JUDGMENT Khundkar, J. - The plaintiff in the suit out of which this appeal has arisen was the holder of a tenure in the Sunderbans area which he held under the defendant by virtue of a mourashi mokurari lease. The plaintiff instituted a suit for abatement of rent owing to deficiency in the area of his tenure under S. 52 (1) (b), Ben. Ten. Act. It was not disputed that the original settlement, as evidenced by the kabuliyat, was of an area of "900 bighas by guess," but that upon subsequent measurement it was found that the actual area of the tenure was 763 bighas. The case made by the plaintiff in the trial Court was that he was liable to pay rent in respect of 733 bighas only, as against the contention of the landlord defendant that rent was payable for an area of 763 bighas. A commissioner appointed to measure the land reported that the entire area of the tenure extending up to the edge of a river which flowed alongside the eastern boundary, and inclusive of an embankment along the river side was 763 bighas, and that the area excluding the embankment and some land lying beyond it and between the embankment and the river, would be 733 bighas. 2. Whatever may have been the case made on behalf of the plaintiff in the Courts below, it is now contended on his behalf that though he is liable to pay rent for all the lands lying to the west of the embankment, he is not liable to pay rent for the land upon which the embankment stands or for the stretch of the land between the embankment and the water's edge on the east. The lower appellate Court has accepted the plaintiff's contention, and has held that the plaintiff is entitled to a reduction of rent in respect of 30 bighas of land being the difference between 763 and 733 bighas. It is against this decision that the landlord has appealed. 3. The facts which are admitted may be shortly stated. From the patta and the kabuliyat executed at the time of the settlement with the plaintiff's predecessor, it appears that an embankment existed at that time which was referred to as the eastern boundary, and it is clear that that embankment was outside the lands of the tenure. 3. The facts which are admitted may be shortly stated. From the patta and the kabuliyat executed at the time of the settlement with the plaintiff's predecessor, it appears that an embankment existed at that time which was referred to as the eastern boundary, and it is clear that that embankment was outside the lands of the tenure. The landlord undertook to maintain the embankment for the protection of the tenure against the inroads of the river. It was agreed between the landlord and the tenant that the tenant would not be entitled in future to claim a reduction of the rent then settled for any reason whatsoever. The embankment was later washed away, and the tenant having called the attention of the landlord to this fact, the latter proceeded to erect a new embankment for the purpose of protecting the tenant's lands as stipulated in the contract of tenancy. Apparently the river had advanced so far to the west that the new embankment had, of necessity, to be constructed upon a strip of the demised land. As found by the Courts below upon the report of the commissioner who was appointed to measure the disputed land, it is apparent that 30 bighas of the area originally demised have been taken up by the new embankment. On behalf of the landlord appellant three points have been taken. It is argued, firstly, that the erection of the embankment has not caused any deficiency in the area of the tenure within the meaning of S. 52 (1) (b), Ben. Ten. Act. It is pointed out in this connexion that the case made in the plaint was one of loss of land by actual diluvion. The evidence and the findings arrived at by the Courts below, however, make it clear that no portion of the tenure originally demised was swallowed up by the waters of the river. Mr. Ten. Act. It is pointed out in this connexion that the case made in the plaint was one of loss of land by actual diluvion. The evidence and the findings arrived at by the Courts below, however, make it clear that no portion of the tenure originally demised was swallowed up by the waters of the river. Mr. Bose on behalf of the appellant has contended that, although it is well settled that loss of land by diluvion or other similar cause would be within S. 52 (1) (b), it cannot be said that any deficiency in the area of the tenure has taken place here, because that area is still intact as dry land in the possession of the tenure-holder, and the fact that an embankment has made its appearance along a strip of that area does not create any deficiency in area within the meaning of the words in S. 52 (1) (b), Ben. Ten. Act. Mr. Bose relies upon a judgment of Biswas and Akram JJ. in S. A. No. 424 of 1941 Reported in Kamada Kumar Chatterjee v. Harapada Banerjee ('45) 32 A. I. R. 1945 Cal. 295 decided on 29th March 1945. In that case, which has not yet been reported, my learned brother (Biswas J.) considered the decision of Jack J. in 38 C. W. N. 974 Achala Dasi v. Bijoy-Chand Mahatab ('34) 21 A. I. R. 1934 Cal. 831 : 154 I. C. 78 : 38 C. W. N. 974, in which that learned Judge had held that if a part of the land of a tenancy becomes covered up by sand so as to become wholly useless, the tenant is entitled to a proportionate reduction of rent under S. 52 (1) (b), Ben. Ten. Act. A passage from the judgment in the later case is instructive and should be quoted : In our opinion, the language used in S. 52 does not justify the