monia are incapable of decomposing a solution of 22·5 of chalk, whereas they are capable of decomposing very nearly 26.

Calcis Murias.-The Edinburgh College has ordered this salt to be crystallized, which is a very inconvenient form, for in hot weather it fuses in its water of crystallization: it is, moreover, incorrectly stated, that “a solution of 76 grains in one fluidounce of distilled water, precipitated by 49 grains of oxalate of ammonia, remains perceptible by more of the test." Dr. Christison states its composition to be chlorine 35-42, calcium 20.1, and water 54, making its equivalent 109.52, and requiring one equivalent, or 62 of oxalate of ammonia for decomposition, consequently 76 grains will require scarcely 43 grains of oxalate of ammonia, instead of more than 49, as stated by the Edinburgh College: so that this latter quantity is sufficient for more than 86 of the crystallized chloride, instead of less than 76 as asserted.

Ferri Oxidum Nigrum.-This is thus directed to be prepared in the Edinburgh Pharmacopoeia:

Take of Sulphate of Iron, six ounces;

Sulphuric Acid, (commercial) two fluidrachms and two fluidscruples;
Pure Nitric Acid, four fluidrachms and a-half;

Stronger Aqua Ammoniæ, four fluid ounces and a-half;

Boiling water, three pints.

Dissolve half the sulphate in half the boiling water and add the sulphuric acid; boil; add the nitric acid by degrees, boiling the liquid after each addition briskly for a few minutes. Dissolve the rest of the sulphate in the rest of the boiling water; mix thoroughly the two solutions; and immediately add the ammonia in a full stream, stirring the mixture at the same time briskly. Collect the black powder on a calico-filter; wash it with water till the water is scarcely precipitated by solution of nitrate of baryta; and dry it at a temperature not exceeding 180°.

It may be first observed, that a fluidscruple, though here directed to be employed, is not admitted by the College in their "system of measures, p. xv.; and this, if we mistake not, is the only occasion on which it is adopted.

The Edinburgh College have given three translations of Aqua Ammoniæ fortior, namely, Concentrated aqueous solution of ammonia, Strong ammonia, and Stronger solution of ammonia; but so much do they appear to approve of what they term a " patchwork" nomenclature, that neither English nor Latin appears to have pleased them on this occasion, and perhaps on some others, and therefore, in defiance of all propriety, a name is used composed of both languages-Stronger Aqua Ammonia. We are quite at a loss to imagine what advantage is gained by using the stronger solution of ammonia in this preparation; it is less economical in preparing than the weaker, and Dr. Christison admits that "it cannot be poured from one vessel to another, or kept unless during winter, and in very well closed bottles, without parting with some of its ammoniacal gas; and hence the commercial Aqua ammoniæ fortior commonly ranges between 886 and 910." The latter part of this statement shows, therefore, that it is apt to lose about one-fourth of its ammonia.

It appears also, that whereas commercial sulphuric acid is sufficiently pure to dissolve sesquioxide of iron, commercial nitric acid is not sufficiently so to convert protoxide into sesquioxide, and accordingly we find pure nitric acid directed for that purpose; it is, however, but candid to admit that, on a similar occasion, in the preparation of Ferrugo, commercial nitric acid is directed to be employed.

The oxide obtained by this process is explained in the Pharmacopoeia and by Dr. Christison to be the "ferroso-ferric oxide, (Berzelius,) a compound of protoxide and sesquioxide of iron," but it is not the ferroso-ferric oxide of Berzelius.

In his Traité de Chimie, Berzelius states the octohedral magnetic iron ore to be the ferroso-ferric oxide; this is composed of one equivalent of protoxide 36, and two equivalents of sesquioxide 80; this, therefore, contains one more equivalent of sesquioxide than the Edinburgh preparation, which consists of one equivalent of each. In his Table Synoptique Berzelius mentions another ferroso-ferric oxide, which is composed of one-anda-half equivalent of protoxide 54, and one of sesquioxide 40, and it consequently contains half an equivalent more of protoxide than the ferri oxidum nigrum; it is therefore evident that this preparation is not either of the ferroso-ferric oxides of Berzelius. Dr. Christison afterwards, and more correctly, states that, according to the analysis of Wohler, this compound may be regarded as composed of an equivalent of protoxide 36, and one of sesquioxide 40; indeed, it is evident that this must be the case, for equal quantities of iron are precipitated together, one half being protoxide and the other sesquioxide, and these oxides, to adopt Dr. Christison's rather singular description, "unite at once in the act of separation."

