Adhesives Pty Ltd v Aktieselskabet Dansk Gaerings-Industri [1935] HCA 83

Adhesives Pty Ltd v Aktieselskabet Dansk Gaerings-Industri [1935] HCA 83 - HCA 1935 case summary — Zoe

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of yeast." The petitioner stated that it was duly authorized by the Attorney-General for the Commonwealth to present the petition ; that it was a company duly incorporated in the State of New South Wales, and engaged, inter alia, in the manufacture of yeast and yeast products; and that Aktieselskabet Dansk Gaerings-Industri was the registered proprietor of the letters patent which were and always had been invalid and of no effect. The grounds, other than ground 1, which was not proceeded with, set forth in the particulars of objection upon which the petition was based were, as amended, substantially as follows : - (2) The alleged invention was not novel at the date of the grant by reason of (a) prior publication, and (b) prior common general knowledge. The particulars of prior publication relied upon were in respect of three British patents granted in 1880, 1888 and 1904 respectively to William Robert Lake, William Phillips Thompson and Evariste Vignier respectively, the specifications of which had been available for inspection at the patent offices of New South Wales and Victoria shortly afterwards, and in the library of the Commonwealth Patent Office since 1905. (3) The alleged invention was not proper subject matter for a patent. (4) The alleged invention was not useful. (5) The specification did not particularly describe the nature of the alleged invention or the manner in which it was to be performed in that no instructions were given in respect to many matters referred to. (6) The specification and claims of the alleged patent did not adequately define the extent of the monopoly sought to be protected. (7) The specification and claims did not give sufficient information to enable the public to ascertain the scope and ambit of the claims. (8) Claim 1, both by itself and as incorporated by reference to claims 2 and 3, was ambiguous in respect of the following expressions: (a) "in accordance with the so-called differential management of the fermentation," (b) "the necessary

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Commercial yeast is an aggregate of a vast number of yeast cells. Yeast is a microscopic single cell organism, the scientific name of which is saccharomyces. There are many different kinds of this organism. The yeast cell lives in a fluid medium of suitable com- position for its growth; it obtains its substance from the required materials in the solution; the fluid medium in which the yeast grows must therefore contain in solution the various constituents that are necessary for the growth of the yeast, and these constituents must exist in the solution in forms in which they are capable of assimilation through the walls of the cell. The main nutritives required by the yeast cell are sugar and nitrogen in suitable chemical forms. Other things, such as phosphorus, are also essential but in smaller quantities. Some forms of sugar are not assimilated by some forms of yeast, but it can be assumed that the specification only refers to those forms which are suitable for the particular type of yeast. Besides utilizing sugar for the purpose of nutriment, the yeast cell also has the property, which is of great commercial value, of converting one molecule of sugar into two molecules of alcohol and two molecules of carbon dioxide, and in this way a given weight of sugar so converted yields approximately half that weight of alcohol and half that weight of carbon dioxide. The alcohol which the yeast cell produces is, if present in the solution in sufficient quantities, inimical to the growth of the yeast cell. Increase of the yeast takes place by budding, that is to say, a small daughter cell appears on the surface of the mother cell and may ultimately become detached. In a normal yeast brew there are usually about eight successive generations. The rate of alcohol production and the rate of growth of the yeast are very variable quantities, and prior to Sak's patent it was generally accepted that the conditions which were favourable to a large yield of alcohol were not favourable for a large growth of yeast, and vice versa. Industrially, yeast is used principally in brewing, wine making, alcohol production, spirit distillery and

