§842.  Responsibility for unlawful acts

No officer or member of any association or organization, and no association or organization participating or interested in a labor dispute, as these terms are herein defined, shall be held responsible or liable in any civil action, or in any criminal prosecution, for the unlawful acts of individual officers, members, or agents, except upon proof by the weight of evidence and without the aid of any presumptions of law or fact, of the doing of such acts by persons who are officers, members or agents of any such association or organization and the ratification of such acts after actual knowledge thereof, by such association or organization.