For the purposes aforesaid, the society shall possess the general powers and privileges, and be subject to the general liabilities contained in chapter 55, title 10, of the Revised Statutes of 1846, so far as the same may be applicable, and have not been modified or repealed; but the real and personal estate which the said society shall be authorized to take, hold, and convey, over and above its library and its scientific and agricultural collections, shall not, at any time, exceed in amount the value of 20,000 dollars.