The nature and effect of the second contract as alleged and claimed by the defendant is, therefore, borne out by the writing itself, to the exclusion of the interpretation claimed by the plaintiff and upon which the efficacy of its demurrer depends. Valente v. Chieppo, 97 Conn. 719, 723, 117 A. 801. Moreover, the defenses are to be tested, on demurrer, not only by the writing itself, but also by the facts which are provable under their allegations and which elucidate the making and the meaning of the writing. Mills v. Roto Co., 104 Conn. 645, 647, 133 A. 913; Blakeslee v. Water Commissioners, supra, p. 649.

Additional pleadings are not necessary where the facts relied upon can be proved under a general denial of the allegations of the complaint. Valente v. Chieppo, 97 Conn. 719, 723. Whether the plaintiff was the charitable beneficiary of the defendant depends upon evidence to be offered upon trial. The rule as to the defense of charitable immunity in relation to a patient of a hospital is set forth in the cases following: Hearns v. Waterbury Hospital, 66 Conn. 98; Edwards v. Grace Hospital Society, 130 Conn. 568; Evans v. Lawrence Memorial Associated Hospitals, Inc., 133 Conn. 311; Parowski v. Bridgeport Hospital, 144 Conn. 531; Martino v. Grace-New Haven Community Hospital, 146 Conn. 735. If any facts provable under the special defense would support the special defense, the demurrer must fail. Cashman v. Meriden Hospital, 117 Conn. 585, 586. This is sufficient reason for overruling the demurrer, but further support in this respect is found in connection with the remaining ground of the demurrer.