The bulk of this book is a rather pointless study of the year-to-year variations in frequency of experiments at the Royal Society. These variations are all more or less accidental and tell us nothing of substance: everyone always loved experiments and slumps in them were always due to external circumstances, such as lack of funds (the Society, being royal by name only, was self-funded, and poorly so, by subscription fees) or ingenuity (although the meetings could sometimes be attended by as many as "neer 40," few were capable of coming up with interesting experiments on a weekly basis). As for the spirit of the Society, which remained the same throughout the period studied, it is clear that the role of experiments was above all to entertain and stimulate lively discussion. This spirit was expressed again and again by virtually all important members of the Society. (Boas Hall also alleges that Baconian considerations were important, though for this she offers virtually no evidence at all.)
One beautiful experiment which may serve to exemplify the spirit is that of blood transfusions. At first "dogs were used; the donor was bled until it died, whereupon the recipient was sewn up and when set free showed itself very lively." A flurry of inter-species blood transfusions followed, with enough success that a human subject was found who agreed to have his blood replaced with that of a sheep. "The subject, one Arthur Coga, an indigent Oxford graduate, not only survived being given the blood of a sheep, but two months later he read a paper to the Society describing the effects which he had experienced." The same experiment was tried with less success by Denis in France. "One of Denis's subjects did die after a second transfusion, whether, as seems likely, as a direct result of the experiment, or, as Denis claimed, from poison administered by his wife. In any case human blood transfusion was then legally banned in Paris and the Royal Society wisely decided to discontinue the practice."