We have already had occasion to point out, in connection with the types of stature, the importance of the thorax.

The relation of the thoracic perimeter (circumference of the chest) to the total stature (see chapter on Technique) was called by Goldstein the index of life, in order to indicate that the organic resistance of any individual depends upon the proportional relation between the thorax and the whole body; whoever has a narrow chest is liable to pulmonary tuberculosis, and in his physiological entirety is a weakling (see chapter on Macroscelous and Brachyscelous Types).

Anatomical Parts.—Anatomically the thorax is determined in height by the twelve dorsal or thoracic vertebrÆ, which are characterised by having a transverse apophysis, which articulates with the twelve pairs of ribs, forming the thoracic cage, or chest.

The first seven pairs of ribs articulate in front, by means of cartilages, with the lateral margins of a flat bone, the sternum or breast-bone, which is formed of three pieces: the manubrium uppermost, then the corpus, then, lowest of all, the ensiform (sword-shaped) process.

The manubrium and the corpus form, at their juncture, an angle more or less marked, according to the individual, and the lateral articulation of the second rib corresponds to this angle. In the new-born child the sternum is a cartilage with points of ossification arranged longitudinally like the beads of a rosary. The seventh vertebra articulates laterally at the point at which the ensiform process is attached to the corpus of the sternum. The next three ribs (8th, 9th and 10th) are articulated together and with the seventh by means of cartilaginous arches; the last two pairs of ribs (11th and 12th) are free or floating. At the top, the thoracic cage is reinforced by the thoracic girdle, which serves also to afford articulation for the upper limbs, and which consists of the clavicles, in front, and of the scapulÆ, behind. The clavicles are long bones placed in an almost horizontal position above the thorax, and they determine the width of the chest; at the inner extremity they articulate with the manubrium of the sternum and at the outer extremity they are attached to the acromial process of the scapulÆ. The scapulÆ are flat bones which are attached to the posterior surface of the thoracic frame, on which they are freely movable, covering a tract extending from the second to the seventh rib. At their upper and outer extremity they are provided with two bony processes; namely, the acromion, already mentioned, which contains the points of maximum width of the shoulders, and the coracoid process, which terminates anteriorly and, together with the acromion, overhangs the articulation of the humerus with the body of the scapula.

Powerful muscles clothe the thoracic frame, serving partly in the movements of respiration and partly in the movements of the upper limbs. It may suffice to mention, among the muscles situated posteriorly, the cucullaris, the great dorsal (m. longissimus dorsi), the rhomboids of the scapulÆ (m. rhomboideus major and minor), and the serratus posterior of the ribs; anteriorly, the large and small pectoral and the great serratus; beside which there are the intercostal muscles, extending from rib to rib and taking part in the movements of respiration. But the most important muscle is the diaphragm, which completely closes the thoracic cavity, rising into it in a convex vault and separating it from the abdomen; this constitutes the most active of all the muscles which participate in the movements of respiration. The thoracic cavity, thus determined, encloses the two most important viscera of vegetative life—the heart and the lungs.

The heart is a muscle shaped like a pear or cone, having its base turned upward, and its apex or point turned downward and outward toward the left, corresponding to the fifth intercostal space; it is divided, as is well known, into four cavities, and constitutes the great motor power of the circulation of the blood. The lungs are two in number, right and left, and surround the heart, completely filling the thoracic cavity. The lungs are divided into superimposed lobes, three in the right and two in the left lung; they are composed essentially of infinitely small ramifications of the bronchi, resolving into tiny series of chambers, the pulmonary alveoli or air-cells. These alveoli, consisting of a single layer of extremely small cells, are surrounded by a dense network of capillary tubes, through which takes place the interchange of oxygen and carbon dioxide. It has been calculated that if we should estimate and sum up the internal surfaces of the pulmonary alveoli, or, what comes to the same thing, if we should spread out and join together the alveolar walls of the lungs, they would have a superficial area of 200 square metres. This area might be compared to the foliage of a great human tree (respiratory surface).

Physiological and Hygienic Aspect.—The importance of the thorax is physiological, because it contains the highly important viscera of vegetative life; but this importance is especially associated with the lungs. The lungs are the organs that acquire the oxygen from the outside environment, and this oxygen, when taken up by the hemoglobin in the blood, will serve to oxygenate the tissues of the entire organism, and thus aid in the processes of cellular metabolism. A large supply of oxygen stimulates this interchange of matter, not only because the organism as a whole is enriched in the substance essential to this process (oxygen), but because the heart responds to the increased activity of the lungs by more energetic pulsations calculated to set the blood circulating in far greater quantities. It is no exaggeration to say that our whole physiological life is enclosed within the thorax, because the digestive system does nothing more than prepare a blood that is unfitted to irrigate the tissues for the purpose of supplying them with nutriment; it is only after this blood has passed through the lungs that it is transformed into oxygenated blood and is adapted to assimilation. Consequently the intestines prepare nothing more than the raw material, and it is the lungs which perform the service of perfecting it; while the heart drives it through its circuit into contact with all the tissues of the organism.

