194 TRAVELS' IN 
China, advanced that ambergris was produced 
by a whale, and gave proofs of it, were there 
not men, your clofet naturalifts, who oppofed 
their affertions ? 
Let us not believe from vague report every 
thing indifcriminately. Such condud would 
by no means accord with the didates of 
reafon. Let us previoufly examine the cre- 
dibility due to the perfon who may ad- 
vance new fads, and the evidence adduced in 
fupport of them ; bat let us not rejed them 
merely becaufe they are new. The more we 
ftudy nature, the more we fliall difcover cir- 
cumftances which it will be impofliblc for us 
to explain. But how many daily occur before 
our eyes, vv^hich we even never think of exa- 
mining 1 Let thofe writers on natural hiftory, 
whofe whole fcientific knowledge confifts in 
reading and reafoning from books, inform me, 
for example, why the fv/allow, when its neft 
is deftroyed, will begin ten or twelve times fuc- 
ceffively to rebuild it in the fame place, while 
indigenous birds abandon theirs as foon as it 
has been touched, and go elfewhere to con- 
ftrud another.. 
With regard to the eggs fet apart by the 
oftrich 
