Judgement PHUKAN,C.J.(Actg.):-This appeal is directed against the judgment and order of the learned single Judge passed on 6-8-93 in Civil Rule No. 101(k)/ 92. By the impugned judgment and order the learned single Judge dismissed the writ petition on the grounds which we shall state at the appropriate place. 2. The writ petitioner who is appellant herein filed the petition under Article 226 of the Constitution impugning three letters dated 20-4-92, 3-7-92 and l1-6-92 (Annexures- B, C and D to the writ petition respectively). It may be stated that the writ petitioner is running a small scale industry, namely, a saw mill, and the production started in the year 1987. According to the writ petitioner due to unforeseen circumstances the unit remained inoperative for about 2 years and only in February, 1992 arrangements could be made to re-start the mill. The Divisional Forest Officer, Dimapur was informed accordingly by letter dated 8-7-92, vide Annexure-A. By the impugned letters, the Divisional Forest Officer asked the writ petitioner to make advance payment of royalty on timber and as it was not paid the mill was closed down by the authorities. However, by an interim order the petitioner was allowed to run the mill. These facts are not necessary for consideration of the present dispute as the main point urged is regarding power of the State Government to realize royalty including advance royalty vis-a-vis the provisions of the Nagaland Forest Act, 1968, for short the Act. 3. In the counter-affidavit filed on behalf of the respondents the allegation that the mill was closed down for about 2 years has been disputed. It has been stated that for realization of royalty on timber used by the mill owners a meeting was held between the officers of the State Government and Nagaland Timber Industries Association, representatives of various Plywood/Veneer and Saw Mills so that royalties could be realized properly and without any evasion. According to the respondents in pursuance of the agreement between the parties ultimately the present procedure of ollecting royalty on timber payable by Saw/Veneer/Plywood mills in Nagaland was duly notified. From AnnexureX to the counter-affidavit we find that a letter dated 5-11-85 was sent by the Chief Conservator of Forests, Nagaland to the Additional Secretary, Forest Department fixing the royalties in timber for various mills at different rates. From AnnexureX to the counter-affidavit we find that a letter dated 5-11-85 was sent by the Chief Conservator of Forests, Nagaland to the Additional Secretary, Forest Department fixing the royalties in timber for various mills at different rates. This was duly approved by the State Government by letter dated 18-11-85, vide Annexure-XI to the counter. The rates of royalty suggested by the Chief Conservator of Forests are quoted below :- "a. Namsa, Naginimora, Mokokchung and Tamlu area = Royalty calculated on 80% capacity B Class and 20% C Class. b. Tiru area = Royalty calculated on 85% capacity as B Class and 15% as C Class. c. Tuensang and Zunheboto areas = Royalty calculated as 5% capacity as All class 60% as B class and 35% C class. d. Wokha, Dimapur and Jalukie areas = Royalty calculated on 5% capacity as all class 30% as B class, 40% as C class and 25% as D class e. Phek area = Royalty calculated on 5% as All class, 25% as B class, 60% as C class and 10% as D class." 4. We have heard Mr. G. N. Sahewalla, learned counsel for the appellant and Mr. D.K. Misra, learned Additional Advocate General, Nagaland, for the respondents. In addition written arguments have also been submitted by both the parties. 5. Learned single Judge by the impugned judgment and order held that by various recommendations of the Committees as mentioned in the counter-affidavit there was a change in the system of realisation of royalty which was followed prior to 1-10-85 and by the present policy only the system of realising royalty was changed. The learned single Judge also held that the writ petitioner was paying royalty on timber and, therefore, now it cannot be challenged. Regarding certain enhancement of royalty, learned single Judge held that as this was not assailed in the writ petition it cannot be challenged. The submission on behalf of the writ petitioner that the royalty which has been imposed is not tenable in law in absence of any legislation or Rules framed under the Act was rejected. 6. The first question that has to be decided is whether the imposition of royalty on the basis of installed capacity of each mill is a tax or royalty. 6. The first question that has to be decided is whether the imposition of royalty on the basis of installed capacity of each mill is a tax or royalty. In this connection, we may refer to a decision of the Madhya Pradesh High Court in Surajdin v. State, AIR 1960 Madh Pra 129, wherein the terms royalty and tax were discussed. Reference was made to the term royalty in whartons Law Lexicon (Fourteenth Edition) where the word royalty has been explained as "payment to a patentee by agreement on every article made according to his patent; or to an author by a publisher on every copy of his book sold; or to the owner of minerals for the right of working the same on every ton or other weight raised". Referring to above dictionary meaning of the term royalty and meaning referred to in another dictionary it was held that royalties are payments which the Government may demand for the appropriation of minerals, timber or other property belonging to the Government and that two important features of royalty have to be noticed : they are, that the payment made for the privilege of removing the articles is in proportion to the quantity removed, and the basis of the payment is an agreement. In that case, the Government imposed a compulsory levy an all liquor contractors irrespective of the fact whether they availed of the privilege of removing fuel from the protected forest or not, and it was held that such levy would amount a tax or a cess which could only be imposed under the authority of law as provided in Article 265 of the constitution. We are in respectful agreement with the above ratio. 