Whoever has inadequate lungs is for that reason alone a person who necessarily receives insufficient nutriment (thin and weak macroscele), and frequently is also a melancholiac. Melancholia accompanies every form of physiological decadence. On the contrary, persons with ample lungs are generally serene of spirit and joyous. In fact, the emotion of joy is at the same time both the cause and the consequence of an active circulation of oxygenated blood (florid or ruddy complexion).

Certain experiments conducted with birds have proved that if free oxygen is introduced under an air-bell in which the birds have been enclosed, they gradually become more and more excited, singing and fluttering as if possessed by a frenzy of joyousness. It is a fact that we often rid ourselves of a fit of melancholy by taking a walk in the open air; persons possessed of good lungs feel within themselves a vital potentiality that perceptibly aids them to make what we call an "effort of will"; when sorrow befalls them, or overexertion has exhausted their strength, persons of this type feel some force spring up within them that seems to give them fresh hope and courage. It is their oxygenated blood, which neither weariness nor depression of spirit can stay in its luxuriant course; the man of weak lungs, on the contrary, is mentally depressed, because his physiological life has slowed down; and, instead of aiding him, it is his physiological life which demands of him a genuine effort of will to reestablish its equilibrium.

Accordingly, those persons who have a well-developed chest are certainly the healthiest and the happiest.

But this is not the only pulmonary function; the lungs are also the organs of speech. In fact, while speech is manufactured in the brain and the cerebral nerves that stimulate the organs of the spoken word, it requires also its "driving power," that is to say, air, in order to obtain utterance; and it is the lungs to which singers and speakers alike owe the physical strength of their voice. Even the respiratory rhythm has a great influence upon speech.

The spoken word requires a most complicated mechanism, and among the details of this mechanism, by no means the least important are the acts of inspiration, by which the air is received into the lungs, and of expiration, by which it is expelled, simultaneously with all the other movements producing speech. Indeed, we know that when speech is further complicated by the act of singing, it becomes necessary to study special rules for breathing; in short, to educate the voice.

Now, why do we not also educate the voice for its ordinary task of the spoken language? Speech is one of the marvels that characterise man, and also one of the most difficult spontaneous creations that have been accomplished by nature. Through the voice, the lawyer defends the innocent, the teacher educates the new generations, the mother recalls her erring son to the path of virtue, lovers unite their souls, and all humanity interchanges ideas. If intelligence is the triumph of life, the spoken word is the marvellous means by which this intelligence is manifested.

We trouble ourselves to educate the voice only for the purpose of singing, and neglect the spoken word. We do not stop to think that singing appeals only to the senses and emotions, while speech appeals to the emotions and the intellect, and therefore charms and at the same time convinces.

Anyone who has heard that wonderfully gifted speaker, Ofelia Mazzoni, expounding our great poets to the labouring classes at the People's University in Milan, rousing the slumbering intelligence of the working man, will understand what an immense educative force we are neglecting.

In a century in which we speak of an intellectual reawakening and a brotherhood of man, we have forgotten the voice! Yet in this new era of humanity that is learning brotherly love and striving for peace, the voice plays a part analogous to that of the trumpet-call in the centuries consecrated to war.

As a matter of fact, our schools so far neglect defects of speech that it is not uncommon to hear a stammerer undergoing examinations for a degree in jurisprudence. The fact that an otherwise cultured man lisps or stammers is treated by us as quite an indifferent matter, just as among savage tribes a king may have unclean nails without anyone observing the fact.

Yet it is now known that stammering may usually be cured by a systematic training in the art of breathing.

Respiratory gymnastics ought to constitute one of the principal courses of instruction in schools for children. I have introduced it into the "Children's Houses," among children between the ages of four and six, combining it with a special instruction in written language (letters of the alphabet), designed to educate the movements of the organs of speech, without worrying or tiring the children, and this method has borne such good results that our little ones, by the time they are five years old, have lost nearly all their defects in pronunciation.

Spirometry.—The pulmonary capacity may be measured directly by means of an instrument called the spirometer; the breath must be strongly expelled through a tube opening into a hollow cylinder, thus raising a graduated piston contained in it; and, by reading the figure indicated on the piston-rod, we learn the volume of air expelled from the lungs.

Such an instrument is better adapted for use by adults than by children; and if it should ever come to be introduced into the schools, it should not in any case be used below the elementary grades.

