Mass. Gen. Laws ch. 29, § 40: Trust deposits with state; form; investment

Section 40. No deposit required to be made by any corporation in trust with the state treasurer, or any part thereof, shall consist of a mortgage upon real estate or of a loan upon personal notes or of notes secured by collateral. The state treasurer may receive, as a part of such deposit, money or certificates of deposit, or certified checks on any approved state depositary, and may hold the same without interest until it may reasonably be invested in a proper legal security.