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bread making. For the bread industry yeast is generally supplied in a form known as " pressed yeast." A cake of pressed yeast consists of myriads of yeast cells which have been first separated from the mother liquid, generally by centrifuging, and from the mass so obtained further water is expressed by pressure. The pressed yeast thus manufactured still contains, chemically, about 72 per cent of water, most of which represents the fluid material within the cell. In yeast manufacture there are, broadly, two stages. In the first stage the object is to prepare a medium which will contain in solution the various ingredients necessary for the growth of the yeast. In the second stage of the process the prepared material is innoculated with specially selected and prepared yeast, called " seed yeast," and that stage of the manufacture aims at obtaining as much yeast as possible from the materials employed in the first stage. When the nutritive liquid in which the yeast was grown has become exhausted, or practically exhausted, the process is brought to a close by the separation of the yeast cells from the liquid in which they have been caused to grow. The meaning of various technical terms used herein is as follows : - " Mash."' - The grains, or whatever other vegetable materials are used for providing the necessary sugar, after being crushed, are mixed with water, and the mass is suitably treated for the purpose of extracting the desired ingredients. The whole mass thus treated is called the "mash." " Wort" is the liquid filtered off from the mash, "Vienna yeast" is yeast grown in the mash itself. " Air-grown yeast" is yeast grown in a wort through which air is caused to bubble from air pipes at the bottom of the tun. "Seed yeast" is yeast used for innoculating the commercial brews. It is specially prepared from a single selected cell, or several selected cells, which is or are propagated under special conditions designed to ensure particularly that the whole batch of seed yeast will be of suitable type and quality and as free as possible from foreign contaminating organisms. "Malt culms."

When a cereal grain, such as a wheat seed or barley seed, is exposed to moisture it begins to sprout; when this occurs, substances, called enzymes, within the grain proceed to act upon the starch and proteins stored up in the grain and to convert them, as far as starch is concerned, into sugar, and as far as the proteins are

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of some alteration of the metabolic process of the yeast so as to enable it to make some use of the only substance left - alcohol - could be - and was - envisaged, even before 1919. There is very definite evidence, in the experiments where a high yield of yeast is obtained, that there is a marked decrease in the percentage concen- tration of alcohol towards the end of the fermentation. This fact must have been observed by Sak at the date of the patent (Table to example II.). The knowledge of the life process of yeast was, as it still is, far from complete. Sak's explanation of the observed disappearance of alcohol as having been caused by assimilation or utilization, was as reasonable as might be expected at the time. Even if the explanation of the facts was not accepted, the facts themselves could not be misunderstood by those competent in the art. In 1908 Trillat and Sauton had shown that bakers' yeast would convert part of a dilute alcohol into acetaldehyde. When bakers' compressed yeast was vigorously stirred with dilute alcohol (with aeration) there was obtained a conversion to acetaldehyde. The action involved is a vitalone. Further acetaldehyde disappeared fairly rapidly when added to yeast in dilute alcohol. Since the year 1919 a number of investigators have confirmed the fact that yeast can in some way convert alcohol into other substances, such as acetic acid and carbon dioxide. It is unnecessary to elaborate this part of the case, but I am by no means satisfied with the some- what lazy inclination to discard the possibility of assimilation of alcohol by yeast. Unfortunately nothing is so painful - even to some scientists - as a new idea. In the American decisions to which reference was made, there were claims involving the same hypothesis of assimilation of alcohol. It is worthy of note that, although their validity was tested in every possible way, the assertion or implication of assimilation was either accepted as true, or ignored as a mere theoretical error involving no possible misdirection to those skilled in the art.

