give the same definition briefly in the following terms: "Under the term 'food' we include those substances which in the solid or the fluid form are required for the nutrition of the body."

2. Hammarsten, professor of physiological chemistry, Upsala, University of Sweden: "Those bodies are designated as food which have no injurious action upon the organism, and which replace those constituents of the body that have been consumed in the exchange of material (metabolism), or that can prevent or diminish the consumption of such constituents."

3. Gould, compiler of the Medical Dictionary, defines food as "anything used for the nourishment or formation of tissue," and defines nourishment as "anything that enters into the formation of living tissue." So the definition might read: Anything used for the nourishment of, i. e., the formation of, tissue.

4. Howell, editor of the "American TextBook of Physiology," and professor of physiology, Johns Hopkins University, defines food thus: "What we eat and drink for the purpose of nourishing the body constitutes our food. . . . The food is utilized to repair the wastes of the body i.e., the destruction of the body material, which goes on at all times, and, in addition, it serves as the source of heat, mechanical work, and other forms of energy liberated in the body."

5. H. Newell Martin, professor of biology, Johns Hopkins University, gave the following conditions which a food must fulfill: "(1) A food must contain what it is to replace in the body, either in the form of such substances, or in forms which the body can build up into them; (2) it must be absorbable; (3) neither the substance itself nor any of the products of its transformation in the body must be injurious to the structure or activity of any organ. If so, it is a poison, not a food."

6. Seneca Egbert, professor of hygiene, and Frank Woodbury, professor of therapeutics, in the Medico-Chirurgical College of Philadelphia, have recently formulated

this definition: "A food is any substance which, when taken into the living animal body, is capable, usually after being subjected to the action of digestive organs, of entering through the absorbent vessels into the general circulation and of supplying assimilative material and potential energy to the cellular elements of the tissues, and of promoting normal metabolism and general bodily health."

The best definition of food will be the one which takes into account the widest range of facts regarding it. Of the definitions. quoted above, those of Howell, Martin, and Egbert and Woodbury are in perfect harmony. They represent the ideas of specialists in physiology, biology, hygiene, and therapeutics.

NATURE'S DEFINITION OF A FOOD.

It is probable that in no other concept which man may wish to define does he get so much assistance from Nature as in the case of the term "food." In fact, Nature gives a very clear-cut and unambiguous definition of food. Fortunately, she repeats this definition for every different branch of the plant and animal kingdom, so that there need be no misunderstanding.

Nature's food for young mammals is milk. Milk consists of two kinds of protein; or fat, milk, sugar, inorganic salts, and water. It is digested, absorbed, and assimilated by the living cells of the young growing body, and built up by them into cell protoplasm. Incident to the vital processes of the young mammal, portions of the cell substances are constantly being catabolized. Oxygen plays an important role in this catabolism, and energy is liberated in the form of heat, or mechanical motion, or nervous energy or secretory energy. Under the influence of this food the young mammal increases in size and strength.

Nature's food for young birds, reptiles, frogs, and fishes, is eggs. Eggs consist of protein, fats, inorganic salts, and water. Egg material is able to furnish all that the young bird, reptile, frog, or fish needs for

the early stage of its growth and development. The protein furnishes the nitrogenous compounds necessary for building up the active portion of every living cell, while the fat furnishes a non-nitrogenous portion of food, also taken within the cells of the growing animal and used there by the living protoplasm of the cells. Eventually it is oxidized, and yields its energy to the body as active heat or motor energy.

Nature's food for the young corn plant is the matter stored away in the corn grain by the mother plant. This food consists of protein, carbohydrates, fats, inorganic salts, and water.

When we subject the animal body to chemical analysis, we find that it is composed of water and solids; we find that the solids are, in turn, composed of organic and inorganic compounds, the former comprising proteins, carbohydrates, and fats, with various extractives representing products of tissue metabolism. The inorganic salts represent the mineral matter of the bones, the salts of the blood and lymph, as well of those of the tissues in general. If we make analysis of various animal organisms, we shall find the tabulated results strikingly similar for all classes of animals. If we make analysis of various foods which Nature provides for the young of these various animals, we shall find (1) that there is a striking qualitative similarity in the analysis; and (2) that the food analyses are strikingly similar to the analysis of the animals which they are to nourish, whose tissues they are to build up or repair.

