spinal axis, may be reflected from it in four directions. 1st. Upon a musculo-motor nerve, causing contraction of a muscle or muscles. 2d. Upon a sensitive nerve, giving rise to neuralgia. 3d. Upon a vaso motor nerve, causing a contraction of blood vessels. 4th. Upon a tissue nerve, producing a secretion or an alteration of nutrition, as the tissue it supplies is glandular or simple. It is also easy to perceive that each of these modes of reflex action may play an important part in the normal and abnormal processes of the organism.

1. Of the abnormal actions falling under the first head, we see "Spasms," partial or general, produced by eccentric irritation. The vomitings of pregnancy, the convulsions of dentition, the laryngismus stridulus caused by enlarged bronchial glands, and the spasmodic asthma of gastric irritation, are instances on a lesser scale; while the frightful spasms of the throat, or of the whole frame seen in hydrophobia and traumatic tetanus owe their origin to the same cause. That the stoppage of the heart's action which results from a sudden blow upon the stomach, or a rapid draught of cold water when heated is due to a reflex excitation of the vagus through the splanchnic nerves, has been shown by the experiments of Dr. Brown-Sequard. For after dividing either the splanchnic nerves, the spinal cord, or the vagus, no gastric irritation could affect the action of the heart.

2. It is not so common for a centripetal irritation to be reflected on a sensitive nerve, yet cases are on record in which reflex neuralgia has been produced by a cicatrix, a stricture of the urethra, a carious tooth or an injury of a nerve. The supra-orbital hemicrania caused by gastric irritation falls under this head."

3. If the centripetal irritation be reflected upon a vaso-motor nerve, we shall have a contraction of the blood vessels supplied by it. It is improbable that such a process plays an important part in the normal actions of the organism; but it is a fruitful source of many forms of disease. We have seen that excitation of the motor nerves of a gland in a full state of activity will immediately check its secretion, by cutting off the normal supply of blood. Now considering the nervous centres as so many glands generating nerve force from the blood, and transmitted through the nerves to its destination, it becomes obvious that a sudden or chronic cessation of their activity may be produced by contraction of their blood vessels by a reflex excitation. Thus we may have from this cause (a.) loss of consciousness; (b.) paralysis; (c.) anæsthesia, according to the functions of the part of the nervous system affected; (d.) sudden contraction of the arteries of the brain proper, by an irritation sent, appears in all cases to be the starting point of an epileptic fit. The extreme pallor of the face which appears as the patient falls, results from the same cause. The same irritation, falling

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upon the laryngeal, cervical and thoracic respiratory muscles, brings them into a state of tonic contraction, thus impeding the arterialization of the blood. From hence proceeds the purple hue which succeeds the primary pallor of the face and the general clonic convulsions throughout the frame. In the so-called petit mal the cerebral arteries alone feel the irritation and loss of consciousness, without laryngismus or convulsions, results. A less degree of contraction will give rise to the vertigo to which epileptics are so subject.

Modus Operandi of Counter Irritants in removing Disease.Each component element of the body maintains a sympathetic relation with the other parts of it. There is no organ and no tissue situated beyond the pale of this influence. As the natural consequence, when one organ is morbidly affected, the disease is reflected upon others. which are distant; on this account, local injuries are quickly followed by constitutional symptoms. A fractured limb excites fever and delirium. An irritated wound propagates its irritation to the spinal cord and invokes traumatic tetanus. The troubles of dentition are not confined to the pain of the distended gum, but excite diseases in almost all parts of the body. A large and superficial blister, such as is frequently produced by a burn or scald by reflecting its irritation upon the upper portions of the intestines, may terminate fatally by ulceration and perforation of them. The local irritation occasioned by the presence of intestinal worms may escape observation and yet be suffi cient to produce epilepsy. A suppurating breast has been known to be the exciting cause of consumption, into which state the patient has suddenly lapsed. These lessons do not instruct us to hope that a local irritant will attract any other elements to itself; on the contrary, they demonstrate that injuries primarily of a local character, through means of the sympathetic system, are reflected upon distant and healthy parts, in which secondary diseases are established. When the physician, therefore, has recourse to a counter-irritant, it is not for the purpose of attracting the disease to the spot artificially. The application of the Spanish fly has nothing whatever to do with the morbid elements which may be present as the result of the natural disease; it is healthy serum, which can be called to the surface at any time, and in any person willing to submit himself to the disease-producing powers of cantharides. The popular impression is adverse to this. The error into which they fall is a natural one, and not unfrequently medical men play upon their credulity and encourage them to regard the redness in the one case and the blister in the other, as a certain amount of the disease brought to the surface." But "when an artificial disease is purposely developed in the hope of relieving the sick, it must be reflected upon an organ already diseased, that organ is at once placed under the influence of two morbid processes, namely the pri

