delivered the opinion of the court:
This is an appeal from the decision of the Board of Appeals affirming the examiner’s rejection of claims 4 and 5 in appellant’s application,1 for “High Temperature Compositions.” The board’s affirmance of the examiner’s action is based on its conclusion that the appealed claims are “based upon a disclosure which does not comply with the first paragraph of 35 U.S.C. 112 and Buie 71(b).” This conclusion is assigned as error in appellant’s notice of appeal.
Appellant’s invention relates to metallic compositions which are characterized by high melting points and resistance to oxidation and abrasion at elevated temperatures. In this regard appellant has produced a solid solution of silicon and a metal selected from a group consisting of uranium, molybdenum, chromium, tungsten, zirconium, and titanium by heating a powdered mixture of the two materials *836until an exothermic reaction occurs to produce a metallic disilicide.2 The metallic disilicide, more particularly the molybdenum disilicide, may be fabricated into shaped objects by various methods of powder metallurgy, among which is the so-called hot press method. Under the hot press method the metallic disilicide, in powdered form and after other preparatory treatments, is:
* * * pressed to the shape desired by the use of graphite form molds. The temperature used for hot pressing may vary between 2600° F and 3100° F. Because of commercial limitations it is more practicable to use temperatures within the range of 2700° F to 3000° F.
The pressure used for hot pressing may be varied generally from 500 to 7000 pounds per square inch depending upon the strength of the graphite dies and the temperature used for pressing. The relative brittleness of the disilicide, however, increases with increase in the applied pressure to the maximum allowable with the graphite dies. It is therefore more desirable to use pressures near the mean of the pressure limits for reasons of cost as well as less brittleness. * * *
Other uses for the metallic disilicide are also disclosed. Thus, the disilicides are stated to be useful in the making of alloys with other metals and as a binder for materials such as beryllia and alumina. With respect to the use of disilicide as a binder material, which is the subject matter of the appealed claims, appellant’s application contains the following disclosure:
The use of molybdenum disilicide as a binder metal for very-high temperature applications (3000° F to 5000° F) with such compounds as beryllia, alumina, and the metal carbides is practical.
Tests were run using BeO (Beryllia) and A2 (⅛ [sic] (Alumina.) Samples containing up to 25 percent of molybdenum disilicide were hot pressed at a temperature above that of the disilicide. The compacts were then heated in air in an induction furnace to temperatures in excess of 3800° F. Little effect was noted on the samples and the use of this type of “ceramal” for very high temperature use looks promising.
With the above background we turn now to the claims on appeal. Appealed claim 4 reads:
4. As an article of manufacture, a body characterized by relatively high re-fractoriness, resistance to corrosion and abrasion consisting essentially of particles of material from the class consisting of beryllia and alumina, and including, as a binder, a material from the class consisting of sintered powdered particles selected from the group consisting of particles of disilicides of uranium, molybdenum, chromium, tungsten, zirconium and titanium powdered substantially 100 percent to particle sizes less than 25 microns, said metallic binder being present from an amount sufficient to bind the particles of alumina and beryllia together up to about 25 percent of the weight of the body.
Claim 5 differs from claim 4 in reciting the use of sintered powdered particles of molybdenum disilicide binder for beryllia and *837alumina. The examiner’s final rejection, refusing claims 4 and 5 as based on an insufficient disclosure, stated:
The specification fails to comply with Rule 71(b) which requires a complete description of a specific embodiment of the invention. The Rule also requires that the best mode contemplated by the inventor of carrying out the invention he [sic] set forth. There is in the disclosure no example of a composition containing a metal disilicide, and beryllia or alumina nor is there any example of a method by which such compositions may be prepared. The first two paragraphs on page 24 do not constitute a working example of the alleged invention since the composition of the test samples is not specified nor are the process conditions given. The phrase “hot pressed at a temperature above that of the disilicide” is without significance since it does not specify the temperature and pressure required to produce the desired article.
