was not a practical one. There was nothing practical until the sulphoacid discoveries were made. In regard to this the paper first cited says: The patent of Caro, Graebe, and Liebermann is dated one day earlier than that of Perkin. If any value at all is to be placed in the date, then Caro must certainly be mentioned first, since the application for a patent by the German chemist was delayed by an error. The signing took place at the patent agent's in Berlin. In reference to the above two English patents, Perkin and the Baden An ́in and Soda Works, proprietors of Caro and Graebe and Liebermanu's patent, made an agreement, in consequence of which the patents became common property. By the publication of these patents the sulpho-acid methods of preparing alizarine became known, and a series of works were erected in States which gave no or insufficient protection to the patentees.

This shows that the only methods practiced commercially were the sulpho-acid methods. The English patent for the bromine methods expired December 18, 1871, for the want of payment of a further fee.

The statement of Graebe and Liebermann is that Caro discovered that, by using anthrachinon with sulphuric acid, he could obtain sulphoacids, and then, with hydrate of potash, procure alizarine, "the same as the bromine compound"-that is, the alizarine of the process of No. 4,321; but that the bisulpho-acid process developed by Perkin produces, not the alizarine of the process of No. 4,321, which is bioxyanthrachinon, but trioxyanthrachinon or isopurpurin. The article sold by the defendants is this last substance made by the bisulpho-acid process, carried on abroad at the present day, and containing large proportions of coloring matters not shown to be found to any practically useful extent in the alizarine of the process of No. 4,321, such as isopurpurine or anthrapurpurine, one or both-two articles, if they are different, or one, if they are the same, as seems to be shown. No. 4,321 furnishes no test by which to identify the product it covers, except that such product is to be the result of the process it describes. The process by which the defendant's article is made is not shown to be the same process as that described in No. 4,321. Graebe and Liebermann, as appears from their own statement, experimented with sulphuric acid and failed. It was not obvious that sulphuric acid would accomplish any result, nor was it obvious how to employ it. Their experiments with it led them to hope little from it and to withdraw their attention from it and devote themselves to improving the bromine and chlorine methods. They state that Caro avoided their mistakes, and was the first to discover the modification which led to success, and that Perkin was an independent discoverer of it about the same time. It is, therefore, impossible to say that the sulphuric acid process was a known equivalent process at the time. It is easy now, after the event, for scientific men to say, with the knowledge of to-day, that the thing was obvious; but the crucial facts contradict the assumption.

It does not satisfactorily appear that the process of No. 4,321 will produce the defendant's article to any useful extent, if at all. The process of No. 4,321 never was, and is not now, practically carried on anywhere.

The article of No. 4,321 was called "artificial alizarine," and the article now in the market is called by the same name; but the identity, in the sense of the patent law, between them and between the processes for producing them is not shown.

The English patent to Caro and Graebe and Liebermann having been granted June 25, 1869, and the full specifications filed January 13, 1870, an application for a patent in the United States for producing artificial alizarine by the sulpho-acid processes was filed by them January 26, 1870. It was granted as No. 154,536 July 28, 1874. The full specification of the English patent and that of No. 154,536 are identical. The specifications state that the invention relates to improvements on the invention described in the English patent to Graebe and Liebermann of December 18, 1868, and in No. 95,465, "in which the preparation of artificial alizarine is based upon the action of caustic alkalies upon bibromanthrachinon or bichloranthrachinon.

They then proceed:

We have now discovered that a similar result may be obtained by substituting sul phuric acid for bromine or chlorine in the above process We thus obtain the sulphoacids of anthrachinon, which, by being dissolved in and heated with an excess of caustic alkali, are converted into alizarine. This invention relates to improvements in the production of coloring matters, and more especially to improvements in the method of producing what is known as "artificial alizarine, from anthracine, a method of producing which was described in [the English patent of December 18, 1868, and in No. 95,465] and consisted in the production of artificial alizarine by converting anthracine into either bibromanthrachinon or bichloranthrachinon, and then acting upon the same by means of an alkali, and precipitating the alizarine contained in the alkaline solution by means of an acid. In the complete specifications of the aforesaid letters patent, granted to Charles Liebermann and Charles Graebe, two different series of processes are desribed for obtaining the bromated or chlorinated derivatives of anthrachinon. In the first of these processess the anthracine is submitted to the action of oxidizing agents, as is well understood, and the oxidized anthracine or anthrakinon is then treated with bromine or chlorine. In the second of these processes the anthracine is first treated with bromine or chlorine, and subsequently submitted to an oxidizing process, in order that the desired compound-videlicet, bibromanthrachinon or bichloranthrachinon-may be obtained. In an analogous manner we now employ sulphuric acid as a substitute for the bromine or chlorine employed in the processes above referred to, and we thus obtain the sulphuric acid derivatives of anthrachinon, which we call "the sulpho-acids of anthrachinon."

