Opinion by

The plaintiff gave evidence of the falling off of his custom concurrently with defendants’ beginning to use the trade-mark, and claimed that the former was the consequence of the latter. It is difficult to see how else he could prove his loss, for. he could not follow Ms customers individually and testify where they went to buy when they ceased to come to Mm. The inference was for the jury. In the language of the logicians he proved the sequence of the events, and it was for the jury to say whether the deduction from post hoc to propter hoc was rightly drawn. The learned judge left it to them with a very full caution, accompanied by illustrations, that a diminution of sales might be due to very many causes. This was as much as defendants were entitled to ask.

The second and third assignments of error are to the affirmance of plaintiff’s points, allowing the jury to infer a fraudulent intent to sell defendants’ goods as those of the plaintiff, from the use of the name and the label. These points must be considered in connection with the admitted facts. Defendants not only used the name wMch plaintiff had adopted but also the exact pictorial representation of the article. It was not an accidental resemblance but an admittedly intentional copy, the *85defendants’ excuse being that they supposed tbe name was a merely descriptive one which any one might use, and as to the picture, that there was a custom of the trade for dealers to “borrow” each other’s cuts for advertising purposes. This explanation may be entirely true, and what defendants did they may have done ignorantly and innocently, but their acts were susceptible of a different interpretation (see Taylor v. Carpenter, 11 Paige, 292; 2 Sandf. Ch. 603) ; and it was for the jury to say what was their true intention. The judge could not have taken this question from them, nor could he have instructed them that such a custom if proved would be a defense. No custom of other people even in the same trade can excuse one man for taking another’s property without his consent. The effect of the affirmance of these points was not as appellants argue to sweep away their defense, but only to put their actions in the two aspects claimed by them and by the plaintiff respectively before the jury for them to decide. In this there was no error.

The remaining assignments of error are based on the refusal to affirm defendants’ points relative to the title “ Burgess ” as a merely descriptive word not susceptible of appropriation as a trade-mark. There was however a radical defect in each of these points which prevented its affirmance, and that was the complete disregard of the admitted facts of the case. The plaintiff with the aid of a physician invented the instrument, and although he did not, and perhaps not being the sole inventor could not, patent it, he did adopt and attach the name of his partner Burgess to distinguish his make of atomizer, and invented and used a certain pictorial representation of it for the same purpose. It appears that it is an imperative rule of ethics, enforced as a by-law of the College of Physicians of Philadelphia, and highly honorable to the medical profession, that a physician who discovers a remedy, or a surgeon who invents or improves an instrument, does not take a patent or a trade-mark for it, but dedicates it at once to the service of humanity, and though it may become known by his name it is nevertheless free for all to use, and the name is regarded as merely descriptive of the article. It was defendants’ error or misfortune to have assumed that the present was such a case, and to have used the name accordingly. Plaintiff, however, *86is not a physician but an inventor and instrument- maker, and testified that he gave his invention the name of. his partner, Burgess, to identify it,, and because it was also at that time attached to a pump and air compressor made by him- and his partner, which worked on a similar principle and was also called the Burgess. Defendants seek to avoid the consequences of their mistake of fact (assuming that it was innocent, though the jury have found otherwise) by showing that other dealers made the same mistake, and their points asked the judge to say that under the circumstances plaintiff could not appropriate a descriptive name of this kind as a trade-mark. Cases are cited to this effect, which need not be discussed specially, as the principle is unquestionable. As said by Wallace, J., in Leclanche Battery Co. v. Western Electric Co., 23 Fed. Rep. 276, “ when an article is made that was theretofore unknown, it must be christened with a name by which it can be recognized and dealt in, and the name thus given it becomes public property, and all who deal in the article have the right to designate it by the name by which alone it is recognizable.” This is indisputable, but it does not follow that all proprietary names thereby become merely descriptive of the kind of ■ article. The presumption is to the contrary. Regard must be had to the purpose of the title adopted. If in addition to the designation of the article it is meant also to indicate the manufacturer, then it has the essential element of a trade-mark and does not become public property. Thus when Daguerre made his great discovery of the means of producing permanent pictures by the agency of light they were called Daguerreotypes, and that name of course became public property because it was the only name by which the things were known. But if he had opened a gallery and called his productions L. J. M. Daguerre’s sun pictures or any similar name, no one could have doubted that while the designation sun pictures might become public property yet the inventor had not parted with his exclusive right to the use of his own name in connection therewith. And it would have been no excuse for an infringement by another producer, that he thought the name of Daguerre was a mere descriptive word to distinguish the kind of pictures from talbotypes, ambrotypes, photographs and other kinds of sun pictures which followed rapidly in the path of the original discovery. *87Practically this was all the defense made by appellants in the present case. The theory on which their case was defended and their points drawn, if it proved anything proved too much, for its line of reasoning would deprive every inventor or maker of the use of his own name as a trade-mark. If the plaintiff instead of using his partner’s name, Burgess, had selected that which most accurately and exclusively indicated his rights, and called his invention J. Elliot Shaw’s atomizer, defendants’ points would have required the judge to charge the jury that an infringement could be justified on the ground that the defendants and other dealers understood J. Elliot Shaw to be the surgeon who invented the instrument and his name a mere descriptive title to-distinguish that particular form of atomizer from other kinds.. A man’s property is not to be taken away so easily.. The descriptive name of the instrument was an atomizer. That was public property and could not be appropriated as part of a trademark by any one. But when the inventor and manufacturer of a new kind of atomizer put his own or his partner’s name to it. the presumption was that he did so to indicate its origin and maker, and intended the name as a trade-mark. That defendants and some other dealers misunderstood the facts was not sufficient to excuse a violation of plaintiff’s rights, or to justify the affirmance of points which would have been equivalent to. a direction to find for defendants.

The last point of defendants was objectionable for another reason. It asked the judge to say that if defendants did not so use the name as to deceive the public the plaintiff could not recover. It is not necessary that the public should be actually deceived in order to afford a right of action. All that is required is that the infringement should have a tendency to deceive. The gist of the action is the intent to get an unfair benefit from another’s trade. Actual deception of the public is only material to the question of damages. On that matter, there-was not only the use of the name Burgess but also, the admitted, imitation of the label or wrapper. The case was properly left, to the jury.

Judgment affirmed.