. For example, was there an analytical method available at the relevant time to lead a skilled person to the invention? The United Kingdom authorities provide useful guidance in this respect.

[36]The United Kingdom authorities are also useful for another purpose. As indicated, although there is little Canadian jurisprudence interpreting paragraph 28.2(1)(a) of the 1996 Act, there is considerable United Kingdom jurisprudence interpreting provisions of the Patents Act 1977 (U.K.), 1977, c. 37, that are, in their substance, similar to paragraph 28.2(1)(a). Courts in the United Kingdom have had occasion to deal with cases of anticipation by prior use or sale under section 2 of the United Kingdom Act and those authorities will be instructive in assisting in the interpretation of paragraph 28.2(1)(a) of the Canadian Act.

Principles Derived from United Kingdom and European Authorities with respect to Anticipation by Prior Use or Sale

[37]I turn then to the United Kingdom authorities. I shall also have regard to decisions made under the European Patent Convention [Convention on the Grant of European Patents (European Patent Convention), October 5, 1973] because it contains provisions similar to the United Kingdom Patents Act 1977. Courts in the United Kingdom appear to be guided by decisions under the European Patent Convention and I see no reason why, where this Court finds the United Kingdom authorities of assistance and the European legislation is similar, it may not also seek guidance from the European decisions.

[38]The United Kingdom Patents Act 1977 contains provisions that are similar in effect to paragraph 28.2(1)(a) of the 1996 Act. Subsection 2(1) of the United Kingdom Patents Act 1977 provides that an invention is to be taken as novel if it does not form part of the state of the art. Subsection 2(2) defines the state of the art as comprising all matter which has been made available to the public in any way:

2.--(1) An invention shall be taken to be new if it does not form part of the state of the art.

(2) The state of the art in the case of an invention shall be taken to comprise all matter (whether a product, a process, information about either, or anything else) which has at any time before the priority date of that invention been made available to the public (whether in the United Kingdom or elsewhere) by written or oral description, by use or in any other way. [Emphasis added.]

The European Patent Convention contains similar provisions.

Article 54

(1) An invention shall be considered to be new if it does not form part of the state of the art.

(2) The state of the art shall be held to comprise everything made available to the public by means of a written or oral description, by use, or in any other way, before the date of filing of the European patent application. [Emphasis added.]

[39]The words employed in the United Kingdom and European legislation are similar, in effect, to the words in paragraph 28.2(1)(a) of the 1996 Act:

28.2 (1) The subject-matter . . . must not have been disclosed

(a) [. . .] in such a manner that the subject-matter became available to the public in Canada or elsewhere;

DMC’s comment: made available (UK) = became available to the public (Canada)

[40]While conceding that the United Kingdom and European legislation is similar to the 1996 Act on this issue, Petrolite argues that a significant difference is that the former (United Kingdom and European) use the term "made available to the public" while the latter (Canadian) uses the term "became available to the public". If I understand the argument, it is that "made available" implies "on the shelf" or, in other words, that the information could be available to the public. On the other hand, "became available" implies that the public was, in fact, in possession of the information. It is argued that the difference means that reverse engineering is permitted in the United Kingdom and Europe but not under Canadian law or, at least, that if reverse engineering is permitted under Canadian law, it must, in fact, have been performed more than one year before the filing date of the patent.

[41]I am unable to agree with Petrolite's argument. Whether information is made available or became available, it is available. Whether information is considered "available" if it is only ascertainable through reverse engineering is a question for determination. But that is so under either the "made available" or "became available" terminology. I see no material distinction between the terms "made available" or "became available" in the context of this case.

The Eight Principles from the UK and EPC Jurisprudence

[42]For the purposes of analysing anticipation in the context of disclosure by prior sale or use under paragraph 28.2(1)(a) and without detracting from the general principles in Beloit, supra, and Free World Trust, supra, I deduce the following principles relevant to this appeal from the United Kingdom and European Patent Office jurisprudence:

1. Sale to the public or use by the public alone is insufficient to prove anticipation. Disclosure of the invention is required to constitute anticipation under paragraph 28.2(1)(a). In Merrell Dow Pharmaceuticals Inc. and Anr. v. H. N. Norton & Co. Ltd., [1996] R.P.C. 76 (H.L.), Lord Hoffmann found that use of a product makes an invention part of the state of the art, i.e. equivalent to disclosure, only so far as that use makes available the information which describes the invention. At page 86, he stated:

. . . to be part of the state of the art, the invention must have been made available to the public. An invention is a piece of information. Making matter available to the public within the meaning of section 2(2) therefore requires the communication of information. The use of a product makes the invention part of the state of the art only so far as that use makes available the necessary information. [Emphasis in italics in original; other emphasis added.]

