S.L. chp. 9

#20

In his Indian captivity, moreover, he had gained much knowledge of the properties of the native herbs and roots; nor did he conceal from his patients, that these simple medicines, Nature's boon to the untutored savage, had quite as a large a share of his own confidence as the European pharmacopoeia, which so many learned doctors had spent centuries in elaborating.

Before any set out across the Atlantic sea there were people called Alchemists who were hired by kings to perform an entertaining mixture of science and magic. Chemicals were abstracted from roots and plants of all sorts for experiments and medical purposes. Magic claimed to be used in alchemy is why I bring up Chillingsworth's time spent in Indian captivity. Indians in general are seen as evil demons by the Puritans and I'm sure that a spiritual gathering would look a lot like a call to Satan. Chillingsworth relates his knowledge of plants from Europe to that of the Indians and finds they are similar. What I'm trying to say is that in a way Chillingsworth is influenced by the "Satanic beings" and performs Satan's bidding through the withholding of information from Dimmesdale.