privilege of doing the necessary acts; or conversely, he is under a duty to Y not to do what is necessary to exercise the power.
In view of what has already been said, very little may suffice concerning a liability as such. The latter, as we have seen, is the correlative of power, and the opposite of immunity (or exemption). While no doubt the term "liability" is often loosely used as a synonym for "duty," or "obligation," it is believed, from an extensive survey of judicial precedents, that the connotation already adopted as most appropriate to the word in question is fully justified. A few cases tending to indicate this will now be noticed. In McNeer v. McNeer,[1] Mr. Justice Magruder balanced the conceptions of power and liability as follows:
So long as she lived, however, his interest in her land lacked those elements of property, such as power of disposition and liability to sale on execution which had formerly given it the character of a vested estate.
In Booth v. Commonwealth,[2] the court had to construe a Virginia statute providing "that all free white male persons who are twenty-one years of age and not over sixty, shall be liable to serve as jurors, except as hereinafter provided." It is plain that this enactment imposed only a liability and not a duty. It is a liability to have a duty created. The latter would arise only when, in the exercise of their power, the parties litigant and the court officers, had done what was necessary to impose a specific duty to perform the functions of a juror. The language of the court, by Moncure, J., is particularly apposite as indicating that liability is the the opposite, or negative, of immunity (or exemption):
The word both expressed and implied is "liable," which has a very different meaning from "qualified" * * *. It's meaning is "bound" or "obliged" * * *. A person exempt from serving on juries is not liable to serve, and a person not liable to serve is exempt from serving. The terms seem to be convertible.
A further good example of judicial usage is to be found in Emery v. Clough.[3] Referring to a gift causa mortis and the donee's liability to have his already vested interest divested by the donor's exercise of his power of revocation, Mr. Justice Smith said:
The title to the gift causa mortis passed by the delivery, defeasible only in the lifetime of the donor, and his death perfects
