CHAKRAVARTTI, C.J.:- An experiment in law-making with a view to establishing some control over the rents chargeable for premises let to tenants, primarily in Calcutta and other municipal areas, has been going on in this Province since 1943 and so far there have been five products of that experiment. As each of the successive pieces of legislation superseded its predecessor, there has on each occasion been some attempt to adjust the new law to the old or to extend some of the benefits of the new law to those against whom the old law had already been set in motion. The question involved in the present reference concerns one such extension made of the Act of 1950.It arises in the following way.

2. The West Bengal Premises Rent Control (Temporary Provisions) Act came into force on 1-12-1948 and remained in operation till 30-3-1950. Under S.12(3) of that Act, a tenant who committed default in paying the rent accruing due from him after the commencement of the Act for three consecutive months, ceased to be a tenant and his interest in the tenancy was, by such default, ipso facto determined. Thereafter, he became a trespasser and if sued in ejectment, had no means open to him to avert either a decree or actual eviction. But the next Rent Act, West Bengal Act No.17 of 1950, which superseded the Act of 1948 and came into force on 31-3-1950, contained no provision similar to S.12(3) of the 1948 Act. It provided instead by proviso (i) to S.12(1) that if a tenant committed default in paying duly the rent legally payable by him for two months, the protection conferred by the Act against a decree for ejectment would not be available to him and even that less stringent provision was made subject to an exception contained in S.14. The exception was that if on a suit being brought, it was found that the only ground which excluded the tenant from the protection of the Act was a default as contemplated by proviso (i) to S.12(1) and the tenant yet paid up all arrears of rent due from him up to date, as determined by the Court, which it would be the duty of the Court to determine, and also paid them by a date which it would be the duty of the Court to fix, ejectment would be refused, in spite of the previous default. This, therefore, was the last chance provided to a defaulting tenant to save him self from eviction. On the other hand, the exception itself was made subject to an exception, added by a proviso thereto. It was to the effect that if a tenant was found to have been in default within the meaning of S.12(1), Proviso (i) on three different occasions within a period of eighteen months, he would not be entitled to the benefit of S.14. Both the exception and the exception thereto are contained in sub-section (3) of section 14 which is in the following terms:

14(3). If within the time fixed in the order under sub-section (1), the tenant deposits in the Court the sum specified in the said order, the suit, so far as it is a suit for recovery of possession of the premises, shall be dismissed by the Court. In default of such payment the Court shall proceed with the hearing of the suit:

Provided that the tenant shall not be entitled to the benefit of protection against eviction under this section if he makes default in payment of the rent referred to in clause (i) of the proviso to sub-section (1) of section 12 on three occasions within a period of eighteen months.

3. When the Legislature passed the Act of 1950, it was mindful of the fact that at the date the Act came into force, there would be some persons against whom a decree for ejectment had already been passed on the ground of a statutory extinction of their tenancies under S.12(3) of the Act of 1948, but who had not yet been actually evicted. Against some others, suits bound to succeed on that sole ground would be pending. Provision for some relief to those two classes of persons was therefore made by S.18 of the Act, as regards the former class, by sub-sections (1) to (4) and as regard