COMMITTEE.

James Manning, Esq.

R. I. Murchison, Esq., F.R.S., F.G.S.

The Right Hon. Lord Nugent.

The Right Hon. Sir Henry Parnell, Bt., M.P. Richard Quain, Esq.

Dr. Roget, Sec. R.S., F.R.A.S.

Edward Romilly, Esq., A.M.

The Right Hon. Lord John Russell, M.P.

Sir M. A. Shee, P. R.A., F.R.S.

The Right Hon. Earl Spencer.

John Taylor, Esq. F.R.S.

Dr. A. T. Thomson, F.L.S.
Thomas Vardon, Esq.

H. Waymouth, Esq.

J. Whishaw, Esq., A.M., F.R.S.

The Hon. John Wrottesley, A.M., F.R.A.S. J. A. Yates, Esq., M.P.

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Barnstaple.-- Bancraft, Esq.

William Gribble, Esq.

Belfast-Dr. Drummond.

Birmingham-J.Corrie, Esq. F.R.S, Chairman.
Paul Moon James, Esq., Treasurer.
Dr. Conolly.

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J. Reynolds, Esq., Treasurer.

J. B. Estlin, Esq., F.I..S., Secretary.
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C. H. Cameron, Esq.
Cambridge-Rev. James Bowstead, M.A.

Rev. Prof. Henslow, M.A., F.L.S. & G.S.
Rev. Leonard Jenyns, M.A., F. L.S.
Rev. John Lodge, M.A.

Rev. Geo. Peacock, M.A., F.R.S. & G.S.
Rev. Prof. Sedgwick, M.A., F.R.S.& G.S.
Rev. C. Thirlwall, M.A.

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William Masters, Esq.

Canton-Wm. Jardine, Esq., President.
Robert Inglis, Esq., Treasurer.

Rev. C. Bridgman,

Rev. C. Gutzlaff,

J. R. Morrison, Esq.,

Secretaries.

Cardigan-Rev. J. Blackwell, M.A.

Carlisle-Thomas Barnes, M.D., F.R.S.E. Carnarvon-R. A. Poole, Esq.

William Roberts, Esq.

Chester-Hayes Lyon, Esq.

Henry Potts, Esq.

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C. C. Dendy, Esq.
Cockermouth-Rev. J. Whitridge.
Corfu John Crawford, Esq.

Mr. Plato Petrides

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Denbigh-John Madocks, Esq.,

Thomas Evans, Esq.

Lt. Col. C. Hamilton Smith, F.R.S. Dublin-T. Drummond, Esq. R.E., F.R.A.S. Edinburgh-Sir C. Bell, F.R.S.L. and E. Etruria-Jos. Wedgwood, Esq. Exeter-J. Tyrrell, Esq.

John Milford, Esq. (Coaver.) Glamorganshire-Dr. Malkin, Cowbridge. W. Williams, Esq., Aberpergwm. Glasgow-K. Finlay, Esq.

Professor Mylne.

Alexander McGrigor, Esq.
James Cowper, Esq.

Guernsey-F. C. Lukis, Esq.
Hull-J. C. Parker, Esq.

Leamington Spa-Dr. Loudon, M.D.
Leeds-J. Marshall, Esq.
Lewes-J. W. Woollgar, Esq.

Liverpool Loc. As.-W. W. Currie, Esq. Ch.
J. Mulleneux, Esq., Treasurer.
Rev. Dr. Shepherd.

Maidenhead-R. Goolden, Esq., F.L.S.
Maidstone-Clement T. Smyth, Esq. "
John Case, Esq.

Malmesbury-B. C. Thomas, Esq.
Manchester Loc. As.-G. W. Wood, Esq., Ch.

Benjamin Heywood, Esq., Treasurer.
T. W. Winstanley, Esq., Hon. Sec.
Sir G. Philips, Bart., M.P.
Benj. Gott, Esq.

Masham-Rev. George Waddington, M.A.
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R. G. Kirkpatrick, Esq.

