Compare also Edison & Swan v. Woodhouse, post, pp. 293, 297, in which the essence of the invention consisted partly in alteration of shape to avoid breakage by expansion of carbon.

See Duckett v. Whitehead, post, pp. 41 and 370.

Alterations in Physical Conditions producing New Chemical Inventions or Improved Results.

Heating a blast of air on its passage to a furnace. See Neilson v. Harford, post, p. 187.

Using a dilute instead of a stronger solution of cyanide of potassium to dissolve gold,from ore, whereby gold is separated from baser metals, which the stronger solution could not do. See (as to claim 2) in The Cassel Gold Extracting Co. v. Cyanide Gold Recovery Syndicate, post, p. 369. Toluene when treated with chloro-sulphonic acid was converted as to one half into toluene sulpho-chlorides and as to the other half into toluene sulphonic acids. Of the toluene sulphochloride only about one half was "ortho-" and useful, the other "para-" and useless. A chemist discovered that, by employing a large excess of chlorosulphonic acid and keeping the temperature down to between o° C. and 5°C., a much larger proportion of orthotoluene-sulphochloride -93 per cent. (instead of 25)-would be produced. Thus

C2H, + SO2(OH)Cl = C2H2SO2Cl + H2O

The reduction of the temperature was not before suggested. Held, that the discovery of the new process was a patentable invention. The Saccharine Corp., Ltd. v. The Chemicals and Drug Co., Ltd., 17 R. P. C. 28.

Proof of Ingenuity.

No general rule can be laid down as to the amount of ingenuity or of additional knowledge required to support a patent. From the reason for this minimum amount of ingenuity it follows that the existence of it can be proved by direct evidence if skilled persons can be proved to have attempted and failed to produce the result in question.1 On the other hand, its absence is proved by showing that skilled persons could produce the desired result without difficulty as soon as they direct their minds to the subject.2 Or skilled persons may give expert evidence as to whether or not a certain result could be attained without research or experiment on their part.3

1 See cases of Vickers v. Siddell, post, pp. 324, 329; White v. Bertrams, 14 R. P. C. 746. E.g. cases of Morgan v. Windover, post, p. 323. See Penn v. Bibby (per Lord Chelmsford, L.C.), L. R. 2 Ch. Ap. 135, 136.

* See case of The Lancashire Explosives Co. v. The Roburite, &c., Co., post, p. 396.

In the absence of such direct evidence the fact that the new invention met with a large sale and proved useful, coupled with the existence for some time of a previous demand for the alleged invention, will be evidence tending to show a sufficiency of inventive ingenuity, for it is to be presumed that skilled persons would, if they could, have supplied the want.

But novelty, great utility, and a large sale alone do not prove inventive ingenuity, for the large sale may be due to changes of fashion, or to a large development in some other manufacture creating a demand for the article in question.

Illustrations.

Prior to Gaulard & Gibbs' Patent for distributing electricity, transformers were so wound as to take off a local current of higher tension than that in the mains. In the patentees' system transformers were constructed to take off low-tension currents from hightension currents in the mains. The need of the new transformers arose merely from the development of electric lighting by glowlamps. Gaulard & Gibbs' Patent, post, p. 329.

An invention consisted in the application to ladies' hats of a comb to secure the hat on the head. A large sale was proved, which was due to the coming into fashion of a mode of wearing hats in which the use of a skewer-like pin, or its equivalent, became necessary. The patent was invalid for want of sufficient ingenuity. Savage v. Harris (per Kay, L.J.), 13 R. P. C. 374.

For another illustration of great utility and large sale not being sufficient to establish sufficiency of inventive ingenuity, see Cooper v. Baedeker, post, p. 433.

For an example of a new application of an old thing meeting a long-felt want, see Brooks v. Lamplugh, post, p. 410.

Cases of Combination Patents.

By far the most numerous class of inventions are those which consist in the applications of principles, not directly, but indirectly, by the combining together of old things or processes, either by the bringing together of the old elements in a new way, or by altering the arrangement of the old elements, or by the application of old things to new uses (see ante, p. 16). In these cases it is the new

1 Per Lord Halsbury, L.C., in Riekmann v. Thierry, post, p. 393; per Rigby, L.J., in Castner-Kellner Alkali Corp. v. Commercial Development Corp., 16 R. P. C. 268, l. 40.

combination, as distinguished from the sum of its elements, that constitutes the addition to public knowledge,1 that is to say, the invention in question.

Like all other inventions, to be patentable they must, besides others, fulfil these two conditions: (1) They must be "new manufactures," i.e. besides being a "manufacture," the claims must not include an old manufacture in the monopoly ; and (2) the invention must not be of such an elementary character as to interfere with skilled workmen making the best use of their knowledge.

With regard to the first of these conditions, the difficulty is to distinguish a "new" manufacture, i.e. the combination, from a mere rearrangement of the elements of an old manufacture or combination, which may only amount to a particular mode of using an old machine, or process. Hence it is of the greatest importance to ascertain in what the old "manufacture" consisted, whether it was a vendible machine, or a product, or a process as distinguished from principles (ante, p. 9), and results (ante, pp. 11-13). Similarly, the nature of the alleged new manufacture must be considered. One principal criterion is the comparison of the functions discharged by the several elements respectively in the old and new combinations. If they be the same, and no new function is attributable to the combination,3 then the combination is not a new manufacture, but a mere rearrangement of old manufactures. Another criterion is the increased utility of the new combination. This test is not conclusive, but is of great value. Utility here mentioned is essentially comparative utility, and must be distinguished from that amount of utility necessary to support a patent, which is discussed post, p. 80.