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negligible quantities is what was aimed at and secured in the old method, aimed at theoretically and secured practically. The word "considerable " is used in this specification in contradistinction to that idea. Also "considerable" is measured with regard to the quantity of sugar available to be turned into alcohol. Tests prove that the specifier was justified in using the word " considerable." He cannot rightly be accused of vagueness. ' Commercially " is used in regard to the quantities produced by this process, that is, on a large scale, as opposed to the infinitesimal quantities produced in a laboratory ; it has nothing to do with profit-making. Under this process yeast can be produced in the presence of a considerable quantity of alcohol. When alcohol is the objective it is recoverable commercially. Experiments carried out for the purpose of this suit, evidence of which is before the Court, support the specifier's claim and justify the conclusions arrived at by Evatt J. that the percentages of alcohol are considerable, and that throughout alcohol is substantially 20 per cent of the raw material. In arriving at those conclusions his Honour had the advantage of consultation with assessors. "' Considerable" in regard to alcohol as a final result, as opposed to alcohol being present during the run of the fermentation and disappearing in the later stages, must be considered in conjunc- tion with the 20 per cent, and with '' commercially recoverable." "20 per cent" refers to the raw material and the manufacture of alcohol, not the mashing material. When the specifier wishes to refer to "mashing materials" he does so expressly. When he mentions the percentage of yeast he desires to obtain he refers to mashing materials. According to the evidence the invariable practice in the trade is to associate yeast production with the mashing materials, and alcohol production with the sugar. It was not wrong to assert assimilation (Journal of Biological Chemistry, vol. 62, p. 834; Stephenson on Bacteriological Metabolism, pp. 29, 31). The appellant has not discharged the onus of proving that the alcohol is not assimilated. The specifier used " assimila- tion" as a synonym for " utilization." In the same specification the word is used, apparently, as a description of what is observed, apart from theory, that it is caused to disappear. It is important that by following the examples given the experimenters obtained

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Yeast is a single cell micro-organism which grows in a nutrient based upon proteins and carbo-hydrates. Sugar and nitrogen in appropriate chemical forms constitute its nutritives. In the pro- cess of yeast manufacture these are obtained from cereals. The grain is malted and mashed with the object of reducing the starch to soluble sugar form. When the mash has reached a suitable stage its contents are used for the propagation of yeast. At one time the seed yeast was directly sown into the mash in which it proliferated. This is the old Vienna method. For many years, however, the practice has been to filter off from the mash a liquor containing the nutrient substances. The mash is washed several times in order to secure from it as great an amount of the nutritive substances as may be. Each successive wash necessarily is weaker in nutrient quality. The liquor forms a wort in which the yeast is sown and propagates. The growth of the yeast is accom- panied by or constitutes a fermentation and, by an intricate chemical process, from the carbon there is a large formation of alcohol. When, owing to exhaustion of the nutritives and retardation by the alcohol, the rate of the growth of yeast has diminished to such an extent that it is proper to stop the ferment, the yeast is taken from the wort by a mechanical process of separation. Before Sak's invention alcohol formed a capital difficulty for the yeast manufacturer. The production of alcohol during the growth of yeast was inevitable. But in the presence of alcohol the growth of yeast was slow and difficult. It was long ago discovered that yeast grew more quickly and with very much less nutrient under the influence of atmospheric oxygen. Indeed it was only by aerating the wort that it became practically possible to change from the Vienna method. In some degree aeration helped in the contest with alcohol. But the chief means adopted by the manufacturer was to use a weak wort. The weakness of this wort meant the dilution of the alcohol. Accordingly the practice was to sow the yeast in a wort which was not strong and to reduce its strength as the proliferation of the yeast continued by adding the weaker solutions obtained from the later washings of the mash. The process, in other words, involved a course of

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the yeast cells. By means of instruments and tables the percentage of aleohol and the degree of concentration are readily ascertainable during the course of the process. As in brewing, so in yeast produc- tion the saccharometer is an essential appliance. In this state of affairs Sak discovered that the method adopted to deal with the alcohol was a mistake in the manufacture of yeast. He found that the greatest yeast production could be brought about by disregarding alcohol and seeking uniformity in the nutrient supply to the increasing yeast. For some reason which even yet has not been satisfactorily explained by bio-chemical science, if the multiplying yeast cells are provided with a nutrient of proportionate strength, while in the earlier stages the production of alcohol proceeds, in the later stages there is an answerable disappearance of alcohol. In the specification, after speaking of the Vienna method, which it calls the skim-yeast method, and the newer method, which it calls the air-grown method, the state of the art is described as follows : - '"'In both cases the yeast propagates in a mash or wort becoming, during the fer- mentation continuously poorer in nutritive substance, one of the reasons for this being the consumption of substance caused by the propagation of the yeast. In the air-grown yeast method the concentration of the nutritive liquid is reduced not solely on account of the consumption of substance due to the propagation of the yeast, but also on account of the nutritive solution being diluted by addition of washing water, which addition is continued during the entire washing process. In the said methods the individual yeast gener- ations will develop under very different conditions of life, their development commencing in a nutritive liquid of high concentration, ie. ina surplus of nutritive substance, while the last generations will develop under unfavourable conditions of life, ie. in a weaker nutritive solution, where they will be wanting nutritive substance. Furthermore, the alcohol formed during the fermentation according to the above-mentioned methods of fermentation will have a retarding effect on the formation of yeast. The retarding action of alcohol on the yeast formation is especially prominent in the skim-yeast (Vienna-yeast) method. In the air-grown yeast method, it has been attempted to remedy this drawback, viz. the alcchol's retardation

