Final answer:
The excerpts provided do not contain information about someone asking the London Constabulary to bring stabbing and slashing victims to them for free treatment, hence an accurate answer cannot be provided.
Step-by-step explanation:
The individual who asked the London Constabulary to bring all stabbing and slashing victims to him to treat for free was not explicitly mentioned in the provided excerpts. The primary sources supplied speak of historical requests for medical assistance and other forms of help, but they do not contain a specific reference to a person who made this exact offer to the London Constabulary. As such, it is not possible to provide an accurate historical figure without further information or context surrounding this particular inquiry.