The principle that a mortgage could not be made irredeemable was thus limited in early days to the accomplishment of the end which was held to justify interference by equity with freedom of contract. It did not go further (x). As established it was expressed in three ways. The first and most general rule was that if the transaction is once found to be a mortgage, it must be treated as always remaining a mortgage and nothing but a mortgage-" once a mortgage always a mortgage"-and is therefore redeemable notwithstanding any agreement to the contrary (y).

(v) 1683, 1 Vern. 190, 2 W. & T.L.C. Eq. 11, 18 R.C. 358.

(w) Kreglinger v. New Patagonia, etc., Co., [1914] A.C. 25, at p. 36; Stapilton v. Stapilton, 1739, 1 Atk. 2, 1 W. & T.L.C. Eq. 234; cf. 2 W. & T.LC. Eq. 19.

(x) The leading case with regard to the principle under discussion is the case of Kreglinger v. New Patagonia, etc., Co., [1914] A.C. 25; see especially the judgment of Lord Parker of Waddington. See also on the general subject the notes in 2 W & T.L.C. Eq. 15 ff. to the case of Howard v. Harris, supra.

It was only a different application of the paramount principle to state in the form of a second rule that a mortgagee should not stipulate for a' collateral advantage which would make his remuneration for the loan exceed a proper rate of interest (z). The third form in which the principle was stated was that any stipulation which restricts or clogs the equity of redemption is void (a).