Probably the second book on whooping cough, written after two of Watt's children died from the disease. After vaccination for smallpox was introduced, Watt found, as he had expected, that the number of deaths from that disease was reduced, and he expected to find a relative reduction in pediatric mortality as a whole. However, he found that no such reduction had occur, as children continued to die from other diseases. This result placed him in direct conflict with advocates for vaccination who hoped to show that curing smallpox would reduce deaths overall. Digital facsimile from the Internet Archive at this link.