to us:

this last sentence, being used not for a musical scale, but for a lever and valve. Let W. P., however, use his flute for a pattern, but learn to be independent of it as soon as possible,-tuning his voice and ear to the chord, as in the earlier exercises, and marking the "mental effect" of notes. These things will give him accuracy of ear.-M. B. S. C. (Edinburgh) must mark the difference between DOH and c. c is a fixed sound, given by string or tuning-fork, that vibrates two hundred and fifty-six times a second. To make the monochord give the true c, our friends must consider not only the length of string, but also the thickness and the tension. They will have, in that case, to tune the monochord by a good c' tuning-fork, bought of a respectable musicseller. The alphabetical letters C' BAG FEDC, are well known throughout the civilised world as the acknowledged names for the fixed sounds, each one indicating a certain pitch. We do not make, therefore, the unphilosophical and useless attempt to force the syllables DOH, RAY, ME, &c., into the places of these alphabetical names; but we use them in a different sense. The principal thing in music, is the key-note of a tune. That key-note may be at one pitch in one tune, and at another pitch in another tune. But there is an essential sameness in the relationship of notes which attends it, and in the mental effect of those notes, whatever be its pitch. to familiarise the learner with that essential law of relationship and mental effect, which constitutes the simplicity and beauty of music, we give a distinct name to the key-note-a name which follows it to any pitch. That name is DOH. And distinct names, also, to its attendant notes. Those names are RAY, ME, FAH, &c. Therefore, whatever be the full length of your monochord string, and whatever be the sound in pitch it gives, you may take that for the key-note (or, as Euclid called it, the Proslamomenos-the "given" sound) and the other notes of its scale will be given by the proportions of the string mentioned.-J. H. P. is right about the metronome. But it is usual to say "Metronome crotchet = 72," or "M, quaver = 72," &c.—UN JEUNE COMMIS must be patient with his breaking voice, and not use it too much. He must also read the lessons with greater care, as well as the remarks above. German Concertina.-As this instrument is founded on the tonic principle, is without temperament, and is moreover cheap, we may probably give, as our correspondent desires, a few brief instructions for its use.

