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GENUS IV.

PARAGEUSI S.

Morbid Taste.

Origin of the generic term.

66

SENSE OF TASTE VITIATED OR LOST.

GEN. IV. PARAGEUSIS is derived from Tapà, "male", and yɛów, gustum præbeo", whence mapayɛúw, and consequently лaşayɛúσis. The author has preferred, with Vogel, the present termination to parageusia, as analogous to the names of the preceding genera of the order before us.

Synonyms.

Association

senses of

taste and smell.

In the senses of taste and smell there is a considerable between the association, partly perhaps resulting from the proximity of their organs and partly from an affinity in the modification of the sentient fluids with which they are supIllustrated. plied. The young lady I have just noticed who was destitute, or nearly so, of the sense of smell, was equally destitute of that of taste, and could not distinguish by this criterion between beef, veal, and pork; and consequently in respect to all these had no preference.

Tongue not the only though the

of taste:

as taste has remained when the

been lost;

The chief organ of taste is the tongue, but this is not the only organ, nor is it absolutely necessary for an existchief organ ence of the sense. The Philosophical Transactions give us examples of persons who possessed a perfect taste after the tongue had been wholly destroyed; and Professor tongue has Blumenbach, in his Comparative Anatomy, affords us a similar example in an adult whom he visited, and who was born without a tongue. Consonant with which many insects appear to have a faculty of taste, though they mals appear have no organ of a tongue: and among these the gustatory function is supposed by Professor Knoch to be performed by the posterior pair of palpi or feelers. While, on the other hand, there are many animals possessing a tongue who do not use it as an organ of taste. All birds possess

or never

existed.

Some ani

to have a

power of

taste that

have no

tongue.

Other

animals

possessing a

Morbid

tongue do

not employ

it as an

organ of

taste.

Few birds

thus em

ploy it.

a tongue, for even the pelican, which has been said to GEN. IV. be tongueless, has a rudiment of this member: yet there Parageusis. are but few birds, comparatively, that taste or are able taste. to taste with this organ. Parrots, predaceous and swimming birds are an exception to this remark; for they possess a soft thick tongue, covered with papillæ, and moistened with a salivary fluid, and select that food which is the most agreeable. Yet in by far the greater proportion of birds we do not find the tongue appropriated to this purpose. In many of them, indeed, it is stiff, horny, and destitute of nerves. The tongue of the Toucan. toucan, though sometimes several inches in length, is scarcely two lines broad at its root: it has throughout the appearance of whale-bone and its margins are fibrous. The tongues of the woodpecker and cock of the woods Woodare equally hard and horny: in themselves they are cock of the pecker and short, and in a quiescent state, lie backward in the woods. mouth, and are covered with a sort of sheath issuing from the os hyoides or the esophagus: but they possess a mechanism which renders them extremely extensile, and capable of being thrust forward to a considerable distance. That of the woodpecker is sharp-pointed with barbed sides, and is darted with great rapidity out of the mouth to an extent of some inches; by which means it follows up such insects as the animal is in pursuit of, through all their crannies in the bark of trees; sticks them through with its apex, and in this state drags them out for food. The chameleon has a tongue of a some- Chameleon. what similar kind, which, in like manner, answers the purpose not of taste, but of preying for food. It is contained in a sheath at the lower part of the mouth, and has its extremity covered with a glutinous secretion. It admits of being projected to the length of six inches; and is used in this manner by the animal in catching its spoil, and especially in catching flies. It is darted from the mouth with wonderful celerity and precision; and the viscous secretion on its extremity entangles minute animalcules, which constitute another portion of its food.

GEN. IV. Parageusis. Morbid

taste.

The tongue, when it forms an organ of taste, as in man, is studded, and especially on its upper surface and lateral edges, with innumerable nervous papillæ issuing The tongue from a peculiar membrane that lies beneath, and has a near resemblance to the skin in other parts, but is softer and more spongy. Its external tunic or cuticle is an

when an

organ of taste

studded

læ :

covered

with papil- exquisitely fine epithelium, which is moistened, not by an oily fluid, like that of the surface of the body, but a peculiar mucus which proceeds from the foramen cæcum of Meibomius, and the rest of the glandular expansion of Morgagni.

with a fine epithelium.

Hence more

We have here, therefore, a more exquisite sense of touch than on the general skin, whose papillæ are not the papilla only smaller but dry.

sensible of touch than

of the skin. Its sentient

fluid differently modi

fied:

and render

ing it capable of discerning qualities

which the papillæ of the skin cannot.

Exact cause

of flavours unknown.

