sometimes spoken of as the "plasmodium of malaria," an erroneous designation, since by plasmodia naturalists mean a collection of similar entities which frequently may be observed in one of the phases of development of the protozoa. Laveran says that the malarial parasite is not found in the state of plasmodia, so the generic name cannot apply to them. The parasite, which he calls a hematozoon, is a sporozoon, one of the amebae.

are not necessarily due to a new infection, but to the reawakening of the infectious agent which has been latent. This latent period has been known to have been as long as several years.

As we are yet quite ignorant of the form in which the malarial parasite exists outside of the body, as well as of the port of entry and the exact conditions under

which infection occurs, it is but natural that the knowledge of the period of incubation should be indefinite and uncerta in It is not even so certain as to which stage

site belong; for instance, the flagellate bodies observed so often in the interparoxysmal stage.

The parasite is seen in the form of a small translucent spot, either attached to the outside of the red corpuscle or in its interior, opinions varying as to this point, altho the greater number of observers contend that it pierces the walls of the corpuscle and matures within it. The next point in the development is the formation of small pigmented spots, presumably of the hemoglobin of the corpuscle, while the parasite increases in size. Then segmentation takes place and the corpuscle finally ruptures, letting a number of small parasites loose in the blood-plasma to seek new hosts and repeat the cycle.

Paludism, or malaria, is as essentially a disease of the country as typhoid is a disease of the town, and the occupations which in the greatest degree dispose toward an attack are those which bring men directly in contact with the soil. All weakening causes, as fatigue, mental or physical strain, anemia from privation or previous disease, predispose to the influence of the poison. As Pasteur says: "Life repels life which wishes to graft itself on it; it is when an individual grows weak that it becomes an easy prey to the parasites which besiege it."

An attack confers no immunity, but the reverse, relapses being the rule. These

The general belief is that it exists as a sporozoon in the slime of decaying vegetable matter, and that these may be either breathed in or taken into the system thru drinking water. Dr. Henry B. Baker, one of the warmest opponents of the germ theory, claims that the disease is entirely the result of atmospheric conditions, the controlling cause of the intermittent type of fevers being exposure to insidious changes, or changes to which one is unaccustomed in the atmospheric temperature. He thinks that in the mechanism of the causation the chief factor is the delay in reaction from exposure to cool air; this delay, extending to a time when greater heat loss should occur, results in the abnormal accumulation of heat in the interior of the body, and in disturbed nervous action, as typified by the chill, and the final reaction is excessive because of the accumulation of heat, and sometimes because it occurs at the warmest part of the day.

He accounts for the fever by calling it the excessive reaction from the insidious influence of the exposure to cool air. Its periodicity he thinks is due to the periodic-e ity of nerve action and because the exposure and the consequent chill are periodical, owing to the nightly absence of warmth from the sun.

Another causative factor, he says, is residence in valleys or lowlands thru which or upon which cold air flows at th night, and thus causes insidious changes in the atmospheric temperature, which favor intermittent fever.

In the climate peculiar to the United States those measures-such as drainage— which enable the soil to retain warmth during the night and thus reduce the daily range of temperature immediately over

such soil, tend to decrease intermittent fever among residents thereon.

Hence, he concludes, that in the cure and prophylaxis of intermittent fever, those remedies are useful which lessen torpidity and tend to increase the power of the body to "react promptly to insidious changes in atmospheric temperature."

In support of this theory, Sir William Moore, who has had great experience with the malarial fevers of India, says: "Socalled malarial fevers are caused by sudden abstraction of heat, or chill, under the influence of cold, and more especially of damp cold. These effects of chill are more marked in hot climates because of the antecedent exposure to great solar heat, the anemia and skin debility resulting from heat and the disregard of proper precautions.''

Following up this line of thought, Dr. Baker says that as the difference between the day and night temperatures is greatest in hot climates, consequently the demands upon and resulting disturbances of the heat regulating apparatus of the body are also greatest there. Perspiration is probably a factor in causation, tending to chill, because evaporation from moist clothing will lower the temperature rapidly. Excessive perspiration tends to change the condition of the blood. When the surface of the body is strongly contracted, the blood is driven from the surfaces, the circulation is impeded, the blood parts with some of its fluid and also with its salts. Then comes a demand of the tissues for blood. Thirst is great, and a rapid changing of the proportions results, tending to the solution or breaking up of the red corpuscles. Naturally the characteristic anemia of malaria appears.