In copying this formula, Dr. Thomson has stated "four fluid ounces and a half" of nitric acid, instead of four fluidrachms and a half." half." With respect to the composition of the ferri oxidum nigrum, he says, "this is an admixture of two oxides, namely, 2 eqs. 72 of the protoxide, and 1 eq. 40 of the sesquioxide, and 2 eqs. 18 of water; its formula being 11 Fe. O.+Fe.1 O1+2 HO. In this statement Dr. Thomson has reversed the equivalents of protoxide and sesquioxide; they being respectively 1 to 2, and not 2 to 1; moreover, when this correction is made, it does not represent the composition of the Ferri Oxidum Nigrum, as we have already shown; if we understand the formula given by Dr. T., it means a compound of one equivalent of an oxide of iron, consisting of equiv. of iron, and 1 equiv. of oxygen, which does not exist, combined with 1 equiv. of protoxide of iron; so that an incorrect composition is illustrated by an incorrect formula.

[To be concluded in our next Number.]

3d.

THE ANATOMY AND PHILOSOPHY OF EXPRESSION, AS CONNected WITH THE FINE ARTS. By Sir Charles Bell, K.H. &c. Edition, enlarged. 8vo. pp. 265. London: Murray, 1844.

THIS work has a peculiar, and even melancholy interest, in more respects than one. It is the first and the last of the gifted author's published writings. It was originally composed while he was yet a student, "before"-as he gracefully says in the dedication to his brother-" the serious pursuits of life began ;" and he was engaged, we believe, in revising the present edition for the press, when he was seized with his fatal illness at Hallow Park, in Worcestershire, on the 29th of April, 1842.

Charles Bell was a man of a truly original cast of mind. From his youth, he had learned to think for himself; and his thoughts had early been turned to the study of the Nervous System. Being an accomplished draughtsman, and having naturally a lively taste for the fine arts, he was in the habit of occupying his leisure hours with portraying, alike with his pencil and his pen, the outward and visible features of the various passions that agitate the human breast. The taste for such pursuits never left him; the very day before his death, he was engaged in his favourite amusement. He much mistook, we have often thought, the part which Nature designed him for, when he applied himself to the active pursuit of practical surgery. The bias of his mind lay in quite an opposite direc. tion. He was too contemplative a character, and, moreover, his feelings were far too sensitive, for many of the every-day duties of a hospital surgeon. He had a dislike for all cutting operations, and an aversion from inflicting pain even on the lower animals. In spite of all his exertions, he never could have become an Astley Cooper or a Dupuytren: he was not made of the same stuff as these men. Each had his reward. The leading surgeon of the French, as well as he of the English, metropolis, enjoyed a boundless reputation during his life, and left an enormous fortune behind him. The fame of both stood high for many years; but now, if we mistake not, it is on the wane: and, ere long, these once great surgeons will cease to be regarded as shining lights in the professional hemisphere. Not so with Bell. But partially appreciated by his cotemporaries, his reputation will unquestionably increase with increasing years; and posterity, we doubt not, will rank his name with those of Harvey and John Hunter.

Sir Charles had early caught a glimpse of that great discovery which shed so bright a lustre over his maturer years; and certainly not the least interesting feature of these Essays is, that they clearly contain the germ of this discovery, and show us some of the steps by which he was led to its attainment. It is a vulgar error to suppose that the finding out of any great and comprehensive truth was ever made by what is generally termed "a lucky thought," or without the previous discipline of long and deep reflection on the subject. There was no exception to this remark in the case of our lamented author. At the very threshold of his professional career, he saw and accurately described the wide extent and the complicated relations of the function of Respiration; pointing out how distant and seemingly unconnected parts of the body are intimately bound and

associated together, in the performance of this vital act, and of the numerous accessory phenomena that are dependent upon it. With no less physiological acumen than with refined artistic taste, he perceived that it was not the lungs and the muscles of the chest alone that are engaged in the carrying on of the process of breathing, under the excitement of any passion; but that the muscles of the face, throat, neck, shoulders and trunk are then all, more or less immediately implicated. The great painters and sculptors of Greece had fully understood the truth of this corporeal complex association, by studying the undressed figures of their countrymen in their gymnastic games, and other exhibitions of agility, strength, and passion. They knew not indeed the cause of those combined physical appearances; but, by closely observing Nature, they had learned to represent them with marvellous fidelity in their pictorial and sculptural designs. It remained for Charles Bell to discover the why of the sympathetic union of so many parts in the production of one effect; to find out the clue of a complex and seemingly entangled web; to educe harmony from seeming discord, and the most orderly design from seeming confusion. Few medical men are, we believe, aware of the simple yet comprehensive grandeur of his discovery of the respiratory system of nerves; they may know its anatomical details, but they have not studied it in a physiological or an artistic point of view: nor have they even learned to appreciate its intimate relations with many of the most common acts of the body, such as crying, laughing, weeping, and so forth. Each of these acts. is nothing but a natural and spontaneous effort of the system to restore, to normal quietude, a disturbed state of the breathing and of the circulation of the blood; and all the visible phenomena or outward expressions of the Emotions, which give rise to them, are more or less directly connected with this instinctive effort this vis conservatrix naturæ.

