Section 6. Such corporation may cremate bodies of the dead, and may provide necessary buildings and appliances therefor and for the disposition of the ashes of the dead on any land within its cemetery which the department of environmental protection determines is suitable therefor, subject to the provisions of section forty-three D, and such buildings and appliances shall be a part of the cemetery and be dedicated to the burial of the dead, and shall be held by said corporations subject to the duties, and with the privileges and immunities, which they now have by law.