Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 59, § 2

All property, real and personal, situated within the commonwealth, and all personal property of the inhabitants of the commonwealth wherever situated, unless expressly exempt, shall be subject to taxation; provided, however, that the personal property of a person having neither his domicile nor a place of business in this commonwealth, which, upon its being brought or shipped into this commonwealth, is forthwith stored in the original packages in a licensed public storage warehouse, shall, while so stored, be deemed to be in transit and not subject to taxation under this chapter; but no portion of any warehouse which portion is owned or leased by a consignor or consignee of the personal property stored shall be deemed a licensed public storage warehouse.