§ 43. Evidence. The doing of anything prohibited by this chapter
shall be evidence of the violation of the provisions of this chapter
relating to the thing so prohibited, and the omission to do anything
directed to be done shall be evidence of a violation of the provisions
of the chapter relative to the thing so directed to be done. The intent
of any person doing or omitting to do any such act is immaterial in any
prosecution for a violation of the provisions of this chapter. Any
person who suffers, permits or allows any violation of the provisions of
this chapter in any room or building occupied or controlled by him,
shall be guilty of such violation and liable accordingly. Any person who
shall keep, store or display any article or product, the manufacture or
sale of which is prohibited or regulated by this chapter, with other
merchandise or stock in his place of business, shall be deemed to have
the same in his possession for sale.

Every certificate, duly signed and acknowledged, of a chemist, analyst
or other expert employed by the commissioner or any analysis,
examination or investigation made by such analyst, chemist or expert
with respect to any matter or product which the commissioner has
authority to examine or cause to be examined, shall be presumptive
evidence of the facts therein stated.