The Board of Appeals expressed agreement with the examiner’s rejection of the claims but cited the first paragraph of 35 USC 112 as well as Buie 71(b) mentioned by the examiner. The essence of the board’s reasoning is stated as follows:
The very meager disclosure in the first two paragraphs of page 24 of appellant’s specification provides no basis for the present claims and appellant’s contention that a skilled metallurgist could without undue experimentation practice the invention is not convincing for even the very characteristics desired in the claimed product are not sufficiently delineated either in the specification or in the claims. ⅜ * *
Thus, although the examiner’s final rejection is based on the lack of a complete description of a “specific embodiment” and “the best mode contemplated by the inventor of carrying out the invention” under Rule 71(b), the board’s decision states a reason for rejecting the claims which calls into operation that portion of the first paragraph of 35 USC 112 which is restated in Rule 71(a). In view of the fact that the first paragraph of 35 USC 112 is included in the assigned reason of appeal in the notice of appeal and further, in view of the fact that the briefs of both parties extensively discuss the first paragraph of 35 USC 112, we will treat the rejection as based on 35 USC 112 and 71(b).
As we have clearly indicated in In re Gay, 50 CCPA 725, 309 F. 2d 769, 135 USPQ 311, there is no statutory antecedent basis for the “specific embodiment” requirement of Rule 71 (b) except insofar as it implements the first paragraph of 35 USC 112. Rule 71(a) requires a written description of the invention in such terms as to enable any person skilled in the art to make and use the invention. We do not equate the terms “specific embodiment” of Rule 71(b) and the “best mode contemplated” of 35 USC 112. In re Gay, supra, If by “specific embodiment” is meant a working example, then the same is not required where sufficient working procedure has been set forth showing that one skilled in the art may prepare the claimed article without undue experimentation. In re Honn, 53 CCPA 1469, *838364 F. 2d 454, 150 USPQ 652. The absence of a working example, denominated as such, does not compel the conclusion that a specification does not satisfy the requirements of 35 USC 112 or Rule 71(b), In re Bosy, 53 CCPA 1231, 360 F. 2d 972, 149 USPQ 789. Wo emphasize that the specification as a whole must be considered in determining its sufficiency and that such consideration must necessarily depend on the facts of each case. In re Honn.
After a careful study of the facts in this case, we are of the opinion that the claims are sufficiently supported by the description contained in the specification as a whole. The two paragraphs in the specification, quoted above, relating to the use of molybdenum disilicide as the binder for beryllia and alumina should not be read in vacuo without regard to the surrounding disclosure as to the method of making and -using the metallic disilicide. When these two paragraphs are considered in light of the disclosure as a whole, we believe that they would- teach a person skilled in the art how to make and use the-claimed article without undue experimentation. In re Bosy.
The-examiner objected to the disclosure in that it failed to specify the tninimnm amount of molybdenum disilicide required to bind the-oxide together. We note, however, that the disilicide binder is specified to be present in an amount from that sufficient to bind the oxide particles to about 25 percent of the weight of the entire article. We are of the view that the minimum amount of disilicide required to bind the oxide particles together can be determined by a skilled metallurgist without an undue amount of experimentation.
The examiner also objected to the disclosure as to the temperature- and pressure to be employed in producing the claimed article. We-note that the quoted portions of the specification show the use of ⅞ temperature above that employed for hot pressing the pure disilicide. The temperature for hot pressing the disilicide is disclosed to be between 2600° F and 3100° F. In addition, the test temperature of 3800° F for the claimed articles is indicative of a value above the-maximum production temperature contemplated. The application reveals that the practical limits of pressures employable for the hot-pressing method appear to be from 500 to 70000 pounds per square-inch. The disclosure relating to the pure disilicide indicates that the pressure to be employed would depend on the strength of the graphite dyes and the temperature used for pressing. Moreover, it-is additionally disclosed that the brittleness of the disilicide increases-, with increase in the applied pressure and, therefore, it is desirable-to use pressures near the mean of the pressure limits.
We are of the view that there is sufficient working procedure in the-specification to enable a skilled metallurgist to make and use the claimed article without an undue amount of experimentation.
*839For tlie foregoing reasons, the decision of the board is reversed.
Judge Martin participated in the hearing of this case but died before a decision was reached.