Dr. Samuel C. Basey, of Washington, gives as his opinion that a poison (character not stated) is generated from decomposing vegetable matter under a combined influence of heat and moisture, which, when introduced into the system, either thru the respiratory organs or the alimentary tract, will produce certain forms of disease, which vary in intensity, form and type according to the virulence of the poison, the temperature, amount absorbed, and individual susceptibility.

The development of this poison is favored by marshes, more especially when containing mixed salt and fresh water, and resting on a substratum of limestone, clay and mud; by swampy, undrained and delta lands; extensive excavations; newly

turned soils; rains after long-continued drought and consequent low water level; careless culture of the soil; neglect of cultivation where vegetation is luxuriant and permitted to decay on the surface; and, in fact, by the requisite combination, wherever present, of the essential elements of high temperature, moisture and decomposing vegetable matter.

It is a point in common sense as well as law that in any dispute the evidence of one witness who did see or hear a certain thing will outweigh that of a hundred who affirm that they neither saw nor heard the occurrence disputed. Hence the affirmative evidence of the presence of a parasite coinciding in its periods of development with the occurrence of the paroxysms of malarial fever must be considered as outweighing the ingenious explanations of the opponents of the germ theory. There is no doubt but that the points mentioned by Drs. Basey and Baker and Sir William Moore have their influence upon the development of the infection, but the preponderance of evidence seems to prove that the disease is caused by a parasite. This is now generally accepted. The alternations of heat and cold alone cannot be responsible for the causation of the fever, else it would be more prevalent in desert lands, which are notably free, but in which a great daily variation in temperature occurs.

nous injections, but is not propagated by contagion from man to man. From this writers argue that people are often infected by the bite of mosquitos, contrary to the idea accepted at one time that the bite of the insect carried with it antidotal properties. The parasite has been demonstrated in the bodies of mosquitos, hence their migration to the human body thru the bite can readily be traced.

The prophylaxis of paludism comprises: (1) The study of individual measures to be taken to escape paludism when obliged to live in a country where the fever prevails.

(2) The study of measures to be taken in order to render healthy the localities where paludism is endemic.

The prophylaxis will yet be founded on more precise data, and may very probably be simplified when it is known exactly under what form the parasites are found in the exterior medium. Meanwhile among the preventive measures in greatest favor are the use of tea, coffee and spiced foods, the boiling of drinking water, and the seeking of as high altitudes as possible, even to sleeping only on the upper floors of the building. Particular care must be taken to avoid insect bites, since the germ may be conveyed by these. It is considered a good measure to take cinchona wine regularly in order to prevent infection.

Avoid all places where old soil is being newly turned up or drained, since marshy land is much more dangerous when it begins to dry than when covered by water. This is probably because, while one instinctively avoids drinking the water from a marsh, in the process of drying, the sporozoa probably take some form that enable them to float in the air, and are thus taken in the system thru the respiratory tract.

Arsenious acid, taken in the form of arsenic-gelatin, is said by Tomasso Crudelli to be an excellent prophylactic. It is given in small doses until symptoms of gastrointestinal irritation appear, when it is intermitted to be taken up again in the course of a fortnight.

Still the best prophylactic must always be quinin, its effects being obtained from the daily administration of about two grains of the sulfate. There have been cases of the fever occurring under this treatment, but they are always mild and short in their course.

A strange point noticed is that malaria seldom occurs in thickly settled localities, the closely built up parts of a city having

comparatively few cases, while houses standing alone are most frequently subject to the infection in some form.

Description of a Typical Case of Malarial Fever.

The tertian fever may be taken as the type of malarial infection. For several days before the occurrence of an actual paroxysm, the patient may complain of indefinite symptoms of headache, backache, loss of appetite, and pains in the limbs. symptoms common to any acute infection. Usually it may be noted that these symp. toms occur on alternate days and often in the mornings. On the day between, the patient may feel perfectly well. Still, the paroxysm has been known to come without any premonitory symptoms upon an individual in apparently perfect health.

