■ BUT 
Sn the contrary^ by evaporating it's moiflurc, in a 
^arm fituation, the animal affumes it's winged ftate 
before it's ufual time^ and goes through the offices 
affigned to it's exiftence. To evince the truth of 
this, Mr. R.eaumur inclofed an aureiia in a glafs 
tube; and found the evaporated water, which ex- 
haled from the body of the infedl, colledted in drops 
at the bottom of the tube : he then covered the au- 
jelia v/ith varnifh ; and, having thereby renciered 
tiie evaporation more difficult and flow, the But- 
terfly was two months longer than it's natural term 
in coming out of it's cafe. He found, on the other 
hand, that by laying the animal in a warm room, 
lie hafl:ened the difclofure of the Butterfly; and 
that by keeping it in an ice-houfe, in the fame 
manner, he retarded it. Warmth, in this cafe, 
adled in a double capacity; invigorating the ani- 
mal, as well as evaporating the moifture. 
When, either by warmth or incrcafing vigour, 
the parts have acquired their neceflTary force and 
folidity, the Butterfly feeks to difembarrafs itfelf 
of thole bands which kept it fo long in confine- 
ment; fome, however, continue under the aureiia 
form only ten days, fome twenty, fome feveral 
months,- and others for a year together. But, in 
general, the Butterfly makes onl)- a fliort continu- 
ance under it's aureiia form ; and, in all, the per- 
{e6t infeft fooner or later burlls not only the natu- 
ral prifon which is formed by the flcin of the au- 
reiia, but alfo that artificial one in which it has in- 
clofed itfelf. The efforts which the Butterfly 
makes to liberate itfelf from it's aureiia fl:ate, arc 
by no m_eans fo violent as thofe which it experi- 
enceci in changing from the caterpillar into the 
aureiia. The quantity of moifliure which fur- 
rounds the Butterfly is by no means fo copious as 
that which attended it's former change; and the 
ihell of the aureiia is fo diy, diat it may be cracked 
betvv^een the fingers. 
When the animal is fhut up within a cone, the 
Butterfly always gets rid of the natural internal fkin 
of the aureiia before it eats it's way through tlie ex- 
ternal covering v^^hich it's own induftry has formed 
round it. In order to obferve the manner by which 
it divefts itfelf of the aureiia covering, it is necef- 
fary to open the cone, and then the cfibrts of the 
inieft to emancipate itfelf from it's natural fliell 
may be plainly perceived. When this operation 
commences, there feems to be a violent agitation 
in the humours contained within the body of the 
little animal; it's fluids feem impelled by a hafl:y 
fermentation through all the veffels; while it la- 
bours violently with it's legs, and makes leveral 
other violent ftruggles to get free. As all thefe 
motions concur with the growth of the infe£t's 
wings and body, it is impolTible that the brittle 
fkin wliich covers it Ihould long refiit; and it at 
length gives way, by burfting in four difliindt and 
regular pieces. The {km of the head and legs 
firft feparates ; then the dorfal fkin flies open, and 
divicUng into tv/o regular portions, difengages the 
back and the wings; and, at length, another rupture 
fucceeds in that portion which covered the rings of 
theaurelia's back. After diis theButterfly,feemingly 
fatigued with it's exertions, remains very quiet for 
fome time, with it's wings pointed downwards, and 
it's legs fixed in the flcin which it has jufl; thrown 
off. At firft fight, the animal, jufl: let free, and 
permitted the future ufe of it's wings, feems entirely 
deftitute of any; and they lie fo clofe, and occupy 
fo little room., as to be entirely imperceptible: 
hov/cver, d^y foon after expand fo rapidly, that 
BUT 
the eye can fcarcely mtnd to their unfolding: 
From reaching hardly half the length of the body, 
they acquire, in a m.oft y/onderful manner, their 
full extent and magnitude, fo as to be each five 
times as large as before. Nor are the wings alone 
thus increafed ; all their fpots and paintings^ before 
fo mdnute as to be hardly perceptible, are now 
proportionably exte^nded; fo that what a few mi- 
nutes before feemed only a number of confufed, 
unmeaning pointS;^ ngw become diftin£i: and beau- 
tiful ornaments. The wing, the inftaat it is freed 
from it's late confinement, is confiderably thicker 
than afterwards ; fo that it fpreads in ail it's di- 
menfions, and grows thinner as it expands in 
breadth. If one of the v/ings be plucked from 
the animal juft fet free, it may be' fpread by the 
fingers, and it will foon become as broad as that 
which is left behind. As the wings extend them- 
felves fo fuddenly, they have not had proper time 
to dry; and accordingly appear like pieces of wet 
paper, foft, and v/rinkled. In about half an hour, 
they become perfeftly dry; their wrinkles entirely 
difappear; and the little animal afllimes all it's 
fplendor. The transformation being thus perfed:- 
ly finiflied, the Butterfly difcharges three or four 
drops of blood-coloured fluid, which are the lail 
remains of it's fupei-fluous moifture. Thofe au- 
relias which are inclofed within cones, find their 
exit more difficult, as they have ftiil another pri- 
fon to break through : this, however, they accom- 
plifh in a fliort time ; for the Butterfly, divefted of 
it's aureiia fkin, butts v/ith it's head violently 
againft the walls of it's artificial prifon : and pro- 
bably with it's eyes, which are rough like a file, it 
rubs the internal furface away, till at laft it is feen 
burfting it's way into open light ; and, in lefs than 
a quarter of an hour, the animal arrives at full per- 
fedion. Thus, to ufe the words of Swammerdam, 
we fee a little infignificant creature diftinguifhed 
in it's laft birth with qualifications and ornaments 
which man, during his ftay on earth, can never even 
hope to acquire. To enjoy life, the Butterfly 
needs no other food than the dews of heaven, and 
the honied juices which are diftilled from every 
flower. The pageantry of princes cannot equal 
the ornaments with which it is inverted, nor the 
rich colouring which embellifhes it's wings. The 
fkies are it's proper habitation, and the air it's ele- 
ment; while man comes into the world naked, 
and often roves about without habitation, and 
without fnelter ; expofed, on the one hand, to the 
heat of the fun ; and, on the other, to the damps 
and exhalations of the earth; both alike inimical 
to his happinefs and exiftence: a ftriking proof 
that, while this little animal is raifed to it's greateil 
exaltation, man, in this world, is only a candidate 
for perfeftion. 
The number of thefe beautiful infedls is amaz- 
ingly great; and though Linnseus has enumerated 
above feven hundred and fixty difterent fpecies, the 
catalogue is ftill very incompleat. Every colletlor 
of Butterflies can exhibit undefcribed fpecies ; and 
he who is fond of minute difcovery, can produce 
animals obfervable only by himfeif. In general, 
however, thofe of the warmer climates are larger 
and more beautiful than fuch as are found in Eu- 
rope ; and v/e can eafily difpenfe with the beauty 
of the Butterfly, fince we are thus freed from the 
ravages of the caterpillar. 
The wings of Butterflies, as already obferved, 
fally diftinguifli them from flies of every other de- 
nominatio-a. They are four in number j and, 
Ihould 
