
    James Wood, Plaintiff in error, v. William A. Underhill and Aschel H. Gerow, Defendants.
    In order to obtain a patent, the specification must- be in such full, clear, and exact terms as to enable any one skilled in the art to which it appertains to compound and Use the .'invention, without making any experiments of his own.
    If the patent be for a new composition of matter, and no relative proportions of the ingredients are given, or they are stated so ambiguously and vaguely that no one could use the invention without first ascertaining, by experiment, the exact proportion required to produce the result, it would be the duty of the court to declare the patent void. . . . '
    But the sufficiency of the description in patents for machines, or for a new composition of matter, where any of the ingredients do not always possess exactly the same properties in the same degree, is, generally, a question of fact to be determined by the jury. • . . ’
    Where a patent was obtained for a new improvement in the mode of making brick,' tile, and other clay ware, and the process described in the specification was, to mix pulverized anthracite coal with the clay before moulding it, in the proportion of three fourths of a bushel of coal-dust to one thousand brick, some clay requiring ope-eighth more, and some not exceeding half a bushel; this degree of vagueness and uncertainty was not sufficient to justify the court below in declaring the patent void.
    The court should have left it to the jury to say, from the evidence of persons skilled in the art, whether the description was clear and exact enough to enable such persons to compound and use the invention.
    ■ .This cáse was brought up, by writ of error, from the Circuit Court of the United States for the Southern District of New York. .
    Tf appeared that, in the-year 1836, Wood took out amended letters patent for £i a' new- arid useful improveihent' in' the mode of making brick, tilé, and other clay ware,” and filed the following specification of his invention :—
    
      u Be it known that I, the said James Wood, have invented a new and useful improvement in the art of manufacturing bricks and tiles. The process is as follows : Take of .cornmon anthracite coal, unburnt, such quantity as will best suit the kind of clay to be made into brick 01-tile, and mix the same, when well pulverized, with the clay before [it] is moulded; that clay which requires the most burning will require the greatest proportion of coal-dust; the exact proportion, therefore, cannot be specified ; but, in general, three fourths of’ a bushel of coal-dust to one thousand brick will be correct. • Some clay may require one eighth ' more, and some not exceeding a half-bushel. The benefits resulting from this composition are the saving of fuel, and the more general diffusion of heat through the kiln, by which the whole cpntents are more equally burned. If the heat is raised too high, the brick will swell, and be injured in their form. If the heat is too moderate, the coal-dust will be consumed before1 the desired effect is produced. Extremes are therefore to be avoided. I claim as my invention the using of fine, anthracite coal, or coal-dust, with clay, for the purpose of making brick and tile as aforesaid, and for that only claim letters patent from the United States.
    James Wood.”
    Dated 9th November, 1836.
    In July, 1842, he brought a suit'against the defendants in error, for a violation of this patent.
    And at the trial the defendant objected to the sufficiency of the specification, ■“ because no certain proportion for the mixture is pointed out, but only that such quantity of coal must be taken- as will, best suit the kind of clay to be made into brick or tile ; but ■that clay which requires most burning .will require the greatest1 quantity of coal-dust; the exact proportion cannot, therefore, - be specified ; but, in general, three fourths of - a bushel of coal-dust to one thousand brick will be correct. ■ Some clay may require, one eighth more, and some not exceeding half a bushel; So that there ■ is no fixed rule by which the manufacturer can make the mixture, but tliat must be ascertained by experiments upon the clay ; and tlie claiming clause in1 the • specification is only for the abstract general principle .of mixing anthracite coal-dust with clay, for the purpose of making brick, without any practical rule as to die proportions, which is too vague and uncertain to sustain á patent ” ; which objection was sustained by the court. The plaintiff excepted. And the verdict and judgment being against him, the case was brought here upon this exception.
    The cause was argued by Mr. Sflliman, for the plaintiff in error, and Mr. Roieley, for the defendant's.
    
