SPEC. I. Parosmis

tensive in quadrupeds and birds, which chiefly trust to the GEN. III. sense of smell in selecting their food, than in man; for it ascends considerably higher, and is, for the most part, acris. possessed of numerous folds or duplicatures. It is hereby the hound distinguishes the peculiar scent thrown forth from the body of the hare, and the domestic dog recognizes and identifies his master from all other individuals.

every

Acrid smell.

Olfactory

nerves

naked.

And hence

easily sti

Yet the nerves of smell are not only spread in great abundance over the olfactory membrane of all animals nearly possessing such an organ, but they are distributed so near the surface as to be almost naked; and hence in class they are easily and hourly excited into action, being mulated covered with little more than a layer of bland, insipid mucus, thin at its first separation, but gradually hardening by the access of air into viscid crusts, and which is expressly secreted for the purpose of defending them. From this nearly naked state it is that they are stimu- by the finest lated by aromatics, however finely and impalpably divided: aromatics impalpably whence the violent sneezings that take place in many per- pulverized; sons in an atmosphere in which only a few particles of sternutatories or other acrid olfacients are floating: and hence also the rapidity with which a sympathetic action and rapidly is excited in the neighbouring parts or in the system at large, and the refreshment which is felt on scenting the pungent vapour of carbonate of ammonia, or vinegar, or the grateful perfume of violets or lavender, in nervous head-aches or fainting-fits. The fetid odours are well known to affect the nostrils quite as poignantly as the pleasant; and to produce quite as extensive a sympathy: and hence the nausea, and even intestinal looseness which often follows on inhaling putrid and other offensive effluvia.

acting by sympathy and afford

ing refresh

ment.

Hence also the ready and extensive effect

of fetid

odours.

Under pecu

liar circum

stances the

sonse be

Under peculiar circumstances, however, the ordinary apparatus for smell possesses an activity, and sometimes even an intolerable keenness, which by no means belongs to it in its natural state. M. Virey, who has written a quisitely very learned treatise upon the subject of odours, asserts that the olfactory sense exists among savages in a far Said to be

comes ex

keen.

keener

higher degree of activity than among civilized nations, among sa

GEN. III.

SPEC. I. Parosmis acris.

Acrid smell.

vages than

tions, and

why. Sense of smell like

all others, capable of cultivation : more fully

relied upon by those who are deprived of sight or hearing.

whose faculty of smell is blunted by an habitual exposure to strong odours, or an intricate combination of odours, and by the use of high-flavoured foods. And he might have added that this sense, like every other, is capable of civilized na cultivation, and of acquiring delicacy of discrimination by use; that savages, many of whom make an approach to the life of quadrupeds, employ it, and trust to in a similar manner; and that this is, perhaps, the chief cause of the difference he has pointed out. It is in like manner relied upon by persons who are deprived of one or two of the other external senses, as those of sight or hearing, or both: not merely in consequence of more frequent employment, but from the operation of the law we have already pointed out, that where one of the external senses is destroyed or constitutionally wanting, the rest, in most cases, are endowed with an extraordinary degree of energy, as though the share of sensorial power, naturally belonging to the defective organ, were distributed among the rest and modified to their respective uses. One of the most interesting examples that I am acquainted with of this transfer of sensorial power is to be found in the history, first given to the public by Mr. Dugald Stuart, of James Mitchell, a boy born both blind and deaf; and who, having no other senses by which to discover and keep up a connexion with an external world than those of smell, touch, and taste, chiefly depended for information on the first, employing it on all occasions, like a domestic dog, in distinguishing persons and things. By this sense he identified his friends and relatives; and conceived a sudden attachment or dislike to strangers according to the nature of the effluvium that escaped from their skin. "He appeared," says Mr. Wardrop, who has also published an account of him, " to know his relations and intimate friends by smelling them very slightly, and he at once detected strangers. It was difficult, however, to ascertain at what distance he could distinguish people by this sense; but, from what I could observe, he appeared to be able to do so at a considerable distance from the object. This was particularly striking when a person en

Striking illustration of this remark.

SPEC. I.

Acrid smell.

tered the room, as he seemed to be aware of such entrance GEN. III. before he could derive information from any other sense Parosmis than that of smell. When a stranger approached him he acris. eagerly began to touch some part of the body, commonly taking hold of his arm, which he held near his nose; and after two or three strong inspirations through the nostrils, he appeared to form a decided opinion concerning him. If it were favourable, he shewed a disposition to become more intimate, examined more minutely his dress, and expressed, by his countenance, more or less satisfaction. But if it happened to be unfavourable, he suddenly went off to a distance with expressions of carelessness or disgust.

as

and other

ascertainable

when ex

keen.