2. For a prior sale or use to anticipate an invention, it must amount to "enabling disclosure". In Merrell Dow, supra, at pages 86-87, Lord Hoffmann quoted with approval the statement of Aldous J. in PLG Research Ltd. v. Ardon International Ltd., [1993] F.S.R. 197, at page 225:

Under the 1977 Act, patents may be granted for an invention covering a product that has been put on the market provided the product does not provide an enabling disclosure of the invention claimed. In most cases, prior sale of the product will make available information as to its contents and its method of manufacture, but it is possible to imagine circumstances where that will not happen. [Emphasis added.]

In Lux Traffic Controls Ltd. v. Pike Signals Ltd. and Faronwise Ltd., [1993] R.P.C. 107, Aldous J. stated at page 133:

It is settled law that to invalidate a patent a disclosure has to be what has been called an enabling disclosure. That is to say the disclosure has to be such as to enable the public to make or obtain the invention. [Emphasis added.]

3. The prior sale or use of a chemical product will constitute enabling disclosure to the public if its composition can be discovered through analysis of the product. The Board of Appeal of the European Patent Office in FISONS plc v. Packard Instrument B.V., E.P.O. case number T 0952/92 - 3.4.1, August 17, 1994, stated at page 21:

. . . in the Board's view it is the fact that direct and unambiguous access to information concerning the composition or internal structure of a prior used product is possible, for example by means of analysis, which makes such composition or internal structure "available to the public" and thus part of the state of the art for the purpose of Article 54(2) EPC. [Emphasis added.]

4. The analysis must be able to be performed by a person skilled in the art in accordance with known analytical techniques available at the relevant time. In FISONS, supra, the Board of Appeal stated at page 21:

If such an analysis is possible in accordance with the known analytical techniques which were available for use by a skilled person before the relevant filing date, the composition or internal structure thereby is available to the public. [Emphasis added.]

This principle, in the context of enabling disclosure arising from prior use or sale, must be applied consistently with this Court's determination respecting prior publication in Beloit, supra. The person skilled in the art, using available analytical techniques, must be able to find the invention without the exercise of inventive skill.

5. In the context of patent anticipation under paragraph 28.2(1)(a), when reverse engineering is necessary and capable of discovering the invention, an invention becomes available to the public if a product containing the invention is sold to any member of the public who is free to use it as she or he pleases. In Bristol-Myers Co.'s Application, [1969] R.P.C. 146 (Q.B.D.), Lord Parker C.J. stated at page 155:

. . . if the information . . . has been communicated to a single member of the public without inhibiting fetter that is enough to amount to a making available to the public. . . . [Emphasis added.]

In Lux, supra, Aldous J. stated at page 134:

In the present case, a light system with a prototype controller was on a number of occasions made available to contractors over five months. Those contractors were free in law and equity to examine it. [Emphasis added.]

It makes sense that sale of a product to even one member of the public constitutes a making available to the public for purposes of paragraph 28.2(1)(a). The value of the patent that is sought lies in the secrecy of its subject-matter. Providing enabling disclosure to even one member of the public destroys this secrecy. The grant of a patent depends on the inventor giving to the public something it did not have before. If the public already has it, then the inventor gives nothing and is not entitled to anything in return, i.e. a monopoly for a period of years. (See Free World Trust, supra, at paragraph 13.)

6. It is not necessary to demonstrate that a member of the public actually analysed the product that was sold. In Lux, supra, Aldous J. stated at page 133:

Further it is settled law that there is no need to prove that anybody actually saw the disclosure provided the relevant disclosure was in public. Thus an anticipating description in a book will invalidate a patent if the book is on a shelf of a library open to the public, whether or not anybody read the book and whether or not it was situated in a dark and dusty corner of the library. If the book is available to the public, then the public have the right to make and use the information in the book without hindrance from a monopoly granted by the State. [Emphasis added.]

Although the comments of Aldous J. use the example of prior publication to make the point, Lux was a prior use case and the principle derived from his example is equally applicable to prior use or sale as well as prior publication.

