_Burden upon Physicians Treating Minors to Show Services Necessary._—But even in such cases the burden is upon the person performing the services, to show that they were necessary, and it is his duty to know, or learn, the true legal status of the patient, and the true legal relations of the patient to the person other than the patient from whom payment is to be claimed. As said in the case of Crain _v._ Baudouin (55 N. Y., 256-261), “in the case of minor children even, the law imposes this duty upon those who would furnish them with necessaries, relying upon the credit of their fathers, and seeking to charge them. (Hunt _v._ Thompson, 3 Scam., 179; Van Valkinburgh _v._ Watson, 13 J. R., 480).” “_A fortiori_, it is so in the case of an adult married daughter living with her husband.” And as to the liability of the husband of a married woman in the absence of statute giving her legal capacity to contract and charge her separate estate. Consult Moody _v._ Osgood, 50 Barb., 628; Potter _v._ Virgil, 67 Barb., 578; Crain _v._ Baudouin, 55 N. Y., 256-261. _Mother of Infant probably Liable after Father’s Death._—It has been a much disputed question whether after the father’s death the mother becomes responsible for necessaries furnished for her minor children. The theory of law upon which a father is made liable proceeds upon the ground that he is bound to support the child and has a right to the child’s services during its minority.[168] It has been held that the mother after the death of the father is entitled to those services. Campbell _v._ Campbell, 3 Stock. (N. J.), 265; Cain _v._ Dewitt, 8 Iowa, 116; Furman _v._ Van Size, 56 N. Y., 435-439, disapproving Bentley _v._ Richtmeyer (4 Comstock, 38), and approving _In re_ Ryder, 11 Paige, 185. If she is entitled to the services of her child, she must be bound to support and care for it; and so it was held in Furman _v._ Van Size cited above. _Estates of Insane Persons Liable in a Proper Case._—Persons of unsound mind are liable for necessaries furnished for their benefit, and can be made to pay therefor at reasonable and proper rates, but they cannot make contracts for a specific rate. It is always a question of fact as to what sum should be charged against their estates, if they have any. _Master Not Liable for Services Rendered Servant without Special Contract._—In the case of master and servant, while at common law as between a master and servant the master was bound to provide medicine and food for the servant when the servant was an inmate of the master’s house, this is an obligation which a third person could not enforce, and the master can only be held liable for services rendered to the servant, upon proof of a specific contract with him to pay for them.