to the laryngeal muscles of respiration, causing dyspnoea and the utterance of odd barking sounds. Breathing in consequence becomes painful and embarrassed, The spasms, excited at first by attempts at swallowing, finally are produced by any afferent stimulant, such as draughts of air, sounds, or even mental suggestion, and extend to involve the muscles of the body generally. During these convulsions the patient snaps with his mouth and ejects foaming saliva in every direction. Mania often accompanies the spasms, while in the intervals the mind is usually clear, though distressed by fearful dread of impending death. Profuse salivation is common. The temperature is usually elevated, although it may be subnormal. The pulse becomes increasingly rapid, feeble, and intermittent. Prostration becomes more marked after each paroxysm. There may be death from asphyxia in any of the paroxysms. This stage usually lasts for from one to three days.

3. The paralytic stage lasts for from six to eighteen hours. The patient becomes quiet, the spasms cease, and the patient may swallow with ease. Unconsciousness is gradually developed, and death from cardiac failure occurs.

Prognosis. Much can be done by preventive inoculations in the stage of incubation. When the disease, however, has once begun, it is invariably fatal.

Treatment.-Immediately after a person has been bitten a ligature should be applied on the proximal side, and the wound be sucked energetically, provided there be no carious teeth or abrasions of the mouth or lips of the operator. The best results have followed an immediate excision of the wound succeeded by thorough disinfection. Cauterization is not so certain as excision as a method of prevention.

Preventive Inoculations.-Pasteur found that the continuous inoculation of the virus from rabbit to rabbit increased its strength to a maximum virulence, while gradual desic

cation of the medulla containing the virus diminished its virulence so that after two weeks' desiccation the virus became innocuous. It is possible, then, to obtain the virus in any grade of virulence.

Inoculations were made in dogs, beginning with injections of an emulsion of the non-virulent medulla, followed by those of increasing strength until injections of medullas of the greatest virulence could be made with impunity. Animals so treated became immune to hydrophobic infection.

The same series of injections are now made in the case of those who have been bitten by rabid animals (although in men the final injections used are not of the most virulent quality), with the result that the occurrence of hydrophobia in nearly all cases is prevented. The mortality of those bitten by rabid animals and treated in this manner has been reduced to 0.60 per cent.

There is another method of antirabic vaccination proposed -the gradual inoculation of an innocent virus obtained by the action of gastric juice upon the cords of infected rabbits. This method has even cured the developed disease in rabbits, but it has not yet been tried in man.

Treatment of the Disease.-When hydrophobia develops the spasms can be relieved only by morphine hypodermics and by inhalations of chloroform. The patient in this way is made more comfortable until he dies.

Pseudo-rabies is an hysterical condition occurring in persons who have been bitten by dogs supposedly rabid, and it may closely simulate true hydrophobia. The symptoms develop frequently too long after the bite to be real rabies; the temperature is not elevated; the disease is of longer duration and is amenable to antihysterical treatment. The diagnosis is corroborated by the knowledge of the fact that the dog was not rabid.

TETANUS.

Definition and Synonyms.--Tetanus is an infectious disease due to a specific bacillus. It is characterized by painful tonic spasms of the voluntary muscles with exacerbations. Synonyms: Trismus; Lock-jaw.

FIG. 3.-Bacillus tetani (coverKitasato).

Etiology. The bacillus appears as a delicate rod swelling at one extremity to contain a shining spore, assuming thus the appearance of a drum-stick or a pin. glass preparation from culture by Pure cultures are obtained with difficulty. Injections of the germs, or even of the sterilized or filtered cultures, cause tetanus convulsions. Brieger has lately isolated from tetanus cultures their distinct toxines, tetanine, tetanotoxine, and spasmotoxine, which act on the nervous centres as does strychnine, causing convulsions and spasms.

The bacilli are found in various kinds of surface soil and street dust. In warm climates the soil acts as an excellent culture medium, hence in these localities the disease is more common than in colder climates. The bacilli may thrive in some particular soil so that the disease becomes endemic in that place, as in the east end of Long Island. It may assume epidemic proportions in institutions, in hospitals, and during wars. The colored race is especially

susceptible.

To acquire the disease the germ must enter through an abraded or a broken cutaneous or mucous surface. It may follow wounds, especially of the hands and feet, or it may infect the umbilicus in newly-born children (tetanus neonatorum). It frequently follows frost-gangrene. In some cases the point of entrance is so slight as readily to be

overlooked. These cases are designated "idiopathic tetanus."

The bacilli are found in the wound-secretions, in the nerves leading from the point of infection, and in the spinal cord of the patient.

Pathology.-There are no distinct morbid changes. There may be seen congestion, perivascular exudation, and granular degeneration of the nerve-cells in the brain and spinal cord. There may be redness and swelling of the nerve-trunks. In tetanus of the new-born there may be inflammation of the umbilicus.

Symptoms. The period of incubation is about two weeks, although from one to twenty-one days constitute its limits. The symptoms begin insidiously with soreness about the neck and pain and stiffness in the muscles. Then develops the characteristic spasm of the muscles of mastication. This trismus, or lock-jaw, is almost pathognomonic, provided local causes for spasm can be excluded. The spasm then spreads to the muscles of the back of the neck, of the face, and of the trunk. The head is drawn backward and held rigidly; the face has a mask-like appearance due to immobility; the corners of the mouth are drawn back, giving the "sardonic grin." The forehead is wrinkled, the patient having a peculiarly aged appearance. The The spasm of the spinal muscles may arch the body backward so that the patient is supported only by the head and the heels (opisthotonos), and less frequently the body. may be flexed forward (emprosthotonos) or curved to either side (pleurosthotonos). In severe cases the body is entirely straight and stiffened from general muscular spasm (orthotonos). The legs may be in a condition of spasm, but the arms more frequently can be moved freely.

The affected muscles are in a condition of tonic rigidity interrupted now and then with violent clonic spasms.

These spasms may be so severe as to tear the rectus abdominalis. The muscles are exquisitely painful and tender, especially during a paroxysm.

The paroxysms are reflex, and are produced by any slight stimulus, such as a noise, a jar, or a draught of air. In some cases they may appear to be spontaneous.

If the intercostal muscles are affected, there is embarrassed respiration with dyspnoea and cyanosis. These symptoms are so aggravated, should the diaphragm be involved, that the patient rarely survives the second or third tetanic spasm.

In rare cases the muscles of deglutition are involved. These cases are spoken of as "hydrophobic tetanus" or the "headtetanus" of Rose, and follow injury of the face. Besides the trismus and the difficult deglutition there is apt to be paralysis of the facial nerve on the side of the injury.

The temperature is always elevated in acute cases, usually running to 104° F. or even higher. There may be a marked rise of temperature after death. In the milder and more chronic cases there may be but slight fever or the temperature may be normal. The pulse becomes rapid and feeble toward the close of the disease. The mind is clear throughout. There is usually profuse perspiration.

The duration varies. The acute forms may be fatal in from one to seven days. If the attack be mild, there may be but little spasm of the muscles of the trunk, and constitutional disturbances are not marked. In these cases trismus is the principal symptom. These mild cases run a course for a number of weeks.

Diagnosis.-Tetanus should not be confounded with the following conditions:

1. Strychnine-poisoning.-Here the maximum symptoms are developed suddenly, the muscles not being involved in gradual order as in tetanus. Trismus is absent and the