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of the formation of yeast, by selecting suitably weak solutions, in which the alcohol formed could not materially injure the propa- gation of yeast. This process, however, has for effect that the alcohol produced will be lost, as it will not be feasible, in prac- tice, to recover the alcohol when diluted beyond a certain limit. In spite of the attempts to remedy these drawbacks, there will always remain, by the said fermentation methods the main draw- back that the yeast during its development must always work in a wort or mash becoming constantly poorer in nutritive substance, so that the last generation will have to fight against conditions of life which become constantly more unfavourable." Sak's invention consists in adopting an entirely new management of the concentration of the wort. From one point of view it may be said to be very simple, and it is from that point of view that the attack on subject matter is made. He takes a relatively weak or dilute wort, and, as the consumption of its nutrient content goes on, he replaces the loss by contributions of stronger wort containing greater nutrient substances. He describes this process in his specification metaphorically, as. "differential management" of the concentrate - a figure which appears to assist the understanding of those who are mathematically inclined and confuse those who are not. The difficulty of the case really arises from the consequences which the invention involves in the production of alcohol. That production rises, and if the fermentation is stopped before the subsequent disappearance of alcohol the yeast may be taken from the wort and the liquid will contain sufficient alcohol to make it worth while distilling. Even when the fermentation is carried to what a yeast manufacturer would consider its completion, alcohol will remain, but not in quantities which in this country would be considered worth commercial distillation. It appears that yeast manufacturers are familiar with methods of providing more alcohol than yeast by the manipulation of concentration and temperature. The specification avails itself of these facts to suggest that alcohol may be obtained from the process. The attack on the patent is to a great degree founded upon the patentee's explanation of the disappearance of alcohol, the nature of his assertion that alcohol can be obtained and the sufficiency of the description of the manner of dealing with alcohol. The first

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learned counsel stated it in the course of his able argument: " The specification represents that the process will produce a yield, calculated on the raw materials used, of about 60 per cent or more of yeast together with a commercially recoverable quantity of alcohol, but in fact it will not do so." This ground raises a pure question of construction. The specification undoubtedly asserts that alcohol may be recovered when the process is used. It undoubtedly claims that by the means of the process a very high yield of yeast can be obtained. The question of construction is whether it claims that a high yield of yeast can be obtained and at the same time a considerable quantity of alcohol recovered. Subsidiary questions of construction attend the main question. For there is an issue upon the topic of the commercial recovery of alcohol. Owing to the local conditions in Australia, into which I need not enter, it is not profitable to distil from liquor containing a percentage of alcohol high enough to make a continental distiller eager to have it. Accordingly it is said on one side that, if the process is completed, commercial recovery is impossible, and on the other that there will always be enough alcohol for commercial recovery however far the process is carried, but that this does not mean profitable recovery in Australia under existing conditions. I am content to disregard this subsidiary controversy and to assume that, if the specification does assert that a large yield of yeast, e.g., 60 per cent can be obtained and at the same time alcohol can be recovered by distillation in commercial quantities, then the patentee's promise cannot be made good. On a fair construction I do not think that it makes such a promise. The passages relied upon by the appellant are set out in the written submissions which were handed up, and I do not wish to encumber this judgment by repeating them. They certainly contain language which, if read apart from context and subject matter, might be so understood. But with a closer acquaintance with the standpoint of the yeast manufacturer, who is necessarily technically equipped to a much higher degree than in most arts, the likelihood of so under- standing the passages is much lessened when the whole specification is read. I think it clearly appears that the specifier is always presenting the recovery of alcohol as an alternative with the recovery

