weakened from any cause, is far less sure of continued life than he might have been. Since he secured this condition through ignorance, he is not to blame. But sad as is the fact, ignorance never saves men from the results of their ignorance.

Why do surgeons dread to do anything for the man who uses alcohol? Because they know only too well that the power of his heart and the elasticity of his arteries have been reduced. They are afraid that his heart may not rally after they have done what cutting is necessary. In writing of this danger, Sir Frederick Treves says:

Having spent the greater part of my life in operating, I can assure you that there are some patients that I don't mind operating upon and some that I do; but the person of all others that I dread to see enter the operating theater is the drinker. He is the most dangerous feature in connection with the surgical life.

It is because of this constant state of relaxed capillaries that the nose of the drinker stays red. In his case the nose is frequently a reliable sign of internal conditions.

CHAPTER XV

AS WE GROW BREATHLESS

If you were ever thoroughly out of breath, recall the sensations you had at the time. Perhaps you were try

ing to catch a train; perhaps

you were running in a relay race. In either case you felt that you must reach the goal at all hazards, and you ran as you had never run before.

But think of the discomfort of it! Since your legs were young and strong you thought nothing about your muscles. but simply used them hard. You ran fast. Your breath came and went freely, and during the first few moments you drew deep, long breaths of equal length. Soon, however, you found that each breath was shorter than the last; also that they came and went in quicker succession. You began to be uncomfortable. There was a tight feeling within you, as if an iron band were closing itself about

your chest; as if it prevented you from expanding your lungs to their full size. You wondered how much longer you could keep it up.

But why were you breathless? To answer the question, follow once more the condition of muscle and bone, tendon and heart, lungs and blood vessels, while you were running. Think for a moment of your unelastic

NINE VIEWS OF THE SAME MAN AS HE RAN

A different set of muscles is at work in each position, so that altogether many muscles are used in running

(After Schmidt)

tendons as they stayed firmly gripped to their bone attachments. Remember how each one of multitudes of muscles, large and small, shortened and lengthened as by means of their tendons they pulled those leg bones of yours up and down and kept them at work. Remember that neither arms nor head nor any other part of your body was quiet as you ran, but that every

muscle seemed to work hard in keeping time and step with the movement of the legs. Remember that such violent action as this means that changes are going on in the substance of the living tissue which is exercised, that these changes involve the giving off of unusual quantities of carbon dioxid, that oxygen is needed by the working fibers, and that in order to supply the oxygen and to carry off the carbon dioxid, fresh streams of blood must be hastened to the active muscles with ever-increasing speed. The most immediate, imperative need of each working fiber is to get rid of the excess of carbon dioxid. There are three things which bring about such a condition of breathlessness:

1. Exercise violent enough to compel the fibers of the muscles to produce unusual quantities of carbon dioxid. As this gas is produced, oxygen is demanded by the fibers. It is indeed as if they themselves were breathing.

2. The activity of the chest walls as they expel the carbon dioxid from the air sacs of the lungs and replace it with air containing oxygen.

3. The rapid work of the heart as it receives larger amounts of impure blood than usual through the veins and sends arterial blood to the tissues to carry oxygen and to bring away carbon dioxid. Te a large extent it is this forced work of the heart that explains the feeling of breathlessness.

We were speaking of this matter the other day, and my friend, who teaches physiology, said:

People used to say that a man was breathless because there was more carbon dioxid in his blood than he could expel through his lungs. But we know better now. We know that it is n't so much the carbon dioxid although of course that has to be driven off overtaxed heart that makes us breathless.

as it is the

Boys come to me for examination, and I tell them that the heart gets tired from overwork, just as the biceps does, and that it is quite as possible to strengthen the heart by training as to strengthen the biceps. At first I put the boys on easy exercises that tax the heart but little; then day by day I give what is harder until, almost before they know it, those boys have developed hearts that are strong enough to do good hard work without making them breathless.

The recognized fact is that we grow breathless in proportion to the force which we put into any exercise in a given length of time; that is, the faster we do the same thing, the more quickly will breathlessness overtake us. It is easy, therefore, to understand an opposite condition, and to believe that the quieter we are, the less oxygen the tissues will use and the less carbon dioxid the body will have to get rid of.

The following figures show the amounts of carbon dioxid which a man gives off while sleeping, sitting, or running for a given length of time: