The opinion of the court was delivered by
Wedell, J.:This action was brought in the district court to obtain a lump-sum judgment covering all past and future weekly installment payments provided for in a judgment previously rendered in a workmen’s compensation case. Plaintiff, the workman, prevailed and defendant, the employer, appeals.
The instant action was brought pursuant to a 1943 law which became effective after the judgment of the district court in the com*214pensation case had been rendered. Appellant contends the legislature did not intend the law should operate retroactively but prospectively and challenges its validity if it be held to.apply retroactively. Appellant also contends that if the 1943 law authorizing an action for a lump-sum judgment be held valid as to a judgment for compensation previously rendered, then the judgment rendered in the instant case cannot stand by reason of certain trial errors.
The workman was injured May 7, 1942. Both parties appealed from the award of the commissioner. On March 23, 1943, the district court rendered its judgment, the pertinent portion of which reads: • .
“It Is Therefore, by the Court, considered, ordered, adjudged and decreed that the claimant is awarded compensation for permanent total disability against the respondent, Kroger Grocery and Baking Company, self-insurer, for a period of four hundred fifteen weks at the rate of $16.50 per week, that compensation now due and owing for Forty-four and 5/7 (44 5/7) weeks from May 14, 1942, .one week after claimant’s said accidental injury, to and including the 23rd day of March, 1943, or Seven hundred and thirty-seven and 80/100 ($737.80) dollars, should be paid in one lump sum less the amount of compensation heretofore paid in the sum of $247.50, leaving a balance due of $490.30. That the balance of the compensation awarded herein shall be paid at the rate of $16.50 per week until fully paid or until further order of this Court or the Workmen’s Compensation Commissioner of the State of Kansas.” ■ .
The entire statute upon which the instant action is based (Laws 1943, ch. 189; G. S. 1943 Supp. 44-512a), including its title, reads:
“An Act relating to workmen’s compensation.
“Be it enacted by the Legislature of the State of Kansas:
“Section 1. That if any compensation awarded, agreed upon or adjudged ■under the provisions of the workmen’s compensation act of this state or any installment thereof shall not be paid to the employee or other person entitled thereto when due, and service of written demand for payment has been made personally or by registered mail on the person, firm or corporation liable to pay the same, payment of. said demand is thereafter either refused or not made within two weeks from the date of service of said demand, then the entire amount of compensation awarded, agreed upon or adjudged shall become immediately due and payable and said employee or other person entitled to said compensation may maintain an action in any court of competent jurisdiction for the collection thereof in like manner as for the collection of a debt. The remedies of execution, attachment, garnishment or any other remedy or procedure for the collection of a debt now provided by the laws of this state shall apply to such action and also to all judgments entered under the provisions of section 44-529 of the General Statutes of 1935; Provided, No exemption granted by any law shall apply except the homestead exemption granted and guaranteed by the constitution of this state.
*215“Sec. 2. This act shall take effect and be in force from and after its publication in the official state paper.”
The statute became effective March 24, 1943, one day after rendition of judgment in the compensation case.. The last weekly compensation payment under the judgment was made November 2,1943, to and including November 9.
On November 29, 1943, the attorney for appellee sent a letter by registered mail to the attorney for appellant which was as follows:
“November 29, 1943
“Mr. P. H. Richart,
“Attorney-at-Law,
“Joplin National Bank Building,
“Joplin, Missouri
"Inre: Wesley John Ellis vs. Kroger Grocery and Baking Company, in the District Court of Crawford County, Kansas, Sitting at Pittsburg. Case No. 15750.
“Dear Mr. Richart:
“As the attorney of record for the above Claimant, Wesley John E'llis and in claimant’s behalf, I am requesting that you please forward to claimant the unpaid installments of compensation awarded and adjudged to claimant by the District Court of Crawford County, Kansas, in the'above entitled cause, now due and accumulated and will you also have the Respondent, Kroger Grocery and Baking Company continue to forward to Claimant compensation installments and payments awarded and adjudged to Claimant by the District Court of Crawford County, Kansas, in the above entitled cause as they become due and accrued. “Very truly yours,
“Sylvan Bruner.”
