T O T H E

Truly Ingenious and Learned Dr. Sloane. 3 Vhyficianextraordinary to Her mofl Sacred Majefty, Secretaryto the Royal Society, and Fellow of the Collegeof Vhyfeciam, London.

I think my felf under many Obligations of offering this Un-dertaking to you, which I mould be much wanting to myielf if I did not acknowledge : The Firft is, that you havebeen a very generous Encourager of this Defign ,• not only byrecommending the Work, but in affixing the Performance,which,is a Favour I beg Leave to thank you for, as well as thekind Prefent you made me of your Natural Hijlory of Jamaica.,And tho' thefe were Inducements, they were not the real Mo-tives that made me think this Work cou'd come to none fo pro-perly as your felf: But it was the Confideration, that you are,wichout the leaft Tincture of Flattery, the only Perfon of theFaculty in thefe Kingdoms, who of late Years have made theMateria Medica your Study: So that it is hard to fay, whe-heryour Difcoveries in the Theory of Medicine, or your judiciousImprovements of thofe Difcoveries in the Practice, have ex-ceeded.

It wou'd look vain in me to attempt the Characters of myAuthors to one who is fo much better acquainted wkh them, and

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