There can be no question, also, that the sentient fluid with which they are supplied is differently modified from that of the skin; and hence the provinces of the two senses, though they occasionally approach each other, are still kept distinct; and the tongue becomes a discerner of certain qualities, which the skin cannot discriminate: as sour, sweet, rough, bitter, salt, and aromatic.

Thus much we know; but we do not know the cause of that different effect, or, in other words, of that variety of tastes which different substances produce upon the paof diversity pillæ of the tongue, and which constitute their respective flavours. It was supposed by the Epicureans, and the doctrine has descended to the present day, that all this depends upon the geometrical figure of the sapid corpuscles; and particularly so with respect to saline bodies, the present which are cubic in sea-salt, prismatic in nitre, and equally day. diversified in vitriol, sugar, and other crystals. It is sufExplanation ficient, however, to annul this explanation to observe, unfounded. that many crystals of very different forms are alike insipid;

Opinion of the Epicu

reans still common in

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while others of the same, or nearly the same, shape, possess very different flavours; as also that the flavour in any of them continues the same even where we are able to change the figure; as, for example, by rendering common nitre cubical. The cause of flavours, therefore, ap

pears to reside in the elementary principles of substances GEN. IV. that lie beyond the reach of our senses.

Parageusis.
Morbid

fluenced by

flavours af

But the variable condition of the peculiar covering of taste. the papilla of the tongue, together with the condition of Flavour inthe adjoining organs, which concur in the purpose of the the state of tongue, as also the changeable nature of the saliva, and the tongue of the substances lodged in the stomach, all concur in and adjoining organs. influencing the taste, and giving a character to the flavour. Whence And hence the same flavours do not affect persons of all the same ages nor of all temperaments; nor even the same person fect differat all times. In general whatever contains less salt than ent persons differently: the saliva does, seems insipid. The spirituous parts of and the plants are received, in all probability, either into the same person papillæ themselves, or into the absorbing villi of the times. tongue; and hence the rapid refreshment and renovation Whence the of strength, not easy to be accounted for otherwise, being inwhich these stimulating materials produce even when sipid. they are not taken into the stomach.

for,

at different

quality of

How the spirituous

plants act.

Diversity of flavours

teaches animals in

their proper

in itself that is of an

taste.

It is from the diversity of flavours by which nature parts of has distinguished different substances, that animals are taught instinctively what is proper for their food: speaking generally, no aliment is unhealthy that is of an agreeable taste; nor is any thing ill tasted that is fit for stinctively the food of man. We here take no notice of excess by food. which the most healthy foods may be rendered preju- No aliment dicial, nor of mineral preparations which are not furnished unhealthy by nature but prepared by art. And hence the wisdom of Providence incites man to select the nutriment that is agreeable best fitted for his subsistence equally by the pain of hunger, and the pleasure of tasting. Man, however, Exceptions. is often guided by instruction and example as well as by his own instinct: but animals which are destitute of such Quadrupeds have a more collateral aids, and have to depend upon their instinct discriminatalone, distinguish flavours, as we have already observed ing taste as they do smells, with a far nicer accuracy than mankind; than man: and, admonished by this correct and curious test, abstain and hence readily dismore cautiously than man himself from eating what would tinguish nube injurious. And hence herbivorous animals, whose tritive from poisonous vegetable food grows often intermixed with a great di- plants when

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well as smell

intermixed.

GEN. IV. Parageusis. Morbid

taste.

versity of noxious plants, are furnished with much longer papillæ, and a more delicate structure of the tongue than mankind, as they are endowed also with a more accurate sense of smell; both which, indeed, they jointly rely upon for the same purpose.

The sense of taste, therefore, which possesses so close an analogy to that of smell, is subject to a similar train of specific diseases, and consequently the genus parageusis must contain the three following species:

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TASTE PAINFULLY ACUTE OR SENSIBLE ΤΟ SAVOURS
NOT GENERALLY PERCEIVED.

GEN. IV.
SPEC. I.

Sense of taste im

proveable by use:

and exhausted by labour.

THE sense of taste, like that of sight, smell, or hearing, is
capable of acquiring a higher degree of accuracy by use:
and hence those who are in the habit of tasting wines by
this
organ, perceive a variety of flavours, or modifications
of flavour, which another person not versed in such trials,
is insensible of. We also perceive that the nerves of
taste, like those of every other sense, become exhausted,
and consequently torpid, by much labour and fatigue.
And hence the nicest discriminater, after having tried a
variety of wines, spirits, or other pungent savours in quick
succession, is far less capable of judging concerning them,
and has at last little more than a confused perception of
gustatory excitement.

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