274 N A T U R A L H I S T O R Y
L E T T E R LVI.
TO THE SAME»
T h e y who write on natural hiftory cannot too frequently advert
to mJi'mB., that wonderful limited faculty, which, in foroe inftances,
raifes the brute creation as it were above reafon, and hi others
leaves them fo far below it». Philofophers have defined faftina. to
be that fecret influence by which every fpecies is impelled naturally
-to purfoe, at all times, the fame way or track, without any teaching
or example; whereas reafon, without inftru&iom, would often»
yary and do that by many methods which -infiM effe&s by one
alone. Now this maxim mud be taken in a qualified fenfe; for
there are inftances in which inJUnd does vary and conform to the
circumftances of place and convenience.
It has been remarked that every fpecies of bird has a mode of
nidification. peculiar to itfelf; fo that a fchool-boy would at once
pronounce on the fort of neft before him. This is the cafe among
fields and. woods, and wikis ; but, in the villages round Loudon,
where mofles and goflamer, and cotton from vegetables, are hardly
to. be found, the neft of the duffinch has not that elegant
finilhed appearance, nor is it fo. beautifully ftudded with lichens,,
as. in a more rural diftrift : and the wr-en is. obliged to canftrudt,
it’s houfe with ftraws and dry grades, which do not give it that
rotundity and compadtnefs fo remarkable in the edifices of that
little architect. Again, the regular neft of the houfe -martin is
hemifphericj
hemifpheric; but where a rafter, or a joift, or a cornice, «nay
happen to Hand in the way, the neft is fo contrived as -to conform
to theobftru&ion, and becomes fiat or oval, .or cemprefled.
In the following inf tancesi s. :perfedt ly «liform and «Son*
fiftent. There,are dir.ee creatures, the fquirrel, the field- andthC
bird called themt-hateh, (fitta Bnrcfaea), which darp much on hazle-
nuts; and yet ,they open them .each in a .different way. The -firft,
after rapping off the frnall end, fplits the fhell in two With his long
for.e-iteetb, as a man does with his knife.; the fecamd nibbles a hole
with his .teeth, fo »regular as .if idsrilled with a w&ffible, and yet fo
frnall that one .would wonder how the kernel can be extracted
through it ; while »the Jail picks an irregular »ragged hole with it’s
b ill: but as this, arti-ft has no paws to hold the »nut firm -while he
pierces it, like an adroit workman, he fixes it, as it were in a vice,
in fome cleft of,a tree, or in fome crevice; when, ftanding over
it, he perforates the ftubborn (hell. We have often placed nuts in
the chink of a gate-pod where nut-hatches have been known to
haunt, and have always found that thofe birds have readily penetrated
them. While at work they make a rapping noife that may
be heard at a confiderable diftance.
You that underftand both the theory and practical part of mufic
may beft inform us why harmony or mehdy Ihould fo ftrangely
affedt fome men, as it were by recdfleStion, for days after a concert
is over. What I mean the following paffage will mod readily
explain:
“ Prshabebat porrh vocibus hufnanls, inftrumentifque har-
“ monicis muficam illam avium : non quod alia quoque non
“ deledlaretur; fed quod ex mufica hurnana relinqueretur in
“ animo continens quasdam, attentionemque et fomnum con-
“ turbans agitatio; dum afeenfus, exfeenfus, tenores, ac muta-
N n 2 “ tiones
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