862 FEDERAL REPOUTEB. �have corne of the negligence of the plaintiff. Indeed, the evidence points to that conclusion, and the explosion which followed was the natural resuit, of which plaintiff should have been informed; or, at all events, defendant was under no duty to inform him. This is the argument against the verdict. And certainly, within limita, the law will assume that every one has knowledge of destructive forces in the ■world and the powers of the earth and air. Of such is the knowl- edge that cornes to every man of sound mind, in the ordinai-y course of his life, that fire will burn ; that water will drown ; that one may fall off a precipice; and the like. Eecently in this court it was said of one who mounted a push car on a railroad, and went down a steep grade, to his hurt, that, knowing the grade, it was his own folly not to heed the law of gravitation ; because it is known to all men of Sound mind and of all degrees of intelligence that wheeled vehicles go down hill with increasing speed if left to themselves. And in this case the jury was told that the plaintiff could not have recovered for a burn caused by spilling the slag on himself. But the explosive power of hot slag when cast into water is not within the intelligence of ordinary men. It is doubtful whether many people of education know the force and violence of such an explosion ; and, if fully in- formed, how many of them, when put to service at a smelting fur- nace, would recall their learning without a suggestion from some source. �What the law will presume as to the knowledge of men in matters of this kind, may, in some instances, be a question of difficulty, and certainly it would not be easy to lay down a general rule on the sub- ject. In the face of the plaintiff's testimony, however, to the effect that he had no knowledge or information of the danger to which he was exposed, it would be manifestly unjust in this instance to hold, as matter of law, that he hud notice of it. �After all, it is not so much a question whether the party injured has knowledge of all the facts in his situation, but whether he is aware of the danger that threatens him. What avails it to him that all the facts are known if he cannot make the deduction that peril arises from the relation of the facts ? The peril may be a fact in itself of which he should be informed. So, in Coombs v. New Bedford Cordage Go. 102 Mass. 573, the machinery which caused the injury was open to view, and probably it was seen by the party injured. But the danger of the position was not explained, as was necessary for the protection of one who had no knowledge of it. In another case in the same court the rule was applied to an adult person who ��� �
