Imagens das páginas
PDF
ePub

circumstance that those who have not had the disease are susceptible to it, and that those who have had it are protected from it.

II. Sex. Sex exerts no influence, predisposing or other, on scarlet fever; male or female are alike infeeted, if they be alike exposed to the disease; so that any distinctions observed as between the sexes in a given population affected with the fever, are caused by difference in the numbers of the sexes present in the population and susceptible to the poison.

III. Meteorological Influences. The seasons materially modify the course and intensity of scarlet fever. The months of October, November, and December furnish in England the maximum amount of the disease; the months of April, May, and June the minimum; the proportions, without decimals, being as 9 for the months of April, May, and June, 11 for the months of July, August, and September, 14 for the months of October, November, and December, and 10 for the quarter included in January, February and March. The influence of season cannot, however, yet be traced to any special meteorological condition; neither temperature, barometric pressure, atmospheric movement, nor electrical modifications, can be shown as yet, to have any direct bearing on the prevalence or absence of the malady.

IV. Recurrence. Scarlet fever may recur once or even twice in the same person; but the event is comparatively rare, and death from a second attack is unknown as a fact.

v. Mortality. The mortality from scarlet fever is greater in towns than in rural districts; while, compared with that arising from other zymotic affections, it is statistically second only to that which attends typhus; and is probably, if the returns under the head "Typhus" were correctly made, first in relative order of the mortalities arising from the zymotici.

VI. Types. In the types of scarlet fever only one disease is recognisable. As causes producing varieties of type we may exclude differences of poison, meteorological conditions, localities, physical conditions of the patient, age, and hereditary predisposition. The only possible cause for difference of type which can be adduced, in the present state of knowledge, is, that in the susceptible organism itself there is a directing agency, which modifies the violence of the disease, or intensifies it. This view does not yet claim the rank of a theory.

VII. Doubtful Scarlet Fever. There is a form of disease, sporadic in kind, which in every symptom resembles scarlet fever. It lasts but a few hours, and does not seem dangerous. It may recur even within a few weeks after a previous attack. It is apparently not contagious.

VIII. Rheumatic Scarlet Fever. Scarlet fever and acute rheumatism may occur simultaneously in the same person. The rheumatic symptoms may subside with or supersede the acute scarlatinal symptoms. The same rheumatic symptoms may recur with indications of albuminuria during apparent convalescence.

IX. Chemical Pathology. Scarlet fever belongs to

I

that form of disease manifestation in which the fibrine of the blood is increased. During the fever, the amount of urea and of uric acid excreted by the urine is increased, while that of the chlorides is decreased. Death commonly occurs from deposit of fibrine in the right side of the heart. Mild cases of the disease occasionally terminate fatally from this cause.

x. The Primary Poison. The primary poison of scarlet fever is probably solid in regard to its physical properties. It travels but a very little distance, except it be held in contact with some other body, such as an article of dress. It is destructible by heat at boiling point. It is thrown off from the affected person by the skin or the lungs, and is received by the susceptible person by respiration.

XI. The Secondary Poison. The symptoms of scarlet fever are probably due to the production in the economy of a secondary poison, having the physiological properties of an acid, such as the lactic. This secondary poison is the product of a modified zymotic process in the blood, induced by the absorption of the primary poison.

XII. Treatment. The curative treatment of scarlet fever consists in producing free action of the skin, and in maintaining the fluidity of the blood by the administration of a solvent remedy. The hygienic treatment consists in the admission of pure air to the patient, and in the establishment of a strict quarantine.

115

ESSAY V.

ON PULSATILE PULMONIC CREPITATION.

By "pulsatile pulmonic crepitation," I mean a stethoscopic sign, in which, without any indication of pneumonia or of tubercle, a crepitant sound, connected with pulsation, is presented to the ear. The sound was first described by myself at the Medical Society of London in 1854, and again at greater length in the Medical Times and Gazette for February 25th, 1860, under the title, "An Auscultatory Sound, produced by the Action of the Heart over a portion of Lung." At the time when this description was written, I had formed an opinion, that for the production of the sound the action of the heart on a tongue of lung was always required; I have since had reason to extend this view, as the sequel will show. I have learned, in a word, that other pulsating structures may excite the crepitation; and for this reason I have found it desirable to give to it a broader definition, and to denominate it" Pulsatile Pulmonic Crepitation." Under this title the sound may now be classified as a stethoscopic phenomenon, having its own explanation and meaning as distinctly defined as ægophony, metallic

tinkling, or other recognised physical sign. To define the sound, I proceed at once to clinical records.

OBSERVED FACTS AND ANALYSES.

From the year 1851 to 1854, I was almost daily in attendance upon a lady, (Mrs. K.), who suffered from dilatation of the bronchial tubes and emphysema of the left lung: these conditions were attended with frequent attacks of urgent dyspnoea. In the last year of her life there appeared, without any acute premonitory symptoms, a well-marked systolic regurgitant murmur, evidently mitral, succeeded by general symptoms of dropsy. For some time, the abnormal heart-sounds continued without modification. The mitral murmur was fully pronounced, and was heard most distinctly towards the apex of the heart, the diastolic sound being perfectly normal and clear over the base. About six weeks before the death of this patient, after the subsidence of a very severe attack of dyspnoea, during which I was unable to make a physical examination of the chest, owing to the oppression which the act produced, I was surprised, when the examination could again be borne, at hearing over the cardiac region an auscultatory sound, which was not only new to this special case, but new to my ear altogether. The systolic rasp was present, as before; it was most distinct about three inches below the shrunken nipple, bearing a little to the left side. The diastolic sound was still perfect; it was most distinctly heard about an inch in a straight line upwards above the left nipple. But an inch below the nipple,

« AnteriorContinuar »