mary or natural disease, and the secondary or artificial one." But, in accordance with the well known physiological law" which even the Lancet recognizes as true, no two actions can go on in the same part at the same time, and the greater must destroy the lesser. "The curative action of a counter-irritant is therefore equivalent to the direct action of a drug-specific to the part. In the one case we depend upon a drug which from experience is known to exercise a specific aotion on the diseased organ; in the other we excite an artificial disease in a distant part, and hope that its influence may be reflected upon the disease which we wish to cure; counter-irritation, although uncertain, when successful, is certainly homœopathic in principle."— (Drummond, 65, Holcombe, North Amer. Jour. Homœopathy. Feb. 1858, Art. XXVII.)

1. TETANUS.

TETANUS. This disease consists of violent tonic spasms of the voluntary muscles, the powers of sensation and of thought remaining unimpaired. When the diseased manifestation is confined to the muscles of the jaws and of the throat, the affection is called trismus or lockedjaw.

We understand by the term tetanus, sudden morbid contractions or cramps of many muscles of the body, with rigidity and loss of voluntary motion in the affected parts. This morbid contraction and rigidity may affect the muscles of almost every portion of the body, or it may be confined to the muscles of a single part, like the lower jaw, when the affection receives the name of trismus; or to the extensors of the back, giving rise to recurvation of the body, when it is termed opisthotonos; or to those of the front part of the body, causing incurvation, termed emprosthotonos; or the muscles of the side, causing a lateral curvature, and called plearthonos.

Tetanus is much more common in hot than in temperate latitudes, and generally selects for its victims individuals of a nervous and irritable temperament, or those whose constitutions have been impaired by the abuse of stimulants, or exposure to a vitiated atmosphere.

There are two varieties of tetanus, the traumatic and the idiopathic. The usual exciting causes of the former are, punctured and lacerated wounds, causing injury or partial division of the nerves; and of the latter, general debility of the nervous system from long-continued illness, or protracted derangement of the different functions of the organism.

DIAGNOSIS. This malady generally commences with uneasiness at the præcordia; stiffness and tension in the muscles of the back of the

neck, back and loins, and some difficulty in deglutition and in articu lation. This contraction and stiffness gradually increases; the sensation of uneasiness in the chest becomes changed to violent and painful contractions about the ensiform cartilage; the pains and cramps extend to the back, jaws, and limbs; the appetite fails; the countenance assumes a flushed and anxious appearance, the bowels are constipated; the mind remains sound until the last stage of the disease, and the body will be rigidly drawn into such a position as will enable us to decide what particular class of muscles are affected, and which of the varieties of tetanus is present.

Traumatic tetanus is always a dangerous affection, but hopes of cure may be entertained when unusual pains in the wound or cicatrix, with pains extending along the limbs in the direction of the contracted parts, ocour simultaneously with the first symptoms of the complaint. But if the symptoms continue to make steady progress, while the original wound is cicatrized, and no pain or disturbance is experienced either at this point, or extending from it the case may be looked upon as highly dangerous.