The person who is going to measure the capacity of his lungs by means of the spirometer, begins by drawing in an unusually deep or forced inhalation; then, after holding his breath for a moment, he proceeds to expel into the rubber tube all the air in his lungs, in a forced exhalation. In an exercise of this sort, all the difficulties of respiratory gymnastics are successively surmounted—inspiration, respiratory pause, expiration.

In fact, in accomplishing the forced inspiration, all the pulmonary alveoli must be dilated to the maximum extent, and at the same time the thorax must reach its maximum dilation. This is a very different matter from normal inspiration, which does not completely dilate the alveoli. As a matter of fact, the tidal air or air of respiration, i.e., the air taken in and expelled in each normal respiration, is about 500 cubic centimetres; but the sum total of air habitually contained in the lungs is made up of two quantities: first, that which may be emitted by a forced expiration, the supplemental or reserve air, amounting to 1,600 cubic centimetres; and secondly, the air which cannot ever be emitted, because no amount of effort could completely expel all the air from the lungs; residual air or respiratory residuum amounting to 1,200 cubic centimetres. To recapitulate, the average pulmonary capacity is the sum of the following average quantities of air:

Accordingly, the total pulmonary capacity is about 5,000 cubic centimetres, or five litres. But in normal respiration, the capacity is less, i.e., about 3,300 cubic centimetres, the air due to a forced inspiration not being included.

Therefore, in each normal respiration a half litre of pure air (assuming that it is pure) is introduced and mingled with the vitiated air already within the lungs; and since, in expiration, a third only of this 500 cubic centimetres is eliminated, it follows that 166 cubic centimetres are mingled with the 3,300 cubic centimetres; in other words, that only one-tenth of the air is renewed in each normal act of respiration.

A very energetic forced inspiration may draw into the lungs, in addition to the customary 500 cubic centimetres, an additional 1,670 cubic centimetres of pure air, complementary air. In this case the lungs contain upward of 5,000 cubic centimetres of air.

The forced expiration which follows upon this extra deep inhalation purges the lungs of the vitiated air which has formed there. In this way we complete an exercise that is eminently hygienic.

Now, these spirometric movements are fraught with difficulties: 1. The forced inspiration, deep enough to extend the alveoli, may be more or less complete. If a cloth wrung out in cold water is laid across the shoulders, the inspiration which follows as a result of reflex action is far deeper than that produced by an act of will; this proves that the lungs can be dilated to a point beyond that which seems to us to be the extreme limit, and therefore that with practice we may learn to dilate our lungs still further.

2. When the attempt is made to hold the breath after a forced inspiration, almost everyone at the first trials will allow more or less of the air to escape; that is, they will discover themselves incapable of controlling their own organs of respiration; therefore, a gymnastic exercise for acquiring such control is necessary. This is the exercise which will make us masters of the movements required to produce vocal sounds at pleasure.

3. A slow expiration so controlled as to give time for the air to penetrate into the spirometer, is accomplished, though somewhat unevenly, the first few times, and is perfected with practice.

It results from the above that: 1. We take in less air than we are able to take in; 2. part of this air is lost outside the spirometer; consequently the spirometer registers a pulmonary capacity below that which the lungs actually have; and we shall find that, with practice, the volumetric figure will successively augment. But the pulmonary capacity has not augmented in proportion; it is only that practice has perfected the respiratory movements. Accordingly, the spirometer may serve as an instrument to test the progress made in respiratory gymnastics, and, in the case of those who have already become skilful in its use, it becomes a really valuable instrument for measuring the respiratory capacity.

When we remember that a portion of the air, i.e., 1,200 cubic centimetres, never issues from the lungs, it follows that the respiratory capacity is less by 1,200 cubic centimetres than the pulmonary capacity, which, as we have seen, is on an average upward of 5,000 cubic centimetres (5,370) in the adult man. Hence, the spirometer directly measures the respiratory capacity, and only indirectly the pulmonary capacity.

When women measure their lungs by means of the spirometer, they have difficulty in registering 2,000 cubic centimetres, and men have difficulty in attaining 2,600 cubic centimetres. Instead of which, a man ought to be able to register between 3,800 and 4,000 cubic centimetres.

What keeps the lungs healthy is an abundant aeration with air rich in oxygen, and not impure with carbon dioxide and other poisonous gases. When the pulmonary air-cells are insufficiently dilated, they are predisposed to attack by the bacillus of tuberculosis. Indeed, pulmonary tuberculosis usually begins at the apexes of the lungs, which are less thoroughly aerated, and also usually attacks persons with narrow chests. The treatment of tuberculosis is eminently a fresh-air treatment; tuberculous patients may be benefited and even cured in a remarkable percentage of cases (50 per cent.) if they are exposed day and night to the open air. In this way the relation between free respiration and pulmonary health is demonstrated.

