In determining whether a partnership exists, these rules shall apply:
(1) Except as provided by article 1825, persons who are not partners as to each other are not partners as to third persons;
(2) Co-ownership or co-possession does not of itself establish a partnership, whether such-co-owners or co-possessors do or do not share any profits made by the use of the property;
(3) The sharing of gross returns does not of itself establish a partnership, whether or not the persons sharing them have a joint or common right or interest in any property from which the returns are derived;
(4) The receipt by a person of a share of the profits of a business is prima facie evidence that he is a partner in the business, but no such inference shall be drawn if such profits were received in payment:
(a) As a debt by installments or otherwise;
(b) As wages of an employee or rent to a landlord;
(c) As an annuity to a widow or representative of a deceased partner;
(d) As interest on a loan, though the amount of payment vary with the profits of the business;
(e) As the consideration for the sale of a goodwill of a business or other property by installments or otherwise. (n)