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Newtown, Montgomeryshire-W. Pugh, Esq.

Norwich-Richard Bacon, Esq.
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Orsett, Essex-Dr. Corbett, M.D.
Orford-Dr. Daubeny, F.R.S. Prof. of Chem.
Rev. Prof. Powell.

Rev. John Jordan, B.A.

E. W. Head, Esq., M.A.

Pesth, Hungary-Count Szechenyl.

Plymouth-H. Woollcombe, Esq., F.A.S., Ch.
Snow Harris, Esq., F.R.S.

E. Moore, M.D., F.L.S., Secretary,
G. Wightwick, Esq.

Presteign-Dr. A. W. Davis, M.D.

Ripon Rev. H. P. Hamilton, M.A., F.R.S. and G.S.

Rev. P. Ewart, M.A.

Ruthin-Rev. the Warden of

Humphreys Jones, Esq.

Ryde, I. of Wight-Sir Rd. Simeon, Bt.
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Shepton Mallet-G. F. Burroughs, Esq.
Shrewsbury-R. A. Slaney, Esq., M.P.
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Henry Coppock, Esq., Secretary.
Sydney, New South Wales-

William M. Manning, Esq.
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John Rundle, Esq.
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Waterford-Sir John Newport, Bt.
Worcester-Dr. Hastings, M.D.
C. H. Hebb, Esq.
Wrexham-Thomas Edgworth, Esq.

J. E. Bowman, Esq., F.L.S., Treasurer
Major William Lloyd.
Yarmouth-C. E. Rumbold, Esq.

Dawson Turner, Esq. York-Rev. J. Kenrick, M.A.

J. Phillips, Esq., F.R.S., F.G.S.

BODI

OTHE

OF

INT

INTESTINES are that portion of the digestive canal into which the food is received after it has been partially digested in the stomach, and in which its further assimilation, the separation and absorption of the nutritive matter, and the removal of that which is excrementitious, take place. In an adult, the intestines consist of a convoluted tube of from 30 to 40 feet in length, and are, from the difference of their diameters in different parts, divided into small intestines, which comprise about the first four-fifths, and large intestines, which constitute the other fifth of their length. The former again are divided into the duodenum, into which the ducts from the liver and pancreas open, and in which the chyme from the stomach is converted into chyle [DIGESTION; CHYLE]; the jejunum, in which the absorption of the nutritive matter of the food is principally effected; and the ileum. The large intestines are divided into the cœcum, colon, and rectum.

The walls of the intestinal canal are composed of three principal coats or membranes. The exterior, which is smooth and polished, is called the peritoneal, and its principal use is to permit the free motions of the intestines within the abdomen, and of their several convolutions against each other, by rendering the effect of friction as slight as possible. Next to and within the peritoneal coat is the muscular, which is composed of two layers of fibres; an external, in which they are directed longitudinally, and an internal, of which the fibres encircle the intestine. By these the motions of the intestines and the propulsion of their contents are effected; the longitudinal fibres tending to shorten each portion of the canal, while the circular contract its diameter; and the two sets together producing a motion of the tube somewhat like that of a worm, whence it has received the name of vermicular motion. Beneath these layers, and separated from them by a stratum of cellular tissue, which has been sometimes called the fourth or nerVous coat, is the mucous membrane, which is the most important part of the intestinal canal. It is everywhere beset by innumerable minute glands, by which the secretion of mucus and the other intestinal juices is carried on. In the small intestines it has a fine velvet-like surface, made up of minute thickly-set hair-like processes, or villi, which are about 4th of an inch in length, and stand up so that their tops seem to form a smooth surface like the pile of velvet. These, as well as all the rest of the mucous membrane, are protected from the irritation which the immediate contact foreign substances would produce, by a covering of an inorganic cuticle of extreme delicacy, called epithelium. The principal functions performed by the intestines are the conversion of the chyme [DIGESTION; GASTRIC JUICE] into chyle, the absorption of the latter, and the removal of the innutritious parts of the food and of a considerable quantity of excrementitious matter. In the first process, which constitutes the last stage of digestion, the secretions of the liver and pancreas take an important part: the P. C., No. 788.

