Opinion by
Van der Voort, J.,Appeal is taken to this Court from the lower court’s order sustaining appellee’s demurrer to the evidence to the charge of selling drugs and discharging the appellee-defendant.
Appellee was arrested and charged with delivery of a controlled substance (phencylidine) to an officer of the Pennsylvania State Police Criminal Investigation team. Following indictment by the Grand Jury on three counts, to-wit, possession, possession with intent to deliver and delivery of controlled substances, in violation of Section 13 of The Controlled Substance, Drug, Device and Cosmetic Act,1 appellee was held for trial. On February 19, 1974, at trial before Honorable John P. Flaherty, Jr., Judge, presiding without a jury, and following the Commonwealth’s case, appellee demurred to the evidence on the ground that the Commonwealth had failed to prove that appellee was not registered with the Secretary of Health of the Commonwealth.2 The demurrer was sustained, and the Commonwealth has appealed.
*311The question before the Court thus is whether as a part of its case the Commonwealth must prove that a defendant is not registered under the Act. The Act being designed to limit traffic in certain enumerated substances, the fact that one can so register and then be able to manufacture, distribute, retail, etc., makes that person exempt from the prohibitions of the Act. With this status of exemption at issue, direction must be focused to Section 21 of the Act3 which provides as follows :
“In any prosecution under this act, it shall not be necessary to negate any of the exemptions or exceptions of this act in any complaint, information or trial. The burden of proof of such exemption or exception shall be upon the person claiming it.”
The recent case of Commonwealth v. Stoffan, 228 Pa. Superior Ct. 127, 323 A.2d 318 (1974), interpreted this provision. Therein Judge Spaeth, speaking for the Court, Judge Spaulding being absent, pointed out the “exemptions and exceptions” referred to in Section 21 of the Act must be taken to mean only those which do not state necessary elements of the crime proscribed, lest an unconstitutional result obtain. “If ‘exemptions or exceptions’ referred to clauses that stated necessary elements (of the crime) and §21 operated to shift the burden of proof as to them onto the defendant, due process would be violated.” Commonwealth v. Stoffan, supra, at 138. Further, we rely upon Commonwealth v. Neal, 78 Pa. Superior Ct. 216 (1922), in which our court said:
“ ‘If an exception is material in arriving at the definition of the crime, it is generally held the State has the burden of showing the exception does not apply because it is then one of the essential elements of the offense. However, where the exception merely furnishes an excuse for what would otherwise be *312criminal conduct, the duty devolves upon the defendant to bring himself within the exculpatory provision.’ (Citations omitted)” quoted in Commonwealth v. Stoffan, supra, at 142.
Recognizing that the registration provision of the Act does grant an excuse for conduct otherwise prohibited, and recognizing that the Act intends control over certain substances, we hold that proving a defendant not to be registered is not a necessary element of the crime of violating the Act. With this belief, we find that the cases support a conclusion that it is not a violation of due process to place upon a defendant the burden of proving his registration. We therefore find support for an application of Section 21 of the Act to its registration — Section 6 — provisions.
The Court would be short-sighted if it did not address the practicalities of placing upon the Commonwealth a burden of proving an allegation the relevant facts of which were never in its possession. In Commonwealth v. Aikens, 179 Pa. Superior Ct. 501, 118 A.2d 205 (1955), footnote 1, page 506, the Court noted that the former Act as well provided that the burden of proving exemption was upon the defendant. To statutorily provide for a rule of evidence in no way would subvert a defendant’s right to the presumption of innocence. “The burden of proof may be placed on the party who must prove the existence of a fact rather than on the party who must prove its nonexistence.” Barrett v. Otis Elevator Co., 431 Pa. 446, 455, 246 A.2d 668, 673 (1968).
We call attention to Commonwealth v. Williams, 231 Pa. Superior Ct. 804 (1975), a case which the Court, at its December, 1974, Philadelphia session, decided to affirm by per curiam order. The question raised there is identical to that of the instant case. In Commonwealth v. Williams, supra, the Superior Court did not support the argument which is raised again herein, but rather affirmed the lower court’s judgment of sentence.
*313For the foregoing reasons, and in order to be consistent with our past holdings, the order is reversed and the case is remanded for new trial.
. Act of 1972, April 14, P.L. 233, No. 64, §13 (35 P.S. §780-113).
. Section 6 of the Act (35 P.S. §780-106) provides that a person entitled to he so registered, and duly registered, may manufacture, distribute, retail, sell, oifer for sale, and solicit the purchase of controlled substances.
. 35 P.S. §780-121.