The Journal des Sçavans for 1667, gives a curious Sex, age, history of a monk who pretended to be able to ascertain, qualities by the difference of odour alone, the sex and age of a said to be person, whether he were married or single, and the man- by this sense ner of life to which he was accustomed. This, as far the fact extended, may possibly have been the result of quisitely observations grafted upon a stronger natural sense than belongs to mankind in general; and is scarcely to be ranked in the list of diseased actions. But among persons of a highly nervous or irritable idiosyncrasy, I have acute, and met with numerous instances of an acuteness of smell particularly to persons almost intolerable and distracting to those who laboured of a under it; which has fairly constituted an idiopathic affection; and sometimes nearly realized the description of the poet, in making its possessors ready at every moment to

Die of a rose in aromatic pain.

Hence often

distressingly

habit: fainted be

who have

neath the smell of a

rose, as

described by

Pope.

This description not

Mr. Pope seems to have written this line as a play of fancy at the time, but the writings of various collectors of medical curiosities abundantly show that he has here fanciful. described nothing more than an occasional and sober fact. Thus M. Orfila gives us an account of a celebrated Examples painter of Paris of the name of Vincent, who cannot re-rectness. main in any room where there are roses without being in

History of James Mitchell, a boy born blind and deaf, &c. By James Wardrop, F.R.S. Ed. 4to. 1813.

of its cor

GEN. III. SPEC. I. Parosmis acris.

Acrid smell

Singular

odour of

pinks:

a short time attacked with a violent cephalæa succeeded by fainting. And M. Marrigues informs us that he once knew a surgeon who could not smell at a rose without a sense of suffocation, which subsided as soon as the rose was removed from him; as he also knew a lady who lost her voice whenever an odoriferous nosegay was applied to her nostrils +.

We have observed that a keen stimulation of the olfactory nerves is often productive of a very powerful sympathetic action in other organs. There are few persons who, on inhaling the fine particles of black hellebore and colocynth, while in the act of being pounded, would not feel their effect on the intestines by a copious diarrhœa; but where the acuteness of smell exists which constitutes the present disease, whether limited to particular odours, or extending to all odours equally, the sympathetic action is sometimes of a very singular description. M. Valtain effect of the gives the history of an officer who was thrown into convulsions and lost his senses by having in his room a basket of pinks, of which, nevertheless, he was very fond. The flowers were removed, and the windows opened, and in the course of half an hour the convulsions ceased, and the patient recovered his speech. Yet for twelve years afterward he was never able to inhale the smell of pinks without fainting. And M. Orfila relates the case of a lady of forty-six years of age, of a hale constitution, who could never be present where a decoction of linseed was preparing without being troubled in the course of a few minutes afterwards with a general swelling of the face, followed by fainting and a loss of the intellectual faculties; which symptoms continued for four and twenty hours §.

like effect

of the odour of linseed.

Predispo

nent cause

of the pre

The predisponent cause of the species before us is a nervous or irritable habit. The occasional causes are sent species. local irritation from a slight cold, in which the contact of the air alone, as inhaled, often produces sneezing; or ex

Occasional

causes.

*Sur les Poisons, Tom. 11. Cl. v. § 972.

+ Journ. de Physique, year 1780.

Hygiene Chirurgicale, P. 26.

§ Sur les Poisons, loc. citat,

GEN. III.

SPEC. I. Parosmis

Acrid smell.

coriation of the mucous membrane of the nostrils from the use of sternutatories in those not accustomed to them. It is often the result of idiosyncrasy; and perhaps at acris. times, as in paracusis acris, of a superfluous distribution of olfactory nerves. As a symptom it is often found in result of ophthalmia and rheumatic hemicrania.

Sometimes a

idiosyncrasy. Often found as a sym

ptom in various dis

eases.

Where the disease is connected with the habit, the nervous excitement should be diminished by refrigerants and tonics, as the shower-bath, bark, acids, neutral, and several of the metallic salts. And where it is chiefly Medical local, we may often produce a transfer of action by blisters treatment. in the vicinity of the organ: or relax the Schneiderian membrane, and moisten its surface by the vapour of warm water. The sniffing up cold water will also prove serviceable in many instances, by inducing torpitude at first and additional tone afterwards. Dr. Darwin advises errhines for the first of these purposes, that of exhausting the excitability and blunting the sense.

SPECIES II.

PAROSMIS OBTUSA.

Obtuse Smell.

SMELL DULL, AND IMPERFECTLY DISCRIMINATIVE.

SPEC. II.

sometimes

a natural

defect.

Sometimes

produced

THIS is often a natural defect, but more frequently a con- GEN. III. sequence of an habitual use of sternutatories, which exhaust, weaken, and torpify the nerves of smell, as long exposure to a strong light weakens and impairs the vision, and sometimes destroys it altogether. To those unaccustomed to sternutatories, the mildest snuffs will produce such an by use of excitement as is marked by a long succession of sneezing, sternutawhich is nothing more than an effort of the remedial tories. power of nature to throw off the offending material;

a too free

Illustrated.