In other cases the proceeding directly under consideration may be said, in some respects, to be equivocal. Such are cases of habeas corpus, mandamus, certiorari and matters of that kind. In these cases you may have to look back to see whether the matter directly under consideration is not merely subordinate or ancillary to some prior and more substantial matter, and whether the decision one way or the other, in the matter directly under consideration, does or does not affect the proceedings on or in connection with, the other and more substantial matter. If you find it does affect the prior matter, whether a proceeding in Court or not, which itself is criminal, then it may be held, and it has been held in many cases, that the proceeding directly under consideration is a criminal matter. . . . If, for example, you have an application for habeas corpus, you cannot determine straight off, simply on learning that fact, whether the matter is criminal or not. If you find that that habeas corpus relates to the imprisonment of some person who is in prison for some offence, then it would probably be held that it is a criminal matter, and if it relates to the custody of a child, apart from any question of imprisonment in the ordinary sense, it may be held to be a civil matter.