Calgon Carbon Corporation v. The Corporation of the City of Northbay
Federal Court of Appeal: per Rothstein J.A. (Linden and Pelletier JJ.A., concurring)
December 6, 2005
 This is an appeal from a judgment of the Federal Court granting the respondent's (North Bay) motion for summary judgment and dismissing the appellant's (Calgon) action against North Bay for patent infringement. The motions judge found that Calgon's patent was invalid because it related only to the unpatentable discovery of a previously unknown advantage of an existing invention. Because there can be no infringement of an invalid patent, he granted summary judgment and dismissed the action.
 The patent in suit is Canadian Patent 2331525 (the '525 Patent) which describes a method for preventing replication of cryptosporidium oocysts using low levels of ultraviolet light (UV) to irradiate water. Cryptosporidium (crypto) is a protozoa that can cause infection from drinking water. Oocysts are immature ova (eggs).
 Calgon acknowledges that low level UV light to irradiate water has been used before in water treatment for the killing of bacteria and viruses, but not for the purpose of preventing replication of the protozoa, crypto. Prior to the '525 Patent, it was thought necessary to kill or inactivate crypto oocysts to prevent crypto infection. To do so, high doses of UV light of at least 3,000 mJ/cm2 were required.
 The '525 Patent says that it has been discovered that it is not necessary to kill or inactivate crypto oocysts to prevent infection. It is only necessary to apply enough UV light to prevent crypto oocysts from replicating. The UV light doses required to prevent replication are orders of magnitude lower than required to kill or inactivate the oocysts. The patent disclosure says that the method described in the '525 Patent provides a substantial increase in the cost effectiveness of using UV light in reducing crypto infection from drinking water.
DECISION OF THE MOTIONS JUDGE
 The motions judge found that the key element of the '525 Patent is "the use of the system (low doses of ultra violet light) to prevent cryptosporidium oocyst replication". However, he also found that the use of this water treatment method was the same as the method that had already existed and was in use. The method had been known to eliminate bacteria and viruses. All that had changed is that the same old method is now known to be effective in the elimination of the danger of disease due to crypto. Therefore, he found that the use of the old method to prevent crypto oocysts replication is a mere discovery and not a patentable invention.
 Applying the decision of the Federal Court Trial Division (as it then was) in Riello Canada, Inc. v. Lambert (1986), 9 C.P.R. (3d) 324 (F.C.T.D.), the judge stated that the test for patentability in these circumstances is that there must be a new process, new result, new product or a new combination for producing an old product or an old result. He found that the process and product are the same; the result is the same even though it was previously undiscovered; and because the use of the method in the '525 Patent for the prevention of crypto oocysts replication is a mere discovery, it is not a new invention. Therefore, in his view, the '525 Patent was invalid.
Application of Shell Oil
 The starting point is the definition of "invention" in section 2 of the Patent Act, R.S.C. 1985, c. P-4:
"invention" means any new and useful art, process, machine, manufacture or composition of matter, or any new and useful improvement in any art, process, machine, manufacture or composition of matter;
« invention » Toute réalisation, tout procédé, toute machine, fabrication ou composition de matières, ainsi que tout perfectionnement de l'un d'eux, présentant le caractère de la nouveauté et de l'utilité.
 The definition of "invention" requires that the art or process be new and useful. Useful points to practicality as opposed to theory. New means that there is a contribution to knowledge, something that was not known before.
 In Shell Oil v. Commissioner of Patents,  2 S.C.R. 536, it was discovered that known compounds could be put to a new use as plant growth regulators. Wilson J. explained that the new use for an old compound was an invention within the meaning of section 2 of the Patent Act. At page 549 she stated:
What then is the "invention" under s. 2? I believe it is the application of this new knowledge to effect the desired result which has an undisputed commercial value and that it falls within the words "any new and useful art". I think the word "art" in the context of the definition must be given its general connotation of "learning" or "knowledge" as commonly used in expressions such as "the state of the art" or "the prior art". The appellant's discovery in this case is added to the cumulative wisdom on the subject of these compounds by a recognition of their hitherto unrecognized properties and it has established the method whereby these properties may be realized through practical application. In my view, this constitutes a "new and useful art" and the compositions are the practical embodiment of the new knowledge.