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to a comparatively low figure. Some attention to the phenomenon has been given by Messrs. A. K. Balls and J. B. Brown, who deal with that and other matters in two papers contributed to the Journal of Biological Chemistry vol. 62, entitled "Studies in yeast meta- bolism." They sum up their conclusions towards the end of the second paper in the following paragraphs : - " In view of these experiments we feel that the actual loss of alcohol observed in our previous work, and the excessive production of carbon dioxide, are in part at least explained by the transformation of alcohol into carbon dioxide by yeast in the presence of air. The carbon dioxide found is by no means the equivalent of the alcohol used up, so that we believe other products, which we have not yet detected, are formed simultaneously. Whether the alcohol suffers a direct oxidation in the presence of the yeast, or whether a passage of the alcohol carbon through the cell materials takes place, resulting in its ultimate appearance as carbon dioxide are questions for which the data offer no solution" (pp. 834, 835). "The opinion is advanced that the removal of alcohol is an oxidation which does not involve metabolism of the carbon, that products other than carbon dioxide are formed by this means, and that the increase in yeast weight is due to a development of the cells rather than to their multiplication " (p. 836). In a note the authors refer to another scientific communication by H. Lundin, who, they say, "' obtained relatively considerable increase in the weight of yeast present, which is attributed to alcohol assimila- tion and carbo-hydrate formation by the cell. The carbon dioxide is regarded as a product of cell respiration, From this view-point, which was first developed for analogous systems containing sugars, the carbon balances have been carefully worked out" (p. 835 n.). Neither the evidence nor the text books which we have consulted pursuant to the parties' consent disclose any further scientific information as to the manner of the disappearance of the alcohol. The scientific explanation of the fact is of no importance to the invention. It is the fact itself which is important. The word "assimilate" may be a misdescription, although science has not proved its incorrectness so far. But on the whole specification it sufficiently appears that by this the claim intends to cover no more

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than the fact that during the later stage of the fermentation the yeast cell disposes of the alcohol so that it is not there. I am quite unable to see that the patentee was called upon to explain scientifically what happened to the alcohol or that the use of the word " assimi- lated," even if it be a misuse of language, corrupts the claim. It is then argued that no information is given as to the quantity or percentage of alcohol; that the words of the claim, "formed in considerable quantities," are vague and that no directions are contained in the specification on the subject and no definition is to be found. This criticism does not, in my opinion, take into account the true nature of the invention. The inventor has not undertaken the task of providing a means of producing specific quantities or percentages of alcohol. It is an invention for yeast production. What is claimed for it is that yeast may be produced notwithstanding the presence of alcohol in quantities previously considered inimical to the growth of yeast. Incidentally, the alcohol if desired may be recovered if the process is interrupted before it disappears. Prior knowledge of the amount enables any manufacturer to determine for himself how to increase alcohol production, when to stop if he wants alcohol, and to gauge from time to time the amount of alcohol present. The process invented is applicable to all sorts of concentra- tions. It is no part of the process to determine the quantity of alcohol present at any given stage. The alcohol content is relative. Under Sak's process it may be relatively great. Under prior processes it was necessary that it should be relatively small. Apart from questions of alcohol production it was contended that the claim and specification were ambiguous and insufficient because the constituents of the nutrient solution were not defined and the degree of departure from uniformity was not defined, and it was not stated whether the process of equalizing extended to additions of inorganic nitrogenous substances. These criticisms again rather miss the point of the invention. The patentee is not called upon to describe all the possible applications of his invention and to deal with the problem which those applications may raise. The tables which illustrate one application of the process make it quite clear that the strengthening of the wort by the addition of a stronger nutrient is not a continuous unbroken process, but is to be done by additions at intervals. The

