1. The testimony of Sleeper was rightly rejected at the stage of the trial at which it was offered; for it then had no apparent relevancy to the case of the plaintiffs. The fact that the gas escaped into the Sumner block did not, of itself, tend to prove that it also escaped into the plaintiffs’ house, on the opposite side of the street; and the fact that the agent of the defendants was negligent as to the Sumner block did not, of itself, tend to prove that he or any one else was negligent in *148respect to the plaintiffs. If the plaintiffs had other evidence to offer which might make this testimony relevant, it was within the discretion of the court to reject this until the other should be put in; the order in which the evidence shall be offered in such a case, being subject to the control of the presiding judge.
2. The testimony of Dr. Bass as to his experience relative to the breathing of burning gas could have no relevancy to the case, except as it might tend to show that he was an expert. It was for the presiding judge to decide whether he was proved to be an expert, and the evidence on that point was addressed tó him, and not to the jury. If he was excluded, no part of his testimony tending to prove him to be such should go to the jury. This court may correct any error in the admission or rejection of evidence on this point, and also in the decision of the judge to admit or reject an expert, so far as it is an error in law. The testimony offered as to Dr. Bass was, that he was a physician, and as such had witnessed the effects of the gas which escaped from the defendants’ pipes at the time when the plaintiffs allege that they were injured. The persons whom he saw lived in another house in the neighborhood. The mere fact that he was a physician would not prove that he had any knowledge of gas without further proof as to his experience; for it is notorious that many persons practise medicine who are without learning; and a physician may have much professional learning without being acquainted with the properties of gas, or its effect on health. And the observation of a man who is at the time inexpert is of.no value, and does not qualify him to give opinions. The court are of opinion that the testimony of Dr. Bass was rightly rejected.
3. Dr. Huntoon’s testimony was also rightly rejected; though, in addition to the fact that he was a physician, it appeared that he had been in practice for several years. But mere practice as a physician did not of necessity give him any knowledge as to gas. His statement of what the plaintiffs told him would not have been evidence if he had been an expert. It could not be admitted as res gestee, but was the recital of past events.
4. One who is an expert may not only give opinions, but *149may state general facts which are the result of scientific knowledge, or professional skill. As it was admitted that Professor Horsford was an expert, the questions put to him and his answers were admissible on this ground.
Exceptions overruled.