The chlorine used in the separation of arsenic (p. 385) must be pure. The best process for making it is to heat pure potass. dichromate with pure hydrochloric acid. The latter may be obtained by heating the “pure” acid of commerce in a retort until a portion of the distillate gives no indication of arsenic by the tests. The remainder in the retort is then arsenic-free.
ERRATUM.
Page 397, line 11, for “Waislow,” read, “Winslow.”
TRIALS FOR POISONING.
CHAPTER I.
CHEMICAL INTRODUCTION.