interpretation which Jack J. was inclined to put upon it. We do not think that deficiency in area can be construed to mean and include deficiency in the area fit for cultivation or for the purposes of the tenancy. That would, in our judgment, be an unwarrantable extension of the ordinary meaning of the word 'deficiency.' Clause (a) of S. 52, which for this purpose may be regarded as a counterpart of Cl. That would, in our judgment, be an unwarrantable extension of the ordinary meaning of the word 'deficiency.' Clause (a) of S. 52, which for this purpose may be regarded as a counterpart of Cl. (b), no doubt speaks of loss of the land of a tenure or holding by diluvion 'or otherwise.' The words 'or otherwise' must refer to a cause similar to diluvion, and those words should be interpreted as referring to something similar to diluvion and cannot, in our opinion, be regarded as wide enough to let in grounds of natural justice and equity. It is not necessary for our present purposes to consider whether an earthquake which might cause a complete subsidence of the land may or may not be regarded as a natural event of the same kind as diluvion. But we are not at all satisfied that a mere deposit of sand,although it may be described as permanent, can be placed on the same footing. In our view, therefore, the defendant in the present case could not claim abatement under the provisions of S. 52, Ben. Ten. Act. For our present purposes, it is of importance to note that Biswas and Akram JJ. recognised that loss occasioned by causes similar to diluvion would bring a case within the meaning of the words "deficiency in the area of the tenure" in Cl. (b), and also that they had in mind such a contingency as a subsidence of land from earthquake, although they were not called upon to decide whether this particular eventuality would be within the intention of Cl. (b). It seems to us that the principle which under lies the rule that a tenant is entitled to abatement of rent in respect of any area which becomes submerged under the waters of a river is the principle that no tenant should be compelled to pay rent for land which has been torn from his tenure as a result of the action of a river. What we have to consider here is whether the taking from the tenure of the land required for the erection of the embankment was the inevitable consequence of encroachment by the river. What we have to consider here is whether the taking from the tenure of the land required for the erection of the embankment was the inevitable consequence of encroachment by the river. In the present case no portion of the area of the tenure became actually submerged by the advancing water, but the change in the course of the river, such as it was, compelled the landlord to take land from the area of the tenure for a new embankment. In the circumstances of the present case, the landlord had no option in the matter, because, as already indicated, be was bound by the contract to continue to protect the tenure by an embankment. It was at one stage suggested by Mr. Bose on behalf of the appellant that the proper remedy of the tenant in the present case would have been to proceed against the landlord for trespass. In the circumstances just referred to, it is clear that such a proposition will not bear examination. The action of the landlord in building the embankment was not only not wrongful, but it was an action to which he was impelled by the contract of tenancy when the river began to change its course. Looking at the purely physical phenomenon brought about by the building of the new embankment, it is clear that a mutilation of a portion of the tenure thereby took place, which, in our judgment, was as much a physical taking away from the tenure of a portion of its lands as would have been the submergence of those lands, had the river flowed over them. In either case there would be what may be called a truncation of the lands of the tenure occasioned by the action of the river. It might be said that in the one case the advance of the river would be the immediate cause of such a truncation, and in the other it would be only the mediate cause. In the special circumstances in which this embankment had to be built, we do not see that it makes any difference. In our judgment, the area of 30 bighas taken from the tenure by the embankment amounts to a deficiency in the area of the tenant's tenure such as entitles him to claim reduction of rent under S. 52 (1) (b), Ben.Ten. Act. 4. Mr. In our judgment, the area of 30 bighas taken from the tenure by the embankment amounts to a deficiency in the area of the tenant's tenure such as entitles him to claim reduction of rent under S. 52 (1) (b), Ben.Ten. Act. 4. Mr. Bose's second argument was that the tenant had contracted himself out of his rights under that section inasmuch as the agreement of tenancy made it clear that he would not be entitled in the future to claim reduction of rent for any cause whatsoever. This argument has an appearance of cogency, because it may well be said that in the Sunderbans area, where rivers are constantly changing their courses, such an eventuality as has occurred in the present case would have been within the contemplation of the parties when by the kabuliyat and the patta the tenant waived his rights to claim reduction of rent in the future on any ground whatsoever. The question cannot, however, rest there. It has to be seen whether the law leaves a tenant free to waive his rights under S. 52, Ben. Ten. Act. Mr. Bose's contention is that