Application of Ernst-Albrecht Pieroh and Horst Werres

SMITH, Judge.

This is an appeal from a decision of the Board of Appeals affirming the examiner’s rejection of claims 1-9 of appellants’ application¹ entitled “Soil Disinfectants and Method of Applying Same”. No claims have been allowed.

Appellants have requested that claim 10 submitted in a proposed amendment filed July 21, 1958 be considered by the court “pro hac vice.” The proposed amendment, which is not in the record, was refused admission by the examiner, was not considered by the board, and therefore, according to our established practice will not be considered here. In re Wiedman, 243 F.2d 798, 44 CCPA 901.

The appealed claims relate to a method of and composition for controlling soil-dwelling nematodes by impregnating nematode infested soil with a “parasiticidal” amount of methyl isothiocyanate (methyl mustard oil) in a suitable liquid carrier.

Rejected claims 1-5, inclusive, are specific to a method for controlling soil dwelling nematodes while claims 6-9, inclusive, are specific to a composition for controlling such nematodes which comprises methyl isothiocyanate in an organic solvent.

Claims 1 and 6 are representative and read:

“1. A method of controlling soil dwelling nematodes which comprises impregnating nematode infested soil with a parasiticidal amount of methyl isothiocyanate.

“6. A composition for controlling soil dwelling nematodes which comprises methyl isothiocyanate in solution in an organic solvent.”

The following references are relied on by the examiner and the board: ²

Payne 2,377,446 June 5, 1945

Hammer 2,419,073 April 15, 1947

Kagy et al. 2,448,265 August 31, 1948

Bicker ton 2,473,984 June 21, 1949

Carter 2,502,244 March 28, 1950

Kay 2,543,580 February 27, 1951

Hilmer 2,695,859 November 30, 1954

Stansbury et al. 2,701,224 February 1, 1955

Hardy 2,769,745 November 6, 1956

Wolf 2,779,680 January 29, 1957

Barrons 2,794,727 June 4, 1957

Heininger 2,809,983 October 15, 1957

1. 29, No. 3, pp. 611-618 (pg. Cupples - Jour. Eco. Int., June 1936, Vol. 617 relied on)

Frear - A Catalogue of Insecticides and Fungicides (1948) Vol. I., pg. 76 Chronica Botánica Co.

All the appealed claims were rejected under 35 U.S.C. 103 as “obvious from the Cupples and Frear publications and the supporting patents cited.”

The Cupples article describes toxicity tests on an insect called California red scale. These tests were conducted with over 300 chemical compounds in an effort to find fumigants better than hydrocyanic acid. The results were grouped according to the indicated toxicity of the tested compound to the test insect. The chemicals listed in Group I show little or no toxicity, Group II compounds are moderately toxic, and Group III compounds are “decidedly toxic.” Methyl isothiocyanate is listed in Group III which includes “the relatively few compounds which have shown a substantial degree of toxicity.”

The Frear reference, which is a catalogue of insecticides and fungicides, lists methyl isothiocyanate as toxic to California red scale.

The secondary references were cited by the examiner presumably as supporting references for the purpose of showing that insecticidal compounds also can be expected to have nematocidal properties. The board’s affirmance of the rejection is predicated upon the concept that a compound known to possess properties as an insecticide and a fumigant “would seem to point to the employment of the compound as a soil nematocide.” This highly speculative position is in direct opposition to the more recent opinion of the board2 ³ in Ex parte Hessel, 137 USPQ 384, in which the board ⁴ stated:

“ * * * We do not consider nematocidal activity to be predictable from insecticidal or fungicidal activity broadly (Ex parte Santmyer, 132 USPQ 202). While soil or grain fumigants having volatility and stability necessary for such fumigating uses would normally be tested for nematocidal activity, we do not believe that one skilled in this art would employ the relatively nonvolatile pyrrolidone of Frear, or butyrolactone of King, not taught to be purpose of appellant’s claim. * * ” soil or grain fumigants, for the [Emphasis added.]