Idiopathic tetanus proceeds from constitutional causes, and is far less dangerous than the traumatic variety. Its approach is also more gradual, and attended with less pain, but when the contraction and rigidity of the parts takes place, they remain in this condition a longer time than in the other form of the disease. The violent contractive pains about the ensiform cartilage, and in the nape of the neck which are so characteristic of traumatic tetanus, are also absent in this variety. Indeed, we have seen cases where no pains or uneasy sensations were experienced in any part of the body, except from the constrained parts affected with the morbid contraction.

CAUSES.-Punctured and lacerated wounds which partially divide one or more nerves, are the most common of causes. The admission of cold air into wounds, sudden checks to the perspiration after long and fatiguing exercise under a hot sun; the irritations of splintered bones, or other foreign substances in contact with nerves and tendons ; amputations and blows upon the spine, are all occasional causes of traumatic tetanus.

The exciting causes of idiopathic tetanus are: suppressed menstruation, or other habitual discharges, low fevers, over-exertion of mind or body, too close confinement in small and ill-ventilated apartments, sitting in unnatural and constrained positions; tight lacing; contused, lacerated, or punctured wounds. It is said to follow more frequently wounds in which the nerve is partially divided or lacerated. Plenk relates a case of the disease excited by the insertion of an artificial tooth. Others have caused it by passing a ligature round an artery so as to include a nerve.

PATHOLOGY.-No pathological changes have been noticed in the brain or spinal cord which can be said to be the cause or consequence of the disease. It has been called "functional disease of the spinal cord" for want of a better name. In traumatic tetanus, the minute. nervous twigs have been discovered diseased at the seat of the wound Mr. Erichsen (on Tetanus, Lancet, Vol. I., 1859, p. 355,) says: "There is in traumatic tetanus, always a certain condition of the nervous system to be met with, if carefully looked for, namely, an unhealthy state of the nervous branch, or twig, running from the wound. This twig will be found implicated in some way, congested, inflamed, infiltrated; its neurilemma thickened, softened and discolored, often for a considerable distance from the wound. I have never failed to find this when it has been carefully looked for. In one instance (which is quite common) a cutaneous branch was found lying bare, and inflamed in the bottom of the issue-wound."

It

The mischief commences in a minute nervous twig, and by reflex action those powerful changes are effected which characterize the disease. Though the disease be called lock-jaw, or trismus, this symptom is not always the first striking symptom, though it is an early one. is often manifested by twitching of the muscles of the trunk or extremities before lock-jaw is developed. It then becomes a prominent symptom. The explanation of this early appearance of this local symptom is thus given by Dr. Hilton, of Guy's Hospital: "Experiment indicates that the gray matter of the interior of the spinal marrow is probably the local seat of tetanus. The fifth nerve, or nerve of mastication-the one involved, and which must be the direct cause of trismus-has a larger connection or continuity with the gray matter of the spinal marrow than any other nerve in the human subject; and in this fact, perhaps, lies the explanation of the early symptoms of lock-jaw; and no doubt the firm closure of the lower upon the upper jaw depends on the relative greater strength of the muscles closing the mouth, as compared with those depressing the jaw. It is curious to observe the gradual ascent of the cause of tetanus-to see how the disease encroaches upon the higher or anterior nerves of the base of the brain, ultimately reaching the third cerebral nerve. Then the muscles which are supplied by this nerve become tetanic and cause retraction of the eye-balls, deep into the bony orbits, so far that in some cases, especially animals, we almost lose sight of the eye as the tetanus goes on." This symptom is one of great danger, for it points to the great extent of the structural lesion of tetanus, though the exact nature and character of the pathological state is not yet explained.

Among the remedies to which the cure of individual cases have been attributed are: Tobacco, Nicotine, Aconite, Atropine, Belladonna, Conium, Henbane, Cannabis-indica, Opium, Camphor, and stimulants.