The specifications then go on to describe the two new processes. The first is to alter the anthrachinon by heating it with sulphuric acid. The product is then put in solution and treated with carbonate of lime, and then with carbonate of potash or of soda, and potash or soda salts of the sulpho-acids of anthrachinon are produced. These are treated with caustic soda or potash under heat, and the artificial alizarine is precipitated by an acid. In the second process anthracine is heated with sulphuric acid, the product is put in solution and treated with peroxide of manganese under heat. Caustic lime is then added in excess till there is an alkaline reaction. The mixture is then filtered and carbo. nate of potash or soda is added to it, and the potash or soda salts of

the sulpho-acids of anthrachinon are produced. These are treated with caustic potash or soda under heat, the product is put in solution, and the artificial alizarine is precipitated by an acid. It is stated in regard to this substance, made by either of these two processess, that it may be employed for the purposes of dyeing and printing, either in the same way as preparations of madder are now used or otherwise.

In each of the two specifications there are two claims, in these words: 1. The manufacture of coloring-matters by submitting anthrachinon to the action of sulphuric acid, so as to obtain soluble compounds, which we have called "sulphoacids of anthrachinon," treating the products of such operation with an alkali, and precipitating the coloring-matters therefrom by means of an acid, as herein described. 2. The manufacture of coloring-matters by submitting anthracine to the action of sulphuric acid, oxidizing the product thereby obtained, heating such oxidized product with an alkali, and subsequently precipitating the coloring-matters therefrom by means of an acid, as herein described.

After the granting of the English patent for the sulpho-acid process, on June 25, 1869, to Graebe and Liebermann, and their application for the United States patent on January 26, 1870, it became apparent that the sulpho-acid processes and products were to be commercially valuable. Then, during the interval of the four years and a half delay in the issuing of No. 154,536, No. 95,465 was surrendered and reissued in two parts, April 4, 1871, one for the process and the other for the prod uct, the claim in the latter (No. 4,321) being so worded as to cover "artificial alizarine produced from anthraciue or its derivatives by either of the methods herein described, or by any other method which will produce a like result." Afterwards Graebe and Liebermann assigned the two reissued patents of April 4, 1871, to the plaintiff on March 1, 1872.

It is very plain that the specification of the original patent (No. 95,465) states the invention to be a process for preparing alizarine, not as a new substance prepared for the first time, but as the substance already known as "alizarine," to be prepared, however, by the new process, which process is to be the subject of the patent, and is the process of preparing the known product alizarine from anthracine. The specification states that "the alizarine" is precipitated, that "the yellow flocks of alizarine" are obtained, and that "the alizarine" is in such a form that it can be employed in the same manner as the different preparations from madder, and the claim is for the "process for the produc tion of alizarine." The provisional specification deposited in England, December 18, 1868, states that "yellow flocks of alizarine are precipitated," and that "the alizarine prepared in this artificial way is perfectly pure," and the full specification, filed in England, June 17, 1869, claims "the artificial production of alizarine." No other conclusion can be reached than that Graebe and Liebermann, in the specification of No. 95,465, intended by "alizarine" the chemical substance known by the formula CH,O,. and thought that was what their process produced. There is no suggestion of anthrapurpurine or isopurpurine

8

or of any process for producing them. Their published statements show that it was the synthesis of the alizarine of madder which they were making, the specification of No. 95,465 shows that and nothing else, and it is not contended that the alizarine of madder contains anthra purpurine or isopurpurine. It is very clear from the testimony that it is to anthrapurpurine or isopurpurine that the artificial alizarine sold by the defendants owes its efficiency as a dye-stuff and its practical success in the market, and that such product is produced by the bisulpho-acid process of Perkin; and it is not satisfactorily shown that the monosulpho-acid process of Caro or the bromine process of No. 4,321 will either of them practically produce that product.