The paroxysm may be divided into (a) the chill, (b) the fever, (c) the defervescent or sweating stage.

Especially characteristic of a malarial paroxysm is its sudden onset. Often the slight prodromata mentioned may be quite absent and the first symptom the patient notices of his illness may be the onset of a sharp paroxysm. The actual chill is, however, usually preceded by some indefinite symptoms of malaise, headache, and a slight feeling of general lassitude. Often repeated yawning and stretching may be observed. Sometimes there is a little giddiness, and there may be at the very beginning nausea and vomiting. Frequently at this period a slight rise in the body temperature has already set in.

The chill generally begins with chilly sensations beginning sometimes in the hands and feet, and running up and down the back. These chilly sensations are at first interrupted by slight flashes of heat, but they rapidly increase until the patient falls into a general rigor. The chill may be most severe. The patient turns livid, cold and clammy, and shakes that the vibrations may be noticed in the next room. He begs for coverings and for hot applica tions. His face is drawn and shrunken, having a pinched look, and the extremities are cold and sometimes pulseless. skin is usually cool and blue-looking. It is often moist. The hair follicles are gen

The

erally erect, giving rise to the characteristic "gooseflesh." The pupils are usually dilated, but in pernicious cases are sometimes contracted or unequal.

The pulse is small and rapid, sometimes irregular, often of rather high tension. The respiration is short and rapid, and the voice broken. Nausea and vomiting are frequent, and there may be diarrhea. The patient usually suffers extremely from headache, and occasionally complains of disordered vision, ringing in the ears, and vertigo. Aching pains in the back and loins are common.

The duration of a chill may vary considerably, sometimes lasting so long as an hour, tho its usual course is from 10 minutes to a half-hour. Sometimes no actual shaking may occur, the patient complaining only of more or less severe chilly sensations, while at times, tho rarely in the simple tertian type of fever, the chill may be entirely absent. During the chill, despite the intense feeling of cold complained of by the patient and the somewhat cold feeling of the moist and cyanosed skin, the body temperature rapidly rises, beginning the state of fever.

The maximum point of temperature is generally reached in about two hours after the beginning of the paroxysm, sometimes in a much shorter time, and the climax may even occur at the beginning of the second stage. With the onset of the second stage, the intensity of the chill slowly diminishes, the chilly sensations becoming interrupted by occasional flushes of heat, which, becoming more frequent, finally wholly replace the rigor. Then the febrile stage begins.

The patient now complains of intense heat. The skin is flushed, dry and generally very hot to the touch. The conjunctivæ are injected. The pulse becomes fuller, but remains rapid, and not infrequently is dicrotic. The headache, vertigo and ringing in the ears become more intense, and the patient complains bitterly of general aching, and acute pains in the back and extremities. The accumulation of bed clothing needed for the chilly stage is thrown aside, the patient calls for air, and complains of intense thirst.

With the beginning of the fever, the patient becomes very restless, often tossing from one side of the bed to the other. Sometimes active delirium may be present. Sometimes the picture varies, the patient being dull and drowsy, presenting an appearance resembling typhoid fever, only

making complaint of the headache and the aching pains. Sometimes there may be marked somnolence, and even deep coma has been reported.

Sometimes the fever stage is accompanied by a slight cough, and occasionally vomiting and diarrhea persist into this stage.

Physical examination shows the patient flushed, with suffused conjunctivæ, and a dry and coated tongue. There is often a slight sallow, dusky yellowish color to the skin, a tint which is almost characteristic of malaria, and becomes familiar to the trained observer. If the fever has lasted or any length of time there is almost always presenta disinct anemia, recognizable by the pallor of the lips and mucous membranes. This may be a point of considerable importance in the diagnosis. heart sounds are usually clear, tho there may be a soft systolic murmur.