freedom of contract is the general rule and that the special rights reserved to the tenant under S. 52 (1) (b) may at any time be abrogated by a contract. He draws our attention to cl. (e) of sub-s. (3) of S. 178, the language of which is as follows: Nothing in any contract made between a landlord and a tenant after the passing of this Act shall-(e) take away the right of a raiyat to apply for a reduction of rent under S. 38 or S. 52. It is pointed out that this provision stands in the way of the abrogation by a raiyat of the rights given to him by S. 52, but it applies only to contracts made after the passing of the Act. The argument is that as regards contracts made before the Act came into force, raiyats were free to barter away the rights given to them by S. 52. This provision shows, therefore, by necessary implication that with the exception of contracts made by raiyats after the passing of the Act, all other contracts made by raiyats would prevail, notwithstanding the rights given to raiyats by S. 52 (1) (b), Ben. Ten. Act. This provision shows, therefore, by necessary implication that with the exception of contracts made by raiyats after the passing of the Act, all other contracts made by raiyats would prevail, notwithstanding the rights given to raiyats by S. 52 (1) (b), Ben. Ten. Act. The answer to this argument is furnished by the fact that S. 178 (3) (e), Ben. Ten. Act, is not a provision which applies to all tenants, but only to raiyats. Tenure-holders are not included within the scope of this provision, nor are they affected by its implications. In order to ascertain whether tenure-holders are free to contract themselves out of the rights given to them by S. 52 (1) (b), it is S. 179, Ben. Ten. Act, which has to be looked at. The material words of that section are as follows: Nothing in this Act shall be deemed to prevent a proprietor or a holder of a permanent tenure In a permanently settled area from granting a permanent mokarari lease on any terms agreed on between him and his tenant. The question which leaps to the eye is, why it was necessary to enact this provision at all, if all tenure-holders were free to waive by contract the rights given to them by various sections of the Bengal Tenancy Act? The section enacts that the terms of mokarari lease of a permanent tenure in a permanently settled area shall prevail notwithstanding anything contained in the Act, that is to say, notwithstanding anything contained in S. 52. This is clearly said, and what is, therefore, necessarily and clearly implied is that the provisions of the Act relating to the rights of tenure-holders, amongst which provisions must be included S. 52, cannot, except as provided, be neutralised by contracts entered into between the holders of permanent tenures and the proprietors of the superior estates. This question was adverted to by this Court in 48 I. A. 39 Khetramoni Dasi v. Jiban Krishna ('21) 48 Cal. 473 : 48 I. A. 39 (P. C), which case later went up on appeal to the Privy Council. The aspect of the matter now under consideration was not argued before the Judicial Committee, but it was referred to by this Court. 473 : 48 I. A. 39 (P. C), which case later went up on appeal to the Privy Council. The aspect of the matter now under consideration was not argued before the Judicial Committee, but it was referred to by this Court. It was dealt with by Woodroffe J. in the following words which appear at page 41 of the report : The question then is, first, as to the meaning of S. 52, Ben. Ten. Act. The plaintiff is a tenant, and S. 52, sub-s. 1 (b) therefore is applicable to this case. The short question really before us is whether or not the plaintiff was competent to contract himself out of the rights which were given to him by that Section, and if so, whether in fact be has so done. It is in the first instance to be observed that S. 52 is not made subject to any proviso. It is not, as in the case of S. 53, for instance, made subject to agreement or usage or the like. Prima facie, therefore, without reference to any further section it would he, having regard to the general scheme of the Act, a statutory right in the tenant which could not be affected by an agreement entered into by him. Then it is said that S. 178 which declares that 'nothing in any contract between a landlord and tenant' shall affect the rights therein stated, does not expressly refer to the case of a tenant who is not at the same time a raiyat, for S. 178 (f) "-(now S. 178 (3) (e)) - " only says that nothing in any contract between a landlord and tenant shall take away the right of a raiyat to apply for a reduction of rent under S. 38 or S. 52. As the plaintiff is not a raiyat it may be conceded for the purpose of this judgment that S. 178 does not deal with the case which is before us... S. 179 does not apply to this case, for it cannot be said that the tenure is situate in a permanently settled area within the meaning of that section. As the plaintiff is not a raiyat it may be conceded for the purpose of this judgment that S. 178 does not deal with the case which is before us... S. 179 does not apply to this case, for it cannot be said that the tenure is situate in a permanently settled area within the meaning of that section. That section, however, I think, does show by implication this : that though S. 178 does not expressly refer to the case of a tenure-holder, yet S. 52 is not subject to agreement except as regards a particular class of tenants in permanently settled areas as dealt with in S. 179. As I have said, the plaintiff does not come within that class. I would, therefore, hold that the plaintiff is entitled under the provisions of S. 52, Ben. Ten. Act, to a reduction of rent and that the right is a statutory right which is not subject to agreement. 