of

INT

ducts by which they are conveyed open into the intestinal canal, near the middle of the duodenum, or about six inches from the aperture by which the food passes from the stomach; and immediately beyond the orifices of these ducts the villi are of great size, and thickly set on prominent folds of the mucous membrane, called valvula conniventes. These folds, at the same time that they increase the extent of surface for absorption, serve to entangle the semifluid mass of food, now completely digested; they are most numerous and prominent in the jejunum, where absorption is carried on earliest and most rapidly, but are found to a slighter extent throughout the whole of the small intestines. The absorption of the chyle is effected by the villi, each of which is composed of a minute tube, which is the termination of a branch of the lacteal or absorbent system of vessels, and is ensheathed in a delicate tissue containing a net-work of capillary arteries and veins. The form and function of the villi may be best demonstrated in an animal which has died suddenly after a full meal; they then appear turgid, and stand erect, filled with a whitish milky fluid, the chyle, which, as fast as it is absorbed by them, is conveyed by numerous converging streams into the main trunk of the absorbent system, called the thoracic duct, through which it is gradually poured into the blood of the left subclavian vein, at a short distance before it enters the right side of the heart. [HEART.] The whole process of absorption is not unaptly compared to that by which the fluids are conveyed from the earth through the roots into the stem of a plant; the villi of the intestine being represented by the tufts of hair-like spongioles which are placed at the terminations of the fibres of the root.

The portion of the food which is unfit for the nourishment of the body is forced onwards by the vermicular motion of the intestines, and being mixed with the resinous and other excrementitious substances secreted by the liver and other glands, is conveyed through the whole tract of the intestines; and after it has been exposed to the absorbing vessels, which are placed in greater or less abundance in every part of the canal, so that not a particle of nutriment can be lost, the residue is voided.

INTONATION, in vocal music, is the tuning of the voice-the singing true or false-in tune or out of tune. Correct Intonation is the first requisite in a singer; this wanting, all his other musical qualities, however good, are unavailing.

INTRA'DOS and EXTRA'DOS, the lower and higher curves of an arch. [ARCH.]

INTRICA'RIA, a small Polypifer from the oolitic rocks of France, allied to Cellaria. (M. Defrance, Dic. des Sci. Nat.)

The nature of the relation which subsists between intuition and reasoning has been strongly contested. While Beattie maintains that the connexion between them, how closely soever they are found in general to be connected, is not necessary, but, on the contrary, a being endued with one may be destitute of the other; Dugald Stewart, on the other hand, insists that the two are not radically distinct, although by most writers they are considered to be different faculties. Locke having rightly maintained that every step which the reason makes in demonstrative knowledge has intuitive certainty, and that consequently the power of reasoning presupposes that of intuition, Stewart thinks that the intuition of Locke implies the power of reasoning; or, at least, that intuition combined with memory explains reasoning. Here his usual sagacity appears to have failed Stewart. While the mind itself is perfectly simple, it has been, for the purpose of attaining accuracy of language and distinctness of theory, supposed to be multiple; and distinct faculties have been ascribed to it according as its several operations comprise more or fewer elements. Ac cording therefore to his own account, reason, which involves the element of time, must be kept distinct from intuition, which does not involve that element.

The proper objects of intuitive certainty are identical propositions. This of course does not mean propositions verbally identical; such as a man is a man. But while the object of thought is perfectly and always one, it may present itself to the thought under a variety of aspects, either dissolved into its elements or as combined into a whole. It is this identity under an apparent diversity that constitutes that original and primary evidence which makes certain propositions, as soon as the respective terms are understood, to be perceived intuitively. On the other hand, the apparent identity of a real diversity is the ground of all sophistical argument. The ultimate form of legitimate argumentation is, a = b, b = c, .' . a = c. But every fallacy, when detected, will invariably be found to be a = br, b = c, .. ac. The sophistry consists in the suppression of the element r, either positive or negative.

