No common carrier shall directly or indirectly issue or give any free ticket, free pass or free transportation for passengers except to its employees and their families, its officers, agents, surgeons, physicians and attorneys at law; to ministers of religion, traveling secretaries of railroad Young Men’s Christian Associations, inmates of hospitals and charitable and eleemosynary institutions and persons exclusively engaged in charitable and eleemosynary work; to indigent, destitute and homeless persons, and to such persons when transported by charitable societies or hospitals, and the necessary agents employed in such transportation; to inmates of national homes or state homes for disabled volunteer soldiers, and of soldiers’ and sailors’ homes, including those about to enter and those returning home after discharge; to veterans of the civil war; to necessary caretakers of livestock, poultry, milk and fruit; to employees on sleeping cars, express cars and to linemen of telegraph and telephone companies; to railway mail service employees, post-office inspectors, customs inspectors and immigration inspectors; to newsboys on trains, baggage agents, witnesses attending any legal investigation in which the common carrier is interested; to persons injured in wrecks and physicians and nurses attending such persons: provided, that this provision shall not be construed to prohibit the interchange of passes for the officers, agents and employees of common carriers, and their families, nor to prohibit any common carrier from carrying passengers free with the object of providing relief in cases of general epidemic, pestilence or other calamitous visitations: provided further, that these provisions shall not be construed to prohibit the privilege of passes or franks, or the exchange thereof, with each other, for the officers, agents, employees, and their families, of telegraph, telephone and cable lines, and the officers, agents, employees, and their families of common carriers, subject to the provisions of this act: provided further, that the term "employees" as used in this paragraph shall include furloughed, pensioned and superannuated employees, persons who have become disabled or infirm in the service of any such common carrier, and the remains of a person killed in the employment of a carrier, and exemployees traveling for the purpose of entering the service of any such common carrier, and the term "families" as used in this paragraph shall include the families of those persons named in this proviso; also the families of persons killed, and the widows during widowhood and the minor children during minority, of persons who died while in the service of any such common carrier: provided further, that nothing herein contained shall prevent the issuance of mileage and commutation tickets or excursion passenger tickets: provided further, that nothing in this section shall be construed to prevent the issuance of free or reduced transportation by any street railroad company for mail carriers or policemen or members of fire departments of any municipality or other department of the government: provided further, that it shall also be lawful for any common carrier to issue a free ticket or other form of transportation to former employees who have been in the employ of such common carrier for a period of not less than twenty (20) years and to those dependent upon such former employees.