DIETETICS. 
the saliva, the pancreatic juice, and the 
bile, (we confine ourselves to the more per- 
fect animals) that are alone able to convert 
this comrainutest chyme into the saccharine 
fluid, called chyle as it descends through 
the pylorus, or inferior orifice of the sto- 
mach, into the duodenum, in which the 
process of chylification is chiefly performed, 
and amidst the folds or valvula conniventes 
of which, the lacteals are most numerously 
seated. 
Yet it is not every thing the stomach is 
capable of dissolving that the secondaiy 
action of the chylopoietic viscera is capable 
of converting into food, or of converting 
with equal facility ; nor is it every substance, 
as we have already seen, containing the 
real principle of aliment, that the stomach 
itself is capable of dissolving in the same 
pei’iod of time, or with the same degree of 
ease. 
Hence the necessity of attending to what 
we have made the second branch in our 
present tract on dietetics, the nature of 
different alimentary substances, and espe- 
cially of the common principle on which the 
aliment of all of them may perhaps depend. 
Regarding this subject on a comprehen- 
sive scale, we have much reason to suppose 
that there is no substance whatever, either 
in animal, vegetable, or mineral existence, 
but contains a basis from which some ani- 
mal or other is capable of extracting nutri- 
ment. N or is this much to be wondered at, 
since we have already observed, that in dif- 
ferent classes of animals the organs of di- 
gestion vary in every possiI)le manner in 
regard to their presence or deficiency ; and 
inhre especially since we know that the 
fluid secreted by the stomach itself, the 
only organ that is universal, is equally dis- 
crepant in its powers and qualities in ani- 
mals of different structure ; being in some 
naturally acid, in others alkaline, and in 
otliers again insipid or neutral. And hence 
we not only discern the truth, but can 
trace the real cause of the fact long ago 
observed by Lucretius, iv. 640. 
Tantaque in hits rebus ^istaritia, differitusr 
que est, 
\Jt, quod aliis cibus est, aliis fuat acre vene- 
rum, 
“ So vast, at times. 
The strange discordance, that which poi- 
sons this. 
To that proves healthful and prolongates 
life.” 
We can hence see the reason why many 
of the serpent tribe should convert a wbole- 
some nutriment into a venemous secretion ; 
why the euphorbia, or spurge, so noxious to 
man, and most quadrupeds, should be gree- 
dily devoured by several of the insect 
tribes ; why the cicuta, which proves poison 
to the human race and the horse, should be 
luxuriously feasted upon by goats and quails ; 
while the horse, on the contrary, feeds 
with pleasure on the aconite, or bane-berry, 
which the goat will not touch. 
A thousand such peculiarities might be 
advanced if it were necessary ; but these 
alone are sufficient to prove that every 
created substance possesses the basis of a 
nutriment for some order of animals or 
other; and tliat all that seems necessary, 
with respect to those generally esteemed 
the most poisonous, is a peculiar power in 
the stomach to select tlie parts that are nu- 
tritious from those that are baneful, and to 
secrete these alone into the system. 
These observations apply to food gene- 
rally. We now proceed to observe, that 
even the same foods, under certain states 
of the stomach, to which they are naturally 
appropriate, will not universally produce 
the same beneficial results. Two questions, 
hence, naturally arise. What are those 
states of the stomach in which its appro- 
priate foods have for the most part a ten- 
dency to prove injurious instead of salu- 
tary (for the digestion of every aliment 
must do either the one-or the other) ? And of 
what nature are those substances which, 
under almost every circumstance form an 
exception to the rule of disease, and may 
still be swallowed with benefit ? 
It is clear then, in the first place, that the 
states of the stomach here referred to, are 
morbid states : morbid either from idiopa- 
thic, or symptomatic affection : and, se- 
condly that, as in all such cases, the com- 
mon action of the stomach must be debi- 
litated, and consequently its secreted or 
gastric juice partake of the debility, or be 
extruded in a much weaker and more dilute 
state, those aliments only can be usefully 
employed, which are both capable of being 
digested with a small portion of gastric 
energy, and at the same time capable, 
when digested, of affording a very large 
portion of the nutritive principle. 
It also happens, and that not unfreqnently, 
that in the preparation of such foods, we 
can add such accessary qualities as may 
tend to oppose tire morbid affection of the 
stomach, or the temperament generally, and 
GOop. 