7. The Apex Court in District Council of Jowai Autonomous District v. Dwet Singh, AIR 1986 SC 1930 , also, considered the term royalty. In that case, the District Council in exercise of powers under an Act made under the Sixth Schedule to the Constitution issued a notification imposing royalty on timber. Their Lordships referred to Jowitts Dictionary of English Law and according to the said dictionary the term royalty means "a payment reserved by the grantor or patent, lease of a mine or similar right and payable proportionately to the use made of the right by the grantee". Their Lordships referred to Jowitts Dictionary of English Law and according to the said dictionary the term royalty means "a payment reserved by the grantor or patent, lease of a mine or similar right and payable proportionately to the use made of the right by the grantee". It was held that the amount claimed by way of royalty under the notification was a compulsory exaction of money by a public authority for public purposes enforceable by law and was not a payment for services rendered and, therefore, in the nature of tax. 8. Coming to the case in hand from the order of the State Government it appears that the amount sought to be realised was on the basis of installed capacity of each saw/ veneer/ plywood mill and the royalty imposed was a percentage of such capacity. Therefore, the fixation of royalty was not on the basis of actual logs/timbers used by each saw mill. On this ground we hold that the impugned notification imposing royalty on the basis of installed capacity of each mill is not royalty but a tax. 9. We may mention here that the State Legislature has no power to impose tax on a matter with regard to which it has the power to legislate but has been given no express power to impose tax. The subject forest was included in the State List and there was no specific provision authorizing the State Legislature to impose tax on forest. Subsequently, however this subject forest was transferred to concurrent list of Seventh Schedule to the Constitution. In the said List also no specific power has been given to the Legislature to impose tax on forest. Therefore, the State Legislature cannot impose tax on forest. We may refer to a decision of the Apex Court reported as K. T. Moopil Nair v. State of Kerala, AIR 1961 SC 552 . wherein the Apex Court held that the State Legislature has no power to impose tax on forest. 10. We shall consider at the appropriate place whether in the case in hand the royalty sought to be realized by the State can be done or not. But before doing so we may consider the question of estoppel as the learned single Judge applying the said principle rejected the writ petition. 11. Our attention has been drawn by Mr. 10. We shall consider at the appropriate place whether in the case in hand the royalty sought to be realized by the State can be done or not. But before doing so we may consider the question of estoppel as the learned single Judge applying the said principle rejected the writ petition. 11. Our attention has been drawn by Mr. Sahewalla, learned counsel for the appellant, to the decision in RHYL UDC v. RHYL Amusements Ltd., (1959) 1 All ER 257, wherein it was held that there cannot be a plea of estoppel against something which is done by the statutory body which is ultra vires. The Apex Court also in Amalgamated Coalfields Ltd. v. Janapada Sabha, Chhindwara, AIR 1961 SC 964 , held that acquiescence in an illegal tax for a long time is not a ground for denying the relief aimed by a person. 12. Reference has been made by Mr. Sahewalla to a decision of the Apex Court in Indira Bai v. Nand Kishore, (1990) 4 SCC 668 : ( AIR 1991 SC 1055 ). It has been held by the Apex Court that estoppel is a rule of equity flowing out of fairness striking on behaviour deficient in good faith. It operates as a check on spurious conduct by preventing the inducer from taking advantage and assailing forfeiture already accomplished. It is invoked and applied to aid the law in administration of justice. It need not be specifically provided as it can always be used as a weapon of defence. 13. In view of the above ratio laid down in the cases referred to above we are of the opinion that the principle of estoppel cannot be made available in the case in hand inasmuch as the proposed royalty which we have held to be tax is not authorised by law. Therefore, the learned single Judge erred in holding that the principle will apply merely because there was some discussion between the Government and mill owners followed by the impugned order of realisation of royalty on the basis of installed capacity of mills. 14. Mr. D. K. Misra, learned Additional Advocate General, Nagaland, has urged that the appellant has tried to make out a new case in this writ appeal. It is true that the appellant has urged that as there is no Government forest royalty cannot be imposed. 14. Mr. D. K. Misra, learned Additional Advocate General, Nagaland, has urged that the appellant has tried to make out a new case in this writ appeal. It is true that the appellant has urged that as there is no Government forest royalty cannot be imposed. According to the appellant forests in Nagaland belong to private parties. It is a very difficult question to answer without proper material and, therefore, we are in agreement with the learned Additional Advocate General that the question as to whether timbers were extracted by the mill owners including the appellant/ writ petitioner from private forest or from Government forests cannot be decided in the case in hand. 15. Mr. Misra has also urged that the present scheme for realizing royalty on the basis of installed capacity of the mills was mainly for the purpose of preventing evasion of royalty. Learned Additional Advocate General has further stated that the State Government has no objection to go back to the old procedure of realizing royalty on logs. 16. Royalty can be realised by the State Government in view of the agreement expressed or implied on logs or timbers used by each mill. Therefore, there cannot be any legal objection in realizing royalty from the mill owners including the present appellant/writ petitioner for the actual requirement of logs by the mills. It has been stated that the mills used to purchase logs from the forest contractors who are to pay royalty before lifting logs from the forest. This is a question of fact and we are unable to go into detail in this aspect of the matter. We however hold that the State Government can realize royalty on logs used by the mills, but if any royalty has already been paid by any forest contractor supplying logs to the mill owners the same has to be adjusted. It is for the State Government to find out the ways and means for realizing the royalty on logs used by the mills. It may be done either from the mill owners or from the forest contractors. But it cannot be realized twice. It is for the State Government to find out the ways and means for realizing the royalty on logs used by the mills. It may be done either from the mill owners or from the forest contractors. But it cannot be realized twice. In other words, if royalty on logs used by a particular mill has already been paid by the contractor the mill owner shall be exempted from paying royalty to that extent and if the royalty has not been paid/realised from the contractor the same has to be paid by the mill owner. For this purpose, the State Government may prepare a scheme, if so advised. But in doing so the rate of royalty should be fixed for logs actually used or supplied to the mills and not on installed capacity. 17. With the above observations and directions the appeal is allowed. However, we make no order as to cost. Appeal allowed.