Opinion by

This is an appeal from a judgment entered for want *551of a sufficient affidavit of defense. Suit was brought against the defendant as surety upon a bond given to secure the faithful performance of a contract to furnish labor and materials for the construction of a reservoir. The action was brought in Cumberland County, where the work was to be performed. The office of the defendant, and its principal place of business, is in Pottstown, Montgomery County, and the writ was served by the sheriff of that county, who was deputized for the purpose by the sheriff .of Cumberland County. This procedure was under the Act of Assembly of March 22, 1911, P. L. 23, entitled “An act relating to suits against corporations, upon bonds in which they have become surety, and the service of process in connection therewith.” The contract in this case was made prior to the passage of the act, and for that reason it is contended that this suit does not come within the provisions of the statute. It will be noticed that in the. title the reference is to bonds upon which the corporations “have become surety,” and this we think indicates the legislative intent that the act shall apply to any suit brought upon a bond which had been issued at the date of its passage. Nor do we find anything in the body of the act which necessarily conflicts with this indication. The general rule of construction that legislation is to be given retroactive effect only when its language clearly requires such construction, is not questioned. But an exception to that rule obtains as to enactments which effect only procedure and practice of the courts. “No person has a vested right in any course of procedure, nor in the power of delaying justice, or of deriving benefit from technical and formal matters of pleading. He has only the right of prosecution or defense in the manner prescribed, for the time being, by or for the court in which he sues; and if a statute alters that mode of procedure, he has no other right than to proceed according to the altered mode. The remedy does not alter the contract or the tort; it takes away no vested right:” *552Endlich on Interpretation of Statutes, 285. Another statement of the principle is this: “Statutes which are designed to change the mode of judicial procedure, where such change relates to the method of enforcing a right and does not affect the right itself, are construed to apply to causes of action which accrued before enactment as well as to those to accrue thereafter:” 26 Am. & Eng. Ency. Law (2d Ed.) 695. The purpose of this statute was purely remedial. It affected in no way any vested right of the defendant. It is in substance merely an extension to those wishing to bring suits against surety companies of the same convenient provisions for service of process that have been available for years in bringing suits in the county where the liability arises, against fire, life and accident insurance companies. We regard the statute as applicable to this case, and we think that the court below was entirely justified in refusing to set aside the service of the writ.

As to the application for change of venue, its foundation disappears in view of the findings of fact in relation thereto by the trial judge.

This leaves for consideration only the action of the court in entering judgment for want of a sufficient affidavit of defense. The action is assumpsit, and the claim is based upon a breach of contract. In the statement of claim it is averred that the plaintiff entered into a contract with certain persons by which they were to furnish labor and materials to construct a reservoir. That the defendant company became surety upon the bond of the contractors for the faithful performance of the work. That the work was not performed in accordance with the contract, and plaintiff after notice to the contractors to complete the work in accordance with their agreement, and their refusal to do so, had the work done at the lowest price obtainable, which was ten thousand dollars, which sum was paid by plaintiff. Thereupon the condition of the bond was broken, and the defendant as surety thereon became liable for the full amount of the *553bond, eight thousand dollars, that being less than the amount paid by plaintiff to secure the completion of the work. To the statement was appended a copy of the bond itself, with the contract thereto attached. If the defendant wished to prevent judgment, it was then bound to file in answer to this statement, a sufficient affidavit of defense: Philadelphia & Reading R. R. v. Snowdon, 166 Pa. 236. The paper filed by defendant, which it styled an affidavit of defense, is in no sense worthy of the term. It amounts to nothing more than a general denial that the contractors violated the provisions of the contract actually made between them and the plaintiff. This was not sufficient. The affidavit should specifically state facts which constitute an adequate defense. An affidavit which is merely argumentative, or which contains only inferences or conclusions of law, is bad. “It is too well settled to need citation of authorities that the affidavit must contain all the facts necessary to make a legal answer to the claim, and that their omission cannot be supplied by possible inferences :” Class v. Kingsley, 142 Pa. 636. Nor is it sufficient to aver merely that the contract was performed: Baum v. Union Surety, Etc., Co., 19 Pa. Superior Ct. 23.

Measured by these well established rules, it is clear that the affidavit in this case discloses no legal defense whatever. Our judgment as to its insufficiency is in entire agreement with that of the learned judge of the court below. The judgment was rightly entered, and is now affirmed.