(Yes, I know it's horrible to be so excited about poisons but for some reasons learning about them has always caused me to do this internally)
There is soooo much information in this chapter! I quit bookmarking segments because they turned into multiples on every page. Several famous poisoning cases of the time period were mentioned: Madeleine Smith (whose courtroom scene was was sketched by Arthur Conan Doyle's father), Florence Maybrick (whose trial was marred by Justice James Fitzjames Stephen, descending into senility), Elizabeth Barlow (killed by an injection of insulin - the forensic pathologist spent two hours searching with a magnifying glass for the marks), and many others.
A brief history of poisons and attempts to ward them off (beazors, etc.) and detect them is given. If you want to know more, The Poisoner's Handbook (not as deadly as it sounds - it covers Alexander Gettler and Charles Norris' work to raise forensic standards in New York City and beyond.
The chapter also covers the Smethurst case, which is credited with being one of the main reasons the field of medical jurisprudence languished in Britain while it took great strides on the Continent. The pathologist who ran the test for arsenic, Alfred Swaine Taylor, basically botched the test and had to admit it in court.
Something I'd not heard before is the that some historians think Dr. Bell hide his connection to forensic cases, such as the Chantrelle case.
I could go on and on but there are too many other chapters still to read. If this interests you, the above book as well as The Inheritor's Powder. A lot of this chapter has brought information from the later flooding back to me.