ANSWERS TO CORRESPONDENTS. MONGREL (Carnarvon): Something will be done for the Principality. -R. J. C.: Reading at meals is injurious to health.-JOHN SOMERS (Huddersfield): Persevere and you will succeed; try to write evenly, that is, parallel to the top and bottom of the page.-J. W. GARLICK (Halifax): We thank him for his useful suggestions.-E. C. (Brixton): We are preparing something of the kind.-GRIERSON (Edinburgh): Maps are to be printed in the P. E. The numerous exceptions in gender, &c., must be learnt from Dr. Beard's "Latin Made Easy," and other yet fuller manuals. We can give nothing more than a general view.-ISAK will succeed, if he perseveres.-XENOPHION: Your exercise is good; good, also, are several that have been sent so good as to show that many are acquiring a sound knowledge of Latin from our pages. This is encouraging. Their progress will be more easy, more sure, and more rapid, if we are able to publish an English translation of the Latin Exercises, and a Latin translation of the English Exercises.-The translation asked for by R. runs as follows:-At Sparta there is no widow so noble as not to appear on the stage under the attraction of gain.-PILATE should pronounce vacca and heus like English words; thus, vaksee and Hughs. Maps will be given.-R. F. T. (Margate): Something will soon be done to meet his wishes, in Latin.-DELECTOR must read a little more carefully; his difficulties will then disappear.-G. PEPPER (Belfast): We think so; but see answers to former correspondents.-WESTMORELAND: Probably less than a couple of years; as to "Emigration," let him look to our "Literary Notices."-J.H.F. (Horbury-bridge): We intend to publish one. -T. SMITH (Islington): To bookkeeping, yes.-ALPHA: No.-R. WOOD (Chepstow): Yes.-W. N. B., an ANXIOUS INQUIRER: There is no artificial means of improving the memory applicable to all subjects. As to the dictionary and the shorthand, we are on the look-out for the best.-An IGNORANT SUBSCRIBER (Edinr.) wants our advice. Let him study English first, and then arithmetic.-J. J. NEWTON (Bridgewater): Under consideration.-A STUDENT (Liverpool): Certainly. As to dans and en, we shall give rules soon: he should read the notices to other correspondents.-J. M. (Bristol): Yes.-G. STRANGE (Hackney): His question has been answered in our notices, to another corre A. FOAD (Whitstable) is recommended to Reid's work on "Watch spondent.-J. VICKERS (Hulme): The error has been noticed and cor- and Clock Making."-POOR PEASANT is advised to drop the subject of rected.-WILLIAM: We are about to publish a work on the subject. perpetual motion.-A. D. (Edinburgh) should study Euclid.-A ARITHMETIC.-JOHN (Berwick-upon-Tweed): We should like to see STRUGGLER (North Shields) should study the Lessons in English well. the work to which the printed paper, he sent us, refers.-The remarks TIRO (Leicester) can get a shilling's worth of "Etiquette," published of JUVENIS on Inverse Proportion are just; when we come to this sub- by Longman. The diphthongs are separated for the sake of the learner. ject we hope to satisfy him-J. L. (Waterhead Mill, Oldham): Yes.--ALPHA (Richmond) should consult " Cassell's Emigrants' Handbook," R. BOLAND (Great Shelford): We thank him for his correct and useful (9d.).-R. J. (Mount Sorrel) is advised to study French first.-CLAUDE remarks; we shall avail ourselves of them.-Answers to queries 1, 2, 3, (Blandford) should read all the answers to Correspondents.-ONE WHO page 80, from P. G. ANDERSON (Birmingham), correct.-J. BOWMAN PERSEVERES is advised to be content with stenography.-JAME STEEL (Preston), is thanked for his very ingenious communication on the (Bradford), B. MILVERTON (Winsham), A FACTORY OPERATIVE mystical number 9.-A. CAMPBELL (Cathcart): Ditto.-LEWIS W. H. (New Lanark), and A YOUNG BEGINNER, should read the notices (Wolverhampton), proposes a curious question: "Can the nine digits be appended to Lessons in French, No. 13.-GEORGE WETTON (Kirkby-inplaced in rows nine times to form an exact square of 81 figures, without Ashfield), received.-E. P. a YOUNG BEGINNER will find what he having two figures of the same name in any one line, either perpendicu- wants at present in the "Illustrated Exhibitor."-DAVID M. (Norwich): larly, horizontally, or diagonally?" We thank him for his second com- Study" Macculloch's Commercial Dictionary."