These coincidences are not the result of chance. Nature follows laws graven in the very foundation of living matter. Protoplasm can use as food only substance which it can bring within its cell walls as a useful constituent of cell sap, or cytolymph. Though the food stuff forms a portion of the cytolymph of the cell, it must still undergo anabolic or assimilative changes before it becomes a part of the living, moving. spongioplasm of the cell.

We are now in a position to define a food in harmony with Nature's definition. Let

us not attempt a brief word formula, but simply state a few of the conditions which a food must satisfy.

I. A food must be digestible and absorbable by the organisms which it nourishes.

2. A food must be assimilable by the living cells of the organism which it is to nour ish. By these cells it is first made a constituent of the cytolymph, where it is held in temporary reserve for use by the active spongioplasm, or, perhaps, by the nucleus of the cell.

3. All assimilated foods-all living tissues-undergo catabolic changes accompanied by oxidation; i. e., all assimilated foods are oxidized within the body.

4. All the energy which the animal organism has at its disposal is liberated incident to the catabolism of assimilated foods. 5. The energy which a food supplies is liberated at such time and place as to be beneficial and advantageous to the organism.

No substance can be recognized as a food which is not properly absorbable and assimilable, and whose catabolism or oxidation is not so controlled in time and place as to be advantageous to the system.

The physiological chemist, Bunge, says upon the point: "In determining whether a particular substance is a food, it is not enough to prove that potential chemical energy is changed to kinetic energy. The oxidation must take place at the right time and location; i. e., at exactly the right stage in the activity of particular tissue elements. It must be demonstrated that the kinetic energy liberated can be utilized in the performance of a normal function."

ANEMIA and constipation are the chief and only symptoms in a great many cases of even well-marked gastritis, and their continuance without apparent cause should justify an analysis of the gastric contents.

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A GREAT many people mistake information for knowledge.

With pelvic asymmetry which introduces a serious element in the progress of labor, the obstetrician is much concerned. The inequalities of the lower extremities are demonstrable by both longitudinal and circular measurements, and the feet which are never alike by nature have their asymmetries intensified by the bootmaker.

When we come to internal and concealed organs of the body our subject receives further illustration. If we admit that we have a double brain it is probable that its corresponding parts are unequally developed. Most of us have our best eye, and our best ear, and are conscious that our motor activities, and sensory impressions are a little more evolved on one side than on the other, and by many people it is admitted that when fatigued one leg leads and the other lags. Popularly the lungs are thought to be symmetrical. Anatomically we know that they are very unlike, and that the heart largely contributes to the differences which are to be noted in their size, shape, lobar divisions, weight, and location. The heart itself is a very unsymmetrical organ. The kidneys may be said to be never symmetrical. Such azygous organs as the liver, spleen, uterus, and prostate gland have some lines of symmetry which disease often distorts. Arterial asymmetry is sometimes seen and often felt in the radials, making the pulses extremely unequal.

In disease we find that similar organs are either not both affected, or, if affected, not in the same degree. Headache and earache are often one-sided. Ear-wax may form in one or both ears. Disease of but one tonsil may be present. Neuralgia of one side of the face and sciatica of one limb are common. While the selective action of many diseases can be easily explained, there are still numerous affections in which it remains a mystery.

We are frequently confused by what may be termed the asymmetry of symptoms. Pain that is present in one condition may be absent under conditions that seem similar. In fevers and inflammations the subjective and the objective symptoms are often said to be