      Mr. Silliman, for the plaintiff in error, made the following points:
    The plaintiff insists, —
    1. .That he has in his specification given a general rule by which every kind of clay may be" much better burned than by any previous process. ’And that the general proportions specified are, with-some exceptions, the very best that can be.used.
    - That a patent may properly be granted for a beneficial general, rulé, although there might be some exceptions to it not provided for.-
    2. That if it is necessary to entitle the plaintiff to a patent for.a most beneficial invention for burning clay of the ;qualities usually found, that he should also discover thé means' o$ burning, to best advantage, cláys of qualities not usually found ; that his patent should not therefore- be deemed void on its face, but he should be permitted to prove, by persons c'onyersant with the buslnéss, that they could instantly determine, on inspection of clays of uncommon qualities, whether they required more or less than the usual.buming, and hów much more or less, so as to regulate the variation of proportions in,such manner as to burn to the best advantage.
    3. The plaintiff should have been permitted to show, under his specification by experts, that any kind- of clay of which bricks can be made, however varied the qualities, can be better burnt under his general rule than by any previous process; and if such is the fact, the plaintiff should be entitled to a patent for the discovery, if he had given the general rule only, and had taken no notice of those exceptions, in which some uncommon kinds of clay can be best burned with a greater or less proportion of coal than that specified in the general rule.
    4. The judge in his decision adopts all the errors of the defendants’ objection, which states that there is no 'fixed rule by which the manufacturer.can make the mixture, but that must, be ascertained by experiments upon the clay. Suppose this to be .so, and that the inventor has only furnished a guide hf which such experiments can be successfully made, and that ’ the subject, on account of the variable qualities of the materials, does not .admit off greater certainty,, and that by the simplest and cheapest experiments the manufacturer, in .consequence office plaintiff’s invention, will be able to burn his bricks much better in less, than half the time, and at. less than half the cost of'burning, by any other process, is not the inventor entitled to a patent for an invention practically so useful ?
    The fact that not a ’single, brick has for some years past been burned, ■ except according to the’ plaintiff’s specification, is pretty good evidence that the manufacturers have, been able to discover something from plaintiff’s specification.
    5- The objection, ás adopted by the court, declares that the claiming clause in the specification is only for the abstract general principle of mixing anthracite coal-dust with clay, for the purpose of making bricks and tiles, without any practical rule as to the proportions, which is too vague and uncertain to sustain a patent. Suppose this objection true in point of fact,-and'that no information had been intentionally suppressed, and that the qualities of clay varied so much that the proportions most useful could only be ascertained by ari experiment on each bed of clay, it might, nevertheless, be a very useful invention, for which the inventor should be, in some measure, compensated by a patent. But this part of the objection is not true in fact, for the claiming clause' is of the invention of Using fine anthracite coal, or coal-dust, with clay.for the purpose of making.brick.and tile “as aforesaid.” These words, “as aforesaid,” refer to the general rulé of three fourths of a bushel of coal for a thousand bricks, with the exceptions, or variations previously ^expressed. -
    ' 6. The judgment should be reversed, with costs, including, the costs in the Circuit Court.
    
      Mr. Rowley, for the defendant in error.
    The ■ patentee’s specification is uncertain and insufficient. It furnishés no rule for making bricks, without the manufacturer’s first . making a series of experiments. The most it does is to prescribe in about what mariner the trials are to be conducted; which is not enough to sustain his patent. The King v. Arkwright, Dav; Pat. .Cases,T06 (per Buller, J.); Turner v. Winter, 1 Term R. 606 (per Ashurst, J.); Boulton v. Bull, 2 Hv Bl. 484 (Buller, J.); Harmer v. Playne,Tl East. 101 (Lord Elleriborongh); The King e. .Wheeler, 2 Barn. & Aid. 345 (Abbptt, Ch. J.) ;'Godson on Patents, 85 ;. Lowell v. Lewis, 1 Mason’s R. 182 (Story, J.');. Langdon v. De Groot, 1 Paine’s R. 203; Phillips on‘Patents, 83, 267, '268, 283, 284, 289. ‘
   Mr. Chief Justice TANEY

delivered the opinion of the court.