In the philosophy of Kant the term intuition (anschauung) is used to denote the single act of the sense upon outward objects according to its own laws. It appears to be employed in a like sense in the following extract from Glanvil-Some say that the soul is not passive under the material phantasms; but doth only intuitively view them by the necessity of its own nature, and so observes other things in these their representatives.' (Vanity of Dogmatising, c. iv., p. 29.)

a

INULIN, a peculiar vegetable substance which is spon taneously deposited from a decoction of the roots of the Inula Helenium. It is a white powder, like starch, is insoluble in cold and soluble in hot water, from which it is deposited on cooling, and this distinguishes it from starch. With iodine it gives a greenish-yellow compound, which is not permanent. Inulin is distinguished from gum by its insolubility in cold water, and by not giving saccholactic acid when digested in nitric acid. INVARIABLE (Mathematics), the same word in meaning as CONSTANT, which see. There are however two sorts of constants, which it is desirable to treat under different names: the first, which we may call a constant, or a common constant, meaning a quantity which is absolutely inbut which does not vary in the processes required by a given equation. This we propose to call the invariable function of that equation, or its invariable.

Thus, in a common differential equation, which is supposed to be true of y and x when passes through all stages of magnitude whatsoever, the only invariable is an absolute invariable, or a common constant. But in an equation of differences, in which only passes from one whole number to another, the invariable function is any one which remains unaltered by changing from one whole number to another. Thus, [INTEGRATION, FINITE] instead of saying that the solution of ▲ y = x + 1 is (x2 + x) + C, where C is a constant, we may allow C to be any function of x, which is unaltered by changing x from one whole number to another. Such a function is (cos. 2πx), so that the solution is † (x2+x) +† (cos. 27X), and the last term is the invariable of the equation. Again, suppose it required to solve the functional equation (x2)=2px. One solution of this is x = clog r, where c is any absolute constant. But the equation is solved if c be a function of x, provided it be one which does not change when x is changed into 2. Such a function is log. log r

or

COS.

{2π

log 2

or any function of it,

{

2π

× log æ.

log. loga log 2

any function of cos. General methods of finding invariable functions, as far as they have yet been given, will be found in the Encyclopædia Metropolitana,' article Calculus of Functions.'

INVENTION. This term, when used in the language of art, has a different signification from what it usually bears in common language. It does not mean discovery, but combines conception, or the peculiar way in which an artist's mind takes cognizance of a subject to be represented, with the mode of treatment, or choice of objects and manner of disposing them best adapted for producing a desired effect. Thus, in painting and sculpture, it is the faculty by which the most perfect mode of illustration, by colour or by form, is suggested to the artist, and by which the mind of the spectator is led to comprehend the truth, the intention, and the whole purpose of the work before him; but so distinct is it at the same time from perfect execution, that it is often found to exist independently of excellence in that particular, some of the finest inventions in art being manifestly defective in technical requirements. It is therefore the highest quality in the constitution of the artist's mind; as Opie says, 'Destitute of invention, a poet is but a plagiary, and a painter a copier of others.' (Lectures on Painting.)

It is hardly necessary to enter into the question whether the power of invention be a primary and original law of the mind, or whether the effect of cultivation. Some have be

I'NULA HELENIUM (Elecampane), an indigenous perennial herbaceous plant, found in moist meadows, the root of which is used in medicine. This part is thick and branching, brown externally, white internally, with an aromatic odour and a mucilaginous taste, at first bitter, afterwards sharp and camphor-like. In addition to mucilage and a large quantity of a variety of starch termed inulin, it contains a crystallized volatile oil (stearopten), a bitter extractive, an acrid resin, and some salts of lime, &c.

and carried on till the power is developed and perfected; others conceive that it is unatatinable by any human effort, and is part of the original constitution of the mind.

which to develop and declare itself. Sir Joshua Reynolds