A signed copy of the above letter was sent by registered mail to the local store of appellant at Pittsburg, Kan. Both letters were received by the addressees on November 30, 1943. No compensation was received from appellant by appellee within two weeks from November 30, 1943. On December 17 counsel for appellant wrote counsel for appellee a letter enclosing four checks covering weekly payments from November 10 to and including January 4,1944. The checks were promptly returned with the advice that since compensation was not paid as required by law appellee had filed an action for a lump-sum judgment on December 16.
On March 21,1944, appellant filed an offer to allow judgment to be taken against it in the sum of $87.21. On the same date it tendered to appellee the sum of $318.21 in cash. These tenders were both refused. On March 22, 1944, appellant filed an application before the commissioner of workmen’s compensation for a review and modification of the award. On April 6 appellant requested appellee *216to submit to a physical examination. On April 27 appellant again made a request for examination on May 3 or 5. The requests were refused. Evidence of such requests were offered at the trial by appellant but were excluded. Appellee entered a special appearance before the commissioner and objected to a review on the ground the instant action was pending in the district court and that the commissioner had no jurisdiction to entertain a hearing for review and modification of the- award. He also alleged sufficient notice was not given.for the hearing before the'commissioner. On April 27,1944, the commissioner declined to act on the ground he was without jurisdiction while the instant case was pending for the purpose of determining whether G. S. 1943 Supp. 44-512a was applicable to this case. The commissioner also advised that the hearing before him for review and modification was then set for May 22, and that it was his opinion that when appellee’s motion came on for hearing on that date it should be sustained and the hearing continued until the instant case was disposed of in the district court. This ruling was forwarded to the examiner and copies thereof were sent to attorneys for the respective parties. At the beginning of the trial on May 6 appellant tendered to appellee in court $421.93, the amount due to that date under the compensation award. The tender was refused. Judgment for a lump sum was rendered May 16, 1944. Three days later, May 19, 1944, the commissioner, apparently having reached a different conclusion on the subject of his jurisdiction, set the hearing for review at Pittsburg for June 26, 1944, and so advised .the examiner and counsel for the -respective parties. The last order of the commissioner was later offered as one of the grounds for- a new trial. Appellant’s application for a review before the commissioner had been offered in evidence at the trial, but it was excluded. Appellant’s motion for a new trial was.overruled.
This brings us to a consideration of the legal questions involved. Appellant contends the trial court erred in overruling (1) its motion, for judgment on the pleadings; (2) its objections to the introduction of any evidence; (3) its demurrer to appellee’s evidence; and (4) its motion for a new trial.
Two fundamental legal questions are involved in each of the first three contentions. They will receive our first attention. Thereafter the subject of alleged trial errors will be treated. The basic legal questions involved are, first, whether the 1943'lump-sum-judgment law was intended to apply to a judgment previously rendered but in *217which default in the payment of compensation installments was made after the enactment of the new law, and second, if the new law is held to be applicable is it retroactive in character and therefore invalid on the ground it interferes with vested rights.
It is true, as appellant contends, that ordinarily statutes are designed to operate prospectively rather than retroactively and will not be given the latter effect unless it clearly appears they were intended to so operate. (Bank Savings Life Ins. Co. v. Baker, 120 Kan. 756, 244 Pac. 862; International Mortgage Trust Co. v. Henry, 139 Kan. 154, 30 P. 2d 311; Beeler & Campbell Supply Co. v. Warren, 151 Kan. 755, 100 P. 2d 700.) It is also true that when a retrospective construction of a statute will disturb vested rights or impair the obligation of an existing contract, it will not be given unless the wording of the statute makes such construction imperative. (Bank Savings Life Ins. Co. v. Baker, supra.)
Was the new law intended to apply to the instant case? Judgment in the compensation case was rendered March 23, 1943. The new law became effective March 24, 1943, but appellant’s default under the former judgment did not occur until November 10, 1943. The 1943 statute, previously quoted, embraces . . any compensation awarded, agreed upon or adjudged ... or any installment thereof . . . when due . . .” The legislature undoubtedly understood at the time it enacted the new law that installments of compensation would be falling due in the future under numerous compensation judgments previously rendered. It will be noted no exception was made with respect to future installments due and payable under judgments previously rendered. The general language employed without the remotest indication of $ny exceptions leads us to conclude the legislature must have intended to cover installment payments which were to become due and payable in the future irrespective of whether the judgment was rendered before or after the passage of the 1943 law. There are cases in which the various provisions of a law, when construed together as they must be, render untenable the interpretation we have given to the word “any” in the instant case. An example is found in the recent pension case of Bulger v. West, 155 Kan. 426, 430, 125 P. 2d 404. The difficulty encountered in that .case with the interpretation of the word “any” does not exist in the instant case. In concluding the new law was intended to apply to installment payments which became due and payable after the effective date of the new law we are *218not applying the new law retroactively but prospectively with respect to defaults in the payment of such installments.