As regards the second condition, the principles on which the presence or absence of sufficient ingenuity is ascertained have been dealt with ante, pp. 37, 38. In the case of combination patents, the requisite amount of ingenuity frequently consists in the idea of putting the old elements together; when done it may appear very

1 Cannington v. Nuttall, post, p. 248; Pneumatic Tyre Co. v. Casswell, post, p. 381. 9 Hill v. Thompson (per Lord Eldon), post, p. 184: Huddart v. Grimshaw (per Lord Ellenborough, C.J.), Dav. P. C. 279, 1 Webs. 87; Bateman v. Gray, Mac. 101.

Allen v. Oates & Green, 15 R. P. C. 303.

See dictum of Tindal, C.J., in Crane v. Price, post, p. 195, and notes; Cannington v. Nuttall (per Lord Hatherley, L.C.), post, p. 248.

For illustration of its application see Penn v. Bibby, L. R. 2 Ch. Ap., 137, and as to its not being conclusive, see Cooper v. Baedeker, post, PP. 44, 431.

simple. This simplicity itself is apt to mislead,1 unless one considers the state of the art or manufacture in question before and after the new combination was produced,2 i.e. from the point of view of the skilled workman. Comparative utility is here again a great aid.3 In the cases of the application of old things to new uses it is necessary to consider whether the old thing or combination is in the track of development of the art under consideration, for a skilled workman may have all the "common knowledge" of the art he practises, and yet not be presumed to know of the discoveries in other cognate manufactures.4

The applications of old things to new uses fall within the definition of combination patents (ante, p. 16). They may amount to new processes or methods, but must fulfil the same conditions as other combination patents.5

The application of the foregoing rules to a number of illustrative cases will now be considered. For convenience of reference they are arranged under the following heads, or divisions:

Patentable.

1. Mechanical combinations of old elements amounting to new methods or inventions.

2. Combinations and rearrangements of processes constituting new manufactures.

3. Applications of old things to new purposes involving sufficient ingenuity to constitute invention.

4. Selections from known things or processes amounting to patentable inventions.

Not Patentable.

5. Combinations of old elements not amounting to patentable inventions.

6. New modes of manufacture falling short of patentable inven

tions.

1 Vickers v. Siddell (per Lord Herschell), post, p. 328 and notes; Fawcett v. Homan (per Rigby, L.J.), post, p. 388.

2 Taylor v. Annand (per Romer, L.J., and Lord Halsbury, L.C.), post, p. 449. 3 E.g. Vickers v. Siddell, post, p. 324.

Penn v. Bibby (per Lord Chelmsford), L. R. 2 Ch. Ap. 136. For illustrations, see Gadd v. Manchester, post, p. 351 and the Shrewsbury and Talbot Cab Co. v. Sterckx, post, p. 377. Losh v. Hague, 1 Webs. 298; Harwood v. G. N. Ry. Co., post, p. 207; Brooks v. Lamplugh post, p. 410.

7. New uses of old means and processes not constituting patentable inventions.

8. New uses that are not manufactures.

9. Result only in question, insufficiency of invention in the results.

1. Mechanical Combinations of Old Elements amounting to New Methods or Inventions.

A machine was invented for singeing lace by passing it over rollers and across a gas-flame, between it and the chimney. Each of the parts was old. The gas-flame, however, replaced an oil one. The result was a machine of great utility. Hall v. Jarvis, post, p. 186. This is an instance of a new manufacture by making a new machine. An appliance for turning forgings consisted of a very simple combination of old mechanical parts. Vickers v. Siddell, post, p. 324. Here the satisfying of a want proved inventive ingenuity, that is, that the invention was not obvious.

A hoist for heavy bodies consisted in a combination of an arrangement of expanding segments and a certain form of brake. The segments allowed of rotation of an axle in one direction and stopped it in the other. They performed this function in older machines. But as applied to hoists the segments did not perform the same function as regards raising and lowering as other and similar ones did in former hoists. The whole constituted a new hoist. See Morris & Bastert v. Young, post, p. 371. Here the function discharged by the respective parts in the old and new machines differed.

An invention consisted in removing a partition and altering the shape and relative positions of old parts in a water-closet to produce successful results. See Duckett v. Whitehead, post, p. 370. Here the alterations enabled natural laws to work more effectively; failure being turned into success proved ingenuity.

A new combination consisted of alterations in a gig-mill so that a new mechanical result was obtained, viz. the power to obtain a known and variable motion for the raising rollers as required. Previously known or variable motion could be obtained, but not both combined. See Moser v. Marsden, post, p. 374. Here the altered machine performed new functions, hence was a "new" manufacture; new mechanism being introduced, it became a new machine. Compare Kay v. Marshall, post, p. 190.

A valve for inflating tyres consisted of an arrangement of old elements which had been used to perform the same functions in other valves, but not all in the same valve, nor for the same purpose.

The