Demarais v. Johnson Et Al‪.‬

Personal Injuries ? Master and Servant ? Motor Vehicles ? Defective Truck ? Cause of Breakdown ? Expert Witnesses ? Opinion Evidence ? When Admissible, When not ? Duty of Master as to Appliances ? Erroneous Instructions. Evidence ? Expert Witnesses ? When Opinion Evidence Admissible. 1. While, as a general rule, a witness must state facts, not opinions or conclusions, where he possesses special skill or knowledge of the subject matter under investigation and the facts are such that inexperienced persons are likely to prove incapable of forming a correct judgment without the assistance of the opinion of such a witness, his opinion is admissible in evidence. Personal Injuries ? Master and Servant ? Defect in Autotruck ? Cause of Breakdown ? Opinion of Expert Admissible ? When Inadmissible. 2. In an action by a truck driver against his employer for injuries sustained, in which the negligence alleged consisted of the failure of the employer to remedy a defect in the truck after his attention had been called to it, with the result that a wheel collapsed while plaintiff was driving the machine, held that the opinion of an automobile mechanic of experience that the cause of the collapse was due to the spokes in the wheel being loose was properly - Page 367 admitted, but that, while it would have been proper for the witness to state by what methods the defect could have been discovered, his further answer to a hypothetical question that it could have been discovered by a reasonable inspection was incompetent, the jury having been as able to determine that from a recital of the facts as was the witness. Same ? Master and Servant ? Instructions ? Extent of Duty of Master in Furnishing and Keeping Appliances in Condition. 3. Instructions that it was defendant employers duty to provide his employee with a reasonably safe and secure truck with which to work, and to keep it in a reasonably safe condition, were erroneous, his duty in that behalf being discharged if he exercised reasonable care in doing either.