out of proportion to what we have read, or have seen, being in this sense unsymmetrical, and introducing an element of doubt and confusion in the minds of many consultants, thus making diagnosis obsucre and prognosis difficult. Much has been written under different heads upon this phase of our subject, and more remains to be learned. The two lungs are seldom equally involved in any affection. In respiration the the sides of the chest may expand unequally or one side may not expand at all. Lagging respiration is sometimes noted as the only symptom in the beginning of pneumonia and pleurisy. Arterial sclerosis advances in different degrees in corresponding vessels, and asymmetry of pulse may come from injuries to the arm, aneurysmal or other tumors of the chest cavity, emboli and autochthonous clots, or from compression of the subclavian artery (Vierordt). Asymmetrical movements of the eyes and of the pupils in disease may be of serious import and multiply diagnostic doubts. It is not yet determined to what extent, in comparing the two sides of the chest, slight relative differences obtained by inspection, palpation, measurement, ausculation, and percussion may be considered within the range of normal asymmetry. As no two individuals are alike, there is no exact standard of percussion note and ausculation sounds in health. Not only do healthy sounds differ in different individuals, but delicate shades of differences, due to relative asymmetries, exist in health in the same individual. The subjective element in the physician introduces another condition of variation, and the time must come when some more exact method of eliciting percussion sounds than that now exist will be adopted.

Symptom asymmetry marks neurological conditions. As we do not know the nature of nervous force, we have to study its effects, which in disease of the nervous system are frequently emphasized by characteristic asymmetry. Slight atrophy or hypertrophy, impaired motion or sensation, absent, lessened, or exaggerated reflexes become of great import in certain cases.

There are paralyses of parts of the face and eyes and cheeks and tongue and lips which are so slight as to escape the untrained eye. There are degrees of ataxia, areas of altered sensibility and limitations of movement which the patient may not note, and the general practitioner may fail to discover, but by the accomplished neurologist they are coördinated to make a diagnosis of a definite and localized nervous lesion.

Much of the work of the orthopedic surgeon is in correcting deformities of early life and in the majority of his cases the first symptoms were the slight pains or asymmetries of movements too often overlooked by the general practitioner, and not infrequently escaping the close observation of the interested mother, or caretaker. It becomes us, therefore, in treating every child, to have it stripped on the initial visit, in order that we may study it, to determine any asymmetry of surface or muscular power and nervous action. Very soon it will be discreditable not to detect early some of those conditions which reach the orthopedic surgeon only when asymmetry is marked by a twisted spine, or a shortened and atrophied member, or hip disease advanced to a well-nigh hopeless stage.

Through disregard of the laws of inheritance many of our patients are the products of unsymmetrical ancestry, inheriting unsymmetrical brains, disproportionate nervous systems, and are weighted for life with various asymmetries of which science can better take account than correct. The emotional, the hysterical, the eccentric individual is decidedly unsymmetrical in his development, and much so-called genius suggests asymmetry. All those complex emotions which represent unbalanced action are just as much evidences of nervous asymmetry as are the gross appearances presented by atrophied or hypertrophied muscles indicative of muscular asymmetry, and the time will come when better than now, we can demonstrate the asymmetry of brain cells.

Numerous occupations have deforming

tendencies. In early school life pupils are subjected to influences that favor asymmetrical development. The stoop of age is often prematurely acquired, and there are tasks which bend the body forward and ankylose the spine. The chronic weary and the heavy laden are always deformed. Some of our recreations have a similar effect. A prominent English writer deprecates ten nis for English girls and speaks of it as "that nasty game which is making our English girls lop-sided, destroying their symmetry of form." This objection does not apply to many exercises. Horse-back riding in a manly way, skating, rowing, walking, running cannot be said to favor one side of the body at the expense of the other side.

The questions which our subject suggests are more easily asked than answered. The profession is not in accord in distingishing between normal and abnormal asymmetry. It is not yet agreed how far the right half of the brain should be educated. There are physicians in this room who could not distinguish with the left index finger between the cervix ureri and the feces in the rectum. In using the microscope there are others who would fail to identify a renal tube cast with the left eye, and some of us could not sign our names with our left hand, or count the pulse with the left fingers, or open an abscess properly if our right hand were disabled.

Is such asymmetry of training to be commended? Is left-handed aptness obtained at the loss of right-handed deftness? As man was not originally right-handed, should we be indifferent to the functional development of parts of the right brain now inactive?

Many phases of asymmetry tend to pathological results, and we should strenuously oppose those habits of dress, study, and work that are compressing, contracting, confining, and disease-producing.

An inference from the foregoing is that the general practitioner must be symmetrically educated and trained in order to be able to recognize asymmetrical conditions with