7. The amount of time and work involved in conducting the analysis is not determinative of whether a skilled person could discover the invention. The relevant consideration, in this respect, is only whether inventive skill was required. In FISONS plc v. Packard Instruments B.V., supra, the Board of Appeal of the European Patent Office stated at pages 21-22:

The likelihood or otherwise of such a skilled person either reading such a written description, or analysing such a prior sold product, and the degree of burden (i.e. the amount of work and time) involved in such reading or in analysing, is in principle irrelevant to the determination of what constitutes the state of the art. [Emphasis added.]

There must be some evidence from which the use of inventive skill may be inferred. Complexity or time and work involved alone are insufficient.

8. It is not necessary that the product that is the subject of the analysis be capable of exact reproduction. It is the subject-matter of the patent claims (the invention) that must be disclosed through the analysis. Novelty of the claimed invention is destroyed if there is disclosure of an embodiment which falls within the claim. In FISONS, supra, the Board held at page 23:

According to the established jurisprudence of the Boards of Appeal, the novelty of a claimed invention is destroyed by the prior disclosure (by whatever means) of an embodiment which falls within the claim. Thus in the Board's view, the novelty of a claimed invention is destroyed by the prior use of a product, for example, sale of a product, if an analysis of a product using available analytical techniques is such as to inform the skilled person of an embodiment of the product which falls within the claim of the patent. The Board therefore does not accept the patent proprietor's submission to the effect that a complete analysis of a prior used product must be possible, so as to enable an exact reproduction of such product, in order to destroy the novelty of the claimed product. [Emphasis in bold in original; other emphasis added.]

[43]The foregoing eight principles (which are not intended to be exhaustive) are particularly relevant to disclosure by prior use or sale in the context of paragraph 28.2(1)(a) in this case, although some may also be applicable to disclosure by prior patent or publication. They supplement, but do not alter the principles relating to anticipation as set out in Beloit, supra, or Free World Trust, supra.

Review of the Findings of the Trial Judge

[74]The Trial Judge's reasons indicate that the standard he was applying for proof of anticipation was the ability through reverse engineering to "successfully analyse and reconstruct W-3053". It is clear that the Trial Judge thought it necessary to reconstruct W-3053 and found the expert evidence wanting for this purpose. The Trial Judge also referred to analysing W-3053, but if the purpose of analysis in his mind was different from reconstructing W-3053, there is nothing in his reasons to indicate what that different purpose was. On the contrary, other portions of his reasons suggest that his reference to analysis was to enable W-3053 to be reconstructed, or, what is the same thing, to determine its composition. A test for reconstruction is consistent with the Trial Judge's previous determination that the invention was, to all intents and purposes, W-3053. I conclude that the test for anticipation used by the Trial Judge was successfully analysing W-3053 to determine its composition or, what is the same thing, to reconstruct W-3053. I am of the respectful opinion that the Trial Judge erred in law in using this test for anticipation.

[75]A defendant relying on the defence of anticipation by prior use or sale of a product does not have to prove that the product can be reproduced (see FISONS, supra, at page 23). The product will contain the invention but may also contain other ingredients. A defendant relying on paragraph 28.2(1)(a) need only prove that the subject-matter of the patent, i.e. the invention, has been disclosed. The invention in this case was contacting natural gas streams with triazine (or its starting components) to reduce levels of hydrogen sulphide in the streams. Because the contacting of W-3053 with sour natural gas streams was known to customers who purchased the product, it is only necessary to consider whether triazine or its starting components were capable of being detected in the W-3053. If so, then the invention was disclosed by the sale to the public of W-3053 and the 946 patent is anticipated. Thus, in the circumstances of this case, the question is whether a person skilled in the art could have discovered triazine (or its starting components) through analysis. It is not whether that skilled person could have reproduced W-3053.

[76]The legal question--whether proof of anticipation required reproduction of the prior used or sold product or discovery of its composition on the one hand, or only discovery of the invention on the other, is extricable from the mixed fact and law conclusion of the Trial Judge, that, based on all the evidence, Canwell did not prove anticipation.

[77]Further, the legal question here is general in nature and not particular to the circumstances of this case. It is important for precedential purposes that, in cases where anticipation by prior use or sale of a product is in issue, the evidence demonstrates that the analysis of the product discloses the invention and not necessarily an ability to reproduce the product. Of course, where the product is the invention, analysis might well have to show an ability to reproduce the product. But that is not the case here. Contacting sour natural gas with triazine (or its starting components) and perhaps methanol, was the only inventive elements of W-3053. Whether or not a skilled person could discover other non-inventive elements of W-3053 is irrelevant to the question of anticipation in this case.