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Yeasts are minute plant organisms, so small that they are visible only under a high-power microscope and hence known as micro- organisms. They have been classified in groups, and are distin- guished according to the shape of their cells. One of these groups is called Saccharomycetes, of which there are several species. Saccharomycetes cerevisiae are used in the brewing and baking industries, whilst Saccharomycetes ellipsoideus are used in the wine industry. The Saccharomycetes are single cell organisms, and multiply by budding. Under proper conditions they grow and reproduce themselves with great rapidity. The yeast cells contain organic substances called enzymes; they are agents by which chemical changes are brought about in living organisms. Some are sugar-splitting agents, and another, called zymase, is a fermenting agent. The fermenting process is the splitting up of certain carbo-hydrates into alcohol and carbonic acid gas. It is this process of alcoholic fermentation that has been used for many years in the fermenting industries, such as the brewing, distilling, baking and wine industries. The cultivation of yeast pure, and what are called "cell" yeasts, has developed into a special industry. The cultiva- tion of the yeasts is often a major production rather than a by-product of the other fermenting industries. It has already been observed that yeasts require proper conditions for their growth and multiplica- tion. For their growth they require sugars, phosphates, nitrogenous matter, and some mineral salts. A medium is prepared, containing in solution the various ingredients necessary for the growth of the yeasts, raw materials are brought together in a mash tub (grain is largely used because it contains the necessary ingredients for the growth of yeasts), they are prepared by grinding, water is added, and other treatment takes place. The resulting mass is called the mash. The object of mashing, as it is called, is to bring the proteins or other nitrogenous bodies into solution, and to hydrolyse the starches into sugar. The mash itself may be inoculated or seeded

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method, is to be worked. Ambiguity is directed to the issue whether the invention is sufficiently described and ascertained so as to enable the public to understand the scope of the monopoly granted by the letters patent" (No-Fume Ltd. v. Frank Pitchford & Co. Ltd. (1). T shall not go through all the objections taken on these grounds. It might be enough to say that two skilled persons appointed by the Court had no difficulty in understanding and carrying out the process according to the directions given in the specifications and in obtaining the results predicted by it. But in addition the specification has a background of knowledge of the art of manufacturing yeast and of methods for determining the temperature, concentration and acidity of the solution in which yeast is propagated and of the aeration of those solutions. So when it is objected that no sufficient directions are given for the management of the fermentation in a manner which is called differential, the answer is that the common knowledge and practice of the fermenting industries and the methods in use in those industries enable anyone to whom the specification is addressed to determine the amount of saccharine or fermentable matter in the wort at any given moment, and the principal chemical reaction according to which alcoholic fermentation proceeds enables him to estimate the alcoholic formation in the solution. And in addition there are the particular examples set forth in the specification itself to guide and instruct him. After all, the only essential direction is that the concentration of the nutrient solution must be maintained during the course of the process. It must be equalized or com- pensated, having regard to the multiplication of the yeast cells. So, as to mineral nutrients. The addition of nutritive salts and the manner of adding them in the fermenting process were well known. The specification states that the usual nutritive salts may be added in the usual manner during fermentation, or even in the wort before sterilization. The specification, having regard to all these con- siderations and circumstances, is not, I think, bad for want of sufficiency or for ambiguity.