Does such interpretation of the law infringe upon appellant’s vested rights? Appellant asserts.it does in various respects. All of its contentions are bottomed on the proposition that where parties are within the compensation act, as it is agreed they are in this case, the substantive rights of the parties are determined by the law in effect on the date of the workman’s injury. That contention is sound. (Moeser v. Shunk, 116 Kan. 247, 226 Pac. 784; Workman v. Kansas City Bridge Co., 144 Kan. 139, 58 P. 2d 90; Baker v. St. Louis Smelting & Refining Co., 145 Kan. 273, 65 P. 2d 284.) The question here, however, is whether the new law is remedial in character, that is, whether it merely provides a method or procedure for the collection of future installments in the event appellant refuses to comply with the terms and requirements of the existing judgment.
Appellant contends it disturbs substantive rights. It claims it had the right to pay the installments as they became due and payable under the terms of the previous judgment and that in case of default in such payment appellee could collect only the amount of installments due at the particular time. (Palmer v. Fincke, 122 Kan. 825, 253 Pac. 583; Trunkey v. Johnson, 154 Kan. 725, 121 P. 2d 247.) The new law did not disturb appellant’s vested right to pay the installments according to the terms of the previous judgment if he complied therewith. It did not render all future installments due and payable in the event of. default in the payment of any of >them. It provided only for the maturity of all future installments in the event appellant failed to pay the installments already due within two weeks after statutory demand was made for their payment. While the new law provided the workman an additional or supplemental remedy for the collection of an existing judgment in the event of the employer’s default it did not deprive the employer of his vested rights, but left it wholly optional with the employer whether he would protect his vested rights by complying with the terms and requirements of the judgment previously rendered against him. In other words, under the new remedy the employer had the choice of protecting his vested rights by merely complying with the judgment by which he was bound until modified, or to permit the workman to invoke the new remedy for the collection of all future installments.
In view of what has been said we think the statute was remedial *219in character and deprived appellant of no vested right. A statute which merely changes a remedy is not unconstitutional, although it is applied retroactively. (State; ex rel., v. Public Service Comm., 135 Kan. 491, 503, 11 P. 2d 999; Dobson v. Wilson & Co., Inc., 152 Kan. 820, 107 P. 2d 676.) Here the new remedy is being applied prospectively. In the Dobson case, supra, we had under consideration a new statute which lengthened the period from ninety to one hundred and twenty days within which a claim for compensation could be filed by the workman. The new law was enacted while compensation was being paid. More than ninety days elapsed between the last payment of compensation and the filing of the claim. If the old law applied the workman was not entitled to recover. We held the new statute did not affect the substantive rights of the parties but was procedural and remedial in nature. In that opinion it was said:
“. . . the amendment did not alter the obligation in any manner, but affected only the remedy to be pursued by claimant if respondent defaulted in its obligation. There are no vested rights to any particular remedy. (See 12 C. J. 974 et seq.; 16 C. J. S. 678; 6 R. C. L. 359; 11 Am. Jur. 1201.)” (p.823.)
Appellant asserts that if the new law is applicable it applies only to installments already due. What previously has been said herein disposes of that contention.
The new law is also challenged on the ground it is too vague and uncertain to determine its meaning and application. We think that contention lacks substantial merit.
. Appellant also asserts the new law, if held applicable to the instant case, in effect amends various provisions of the compensation act in force when the judgment for compensation was rendered. It contends the new law deprives it of the right to apply for a redemption of ninety-five percent of the prospective payments under an award (G. S. 1935, 44-531); deprives it of the right of a review, modification or cancellation of- an award (G. S. 1935, 44-528); deprives it of having compensation suspended if the employee refuses to submit to a medical examination (G. S. 1935, 44-518; 44-515); deprives it of the statutory prohibition against the rendition of a lump-sum award except as to compensation then due (G: S. 1935, 44-525-); and deprives it of the statutory provision that in the event of death of the employee from independent causes the right to compensation shall terminate (G. S'. 1935, 44-510 [23]). Appellant argues that since the new law in effect amends the above provisions of the com*220pensation law without mentioning the various sections so amended it violates article 2, section 16 of our constitution, which provides:
“No bill shall contain more than one subject, which shall be clearly expressed in its title, and no law shall be revived or amended, unless the new act contain the entire act revived or the section or sections amended, and the section or sections so amended shall be repealed.”
