L. HAND, Circuit Judge

(after stating tho facts as above). We do not find it necessary to say whether the substitution of phenolphthalein for cascara in a laxative chewing gum would be an invention. Perhaps not, however great the success when it appeared. Again, we do not find it necessary to say whether, if that substitution be an invention, the claim in suit will cover a gufn in which the laxative is not mixed in during manufacture, but is dusted upon the outside and held in place by an outer layer of sugar. Given an adequate disclosure of one way to practice the invention, perhaps the underlying notion might be generalized so far. Granting to the appellant favorable answers to both questions, we think, not that the invention is inoperative in tho sense that it cannot be practiced at all, for the plaintiff has proved that it can, but that the specifications do not disclose how the drug can he mixed so as to insure its release. It is scarcely necessary to labor the principle that specifications must be more than a suggestion for promising experiment, hit or miss. They must contain complete directions, leading with certainty to the result. Matheson v. Campbell, 78 F. 910, 916 (C. C. A. 2); Hemming Mfg. Co. v. Cutler-Hammer Mfg. Co., 243 F. 595 (C. C. A. 7); Leonard v. Maxwell, 252 F. 584, 590 (C. C. A. 2); Electro-Dynamic Co. v. United States L. & H. Corp., 278 F. 80, 84 (C. C. A. 2).

Tho plaintiff attempts to discredit the defendant’s proof that obedience to the disclosure will not produce a laxative gum, by appealing to the well-known reluctance of courts to place much weight upon ex parte experiments. Kuehmsted v. Farbenfabriken, 179 F. 701, 709 (C. C. A. 7); Rynoar v. Evans (C. C.) 83 F. 696. The reasons which justify that reluctance do not extend to what is done ante litem motam, when there is no motive to fabricate. Gordon ma'de two efforts to make a phenolphthalein chewing gum in 1917, long before the Sulzberger patent was being exploited, and when, so far as appears, he had no reason to fear it. He failed in each case, and succeeded only when he adopted the present commercial practice of both the parties here. He had no common interest with the defendant, and was a qualified chemist in the employ of tho American Chicle Company. We see no ground to discredit his testimony, or his efforts, except that he would not tell upon the stand all the gums which he used in his base, that being a trade secret. It would, however, be extravagant to seize upon that as a reason for doubting that the base was a genuine chewing gum, as it certainly was. If it contained gums which combined with the drug, but which gum makers might add, not gratuitously or disingenuously, Sulzberger gave no intimation of them, as he should have. Else how was a maker to know what to omit from his formula? As it read, the disclosure was general; if it was applicable only to some species of gums, no one could tell which.

Davis, also a gum maker, made a similar trial long before he could have had any motive to prove it unsuccessful, and this also was a failure. So far as appears, there was nothing peculiar in his gum, and x>erhaps the trouble was in the tenrperature of the mix. Surely we ought not to discredit his testimony on any score, and it shows that there is more in .the art than what Sulzberger ever knew.

The trials of Kiss are indeed subject prima facie to the suspicion generally felt in such eases, but they are not for that reason to be wholly ignored. Putt, the plaintiff’s export, gives tho probable explanation of Kiss’s failure, without assuming that he wanted to fail. Chewing gum is a complex organic solvent for other organic compounds, such as phenolphthalein. Care must bo taken lest the two combine chemically, after which the saliva will not extract tho drug, however gallantly one may chew. Perhaps the result depends upon the temperature of the mix; perhaps on other factors. It is enough to break tho force of the objection that the plaintiff has itself given an explanation consistent with good faith in the experiment. Moreover, even if we attribute bad faith to Kiss, because of knowledge acquired outside the patent, at least it is apparent that, unless we should impute that knowledge to gum makers as such, the disclosure was not adequate.

*288 Putt, it is trae, says that any one could have corrected all difficulties by two days of experiment, if he had had adequate facilities, and upon this we are urged to apply what we said in Dick v. Barnett, 288 F. 799. We agree that a patentee is entitled to expect those who follow his teaching honestly to try to reach his result. Certainly they may not blind their eyes to his obvious omissions or errors. Nevertheless the law demands of them little imagination, and a patentee may not ground his monopoly upon mere cues for promising experiment. This consideration is especially important in the case at bar. These specifications are not addressed to pharmacists, but to gum makers, men charged with knowledge of that art, but not with the chemical affinities of phenolphthalein. In the laboratories of great manufacturers, indeed, there may be men versed in both arts; but the specifications must be enough for lesser folk as well. It appears to us quite unwarranted to assume that every one, though a competent gum maker, would by simple trials learn the cause of his failure and the means of its correction. Rather, it is extremely probable that Sulzberger himself had no notion that there were any difficulties at all. His grouping of all laxatives generally in one class, and his addition of any other drugs one chose, strongly suggest that he ignored the chance of chemical affinities which would tie up the active agents. It seems to us incredible, if he had, that he should have given no clue to so essential a part of his practice. We agree with Judge Moseowitz that the disclosure of a gum and drug mix was insufficient.

If so, plainly there was no disclosure of the actual commercial practice. Even if the claim covers the practice, the practice will not support the claim. Indeed, the disclosure not only fails to give even an inkling of the practice, but so far directs attention to the mix as to make it doubtful how far the claim will stretch.

Decree affirmed.