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Several passages in the specification insist that alcohol, in quite considerable quantities, may be present during the fermentation, and may be recovered commercially or assimilated by the yeast, or disappear during the process. "The yeast thus produced, while quite considerable quantities of alcohol are present, appears in quantities corresponding to a yield of about 60 per cent or more, and besides it possesses internal and external qualities of exceedingly high value." And the claim itself is limited to a process "' whereby alcohol is formed in considerable quantities, which alcohol is either recovered or assimilated by the yeast, but only during the subsequent period of the fermentation." Now, if the specification suggests that the process will yield a high percentage of yeast, and at the same time a quantity of alcohol sufficient for commercial recovery, then the suggestion cannot be made good: a false representation would have been made, invalidating the grant of letters patent. Buta true interpretation of the specification does not, F think, lead to this construction. The process may be adjusted, says the specification, according to the varying state of the market for yeast and alcohol. The alcohol may be recovered, assimilated by the yeast, or caused to disappear. All this suggests that though the production of yeast is the main object of the invention, still the production of alcohol, if alcohol be required, is not limited or precluded. The effort of a manufacturer in the fermentation processes was not always to grow yeast, but "rather to produce just enough yeast to catalyse the alcohol-forming reaction." The specification suggests that the process described permits the regulation of the production and utilization of yeast and alcohol according to the requirements of the manufacturer or the state of the market. There is no difficulty in so regulating the process, having regard to the known methods and practices of the fermenting industries and the examples given in the specification itself.

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The present case is concerned with their relation to the commercial production of pressed yeast. The procedure followed in its production falls naturally into two parts. The grain is mixed with the malt and mashed at a proper temperature so that, to as great an extent as possible, the starch will become soluble sugar or dextrose. The mash must stand 'some time and much bacterial and chemical action takes place. As yeast, a micro-organism, is to be grown in it, the degree of acidity of the mash must be controlled. At one time, when the mash was considered ready, it was sown directly with yeast, which propagated in it. This was called the "Vienna method." But for many years another practice has pre- vailed. The mash is prepared from grain which is softened with water and crushed, not ground. The nutrient materials, nitro- genous or protein as well as sugars, are drawn off in liquor. The mash is washed again and the liquid of the wash filtered off, and this is done yet a third and a fourth time. These filtrations are the wort into which the seed yeast is sown. It was established many years ago, by Pasteur it is said, that in the absence of atmospheric oxygen yeast consumed in its growth a quantity of sugar surprisingly greater than in the presence of air. Accordingly the liquid wort is aerated throughout the period of the yeast fermentation. The control of temperature, sterilization, the use of inorganic contributions to the nutriment and many other matters are involved in the process. When the yeast has broken down the nutrient properties of the wort to such an extent that the ferment should be terminated, the yeast is separated mechanically from the liquor. The alcohol contained in the liquor may be worth recovering and this is done by distillation. The sugar content of the wort, determining, as it does, its density, is ascertainable by a saccharometer. Tables have been constructed by means of which the concentration of the wort can always be found. The proportion of alcohol in the wort is also ascertainable without difficulty. Alcohol is, of course, a product of the fermentation and its increase in the wort appeared to be an unavoidable concomitant of the growth of the yeast. But alcohol, at any rate in particular conditions and proportions not exactly determined, proved a most powerful retarding agent in the propagation of yeast. It was said to bea poison for the yeast. Rich worts produced alcohol; " strong

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it would not mean anything. The passage of the specification referring to 20 per cent does not, as I read it, deal with the recovery of alcohol but only with the amount of alcohol occurring at a stage of the process. But the substantial question is whether the specifica- tion does represent that the process may be so applied that by the same fermentation from the same wort a large yield of yeast will be obtained and alcohol will remain available in a quantity sufficient for commercial distillation. A number of statements and expressions contained in the specification were collected together in order to establish the making of this representation. It is needless to set them out again. They combine to make the interpretation plausible. Nevertheless, an examination of the whole document has led me to the conclusion that it is a mistaken reading of the specification. It arises from a failure to appreciate the nature of the incidental advantage claimed for the process. It is that it allows the subor- dination of the production of yeast to the recovery of alcohol. This incidental advantage is a consequence of the otherwise apparently accidental feature of the invention, that it makes possible the growth of yeast in the presence of alcohol. But it is another feature of the process that, if the fermentation to which it is applied is carried through to its normal conclusion when the yeast is separated from the wort, the alcohol will have been largely consumed. This feature is incorporated in the claims themselves, which afford a striking illustration of the alternative character of the recovery of alcohol. The first claim, which is embodied in the two succeeding claims, - ends with the words "whereby alcohol is formed in considerable quantities, which alcohol is either recovered or assimilated by the yeast, but only during the subsequent period of the fermentation." It means that to recover the alcohol the fermentation must be stopped, otherwise the alcohol will be used up. But the fermentation can be prematurely stopped only at the expense of the yield of yeast. To some extent a misunderstanding of the specification is made easier by the ambiguity of the word " during" which is used many times in the course of describing the relation of the process to aleohol. It is used, not in the sense of " throughout the period of the fermentation," but in the sense of "at a point of time within