We think the contention is unsound. The new law disturbs no vested rights under the provisions of the statutes referred to by appellant. Those rights remain ■ available to appellant so long as he 'complies with the terms and requirements of the judgment rendered against him. The new law is supplemental in character. It was intended to supplement existing remedies as indicated therein. It applies to a different state of facts from those 'embraced in, the former provisions of the compensation act. Furthermore statutes which affect the amendment of existing laws by implication are not within the purview of article 2, section 16, of our constitution. [Parker-Washington Co. v. Kansas City, 73 Kan. 722, 85 Pac. 781; Bank v. Pearce, 76 Kan. 408, 409, 92 Pac. 53; State v. Pauley, 83 Kan. 456, 464, 112 Pac. 141.)
Appellant insists no demand for‘compensation after default was made as required by the new law. The facts pertaining to this demand have been stated previously herein and need not be repeated. It is appellant’s contention the letter from counsel for appellee could not reasonably be interpreted as a demand but was rather in the form of a request. The statute does not say the word “demand” must be used. No particular form of demand is prescribed. The letter clearly indicated claimant wanted the employer to pay the compensation which was past due and payable. We think that was a sufficient compliance with that feature of the statute.
Appellant argues the demand was not served on any “. . . person, firm or corporation liable to pay the same. . . .” Under the statute service of the demand could be made personally or by registered mail. In this case service was by registered mail. One letter was sent to counsel for appellant who had represented appellant in the original compensation case and who was representing appellant in the instant case. Various payments of compensation, if in fact not all of them, had been made through his office for appellant. That included compensation which was tendered after the instant action was filed. A copy of the letter which was also served upon appellant’s local store in Pittsburg contained the caption of the *221former compensation case filed in the district court of Crawford county. In support of appellant’s contention that the demand was insufficient it cites Richardson v. National Refining Co., 136 Kan. 724, 18 P. 2d 131; Baxter v. Chicago, R. I. & P. Rly. Co., 139 Kan. 443, 32 P. 2d 451; Smith v. Sonken-Galamba, 149 Kan. 693, 88 P. 2d 1114. Those decisions do not require us to hold the instant demand insufficient.
The provision of the compensation act must be liberally construed in favor of the workman with the view of effecting its purpose. (Mendel v. Fort Scott Hydraulic Cement Co., 147 Kan. 719, 78 P. 2d 868; Rupp v. Jacobs, 149 Kan. 712, 718, 88 P. 2d 1102.) So construed and applied to the facts before us we have no doubt the' purpose of the demand statute was accomplished. In this connection we also may note that appellant does not contend it was not fully apprised of the demand and that therefore it failed to pay the compensation within the statutory time.
Appellant complains of rulings excluding its evidence, (a) that the award was for an unscheduled injury; (6) of its application before the commissioner for review' of the award; and (c) of its requests that appellee submit to a physical examination. These complaints may be treated together. The same district court previously had reviewed the transcript of the record in the original compensation case and rendered judgment therein. The journal entry of judgment had already been introduced in evidence by appellee. Additional evidence on that point was not essential. For the purpose of this appeal we have assumed and are_ now assuming the award was for an unscheduled injury and that ordinarily the award would have been subject to review and modification. In fact the judgment in the compensation case, previously quoted herein, conforms to that view. Here, however, the application for a review by the commissioner and the requests for physical examinations were all made after appellant had failed to comply with the demand for compensation under the new law and after the district court had acquired jurisdiction of the parties and subject matter in the instant case for a lump-sum judgment. The remedies mentioned in (a) and (6) above would have remained available to appellant had he seen fit to pay the installments, which were past due and payable, within two weeks after the service of the statutory demand. Appellant did not see fit to protect his rights under those remedies. Under these circumstances it did not constitute error to exclude the testimony in question.
*222In view of what previously has been said herein we need not give further consideration to the order overruling the motion for a new trial.
The judgment is affirmed.