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In

On examination of the lungs, a few sonorous and sibilant râles may be heard. The abdomen presents no abnormalities on inspection. On percussion, however, a well marked enlargement of the spleen is demonstrable, while the splenic border is to be felt in the great majority of cases, fresh acute infections the border may be soft and round, but where numerous infections have occurred, the edge is usually hard and sharp. After repeated attacks the spleen may attain a very considerable size extending as far as and even below the navel. In acute cases there is often a well marked tenderness on palpation over the region of the spleen. Occasionally hives appear, and these are a distinctive feature of the malarial infection, never appearing in typhoid fever or other disorders with which malaria may be confounded. Another diagnostic point of importance is the appearance of herpes on the lips and nose.

During the so-called fever period, the temperature reaches its maximum, some times registering so high as 108°. The duration of the febrile period is usually four or five hours, tho not infrequently it may be considerably longer.

After the stage of fever has existed some hours, the severity of the symptoms begins to abate. The mouth becomes less dry, the skin begins to grow moist, and profuse. perspiration follows, associated with relief from the distressing sensation of heat from which the patient has been suffering. The sweating is usually excessive, even when considered in relation to the degree of heat expressed during the febrile stage. The

temperature falls rapidly and the pulse becomes slow and full. During this stage the patient, exhausted, falls into sleep. Within a relatively short time, rarely over four hours, often only two, the temperature reaches the normal. It does not, however, remain at this point, but becomes subnormal, and lasts so during the greater part of the intermission, or until after the beginning of another chill.

The length of the entire paroxysm, from the time the temperature passes 99° until it again reaches that point on the downward course, averages eleven hours. These paroxysms are more frequent during the day than in the night, and the onset is usually during the morning hours, tho paroxysms during the afternoon and night are not unknown.

After the immediate exhausting effects of the paroxysm have passed away, the patient very commonly feels perfectly well, so much so that he may leave his bed and go about his business. Indeed, many patients feel so well between paroxysms that they allow several to pass before seek ing treatment, believing after each paroxysm that the fever is at an end. However, almost exactly 48 hours after the onset of the first paroxysm; a second similar attack follows, the febrile periods and intermissions continuing thus with great regularity.

Malarial Manifestations in Children.

In children the clinical manifestations may be very different from those observed in adults. Frequently both the chill and the sweating stage may be quite absent or only abortive; under these circumstances the first stage is generally represented by a slight restlessness, the face looks pinched, the eyes sunken, the finger tips and toes become cyanotic and cold, while the child yawns and stretches itself. These may be the only manifestations of the first stage. Nausea and vomiting and diarrhea are very common.

These symptoms are often followed by grave nervous phenomena. The chill in malaria, as in other acute diseases, is frequently in a young child represented by general convulsions. These may begin with a slight spasmodic twitching of the

eyelids and extremities, the spasm soon becoming general. The febrile stage and the whole paroxysm are often shorter than in the adult, while the sweating stage may be entirely absent.

Following the sweating stage the patient passes thru an afebrile stage, lasting usually 37 hours. Often during the greater part of this time the temperature is sub-normal. It is almost invariably so during the hours following the paroxysm.

General History and Different Types of Malaria.

Beyond the presence of parasites the blood shows usually little that is remarkable. If the infection has lasted for any great length of time, the evidences of acute anemia become apparent, such as pallor of the red corpuscles, marked difference in the size of the individual elements, and perhaps a little poikilocytosis. The most striking fact is that the number of the leucocytes is always sub-normal, while the large mono-nuclear forms are relatively increased at the expense of the polymorphonuclear varieties.

The double tertian or quotidian types of intermittent fever are double infections, the parasites reaching maturity on alternate days and therefore giving rise to daily paroxysms. These differ in no wise from those of the single tertian type already described, unless they be a trifle shorter, lasting on an average only about 10 hours, consisting of the regular stages of chill, fever and sweating. The regularity in the recurrence of these paroxysms is not quite so great as in quartan infections. The chills on alternate days often come at hours surprisingly similar, the cause of this being hard to understand.

Irregular or continued malarial fever is due probably to infection with multiple groups of parasites or to the lack of arrangement of the parasites in well-defined groups. This condition is rare in adults, being more often seen in children, where the malarial infections pursue a much less regular

course.

Single quartan fever depends upon infec