Section 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.