[The court physician, the clergyman, a learned society and smallpox]

Variolation was introduced in England in the first half of the 18th century. The positive effects of this new method for preventing smallpox were already known in the Netherlands around 1720, one of whom was the Dutch physician Boerhaave. In spite of this, it took another 30 years before variolation was used in the Netherlands. Despite receiving positive advice and information from his learned English friends Sloane and Sherard, Boerhaave did not apply nor advise the use of variolation. There were various arguments for this restrained approach. In 1754 Thomas Schwencke found that conditions were favourable for the introduction of variolation in The Hague. There was support from the House of Orange-Nassau (the current royal family in the Netherlands) and from a learned society; a highly motivated clergyman acted as ambassador for the new technique and the court physician Schwencke was willing to take the lead. A similar combination had previously been effective in England, though the ambassador there was not a clergyman but an influential noble lady.