Apparently a significant factor which influenced the board in here reaching a conclusion diametrically opposed to the position stated in the Hessel case is found in the following statement:

“ * * * The methyl isothiocyanate agent, appellants’ specification indicates, is related to the mustard oils known to exhibit nematocidal action and the near homologue of the ethyl isothiocyanate so employed. * * ”

As we had occasion to observe in In re Mills, 281 F.2d 218, 47 CCPA 1185:

“ * * * Homology provides for the chemist a convenient system of structural classification. Inherent in that system are differences as well as similarities in the properties and reactions of the members of any given homologous series.

“A chemist, and it is from the standpoint of a chemist skilled in this art that the question of obviousness must be resolved, would consider the differences as well as the similarities in properties and reactions of the members of any given homologous series. * * '* ”

Appellants’ specification admits that various mustard oils were known to exhibit nematocidal action but that:

“Despite their favorable action against soil nematodes, the various other mustard oils have heretofore found no practical utilization, since every one of the mustard oils previously proposed for this purpose is extremely toxic to plants.” [Emphasis added.]

Certain discoveries and observations-which underlie appellants’ invention are stated in the specification as follows:

“It was now found, in accordance with this invention, that methyl isothiocyanate, which hitherto was not known to be a soil disinfectant, exhibits a far greater activity against soil dwelling nematodes and fungi than any of the mustard oils previously suggested for this purpose. It also far exceeds in effectiveness the conventional commercial preparations used as soil disinfectants, such as the sodium salt of N-methyldithiocarbamic acid, dichlorpropanedichlorpropene mixtures, or ethylene dibromide. Even more surprising was the discovery that methyl isothiocyanate exhibits a high degree of compatibility with plants. This was especially unpredictable since it was. precisely their excessively strong phytotoxic action which successfully militated against the adoption of the previously studied mustard oils. The methyl isothiocyanate agent of the present invention also displays excellent long-lasting action, which is far superior to that, for example, of the commercially used sodium N-methyldithiocai"bamate.” [Emphasis added.]

In considering homologous relationships in relation to the question of obviousness, we think the express language of 35 U.S.C. 103 requires a consideration of the differences between the claimed invention and the prior art. Here the examiner and the board considered only the chemical similarities between the claimed compound and the known homo-logs which comprise the group of mustard oils. The differences between the methyl mustard oil here claimed and the prior art compounds as a soil nematocide were not discussed in the opinion of the board. It is significant that the claimed methyl mustard oil kills nematodes and does not kill plants. The mustard oils which with methyl mustard oil allegedly comprise an homologous series kill both nematodes and plants.

The mandate of 35 U.S.C. 103 which 'has been ignored below is that “the differences between the subject matter . sought to be patented and the prior art” must be found to be obvious. Neither the examiner nor the board discussed the significant and controlling difference in ■phytotoxic properties between the claim■ed invention and the prior art. Stated in more technical terms, methyl mustard oil is not phytotoxic. The allegedly homologous members of the mustard oil family .are. When used in the soil to control nematodes this difference is critical.

The record here discloses that while the previously tested mustard oils possessed nematocidal activity, they were ■extremely toxic to plants. Certainly the -prior art teaching of a soil nematocide -which kills both nematodes and plants is mot a teaching which we think would lead one of ordinary skill in controlling .■soil dwelling nematodes to expect that a •chemically related but untried member >of a family of chemicals, all of the tested members of which are phytotoxic, would Tie an effective soil nematocide which was mot toxic to plants. The view, stated in .Ex parte Hessel, supra, that nematocidal ■activity is not predictable from insecticidal or fungicidal activity broadly, also .seems to us to be applicable here.

While in some cases an homologous relationship between a claimed compound and the prior art compounds could suggest testing the members of the homologous series for a desired effect, we think the record as a whole here teaches away from the employment of any mustard oil .as a soil nematocide. The decision of the Board of Appeals rejecting claims 1-9 as •obvious over Cupples and Frear in view •of the other references is reversed.