The question presented in this case is a narrow one, and may be disposed of in a few words.

The plaintiff claims that,he has invented ■ a new and useful irm provement in the art of manufacturing bricks and tiles'; .and states his invention to consist in using fine anthracite coal, or ceal-dust, with clay, for the purpose of making brick or tile ; — and for that only he claims.a.patent. And the only question presented by the record is, whether his description of the relative proportions, of coal-dust ánd clay, as given in his> specification, is upon the fa-'e of it too vague and uncertain to support a patent:

The'degree of certainty which the law requires is set forth in the act of Congress. The specification must be. in such full, clear, and exact terms as to enable any one skilled in the art to which it appertains to compound and use the- invention ; that is say, to compound and use it without making any experiments of his own.. In patents for machines the sufficiency of the description must, in general, be a question of fact to be determined by the jury. And this must also be the case in compositions of matter, where any of the ingredients mentioned in the specification do not always possess exactly the same properties in the same degree.

. But when the specification of a new composition of matter gives only the names of the substances which are to be mixed together, without' stating any relative proportion, undoubtedly it would 'be the duty of the court to declare the- patent to be void. . And the same rule would prevail where it was apparent that the, proportions were stated ambiguously and vaguely. For in such cases it would be evident, on the face of the specification, that no'one could use the invention without -first ascertaining by experiment the exact, proportion of the different ingredients required to produce the result intended- to be obtained. And if the specification hefore us ■was liable to either of these objections the' patent would be void, and the instruction given by-the Circuit Court undoubtedly'right.

But we do not think this degree of vagueness ■ and uncertainty exists." The patentee gives a certain proportion as a general rule ; that is, three - fourths of a' bushel of coal-dust to' one thousand bricks. ’ It is true he also states that clay which requires the most burning will require the greatest proportion of coal-dust; and .that some-clay may require one eighth more than the proportions- given, and some not more than half a bushel instead of three fourths. The two last-mentioned proportions may, however, be justly considered as exceptions to the rule he has stated; and as applicable to those cases,only where the clay has.some peculiarity, and differs in quality from that ordinarily employed in making bricks. • Indeed, in most compositions of matter, some small difference in the proportions must occasionally be required, since the ingredients proposed to be, compounded must sometimes be in some degree superior or inferior to those most commonly used. In this case, however, the genéral rule is given with entire exactness - in its terms; and the notice of the variations, mentioned in the specification, would seem to be designed to guard the brick-maker against mistakes, into which he might fall if - his "clay was mor.e or less hard to burn than the kind ordinarily- -employed in the manufacture.

It may be, indeed, that the qualities of clay generally differ so widely that’the specification of the proportions stated in this case' is of no value ; and that the improvement canno. be used with advantage in any case, or with any clay, without first ascertaining by experiment the proportion to be employed. If that be the case, then the invention, is not patentable. Because, by the terms,of the act of Congress, the inventor is not entitled to a patent unless his description is so full, clear, and exact as to enable any one skilled in the art to compound and use it. And if, from the nature and character of the ingredients to be used, they are not susceptible of such exact description, che inventor is riot entitled to. a patent. But this does not appear to be the case on the face of this specifi- ' cation. And.whether the fact is so or not is a question to be decided by a jury, upon the evidence of persons skilled in the art to which the patent appertains. The Circuit Court therefore erred, in instructing the jury that the specification was too vague and uncertain to support the patent, — and its judgment must be reversed. '

Order.

This,cause came on to be heard on the transcript of the record from the Circuit Court of the United States for .the Southern District of New Fork, and was argued by<counsel. On consideration whereof, it is now here ordered and adjudged by.'this court, .that the judgment of the said Circuit Court in this cause be and the same is hereby reversed with costs, and that this cause bé and the same is hereby remanded to the said Circuit Court, with directions to award a veni/re facias de novo  