-J. T. D. (Bloomsbury) munication, and shall keep it in view.-DELECTOR: His answer to the should try by himself first.-S Y. (North Shields): His problems are arithmetical question is right.-G. J. E. (London): His difficulty is not sufficiently explicit.—Oμarns (Backwell): See above.—GEORGE removed by making the second distance 2 and seven-eights, instead of 2 HERBERT (Brid. Quay): Thanks for his hints.-AMICUS (Delph); and one-eighth miles.-W. FAULKNER (Smethwick): Ingenious and His question shall be inserted. -JAMES WILKINSON (Earby): We correct.-A. Fleming (Broughton-in-Furness): Correct.-J. CAREY advise him to let such words alone as he sent to us; their meaning is (Clapham): Ingenious.-F. R. W. (Islington): Not so foggy either.- bad.-JOHN GOWANS (Liverpool): His reasons are excellent for haste, J. N. L. (Dublin): Under consideration.-Correct solutions of Problems but ours are better for delay at present.-A. M. BELL (Liverpool): As and Queries from H. S. T., of No 2, p. 111.-JOHN (Berwick-upon- soon as other subjects are disposed of.-WILLIAM PEET (Bedford): Tweed), of No. 5; and from G. W. (Dundee), of No. 3. Right.-H. F. (Belfast), DUNC. F. (Glasgow), A Subscriber (Dublin), MUSIC.-JOHN is informed that some of the best flute instructors are THEOPHILUS (Caledonian-.oad): The subject of German pronunciathe following:-Tegg's "Flute Preceptor," 28.; "Alexander's Flute tion will soon be discussed more fully.-S. S H. (Holywell-hill, St. Preceptor," 3s.; "Dressler's Flute Instructions," 9s.; and Richardson's, Alban's): We are not in a state at present to avail ourselves of his kind Pratten's, and Wragg's "Flute Tutors."-GEORGE CON : The ME, in ex- offer-ERNEST M. (Wolverhampton): His criticisms are on the whole ercise 5, is printed on the wrong line.-A GREENWICH AMATEUR just; errors will be corrected. Study Macculloch. above mentioned.— suggests for the monochord, instead of a weight, "a peg, similar to those THOMAS PATTISON (Newcastle-on-Tyne) is right; the solution of of a violin, where weights cannot be easily obtained." If so, there James Veecock is defective.-C. F. P. (Dunmanway, Cork): His solushould be one at each end, and both should be used in tightening the tions are correct and good.-D. D. O. (Great Yarmouth): We say go string. He finds a string of thirty inches quite sufficient," and wants on and prosper in the Co-instruction Society.-A. M. WHITE (Woodus to print "a scale of the divisions of the monochord fifteen inches street): Thanks for his suggestions, they shall not be lost sight of.long." Any length is sufficient if the divisions are correct. There DANKBAR: Yes.-A. D. is premature.-MURAT (Halifax), a system would not be sale enough for the scale he proposes.-W. G. (Bury): A of bookkeeping is preparing. The least charge for an advertisement is guitar is one of the worst instruments for a "pattern," on account of its 5s.-R. S. DALE (North Shields): It is in progress.-J. S.: The numinaccuracy of tune. Let W. G. take a pattern from the best instrument ber of years from the creation of Adam to the deluge was 2262, accordat hand, but use his pattern as little as possible. The natural ear, with ing to the Scriptures and by the Christians. According to rule g is soft in frequent practice, will soon guide him to sing better than a falsely- Dolgelly.-P. E. A. (Bywell, Newcastle): "The Popular Educator."— tuned instrument. Let him practise well the first exercises, and study T. CROX (Fareham): We are entirely of his mind. We should only the mental effect of notes.-W. L. H. S.: We shall be happy to see his be too happy if our numerous subscribers wanted lessons in religion. views on Pianoforte Teaching.-WM. PARKER (Newnham): GeneWe hope and trust this will be a blessed consequence of the spread of rally speaking, any simple instrument that allows you to play only in education among all classes of the people.-WILLIAM LIVSEY (Manone key (the key of c for instance), is, for that key, correctly tuned. It chester): We cannot positively say how soon, but they are sure to be given. is only when they attempt to combine several keys that the common instruments require " temperament." The eight-keyed flute is, therefore, not so free from temperament as that with one key; the word key in