In addition to the foregoing rejection, appealed claims 6-8 were also separately rejected by the examiner as “lacking invention over Frear.” The board in affirming this rejection stated: “ * * * we understand that implicit in the disclosure of the methyl isothiocyanate as a fumigant is the employment of such a compound with the conventional solvents and emulsifying agents of the art.” This “understanding” seems to us to but confuse the examiner’s position. In summary that position appears to be:

“(1) since Frear shows methyl isothiocyanate to be old, appellant cannot claim a new use for an old compound, and

“(2) while claims 6-8 claim a composition of methyl isothiocyanate in solution in a solvent, solvents are conventionally employed in the compounding of pesticidal compositions.”

While we agree with the general proposition stated in (1), claims such as 6-8 to a composition cannot be disposed of on such a summary basis. In many instances very slight physical or chemical changes may be sufficient to avoid such a rejection. For example, very slight changes may be responsible for imparting new properties to the “old compound” and such changes may create a patentable new “composition of matter.” It is not sufficient to support such a rejection to rely upon some “rule” which asserts that a known compound “cannot be made patentable merely by adding thereto conventional adjuvents or carriers” as here urged by the solicitor. Each situation must be analyzed in the light of the particular facts disclosed in the record. Cf. Old Town Ribbon & Carbon Co. v. Columbia Ribbon & Carbon Co., 2 Cir., 159 F.2d 379. See also In re Riden et al., 318 F.2d 761, 50 CCPA-.

There appears to be nothing significant or critical in the particular form in which methyl isothiocyanate is used as a nematocide. Appellants’ specification states:

“Methyl isothiocyanate may be applied for the destruction of nematodes and fungi in any suitable form. It can be used either as such or in parasiticidal amounts in solutions of any desired concentration. Although the concentration of the solution may have as its upper limit the solubility of the methyl isothiocyanate in the particular solvent, it may be present in a wide range of concentrations below this limit. Thus fairly dilute solutions may be employed. The choice of solvents and concentrations is directed toward providing, in the soil to be disinfected, a minimal amount of about 15 to 20 mg. of methyl isothiocyanate per liter of soil.

“A large number of solvents may be used for the preparation of disinfectant solutions of methyl isothiocyanate, for which the only requirement is that they be inert toward this compound. * * * ”

As indicated by the above portion of appellants’ specification, methyl isothiocyanate can be used as a nematocide as such⁵ or in a solvent. The addition of a solvent is not disclosed as affecting the nematocidal properties of the known compound. The addition of solvent is not disclosed as doing anything more than to provide a convenient form for using the methyl isothiocyanate. None of claims 6-8 specify concentrations of the methyl isothiocyanate nor does the specification indicate any critical requirements in this respect. The disclosure requires only that the solvent used be “inert towards this compound.” It is therefore our conclusion that the addition of the solvent to the old compound methyl isothiocyanate in the manner disclosed by appellants does not establish a factual basis upon which to find claims 6-8 patentable as a new and unobvious composition of matter. We therefore affirm the separate rejection of claims 6-8.

In thus affirming the rejection of claims 6-8 for the composition of methyl isothiocyanate and a solvent, we do so on a factual basis and for the reason that there is no showing in the record before us that the claimed composition possesses any new properties as a soil nematocide. There is nothing in the record here to indicate that the addition of solvent had any use other than that of a carrier for the methyl isothiocyanate. Cf. In re Jan Rosicky, 276 F.2d 656, 47 CCPA 859.

In summary, we affirm the separate rejection of claims 6-8, but reverse the rejection of all claims over the prior art..

( Modified.

1 Serial No. 691,793 filed October 23, 1957.

2 . «* * *"■ It seems necessary to apply to patent litigation from time to time the maxim that one cannot make omelettes of bad eggs — no matter how many are used. One good reference is better than 50 poor ones, and the 50 do not make the one any better. * * * ” (Ball & Roller Bearing Co. v. F. C. Sanford Mfg. Co., 2 Cir., 297 F. 163).

3 . Opinion dated March 19, 1962; Patent No. 3,086,907 issued April 23, 1963.

4 . Two of the same board members participated in the Hessel decision and in the presently appealed decision.

5 . The specification states that methyl isothiocyanate “is a solid crystalline substance with a melting point of 35-37°C., and a boiling point of 118-120° 0., and hence is not a gaseous material.”