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A sentence in which the ambiguity is removed by the context serves also to make it clear that recovery of alcohol is not contemplated where the process is carried to its normal conclusion. The material part is expressed thus: "Even quite considerable quantities of alcohol may be present during the fermentation, and the process should therefore be carried [out] not only in such manner that such quantities of alcohol are formed and are present during the fermenta- tion but also so that the alcohol is not utilized by the yeast until during the further run of the fermentation, the alcohol being utilized or assimilated." Again it is stated that by the process an adjust- ment of the concentrations is made, not only favourable to the growth of yeast, but also giving "a quite appreciable formation of alcohol, so that the alcohol may either be caused to disappear again slowly during the process, or may be caused to remain, wholly or partially, as desired." The very next sentence speaks of "a forma- tion and conversion of alcohol going on co-ordinarily with the attain- ment of high yields of the best yeast." " Conversion" means that the alcohol is transformed and lost. It does not mean that it is distilled. Distillation does not "go on co-ordinarily." It is a subsequent process, and "conversion," in any event, is a word which could not be used to describe it. The table contained in the second example given in the specification affords a detailed illus- tration of the progress of such a "conversion." The greater initial concentration of the wort in the first example gives an application of the process of a kind in which "the alcohol will be present, or may be present, in a concentration enabling it to be recovered commercially". But, that this result is obtained at the expense of the yield of yeast is made plain by the text, and not merely left to the common sense of yeast manufacturers. For the specifica- tion proceeds: "By a slight variation of the temperature, the aeration or the manner in which the wort is added, the amount of alcohol present at the end of the process may be varied. The present process thus allows the manufacture to be adjusted according to the varying state of the market for yeast and alcohol."

[406]

The object of the alleged invention as stated in the specifica- tion is to give "uniform and favorable conditions of life during the entire fermentation process without using other nutrient sub- stances than those utilized in the heretofore-known fermentation process." It is said that it is possible to provide these uniform and favourable conditions for the propagation of the yeast " when the usual nutritive substances (that is, for instance, mash and wort) are supplied in an entirely different manner from that heretofore known." The patentee discovered that, by the management of the fermentation in a manner which he calls " differential," uniform and favourable conditions of life are given to the yeast, resulting not only in an uncommonly large yield of yeast, but also in the formation of "considerable quantities" of alcohol. The manner of manufactur- ing yeast by the differential management of the fermentation is then described, and two examples of a fermentation conducted according to this method are given. The alleged invention is this manner of manufacture. The yeast is sown in a " diluted wort or mash suitable for the propagation of yeast " and " the concentration of the nutritive liquid is maintained by equalization or compensation of the consumption of substance." The method of maintaining the concentration, which constitutes part of the manner of manufacture, is explained in the following terms: "In contradistinction to the heretofore followed practice, the process may be commenced for instance by sowing the yeast into the last or a mixture of the last and the last but one washing water (the term ' washing water' being taken to mean the liquid flowing from the filtration plant), where- after addition is made of the stronger washing waters obtained at the beginning of the filtration, and of the first wort, according to requirements in order that the concentration may be maintained in spite of the consumption of substances occurring." The process is also illustrated by the two examples. Before this specification it was common practice to avoid forming alcohol during the fermenta- tion as it was regarded as detrimental to the propagation of yeast. Accordingly yeast-makers strove for a solution with the lowest degree of sugar concentration compatible with the growth of yeast,

At a glance

Court

Decision date

Before

Source

Judgment (416 paragraphs)