5. In our judgment, it is reasonably clear from a reading of S. 52 (1) (b) together with S. 179, Ben. Ten. Act, that in so far as a tenure-holder is concerned, the right given to him to apply for an abatement of rent on account of deficiency in the area of his tenure cannot be taken away by any contract except one which answers the description contained in S. 179. This brings us to a further branch of the argument made on behalf of the appellant which was founded upon the contract of tenancy. Mr. Bose has contended that the tenure in question falls within the exception embodied in S. 179, because, firstly, it was granted by a permanent mokarari lease and, secondly the lands lie in a permanently settled area. With regard to the first mentioned condition, it is not disputed that the lease was a permanent mokarari one. With regard to the other requirement of the section, a difficulty arises. In 48 I. A. 39 Khetramoni Dasi v. Jiban Krishna ('21) 48 Cal. 473 : 48 I. A. 39 (P. C.), an argument similar to that now advanced was made before the Judicial Committee, but their Lordships held upon the facts found that the appellant had failed to establish that the land was in a permanently settled area. In 48 I. A. 39 Khetramoni Dasi v. Jiban Krishna ('21) 48 Cal. 473 : 48 I. A. 39 (P. C.), an argument similar to that now advanced was made before the Judicial Committee, but their Lordships held upon the facts found that the appellant had failed to establish that the land was in a permanently settled area. Now, as is clear from what has been stated before, S. 179 embodies a provision in the nature of an exception. The onus to establish every element necessary to constitute the exception is, in the present case, undoubtedly upon the appellant who claims the benefit of it. From the judgments of the Courts below, it does not appear that any attempt was made on behalf of the present appellant to prove that the tenure of the plaintiff respondent existed in a permanently settled area. In the argument before us, an attempt has been made to show that the area in question was a permanently settled area by citing a recital in the kabuliyat which alleges that the parent estate had been made nishkar. This is clearly not sufficient to prove that the touzi out of which the tenure was carved was a permanently settled one. 6. The third point taken on behalf of the appellant was that the plaintiff was not entitled to claim any reduction under S. 52 (1) (b), Ben. Ten. Act, inasmuch as he had by a subsequent act clearly surrendered such a right. Mr. Bose has drawn our attention to some evidence in the case which serves to indicate that after the old embankment was washed away, the tenant requested the landlord to put up a new one in its place. The contention is that such a request is consistent only with an offer by the tenant to give up voluntarily a portion of his land for a new embankment. It is said that from the request made we must infer that the tenant was offering to surrender and sacrifice his land in order that he might obtain the embankment, and it is argued that as that offer formed part of the new bargain between him and the landlord, he cannot complain of any reduction of his tenure caused by the building of the new embankment, and may not, therefore, ask for reduction of rent on that ground. This argument is founded upon the assumption that the tenant's request to the landlord to build an embankment carried with it the implied offer to voluntarily surrender some land for that purpose, and upon the further assumption that the landlord would never have agreed to erect the new embankment had such an offer not been made. The terms of the potta and the kabuliyat would make it clear that these assumptions are erroneous. As already stated, the landlord was under a contractual obligation to protect the lands of the tenure by an embankment and he was, therefore, only discharging a legal duty when he constructed a new embankment to replace the old one which had been washed away. In the light of the contract of tenancy the tenant's request to the landlord to put up the new embankment amounted to no more than a request that the landlord should do what he had already undertaken to. We cannot see how such a request can be construed as implying that the tenant was abandoning any of the rights vested in him by the Bengal Tenancy Act. All the points taken by Mr. Bose on behalf of the appellant accordingly fail and this appeal must be dismissed with costs. Biswas, J. 7. The arguments in the case have covered a wide field and my learned brother has dealt with them fully in the judgment he has just delivered. I agree that the appeal should be dismissed with costs, and the respondent held entitled to the reduction of rent which the Courts below have granted him. I should like, however, to add a few words, as it appears to me that there was some confusion of thinking on the part of the learned Munsif and the learned Subordinate Judge as to the applicability of S. 52, Ben. Ten. Act, to the facts of the case. 8. In the plaint the plaintiff did not specifically mention this section, but there can be no doubt that he made a case of abatement under sub-cl. (1) (b) thereof. It was alleged that there had been diluvion which had caused a diminution in the area of the tenure, and a reduction of rent was claimed on that ground. 