valuable works, relative to the foffil kingdom ; and, after Having
examined them, you have, doubtlefs,. vifited the moft inte-
refting fpots in perfon, with the certainty o f not going in vain.
I, "on the contrary, have been travelling over a vaft country,
where fcienc.e is but little cultivated, ande where .natural hiftory
is fcarcely known byname. My expeditions were made-at a
venture;. I often wandered over vaft. deferts, and. craggy,
mountains, with the hopes o f finding fomething to compenfate
my fatigue, but was- too often difappointed. i could obtain
no knowledge o f ufeful or curious productions, but what I
difcovered with my own eyes.;. and I hardly met a perfon who
was qualified' to direct my fteps rather to one fiae than ito another.
Under fiich difadvantages, I fhould not have had the:
courage to addtefs my details to you, had I not known, that
exact obfervatioas on. common and obvious: things, which have,
been ill examined by the generality of writers, are more in-;
terefting to a true naturalift,, than more wonderful and uncommon
phenomena o f fmall extent, which ufually contribute not'
very much to fupport general theories;.. I have learned from you.
many things in the art of obferving,. and your .example has . con
firmed me in many particular cuftoms o f my own; hence, as it.
has often happened to you, fo it has;alfo fometimes.o.ccured.' ta.
me, that the ailertions o f reputable writers, on points o f phyfieal.
facft, are frequently falfe and erroneous.. Neither the authority
o f few, nor the voice o f many, can, I hope, impofe on either o f us,
to fuch a degree, .as to make us hafty in.<alTerting things not examined
by our own eyes. I therefore prefume, that the obfer-
vations which I have now the honour to tranfinit to you, will be'
received with confidence, in regard to .their exacftnefs, in the
fame manner as thofe you often favour me with are ever received,
by me. Reciprocal faith is both reafonable and neceffary, when
men,