NUTRITION. 
fimilar to the fubftance of the being which it is to nourith, 
wafte it is to _ and 
matter to our organs, 
mafelves, con- 
t into our own fu e. 
The component aces of an animal body are in a 
ftate of conta change ; the old ones are detached and 
aati Py the abforbents, and their place is {upplied by 
t laid down by the plas Until the body 
has a its full fize, the movemen compofition 
predominates over that of decompolition, and all the parts 
3 
BOD 
= 
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arts. Hence y has been compared b 
phyfiologift to the veffel of the Argonauts, fo often re- 
performed by mixing madder with the 
ve moft unqueftionably this cana decompofition of 
animated and living matter. is mixture, in confequence 
a chemical affinity between the madder and phofphat 
of lime, dyes all the bones of a red colour; when the 
madder is left off for a fufficient length of tim 
It is obvious, that the 
m 
moved, and place fupplied by the coloured eart 
while this is again = aaa in its turn, peal the ee 
is difcontinued, to m r coloured de- 
pofition. If the hard deft a ‘not folid a apparently 
the moft calculated to refi y, are under per- 
petual motion of decompofition and regeneration; the 
an be little doubt that t i more 
c 1 
rapid in thofe, whofe power of cohefion is much inferior; 
for example, in the fluids. In the nails, hair, and cuticle, 
a conftant growth is fo regularly obferved, that it is not 
neceflary to particuiarife the phenomena. & is not 
all pofflefs, can orly be 
frequently fee confiderable enlargement or dimin 
the body or a part, when eee the addition or ae 
tion acquires an undue a aaa 
Attempt to eerae the period, at 
s have been m 
; it has been fup- 
ut this is a point bale fufceptible of any preci 
termination. The change goes on more rapidly in childhood 
and moult require 
all the organs become frmer, and the vital powers mor 
languid. There can be no doubt that fex, habit, climate, 
mode of life, and various other circumftances, accelerate or 
retard it. 
efe Sonidemt one render it obvious, that the notion . 
perfonal identity cannot conlift in famenefs of the body ; 
nimal dees not confift of the fame parts in the fame age: 
ment, not only at no two ae periods, but not in two 
following days or even hou 
the old matter, ad 
oie nged. Were otherwife 
would be undergoing perpetu ual 
This fun Gtion of reparation is alloted to the circulatin ng 
organs 
8 & 
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48 
into 
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co 
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Oo 
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3 
are ob- 
tect the variations of compofition, 
may be reafonbly epee to arife from the cir- 
— $ ju enu 
From this common Gee fluid, the blood, conveyed 
in shes ehh. anatomy fhews us to be eve 
dra 
{wer particular purpofes in the economy, and are then ex- 
pelled from the body; in the former, the new produéts 
drawn from the blood are added to the body, and become 
identified with i u iti ifferent 
re. Nutrition muft differ 
ppropriating to itfelf whatever 
» in the flui 
of all our organs: cellular tiffue, arteries, veins, par ex- 
halants, and abforbents, are the un 
verfally found : nutrition, refulting from 
of compofition, which bri 
and of decompofition, which removes it, fuppofes their ex- 
iftence; the exhalants are the agents in the firft of thefe 
motions, the abforbents in the fecond. The general fyftems 
above-mentioned conftitute the nutritive parenc 
i 
organs. It is phof{phat of lime 
and faa in the bones, gelatine only in the cartilages and 
as te fibrine in the mufcles, &c. See the article 
Fis 
is 
The nutrition of a part ee a fupply of seer blood, 
the fource of its materials. ing the principal artery of a 
limb does not interrupt this funtion, pene the blood is 
conveyed through other channels ; neral ligature, 
impeding the entrance of bloo aioe is followed by 
death of the part. The influence of the brain and nerves is 
