. . "Said chapter 140 of the General Laws is hereby further amended by inserting after section 122B the following 2 sections:- Section 122C. (a) As used in this section and section 122D, ???self-defense spray??? shall mean chemical mace, pepper spray or any device or instrument which contains, propels or emits a liquid, gas, powder or other substance designed to incapacitate. (b) Whoever, not being lic" . . .