8. In the plaint the plaintiff did not specifically mention this section, but there can be no doubt that he made a case of abatement under sub-cl. (1) (b) thereof. It was alleged that there had been diluvion which had caused a diminution in the area of the tenure, and a reduction of rent was claimed on that ground. At the trial the case also proceeded on the basis of S. 52, and I have no doubt that upon the facts of the case, as my learned brother has pointed out, that section is attracted. It appears, however, from the judgments of the Courts below that although they purported to apply S. 52, they were not still quite accurate in stating the grounds on which a reduction of rent would be justified in terms of this section. The learned Munsif said that the disputed strip of land covering about 30 bighas, which made the difference between the plaintiff's claim and that of the defendant, had become "useless for agricultural purposes". The learned Subordinate Judge also adopted the same language, adding the further fact that the tenant was out of possession of the afore, said area. This seems to suggest that in the opinion of the learned Munsif as well as of the learned Subordinate Judge, it would be a fit ground for allowing reduction of rent under S. 52 (1) (b), Ben. Ten. Act, if it was established that some portion of the lands had become unfit for the purposes of the tenancy, or that the tenant had been out of possession of the same. With all respect, I do not think that S. 52 contemplates any such ground. Whether or not, at general law or under the provision of any Statute, a tenant may claim abatement of rent on the ground of deterioration of any portion of the tenancy or on the ground that he had lost possession of any land or been otherwise deprived of its use, is a different question altogether, a question which, it may be stated, is not altogether free from difficulty. As will appear from certain very instructive observations of Rankin C. J. in the Full Bench case in 59 Cal. 155 Arun Chandra Sinha v. Shamsul Huq ('31) 18 A. I. R. 1931 Cal. 537 : 59 Cal. As will appear from certain very instructive observations of Rankin C. J. in the Full Bench case in 59 Cal. 155 Arun Chandra Sinha v. Shamsul Huq ('31) 18 A. I. R. 1931 Cal. 537 : 59 Cal. 155 : 133 I. C. 577 (F. B.), the English law and the Indian law on the subject are perhaps not quite the same, and it will further be seen that even so high a authority as Sir Barnes Peacock C. J., had misstated the English law on the point in some earlier case reported in the Weekly Reporter Series to which reference is made in the Full Bench judgment. On the facts of the present case, we are not called upon to decide this debatable point. It is sufficient to hold that the facts make this out to be a case proper under S. 52 (1) (b). It is not disputed that owing to the erection of the new embankment on a site inside the original tenure, some lands which belonged to the tenure were effectively taken away from it. This was undoubtedly a physical diminution in the area of the tenure, and if this did not constitute a "deficiency" within the meaning of S. 52 (1) (b), Ben. Ten. Act, I do not know what would. It cannot be disputed,-in fact it has been so held in numerous decisions of this Court and has also been recognised in the Statute itself,-that diluvion comes within S. 52, The section also covers grounds similar to diluvion. In this case, although it cannot be said that the disputed area had been actually washed away by the river and that the deficiency in the area had been directly caused thereby, it cannot be disputed that this was the ultimate result of diluvion. It was the advancing waters of the river which made it necessary to abandon the old embankment; the old embankment itself had in fact gone under water. By virtue of the agreement which was embodied in the lease the landlord was bound to put up a new embankment, but the only available site was inside the tenure. By putting up the embankment there, the landlord could not be said to have dispossessed the tenant in any way, but whether it did or did not amount to dispossession, there can be no doubt that it did cause a diminution in the area. By putting up the embankment there, the landlord could not be said to have dispossessed the tenant in any way, but whether it did or did not amount to dispossession, there can be no doubt that it did cause a diminution in the area. That being so, S. 52 would be clearly attracted. The case would accordingly come within the scope of the decision of the Judicial Committee in 48 I. A. 39 Khetramoni Dasi v. Jiban Krishna ('21) 48 Cal. 473 : 48 I. A. 39 (P. C). In that case the Judicial Committee held on a construction of the terms of the grant to the landlord respondent that the tenancy did not come within the description of a permanent tenure in a permanently settled area under S. 179, Ben. Ten. Act. The grant is not forthcoming in the present case, but the onus lay upon the landlord defendant to prove the terms of the grant, if he desired to bring his case within the exception embodied in S. 179. That onus, as my learned brother has pointed out, has not been discharged. The recital in the mokarari lease that the estate had been redeemed from rent or revenue is not sufficient to show that it had been permanently settled. In this view of the matter, as I have said, I agree with the judgment delivered by my learned brother.