two hundred years ago, the real source of the discharge from the head which accompanies. a cold was described by Schneider. Before his time, the discharge was thought to come from the brain! In anatomical language, the internal lining of the nose has ever since been termed the Schneiderian membrane.

It has been held by certain writers that what is called disease is the expression of a beneficent design, as much as the adaptation of organs to their particular functions. They point to the eruptions on the skin in small-pox and like diseases as being the means adopted by nature to throw off from the blood, which alone sustains life, some noxious element which had gained access to it. They tell us that in other cases

in which no curative our ignorance in interpreting nature. They assert that when death occurs from disease, it is an accident incidental to the process to which the vital power succumbs. Now, whether this is true in every instance or notand the proof is at present impossible-it seems in some instances well borne out. In this very case of cold in the head, we see suppressed perspiration, followed by febrile disturbance of the system, together with retention of materials in the blood which should have been thrown out. This is succeeded by a discharge from the nostrils containing the same salts as those ex

effort is obvious, it is because of

creted in perspiration, which are thus in a vicarious manner expelled from the blood, and this continues until the disturbed balance is restored.

People often say when they have a cold in the head that they have got influenza, and, on the contrary, this is sometimes mistaken for a simple cold.. But the two affections are quite distinct in origin as well as in effects. It is true that many of the symptoms are alike in both, except that they are all generally much more severe in influenza. It is commonly attended by headache, discharge from the nostrils, great languor and depression, followed not unfrequently in the aged and the weakly by death. Influenza is, in fact, a very serious and often a fatal disease. It was described more than two thousand years ago by Hippocrates, the father of medicine, himself. Truly an epidemic, many of its visitations to this country in former times can be accurately traced. These are fortunately not very frequent, and have not usually lasted more than a month or six weeks at a time. Many theories have been advanced to account for influenza. Some have attributed it to a disturbance in the electrical condition of the earth and the atmosphere. One authority went so far, from confidence in this view, as to recommend the use of socks made of oiled silk, or

some other non-conductor of electricity, as a means of guarding against an attack. Others have supposed it to be caused by some peculiar miasm in the atmosphere, which, travelling over the earth, accounts for the remarkable manner in which, like cholera, influenza passes from one country to another. But these and other theories are altogether deficient in proof. As in many other things connected with disease, we must for the present admit that we do not know its cause, and be content to wait until patient investigation throws light upon our dark

ness.

One thing, however, we do know, namely, that while the origin and progress of cholera and influenza have much apparent resemblance, both are also capable of being communicated by infection.

There is another affection, far more prevalent than is supposed, which is sometimes mistaken for a common cold. It is curious that many substances which have no effect whatever on people in general, act most injuriously on the air-passages of a few. Thus, some persons are at once affected with sneezing, and other signs of catarrh, whenever powdered ipecacuanha is exposed to the air near them, and even linseed meal sometimes acts in the same manner. But of all the causes which produce this kind of irritation, none is

so widely diffused as that which is derived from our hay-fields in summer. It is now pretty generally known that the emanations from hay injuriously affect a considerable number of people in a variable.degree. Some complain merely of symptoms like those of cold in the head and eyes, while in others a severe asthma is produced. Whether these effects are due to exhalations, or to minute particles given off by the hay plants, is not certain. Whichever it may be, one plant in particular, the sweet-scented vernal grass, Anthoxanthum odoratum, has been accused as the chief, if not the sole, offender in the matter.

It too often happens that the effects of taking cold are not confined to the nose and its appendages in the front of the head. This might be expected, when it is considered that the connections of these portions of mucous membrane with others are very extensive. There are minute tubes lined with this membrane, which pass from the inner edges of the eyelids, where their little apertures can be distinctly seen, to the interior of the nose. The use of these tubes is to drain off any superfluous moisture from the surface of the eyes. The nose, too, communicates with the throat, and from the throat other tubes extend to the interior

of the ear. All that concerns the ear and its appendages is treated of in its proper place. It is enough

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here to indicate that this continuity of structure leads to the same affections of the parts concerned. When a cold in the head is severe, it is very apt to affect the eyes; and when the ear-tubes are obstructed from pressure of adjoining parts, which have become swollen from inflammation, deafness is caused.

The mucous membrane of the throat also communicates not only with the gullet, or passage which leads to the stomach and bowels, but by another avenue which descends for some distance by the side of the gullet to the lungs. This is the windpipe, by which the constant renewal of air in the lungs is effected.

But

It often happens, then, that the inflamed condition of the nose extends to the throat, which is felt stiff and slightly sore in the act of swallowing. The tonsils, or glands which stand out at each side of it, become enlarged. The inflammation is also now very liable to extend more or less into the windpipe. the disorder does not always advance in this particular manner. Not only are the nose and its immediate appendages sometimes alone attacked, but at other times catarrh affects the throat alone, at others the windpipe only. Now, whenever the latter is affected, we have cough produced in addition to other symptoms.

Cough indicates irritation in the air-passages of the