and Published by JOHN CASSELL, 335, Strand, and Ludgate-hill, London.-July 10, 1852.

tuents is named UREA, and it is in this substance that the nitrogen of decomposed tissues and superfluous food is carried off from the body. If the nitrogen were not so removed, its retention in the blood would be followed with the most pernicious effects.

We have disposed of the liver and its functions. But import- | as its ordinary constituents. The principal of these constiant as the office of that organ may be in separating and withdrawing certain superfluities from the blood, there are certain other matters which must be immediately and completely removed from the system, which would otherwise prove highly injurious. This is effected by the KIDNEYS, which are, perhaps, the most purely excreting or draining organs in the body. In each kidney, there are numerous secreting tubes, which project into its pelvis or basin; and from this basin there is a small but somewhat extended canal, called the URETER, which carries the urine from the kidney to the bladder. Each kidney has its own ureter or conducting canal. The secreting tubes are about both part of an inch in diametor, and are lined throughout with nucleated gland-cells, as if the urine were filtered through those cells in its way to the pelvis.

But how is the urine formed? If we take a section of the kidney, and examine it with a slightly magnified power, we shall find that its cut surface is studded with a number of little dark points, each of which consists of a knot of minute blood-vessels. Each of these knots is included in the extremity of one of the secreting tubes, and is directly supplied by a branch of the renal artery. This artery arises from the aorta, passes across, enters the kidney, divides into numerous branches which become very minute, frequently unite and form arches in the outward covering or substance of the organ; their extremities at last wind in toward the medullary or internal substance, and are coiled up into clusters, which take on the appearance and form of corpuscles. In these corpuscles or small bodies, which are situated in the external substance of the kidney, the urine is secreted, and is there received by the secreting tubes, which gradually unite to form larger tubes, and then converge towards the pelvis of the organ.

The separation of urine, as a surperfluous fluid from the blood, is in all likelihood effected by the agency of the glandcells which line the secreting tubes, and equally in all parts of these tubes. There are certain matters existing ready-formed in the blood, which require only to be separated from the vital fiuid. That is to say, that all such matters may pass from the blood to the urine without any further elaboration; but there are certain other properties which do not exist in the blood, and must therefore be formed by the chemical agency of the cells. These, also, must be carried off, or life would soon

cease.

But how do we know that this urea takes off the nitrogen of wasted tissue and superfluous food? We get at this conclusion in two ways. If we substitute an animal for a vegetable diet, we find an increase of urea, and therefore it must be derived in part from those unassimilated elements of this highly nitrogenous food which circulate with the blood. That is one method. The other is this:-If we exclude all nitrogenous substances from the food, and let the diet for several days consist of sugar, starch, gum, oil, and such like articles, the quantity is diminished, still urea is excreted or thrown off. It comes off even if there be no food taken for a considerable time. And therefore it must, in a still larger part, be derived from the waste of those animal tissues of which the body is made up. Whatever of this injurious substance exists ready-formed in the blood is withdrawn by the kidneys; but by far the larger portion passes off with the water.

Another animal substance, rarely absent from the urine, is URIC ACID, which is derived from the breaking down or waste of albuminous tissues. The relation which this acid bears to urea has not yet been determined. It is increased like urea by the use of animal food, and is diminished by adopting an exclusively vegetable diet, or such as is free from nitrogen. A nitrogenous compound, named HIPPURIC ACID, in the quantity of about one-third of the uric acid, exists in the urine, and is removed from the system in the same way as the others. It is now clear that the grand purpose of the urinary secretion is to carry off those products which neither can be set free in the condition of carbonic acid and water through the lungs, nor be got rid of by the agency of the liver in the form of solid biliary matter. In all this there is evident design. This design bespeaks a wisdom which is infinite, and a goodness which is exhaustless. The Father of our spirits is to be worshipped no less as the Framer of our bodies. The creation of man was nothing fortuitous-not a thing which happened by chance. It was one of the highest acts of divine power. How perfect is the structure of every organ! How beautiful and harmonious is their arrangement! end, and how beneficent in their functions! In the midst of How adapted to their such profound contrivance and skill-such arrangement, and harmony, and beneficence, we are lost in wonder, and fall down in silent adoration.

But we have not done with the process of secretion. The little glands which are disposed in the substance of THE SKIN, and in the walls of THE INTESTINAL CANAL, although individually minute, serve a most important end in the human economy. In the skin we meet with two distinct classes of these little glands, one of which is destined to free the blood of a large quantity of fluid, and is named PERSPIRATORY OF considerable amount of solid matter is styled SEBACEOUS or SWEAT GLANDS; and the other being designed to draw off a OIL GLANDS. The first class presents the appearance of small oval or globular masses, situated just beneath the skin, and found in almost every part of the surface of the body. Of their number some idea may be formed from the fact that not fewer than three thousand five hundred and twenty-eight of these little glands exist in a square inch of surface in the palm

Healthy urine is a clear limpid fluid, of a pale yellow or amber colour, with a peculiar faint aromatic odour; and yet, consistently with a good state of health, it may be ali but colourless, or present every shade between that and a deep orange tint. Clear and transparent at first, it often becomes, as it cools, opaque and turbid from the settlement of those particles which before were held in a state of solution. The average amount of this fluid which is excreted within the four-of the hand. Now if we allow that each of these little coiledand-twenty hours by an adult healthy man, is thirty-five ounces, and ite average specific gravity may be taken as very near 1,020. Ir summer, owing to the larger proportion of fluid exhaled by the skin, its quantity is less than in winter, and consequently its specific gravity is proportionally higher. The water holds in solution certain animal and saline matters

TOL. 1.