In America at the present time the hygienic rule of sleeping at night, winter and summer, with the windows open, is gaining ground, and even the practice of sleeping in the open air. And the various forms of sport also have the beneficial effect of bringing those who indulge in them into a healthy contact with fresh air, which civilised man has shown a fatal tendency to abandon.

The same exercise which dilates the lungs (the contents) also dilates the thorax (the container). The result is that man ends by acquiring the thorax corresponding to his vocation, or in other words, a thorax corresponding to the life that he leads in consequence of the form of work to which he devotes himself. Shepherds in mountain districts and mountain peasants have the largest thorax, notwithstanding, as we have seen, that they are more scantily nourished. In cities, the maximum average circumference of chest is found among the cart-drivers, and the minimum among university students and in general among those who have grown up in an inclosed environment, with the thorax artificially cramped by the position assumed while writing or reading at a desk; yet this is the class of persons who have abundant nutriment.

Consequently, we find a division of air and bread between different social castes; those who have air, do not have bread, and they possess large lungs, out of proportion to bodies which, being underfed, have been unable to grow; and those who have bread do not have air, and they possess lungs that are insufficient for the needs of bodies that have grown under the influence of abundant nutrition. Consequently, all civilised men are physiologically out of equilibrium, and their physical health is lessened. But those who suffer most from this loss of equilibrium are the studious class, who have nourished themselves upon hopes and opened their minds to great ideas, and deluded themselves into undertaking big enterprises; but in real action they find that they are weak, and that they easily fall into discouragement and depression, and when their will-power forces them onward, their organism responds with nervous prostration and melancholia.

It is a sad fact that at the present day the best energies of man reach maturity possessed of insufficient lungs, and consequently liable to break down in health, energy and strength.

A large part of the studious class, such, for instance, as the teachers, are at the present day devoting themselves to a form of work which is not a pulmonary exercise, but pulmonary destruction.

We must remember that healthy exercise of the lungs should take place in the open air, and consists of indrawn breaths deep enough to dilate the air-chambers. Instead of this, the teacher speaks, which means that he makes forced expirations, during many hours in an enclosed environment and in an assemblage of persons who, for the most part, are far from clean. The bacillus of tuberculosis finds in the teacher its favourite camping-ground. In fact, statistics indicate that the maximum mortality from tuberculosis is among teachers; higher even than among nurses. It is really distressing to think of the ignorance of hygiene in which our schools are even yet steeped, so that they seem forgetful of the body, in their pursuit of a spirit that eludes them and that, as a matter of fact, is not being educated in anything approaching a rational manner.

When we enter a class-room, we see rows of benches constructed like orthopedic machines, to the end that the vertical columns of the pupils shall not be distorted during their enforced labour; and the thought arises: this is the spot in which the teacher becomes a consumptive for the sake of transforming the children into hunchbacks. What is the reward of so great a sacrifice? What sort of a preparation in ideals and in character are they giving to the new generations through such disastrous means? What are the obstacles which they are being taught, through so much suffering, to surmount and to conquer? What, in short, is the spiritual gain achieved at the cost of so great an impoverishment of the body?

The answering silence that greets these questions indicates that we have a great mission to accomplish.

Anthropological studies made upon pupils have demonstrated that school-children rarely attain a sufficient chest development. I also have made my modest contribution, proving that the brightest scholars, the prize-winners, etc., who, as a general rule, also enjoy an advantage in social position, have a narrower chest measure. Among the children that are recognised as the brightest in their classes, I have been able to distinguish two categories: those who are exceptionally intelligent, and those who are exceptionally studious; the former have a better chest development than the latter.

Signorina Massa, one of my pupils at the University, in the course of kindred studies made among pupils of a uniform social grade (the poorer classes) observed that the best and brightest scholars, etc., have a chest circumference and a muscular strength notably inferior to the children who are not studious. There can be no doubt that an assiduous application to the study table impoverishes the organism and above all impedes the normal development of the thorax. This fact has a really overwhelming importance. Study the tables of mortality in Italy for infective diseases, i.e., those diseases in which mankind meets the assault of the microscopic invader either with a strong constitution, or with one already predisposed to defeat. The most dreaded diseases, such as diphtheria, typhoid, measles and scarlet fever are all grouped together under a mortality oscillating between five and twenty-five thousand deaths a year. But bronchitis and pneumonia each cause a mortality that ascends to between seventy and eighty thousand deaths; in this group it is evident that we must take into consideration, not only the infected environment, but also the organic predisposition. Every man and woman has been prepared, by their years in school, to have in the form of a narrow chest and an insufficient development of the organs of respiration, a locus minoris resistentiÆ. Whoever talks of the war against tuberculosis ought first of all to investigate the school and its pedagogic methods.

Anthropological Aspect. Growth of the Thorax.—In the course of its growth the thorax undergoes an evolution, not only in itself, but also in its relation to the vertebral column.

Fig. 124.