- A licence-holder shall not sell powdered white arsenic to any person, unless the same is, before the sale thereof thoroughly mixed with soot in the proportion of an ounce of soot at least to one pound of the white arsenic or with indigo or prussian-blue in the proportion of half an ounce of indigo or Prussian blue to one pound of white arsenic, and so on in proportion, for any greater or lesser quantity:Provided that the licensing authority may, after full investigation and reference, if necessary to higher authorities, permit on such conditions and subject to such restrictions as he thinks necessary, and licence-holder to sell white arsenic without any admixture.
