Of surgeons and apothecaries, [15], [16].

Of physician and surgeon, [16].

In Scotland and the Colonies, [17].

In America, [17].

No express promise to pay necessary, [18].

How fixed, [18], [19].

Must be reasonable, [19].

In some countries fixed by law, [19].

Services of assistants, [20].

Not dependant upon cure, [20], [21].