T O 
Sir HJNS SLOANE, Bar*. 
Phyfician in Ordinary to his M a j e s t y, 
Late President of the Royal College of Physicians, 
London, and of the Royal Society. 
Honoured S I Ry 
UPPER me to caft this weak Effay (towards 
Natural Knowledge) into your boundlels Trea- 
fury of Nature, that it may be fupported by 
your Charitable Prote6lion, and skreen’d under 
your Illuftrious Name from the Malice of Detractors. If 
there be any Thing in it worthy your Notice, it is prin- 
cipally owing to your Generofity, in giving me all poffible 
Encouragement in the Art of Deligning after Nature, in 
which Employment you have ( without fparing your 
Purfe) continued me for many Years, to my great Im- 
provement in that Art: Yet, Sir, your indulgent Kind- 
nefs, in giving me a full Liberty at all Times, for thele 
many Years paft, to confult and examine that ineftimaale 
Treafure of Nature and Arts, colleCted by the worthy In- 
duftry and Labour of a great Part of your Life, engages 
my Gratitude more than any mercenary Confiderations. 
I have often refleCted on my own good Fortune, 
when I have confidered that the Benefit which I enjoy has 
for 