Inasmuch as the defendant's article is produced from anthracine or its derivatives by some method, and is a dye-stuff called "artificial alizarine," it is contended that the sale of it infringes No. 4,321. The articles in market, called "artificial alizarine" at the present day, are substances all of which are made from anthracine; but they vary all the way from nearly pure alizarine made by the monosulpho acid process through the products of the bisulpho-acid process, which contain combinations of alarizine and anthrapurpurine, up to an article of pure purpurine, free from alizarine. All of these are used as dye-stuffs, according to the shade of color and other qualities desired. The specific article put in evidence in this case as an infringement contains about 60 per cent. of anthrapurpurine. It is claimed by the plaintiff to be the artificial alizarine described in No. 4,321, and to be physically, chemically, and in coloring properties similar to that. But what that is is not defined in No. 4,321, except that it is the product of the process described in No. 4,321. Therefore, unless it is shown that the process of No. 4,321 was followed to produce the defendant's article, or unless it is shown that that article could not be produced by any other process, the defendant's article cannot be identified as the product of the process of No. 4,321. Nothing of the kind is shown. On the other hand, the defendant's article is made abroad and by a process different from that of No. 4,321. It therefore cannot be the product of that process. If the words of the claim "by any other method which will produce a like result" mean any other method which will produce the only product mentioned in the description, namely, alizarine, as then understood, having the formula C1HO, the defendant's article is not that product, for it contains other dyeing ingredients which the alizarine of the patent does not contain. If the words of the claim are to be construed to cover all artificial alizarine, whatever its ingredients, produced from anthracine or its derivatives by methods invented since Graebe and Liebermann invented the bromine process, we then have a patent for a product or composition of matter which gives no information as to how it is to be identified. Every patent for a product or composition of matter must identify it so that it can be recognized aside from the de9373 PAT-16

scription of the process for making it, or else nothing can be held to infringe the patent which is not made by that process. The circuit court found as a fact that the defendant's article was produced by the process described in No. 154,536. But it regarded that process as the same process chemically as the process of No. 4,321, on the view that the bromine used in the latter was merely a vehicle, and in the former sulphuric acid was substituted as a vehicle, and though superior performed the same office in the same way; and so, as it regarded the two processes as the same, it held the two products to be the same. We consider it, however, to be established that the defendant's article is not made by the process of No. 4,321, but is made by the bisulphoacid process of Perkin, which yields anthrapurpurine, aud which, while it may involve the process of No. 154,536, goes beyond it. The bisulpho-acid process puts in two atoms of anhydrous sulphuric acid instead of one, and additional oxygen is carried in and anthrapurpurine is produced, the formula of which is C4H9O5. Aside from this, it is shown that the dyeing qualities of the defendant's article depend on the anthrapurpurine or isopurpurine it contains, and not on the alizarine. As the only alizarine mentioned in No. 95,465 or in No. 4,321 is alizarine the formula of which is C4H8O4, the alizarine of madder, the process described in those patents, to be a sufficient support for a valid patent, as being properly described, must be a process which will produce that article and no other; and No. 4,321, to be valid as a patent for a prod uct, must be a patent which will produce, by the process it describes, that article and no other. Unless that process will practically produce the defendant's article, No. 4,321 is not infringed; and it is not estab lished by the evidence that it will.

There is another view of the case. According to the description in No. 95,465 and in No. 4,321 aud the evidence, the article produced by the process described was the alizarine of madder having the chemical formula C14H,O4. It was an old article. While a new process for producing it was patentable, the product itself could not be patented, even though it was a product made artificially for the first time, in contradistinction to being eliminated from the madder root. Calling it artificial alizarine did not make it a new composition of matter, and patentable as such, by reason of its having been prepared artificially for the first time from anthracine, if it was set forth as alizarine, a wellknown substance. (The Wood Paper Patent, 23 How., 566, 593.) There was therefore no foundation for Reissue No. 4,321 for the product, because on the description given no patent for the product could have been taken out originally.

Still further, the claim of No. 4,321 is not a claim merely for the prod uct of the process described in it, but is a claim for anything which may be called "artificial alizarine," produced from anthracine or its derivatives, by either of the methods described, or by any other method,