DMC’s comment: Thus, it appears, that the invention was anticipated by W-3053 because, if it had been analyzed by techniques available at the relevant date, one could discern that the natural gas had been exposed to triazine because triazine was present in the natural gas.

DMC: Does the prior art have to lead to the invention in every case? Incorrectly performed procedures may be excused.

[90]There was evidence of a number of other analyses of W-3053 and Canwell's CW1000 product. In most cases, these tests were performed under conditions in which either the starting materials were known or a particular component was being tested for. Therefore, these are not valid tests for anticipation because the analysts were provided with some information that would not have been available to the person skilled in the art conducting the analysis prior to December 19, 1988. A purchaser of W-3053 at that time would not have known that its starting materials were MEA and formaldehyde or that triazine was the reaction product in the mixture.

[91]Be that as it may, in all but one of the analyses, either triazine or the starting components, an alkanolamine and an aldehyde or, more specifically, MEA and formaldehyde were detected. In the one analysis that failed to discover triazine or its starting materials, the analysis was incorrectly performed. Chloroform, rather than deuterated water, was used as a solvent causing the triazine to disappear from the sample. However, Professor Keay avoided this problem by conducting a simple solubility test in his analysis, leading him to use deuterated water, rather than chloroform, as the solvent.

[92]Just as it is implicit under the Beloit test, that a person skilled in the art will, correctly and without error, read and follow the directions in a prior patent or publication, the same implication must be applicable in the case of reverse engineering. A flawed procedure leading to the wrong conclusion is not evidence that a person skilled in the art employing a procedure and correctly using data and methodology available at the relevant time, would not be led to the claimed invention.

[93]In the result, all analyses that were correctly performed led to the discovery of triazine or its starting materials. As I have stated, other than for Professor Keay's analysis, these other analyses are not in themselves sufficient evidence of anticipation because information not available to a purchaser of W-3053 at the relevant time, was known by the analysts performing these tests. However, all these analyses are remarkably consistent in leading the analysts to the invention. That leaves uncontradicted the Keay analysis, which is valid evidence of anticipation.

DMC’s comment: Customers can and are members of the public for purposes of anticipation

[96]Petrolite says that the deliveries of W-3053 in western Oklahoma were to the private property of the purchasers and W-3053 was, therefore, not available to the public. This argument fails to appreciate that the purchaser is a member of the public, and that the Trial Judge found that sales were made unconditionally. To prove anticipation under paragraph 28.2(1)(a), it is not necessary to demonstrate that a particular purchaser did or would have conducted an analysis of the product. It is sufficient that the purchaser could have done so (see Lux, supra, at page 133).

[97]The same may be said about Petrolite's argument that the results of a reverse engineering analysis would be kept confidential by anyone performing the analysis and would, therefore, not be available to the public. It is the unconditional sale of the W-3053 to the purchaser that makes the product available to the public. If the purchaser is free to perform reverse engineering, that is sufficient. How a purchaser chooses to treat the analysis, i.e to keep it confidential or not, is not a relevant consideration.

DMC’s comment: Reverse engineering (experimenting to analyze) is permitted for anticipation

[98]Petrolite argued that reverse engineering involves adopting a mosaic approach which is not permitted to prove anticipation. The mosaic rule applies to prior publications or patents and says that it is improper to assemble a dossier of prior art with the benefit of hindsight (see Free World Trust, supra, at paragraph 24). However, this is not what occurred here. It was W-3053 only that was the subject of analysis, and disclosure of triazine and methanol came from reverse engineering of it. The analysis of a previously used or sold product employing available techniques and data is equivalent to the reading by a skilled person of a single prior publication and following it to the claimed invention (see Beloit, supra, at page 214, and FISONS, supra, at page 21).

DMC’s comment: The claims were anticipated and were invalid

[100]Canwell has proven the disclosure contemplated by paragraph 28.2(1)(a). Having found the invention, described by claims 1 and 2 and the series I, II, III and IV claims of the 946 patent, to be anticipated, I conclude that the claims relied upon by Petrolite in the case at bar are invalid. I do not find it necessary to address the other issues raised in this appeal.

[101]The appeal should be allowed and the decision of the Trial Judge should be set aside. The claims in issue in the 946 patent should be found to be invalid by reason of anticipation. The respondents' claim against the appellants should be dismissed with costs here and in the Trial Division.