From the Latin word ren, the kidneys or reins.

up tubes measures one-fourth of an inch, we have thus within a single square inch, a length of tube equal to eight hundred and eighty-two inches, or seventy-three feet and a half, or twenty-four yards and a half. Nor is this all :-the number of square inches of surface in the body of a man of ordinary height and size, is computed at ten thousand five hundred, and if we allow two thousand eight hundred pores at an average in every square inch, then the number of pores in the human body cannot be fewer than twenty-nine millions!

16

We have said that each of these little glands consists of a small globe-like mass. Now from this mass there ascends a

conducting-tube which makes numerous spiral turnings in its course, penetrates the outer skin rather obliquely, and opens by a sort of valve to allow the fluid to issue from it. On the palm of the hand, the sole of the foot, and the ends of the fingers, the opening of these ducts or tubes is visible to the naked eye. By means of this gracious and wonderful arrangement, a secretion of watery fluid is continually taking place, while a considerable amount of solid matter is at the same time drawn off by the cells which line these small tubes. The fluid secreted is formed so gradually, that as fast as it reaches the surface, the watery portions of it escape by evaporation. This is called insensible perspiration. But during strong exercise, exposure to great external warmth, in certain diseases, or when evaporation is prevented by any means, the secretion is increased and collects on the skin in the form of drops of sweat. This is named sensible perspiration. But the amount of fluid sent off by the skin depends very much upon the temperature of the surrounding medium. When the surface of the body is exposed to a high degree of external heat, an increased amount of fluid is set free from the perspiratory glands. But as this fluid is carried off in a state of vapour as fast as it is set free, and in this form withdraws a large quantity of caloric from the surface, the temperature of the body itself is kept down and regulated. On the other hand, if the hot atmosphere be already loaded with vapour, this cooling power fails to be exerted. The temperature of the body is raised, and if this temperature contínues for any length of time, there follow the most fatal consequences.

hair. These hair-follicles, into which the sebaceous glands open, are in fact among the secretory organs of the skin; since it is only at their root or lowest part that the material produced from their walls is appropriated to the growth of hair. All the rest goes to anoint the hairs and the surface of the skin. Hence it is that this secretion is much more abundant in the inhabitants of tropical climates than in those which inhabit cold countries. But for this benevolent provisior of the great Creator the skin would become parched and dry. And even with this provision of nature, the natives of the warm countries are in the habit of lubricating their skin with vegetable oils of various kinds, to protect it from the scorching influence of the solar rays, pane

These wonderful functions of the skin have led some medical men to the conclusion, that hydropathy, or the use of the wet sheet, is the most valuable curative means we possess for almost every form and variety of disease to which the human body is subject. It is possible that not enough has been made of this most powerful of all diaphoretics-it is possible that it may come to be more generally employed as the functions of these glands are better understood-but we can never believe that any one remedy is equal to every type and development of disease. At the same time, we can, while in health, never be too lavish in our daily use of cold water.

