The Yogi teachings go further than does Western science, in one important feature of the Nervous System. We allude to what Western science terms the "Solar Plexus," and which it considers as merely one of a series of certain matted nets of sympathetic nerves with their ganglia found in various parts of the body. Yogi science teaches that this Solar Plexus is really a most important part of the Nervous System, and that it is a form of brain, playing one of the principal parts in the human economy. Western science seems to be moving gradually towards a recognition of this fact which has been known to the Yogis of the East for centuries, and some recent Western writers have termed the Solar Plexus the "Abdominal Brain." The Solar Plexus is situated in the Epigastric region, just back of the "pit of the stomach" on either side of the spinal column. It is composed of white and gray brain matter, similar to that composing the other brains of man. It has control of the main internal organs of man, and plays a much more important part than is generally recognized. We will not go into the Yogi theory regarding the Solar Plexus, further than to say that they know it as the great central store-house of Prana. Men have been known to be instantly killed by a severe blow over the Solar Plexus, and prize fighters recognize its vulnerability and frequently temporarily paralyze their opponents by a blow over this region.

The name "Solar" is well bestowed on this "brain," as it radiates strength and energy to all parts of the body, even the upper brains depending largely upon it as a storehouse of Prana. Sooner or later Western science will fully recognize the real function of the Solar Plexus, and will accord to it a far more important place then it now occupies in their text-books and teachings.

One of the first lessons in the Yogi Science of Breath, Is to learn how to breathe through the nostrils, and to overcome the common practice of mouth-breathing.

The breathing mechanism of Man is so constructed that he may breathe either through the mouth or nasal tubes, but it is a matter of vital importance to him which method he follows, as one brings health and strength and the other disease and weakness.

It should not be necessary to state to the student that the proper method of breathing is to take the breath through the nostrils, but alas! the ignorance among civilized people regarding this simple matter is astounding. We find people in all walks of life habitually breathing through their mouths, and allowing their children to follow their horrible and disgusting example.

Many of the diseases to which civilized man is subject are undoubtedly caused by this common habit of mouth-breathing. Children permitted to breathe in this way grow up with impaired vitality and weakened constitutions, and in manhood and womanhood break down and become chronic invalids. The mother of the savage race does better, being evidently guided by her intuition. She seems to instinctively recognize that the nostrils are the proper channels for the conveyal of air to the lungs, and she trains her infant to close its little lips and breathe through the nose. She tips its head forward when it is asleep, which attitude closes the lips and makes nostril-breathing imperative. If our civilized mothers were to adopt the same plan, it would work a great good for the race.

Many contagious diseases are contracted by the disgusting habit of mouth-breathing, and many cases of cold and catarrhal affections are also attributable to the same cause. Many persons who, for the sake of appearances, keep their mouth closed during the day, persist in mouth-breathing at night and often contract disease in this way.

Carefully conducted scientific experiments have shown that soldiers and sailors who sleep with their mouths open are much more liable to contract contagious diseases than those who breathe properly through the nostrils. An instance is related in which small-pox became epidemic on a man-of-war in foreign parts, and every death which resulted was that of some sailor or marine who was a mouth-breather, not a single nostril-breather succumbing.

The organs of respiration have their only protective apparatus, filter, or dust-catcher, in the nostrils. When the breath is taken through the mouth, there is nothing from mouth to lungs to strain the air, or to catch the dust and other foreign matter in the air. From mouth to lungs the dirt or impure substance has a clear track, and the entire respiratory system is unprotected. And, moreover, such incorrect breathing admits cold air to the organs, thereby injuring them. Inflammation of the respiratory organs often results from the inhalation of cold air through the mouth. The man who breathes through the mouth at night, always awakens with a parched feeling in the mouth and a dryness in the throat. He is violating one of nature's laws, and is sowing the seeds of disease.

Once more, remember that the mouth affords no protection to the respiratory organs, and cold air, dust and impurities and germs readily enter by that door. On the other hand, the nostrils and nasal passages show evidence of the careful design of nature in this respect. The nostrils are two narrow, tortuous channels, containing numerous bristly hairs which serve the purpose of a filter or sieve to strain the air of its impurities, etc., which are expelled when the breath is exhaled. Not only do the nostrils serve this important purpose, but they also perform an important function in warming the air inhaled. The long narrow winding nostrils are filled with warm mucous membrane, which coming in contact with the inhaled air Warms it so that it can do no damage to the delicate organs of the throat, or to the lungs.

No animal, excepting man, sleeps with the mouth open or breathes through the mouth, and in fact it is believed that it is only civilized man who so perverts nature's functions, as the savage and barbarian races almost invariably breathe correctly. It is probable that this unnatural habit among civilized men has been acquired through unnatural methods of living, enervating luxuries and excessive warmth.

The refining, filtering and straining apparatus of the nostrils renders the air fit to reach the delicate organs of the throat and the lungs, and the air is not fit to so reach these organs until it has passed through nature's refining process. The impurities which are stopped and retained by the sieves and mucous membrane of the nostrils, are thrown out again by the expelled breath, in exhalation, and in case they have accumulated too rapidly or have managed to escape through the sieves and have penetrated forbidden regions, nature protects us by producing a sneeze which violently ejects the intruder.

The air, when it enters the lungs is as different from the outside air, as is distilled water different from the water of the cistern. The intricate purifying organization of the nostrils, arresting and holding the impure particles in the air, is as important as is the action of the mouth in stopping cherry-stones and fish-bones and preventing them from being carried on to the stomach. Man should no more breathe through his mouth than he would attempt to take food through his nose.

Another feature of mouth-breathing is that the nasal passages, being thus comparatively unused, consequently fail to keep themselves clean and clear, and become clogged up and unclean, and are apt to contract local diseases. Like abandoned roads that soon become filled with weeds and rubbish, unused nostrils become filled with impurities and foul matter.

One who habitually breathes through the nostrils is not likely to be troubled with clogged or stuffy nostrils, but for the benefit of those who have been more or less addicted to the unnatural mouth-breathing, and who wish to acquire the natural and rational method, it may perhaps be well to add a few words regarding the way to keep their nostrils clean and free from impurities.