As the majority opinion recognizes, the function of the description of the invention requirement of 35 U.S.C. § 112, first paragraph, is to insure that an inventor had possession of the claimed subject matter as of the filing date of his application.
Appellants’ parent application states that their invention involves “a new class of polyols”; also, it teaches use of the “entire crude Mannich reaction product” (“without attempting to isolate the individual components thereof”) as the preferred embodiment of the invention in the further reaction with alkylene oxide to form polyol compounds within that class. From this disclosure, I am persuaded that one skilled in the art would conclude that appellants were not concerned with any specific polyol compound. Indeed, practice of the preferred embodiment of the invention would yield mixtures of polyol compounds.1 (This does not ignore the statement in appellants’ parent application that it is within the scope of the invention to separate the crude *1355reaction product. However, merely being “within the scope of the present invention” provides no guidance to convey clearly to one skilled in the art that appellants were in possession of the presently claimed subject matter; whereas, a preferred embodiment is a reliable guide, as the majority opinion appears to acknowledge.)
I do not see how the majority can properly conclude that, “on the facts of this case, an adequate description of the reactions [Mannich reaction and further reaction with alkylene oxide] is, concomitantly, an adequate description of the claimed compound,” considering that the preferred embodiment in the parent application would yield an almost infinite number of different mixtures of polyol compounds. At best,2 one of ordinary skill in the art, looking at the parent’s claim 2 and example III on which the majority relies, would only be guided to a mixture of polyol compounds— not to the specific claimed polyol compound.3 Nor can I accept the majority’s conclusion that disclosure of from 1 to 5 moles “provides adequate direction [to one skilled in the art] for using three moles of propylene oxide in example III.” There is nothing in appellants’ parent application that would lead one to select 3 moles, rather than 1, 2, 4, 5, or the fractions thereof. The majority’s assertion that “we will assume that exactly 3 moles of propylene oxide per mole of MRP is required to produce the compound of appealed claim 3” has no evidentiary support in the record.4
The majority opinion fails to explain why or how the mere disclosure of a mole range of a reactant that would result in the formation of an almost infinite number of different mixtures of polyol compounds, depending upon the number of moles of reactant chosen, provides an adequate description in this case, while the disclosure of at least 19 possible amine reactants in In re Ruschig, 379 F.2d 990, 54 CCPA 1551, 154 USPQ 118 (1967), and the naming of a number of possible substituents, in Flynn v. Eardley, 479 F.2d 1393, 178 USPQ 288 (CCPA 1973), and Fields v. Conover, 443 F.2d 1386, 58 CCPA 1366, 170 USPQ 276 (1971), did not. Absent an explanation, the decision of the board should be affirmed.
. It should be noted that claim 1 (also dependent claim 2), for example, recites “polyol.” However, the claims actually are to polyol compounds.
. Also noteworthy is the lack of direction (to one skilled in the art) of how to select the correct phenolic compound as an initial reactant. Appellants have admitted that some experimentation would be involved. Thus, although the enablement requirement of 35 USC 112 might be satisfied, the description of the invention requirement is not. In re DiLeone, 436 F.2d 1404, 58 CCPA 925, 168 USPQ 592 (1971).
. The majority improperly assumes that one skilled in the art would find appellants’ parent application directed to individual polyol compounds and that, therefore, a disclosure of a range of from 1 to 5 moles of alkylene oxide reactant would result in the formation of only five compounds. This ignores the fact that the preferred embodiment of the parent application calls for the entire crude Mannich reaction product which, upon further reaction with alkylene oxide, would yield an almost infinite number of different mixtures of polyol compounds.
. Although the Solicitor appears to admit that reaction of 3 moles of propylene oxide with the appropriate Mannich reaction product will yield the claimed compound, neither the examiner nor the board did so, and no disclosure in appellants’ parent application supports such a conclusion. The board, in discussing the issue of appellants’ claim to the benefit of section 120 (and appellants’ satisfaction of the requirement of section 112), referred to combining propylene oxide “in an amount sufficient to obtain the pentol of claim 3,” and the examiner referred to a product containing 3 moles of propylene oxide.