The Breast is the part of the body that is instinctively referred to as the seat of the passions; and the common language of every people gives currency and sanction to this idea. And yet we know that they are only mental acts or varying conditions of the immaterial mind, and cannot therefore be seated in the body, however much they may influence or be influenced by it. The effect is thus substituted for the cause; the bodily feeling for the mental act. So intimate however is the connection between these two states that, if the bodily sensation is in any way induced independently of the operation of the mind, the cognate and corresponding sentiment, or something very much akin to it, will at once be experienced. For example, do we not daily observe that the tremour of the limbs, the coldness of the skin, the chattering of the teeth and rapid throbbing of the heart, in the common act of febrile shivering, are invariably accompanied with the feelings of trepidation and fear?—and will not the mere effort of clenching the fist, holding the breath, and steadily fixing the eye upon one object, induce-almost in spite of our efforts to the contrary—a sentiment of indignant resolution in our breasts? How admirably has Shakespeare illustrated the force of this alliance in the following wellknown passage, in which Henry V. strives to inflame the zeal and courage of his soldiers!

"But when the blast of war blows in our ears,

Then imitate the action of the tiger:

Stiffen the sinews, summon up the blood,
Disguise fair Nature with hard-favour'd rage!
Then lend the eye a terrible aspect;

Let it pry thro' the portage of the head,

Like the brass cannon: let the brow o'erwhelm it,
As fearfully as doth a galled rock

O'er-hang and jutty his confounded base,
Swill'd with the wild and wasteful ocean.

Now set the teeth, and stretch the nostril wide;
Hold hard the breath, and bend up every spirit
To his full height.”*

Sir Charles ingeniously attempts to explain, or at least illustrate, this connexion between certain bodily states and the development of certain mental emotions, by directing our attention to something analagous to it in the exercise of our sensual perceptions. The following passage will best convey to our readers the train of reasoning whereby he endeavours to show, that what the Eye, the Ear, or the Tongue is to the mind, as exciting those ideas which have been appointed to correspond with the qualities of the material world, the organs of the Breast are to the development of our affections.

"By emotions are meant certain changes or affections of the mind, as grief, joy, astonishment. That such states or conditions of the mind should in any degree pertain to the body, may not, perhaps, be willingly admitted; unless we take along with us that the ideas of sense, as light, sound, or taste, are generated by the organs of the senses, and not by any thing received and conveyed by them to the sensorium. It is ascertained that the different organs of the senses can be exercised, and give rise to sensation and perception, when there is no corresponding outward impression; and the ideas thus excited are according to the organ struck or agitated: that is, the same impression, conveyed to different organs of sense, will give rise to a variety of sensations; as light, when the eye is struck; sound, when the ear is struck; and so on with the other organs; the sensation corresponding with the organ which is exercised, and not with the cause of the impression. A needle passed through the retina, the organ of vision, will produce the sensation of a spark of fire, not of sharpness or pain; and the same needle, if applied to the papilla of the tongue, will give rise to the sense of taste; while if it prick the skin, pain will follow. This law of the senses is arbitrarily or divinely ordered; it might have been otherwise. Accordingly, when we observe that the organs of the senses operate in producing specific ideas, independently of their own peculiar exciting causes, we can comprehend better how other organs of the body may have a relation established with the mind, and a control over it, without reference to outward impressions." 85.

Without pursuing this subject, which touches on the limits of metaphysical inquiry, let us now endeavour to illustrate, by a few examples, the expression or corporeal manifestation of certain strong mental emotions, with the view of pointing out the intimate alliance between the development of such expression, and a disturbed state of the heart and the machinery of respiration: and first, of Fear. What says the sacred penman, in the account of the solemn vision that he saw, when deep sleep falleth on men? "Fear came upon me and trembling, which made all my bones to shake. Then a spirit passed before my face; the hair of my flesh stood up. It stood still, but I could not discern the form thereof; an image was before mine eyes; there was silence, and I heard a voice."