175. Sale of adulterated drugs. Any person who, knowing any drug or medical preparation to have been adulterated in such a manner as to lessen its efficacy, to change its operation, or to render it noxious, sells the same or offers or exposes it for sale, or issues it from any dispensary for medicinal purposes as unadulterated, or causes it to be used for medicinal purposes by any person not knowing of the adulteration, commits a misdemeanour. 176. Fouling water. Any person who voluntarily corrupts or fouls the water of any public spring or reservoir, so as to render it less fit for the purpose for which it is ordinarily used, commits a misdemeanour. 177. Fouling air. Any person who voluntarily vitiates the atmosphere in any place so as to make it noxious to the health of persons in general dwelling or carrying on business in the neighbourhood or passing along a public way commits a misdemeanour. 178. Offensive trades. Any person who, for the purposes of trade or otherwise, makes loud noises or offensive or unwholesome smells in such places and circumstances as to annoy any considerable number of persons in the exercise of their common rights, commits an offence and is liable to be punished, as for a common nuisance. CHAPTER XVII—DEFAMATION. 179. Definition of libel. Any person who, by print, writing, painting, effigy or by any means otherwise than solely by gestures, spoken words or other sounds, unlawfully publishes any defamatory matter concerning another person, with intent to defame that other person, commits the misdemeanour termed libel.