The admission by a party to the record shall be admissible in evidence when offered by the other side, except in the following cases:

(1) Admissions of a mere nominal party or naked trustee;

(2) Admissions of one of several parties with no joint interest, unless the issue is of such a character that the effect of the admission can be confined to the one party alone;

(3) Admissions of a trustee before he is clothed with the trust;

(4) Admissions of defendants in execution in claim cases, after the pendency of litigation.