(Chapter 39) Footnote 1:

The 1555 edition omits this clause; ad solos syrupos scribendos refers to the writing of prescriptions for remedies whose bad taste is masked by sweetening. For Vesalius’ disapproval of such medication, cf. the last sentence of this chapter and see chapt. 21 above, a Syropis & Iulepis interdum animum avocantes, with note 62.