Another fact on this subject of secretion. The mucous surface of the alimentary canal, is, like the skin, furnished with & vast number of these small glands. There are simple follicles to secrete the mucus; there are more complex follicles to elaborate the gastric juice; while those which crowd the walls of the small intestine are destined to withdraw the putrescent The entire loss by exhalation from the lungs and skin may matters from the blood, and convey them by the readiest chanbe taken at the average of two pounds and a half in the nel completely out of the body. It may be very necessary twenty-four hours. In a warm, dry atmosphere, it will rise indispensable, if you will-to take food to repair that constant above this, and in cold and damp, it will fall below it. Of waste of the tissues which is going on within us at every sucthis quantity, the exhalation from the lungs is about one-third, cessive moment of our earthly life; but there is a far greater and rather more than two-thirds from the skin. The variations necessity why these tissues, in a state of disintegration or in the amount of fluid set free at different times, and in differ-decomposition, should be removed from the body. Life ent states of the body, by exhalation from the skin and lungs, may be prolonged for a considerable period with little if any are counterbalanced by the action of the kidneys. If the ex-food, but the retaining of this morbific matter in the system for halation be less, then the kidneys allow a larger proportion of even a short length of time would issue in a fatal result. For water to be strained off in a liquid state from the blood-vessels. its removal the most beautiful provision has been made, and On the contrary, the kidneys have less to do in proportion to as we study, and perceive, and understand this provision, does the quantity that is exhaled from the lungs and skin. It is it become us to lift up our hearts in adoring gratitude and love supposed that at least one hundred grains of effete nitrogenous to God, whose tender mercies are over all his works. matter are daily thrown off from the skin; but let this excretion be checked or arrested, and how much more labour is imposed on the kidneys, since if it is not got rid of-if it accumulate in the blood-it must prove fatal to health and life! Great attention, therefore, should be paid to the functions of the skin, so as to keep its pores open, and its action free, and for this purpose nothing is so efficacious as bathing in cold water, followed by friction and exercise.

Besides this beautiful arrangement for the perspiration, the skin is provided with another set of special organs, named SEBACEOUS GLANDS, whose office it is to withdraw a peculiar fatty matter from the system, while the secretion itself prevents the skin from being dried and cracked by the influence of the sun and air. These glands are distributed more or less closely over the whole surface of the body, but are most numerous in those parts which are largely supplied with hair, such as the scalp and face, and are thickly distributed about the entrances of the various passages into the body, as the anus, nose, lips, and external ear. They are altogether absent in the palms of the hands and the soles of the feet. As the engraving very nicely indicates, they appear to be made up of an aggregate of small vesicles, and these small vessels are filled with an opaque white substance, something like soft ointment. These glands are overspread with minute capillaries or blood-vessels, and their ducts open either in the surface of the skin, or, which is more usual, directly into the follicle of the'

QUESTIONS FOR EXAMINATION.

What is the function or the office of the kidneys?aut kas
How is the urine carried from the kidney to the bladder?
How is the urine formed?

How is the separation of urine from the blood effected?
What is the grand purpose of the urinary secretion ? d)
With what little organs do we meet in the skin ?

Can you give their names and functions?

Where are the perspiratory glands situated?
What is the secretion which is effected by these glands?
On what does the amount of fluid sent off by the skin depend?
What is the entire loss by exhalation from the lungs and skin in
the twenty-four hours?

What quantity of effete matter is daily thrown off from the skin?

Where are the SEBACEOUS GLANDS chiefly distributed?
What is their peculiar function?

Do the functions of the skin in any way favour the practice of hydropathy?

Is the alimentary canal furnished with many of these little glands?

Can you describe the various offices performed by these intes tinal glands?

How is it more important to remove effete matter from the body than to supply the body with good nourishing food? How do these facts illustrate the goodness of God?

Je conduis, I conduct, do J'écris, I write, do write, Je lis, I read, do read, conduct, or am con

France. 7. Voilà votre livre, en avez vous besoin? 8. Je n'en ai pas besoin, j'en ai un autre. 9. Avez vous encore besoin de mon canif? 10. Je n'en ai plus besoin, je vais vous le rendre. 11. Notre cousin demeure-t-il à la ville? 12. I ne demeure plus à la ville, il demeure à la campagne. 13. Aime-t-il à aller à la chasse? 14. Il n'aime pas à aller à la chasse. 15. Il va tous les jours à la pêche. 16. Notre associé est il à Paris ou à Rouen? 17. Il est à Marseille. 18. On avez vous l'intention de conduire votre fils? 19. Je vais le conduire en Italie. 20. Demeurez vous à Milan ou à Florence? 21. Je ni demeure ni à Milan ni à Florence, je demeure à Turin. 22. Votre ami demeure-t-il en Suisse? 23. Il ne He writes well enough and rapidly domestique est il à l'eglise? 25. Non, Monsieur, il est à l'école. demeure plus en Suisse, il demeure en Prusse. 24. Votre