 It appears that the motions judge distinguished Shell on the grounds that in Shell the unrecognized properties were new properties, whereas in this case, the method was old. He stated at paragraph 16:
In Shell Oil, the Supreme Court of Canada recognized that a patent must establish a, "method whereby these [new] properties may be realized through practical application". In the instant matter, there is no new method. The water treatment system still uses the same "old" method as the existing systems in, amongst other places, Fort Benton and Trout Lake. The old method is the same as the new method, as affirmed by Dr. Huffman. Likewise, the results obtained have not changed: under both the old and the new methods the replication of crypto is effectively prevented. All that has changed is that the system of water purification previously used to eliminate bacteria and viruses has now been shown to be effective as well in the elimination of the danger of disease due to crypto.
The motions judge was of the view that the use of an old invention to prevent crypto oocyst replication is a mere discovery, not a new invention, even if the advantage in respect of crypto was previously unknown.
 I have carefully considered the reasoning of the learned judge but I am unable to agree with his conclusion. Shell teaches that the discovery of a new use for an old invention which is capable of practical application is an invention. At page 549, Wilson J. stated:
If I am right that the discovery of a new use for these compounds which is capable of practical application is an "invention", I can find nothing in the statute which would preclude a claim for these compositions.
. . .
This is a case where the inventive ingenuity is in the discovery of the new use and no further inventive step is required in the application of the compounds to that use, i.e. in the preparation of the appropriate compositions.
 In Shell, Wilson J. relied on the decision of the English Court of Appeal in Hickton's Patent Syndicate v. Patents and Machined Improvements Co. (1909), 26 R.P.C. 339. The situation in Hickton's appears very similar to the circumstances in this appeal.
 I closely paraphrase Wilson J.'s explanation of Hickton's at page 550 of Shell. An applicant had an idea for equalizing the consumption of thread on lace-making machines by the process known as "shogging". There was nothing new about "shogging". It was a technique customarily employed in creating a pattern in the piece of lace being made. But it had not hitherto been thought of as a means of equalizing thread consumption. This was done by hand by interchanging the bobbins. It was clear on the evidence that once the idea was formed, no further inventive ingenuity was required in order to put it into effect. The plaintiff, who had obtained a patent on the idea and on its method of carrying it out, brought an action for infringement. At trial, the action for infringement was dismissed on the grounds of patent invalidity. The Court of Appeal reversed. Cozens-Hardy M.R. stated at page 347:
When once the idea of applying some well-known thing for a special and new purpose is stated, it may be very obvious how to give effect to that idea, and yet none the less is that a good subject-matter for a Patent.
Wilson J. observed that in Hickton's, "the English Court of Appeal had found that an idea was patentable not withstanding the lack of any novelty in its implementation. No further invention was required in putting it into practice."
 A mere discovery, such as a scientific observation, is not an invention. If, as an observation, it is discovered that UV light prevents crypto oocysts from replicating, that is a scientific observation for which no patent may be obtained.
 However, as Hickton's demonstrates, the discovery of a new, useful application for an existing method is more than a scientific observation. In this case, the patent claims are for a practical solution to a practical problem. That is more than a mere discovery. A scientific observation, on its own, has no practical application. Here, what is useful is the method of using UV light at particular levels for preventing crypto oocyst replication. What is new and was not previously known is that using UV light at particular levels adequately treats water to prevent crypto infection. Because of this, a more costly means of producing that desired result can be avoided. That meets the definition of "invention".
 To paraphrase the words of Wilson J. in Shell, it is the application of the new knowledge that irradiating water with low doses of UV light prevents crypto oocyst replication that has commercial value. This new application of an existing process therefore falls within the words "new and useful art" in the definition of "invention" in section 2 of the Act. Calgon's discovery has added to the cumulative wisdom in the use of low doses of UV light in the water treatment process.
 There may be cases in which the use of high doses of UV light, with their added energy costs, may be avoided or cases in which other methods of treating water for crypto may be abandoned altogether. As such, irradiating water for crypto using low doses of UV light, while not a new method itself, constitutes a newly discovered use for that method and therefore is a new and useful art.
 Although anticipation was referred to by the motions judge, his decision to grant summary judgment and dismiss Calgon's action rested entirely on a discovery not being patentable. He did not decide the summary judgment motion on the basis that the '525 Patent was invalid by reason of anticipation. The issue of anticipation in this Court was argued cursorily in the parties' factums and in their oral arguments. Because the motions judge did not decide the question of anticipation and the arguments in this Court were cursory, I do not consider it appropriate for this Court to decide that issue in this appeal.
 Because I am of the view that the learned motions judge erred in granting the motion for summary judgment on the grounds that the '525 Patent was invalid by reason of it being only a discovery, the appeal should be allowed, the decision of the motions judge should be set aside and the motion for summary judgment should be dismissed with costs here and in the Federal Court.