are not equally elastic, they yield to this distention unequally. When the chest enlarges, the lungs yield most; the veins and heart, in a state of relaxation, next; the contracting heart and the arteries scarcely expand at all. (2.) If the veins contained air and communicated with the atmosphere, they would fill as rapidly as the lungs; actually their expansion is much slower. Hence the first effect of inspiration is to increase the proportion of thoracic space occupied by the lungs, by which they become relatively more distended than the other organs. So soon, however, as the veins and auricles have time to fill, equilibrium is more or less restored. (3.) Hence it follows (a) that the dilatation of the chest in inspiration aids the expansion of the heart during diastole, and of the thoracic veins; and (b) that these events can not occur simultaneously with their cause, but must follow at an interval varying according to the condition of the circulation. (4.) Other things being equal, the force and frequency of the contractions of the heart are increased by whatever causes it to accelerate its diastolic impletion. The more rapidly the cavities fill the shorter must be its period of relaxation, the more vigorous its systole, and consequently the greater the arterial pressure. (5.) The effect of thoracic expansion on the intra-thoracic veins varies both as regards its degree and the time of its Occurrence. Both kinds of variation depend on the velocity of the circulation and the pressure existing in the veins outside of the chest. When the systemic veins are distended, the circulation rapid, and the arterial resistance in consequence diminished, the heart almost empties itself at each contraction, and the expansion of the chest fills the thoracic veins and the relaxed heart with great rapidity. In the opposite case, when the systemic veins are comparatively empty, the cavities of the heart fill slowly, and discharge themselves imperfectly on account of the excessive arterial resistance. (6.) Hence the effect of inspiration in facilitating the diastolic impletion of the auricle, and consequently in increasing the frequency and force of the heart's action, varies directly as the velocity of the circulation, inversely as the arterial pressure.

Conclusions.-I. In natural breathing the influence exercised by the thoracic movements on the heart is entirely mechanical. So long as the respiration is tranquil, variations of air-pressure in the bronchial tubes and vesicles of the lungs do not materially affect the arterial pressure; but violent respiratory movements are accompanied by simultaneous increase of vascular tension.

2. When the respiratory orifices are closed, the variations of blood pressure in the arteries are synchronical with those of air pressure in the respiratory cavity, and take place in the same direction.

3. The increased action on the heart which results from chemical changes produced in the circulating fluid by exposure to air, is of the same nature as the mechanical effect of inspiration, both being indicated by increased arterial tension and acceleration of the pulse. The former may be distinguished from the latter (a) by the length of time required for the production of the effect, and (b) by its dependence on a previous venous condition of the blood.

4. Hence the influence of the thoracic movements on those of the heart may be either directly mechanical, as in suffocation, indirectly mechanical, as in ordinary breathing, or chemical.

I.

PRACTICAL MEDICINE.

The Treatment of Chorea by the Sulphate of Zinc. By E. S. DUNSTER, M.D., Physician to the Out-Door Department of Bellevue Hospital.

[Med. Gazette, Nov. 16, 1867.]

The publication, by Dr. HAMMOND, in the Gazette of Nov. 2, of two cases of chorea successfully treated by the sulphate of manganese, induces me to present the following cases, in which a cure was effected by another mineral tonic, viz., the sulphate of zinc. In all of these cases, no medication whatsoever, beyond the zinc, was employed; there was, therefore, no perturbating element to be allowed for in estimating the efficacy of the remedy. The hygienic treatment of the patients, however, was most rigidly enforced, and it is to this element in the treatment that I desire to call especial attention, for my belief is that almost any analeptic medication will suffice to cure this troublesome affection, provided the strength and vigor of the system be maintained by proper hygienic and nutrient means. Indeed, very many cases, left to themselves, will recover without medication, if the patient be put through a course of nourishing food, well-regulated exercise, careful cleanliness, abundance of fresh air, frequent change of surroundings, proper moral influences, etc.; or in other words, if due attention be paid to the rational and hygienic treatment. The very success of so many different remedies which have been so largely extolled by various authors, substantiates this view; for in general it may be assumed that where, in the treatment of any given disease, a large number of remedies is found to be successful, there is an intrinsic tendency in that disease to recovery. I do not therefore claim for the zinc any special advantage over the other remedies which have been used as specifics in this disease, and would especially caution against too great a reliance upon such. The rational treatment of each case should be a study in itself, and should never be overlooked.

One or two points in the three cases are worthy of notice.

Ist. No amendment was observed until the dose of the sulphate had reached some eight or ten grains; but it must be borne in mind that a certain length of time is necessary for the effects of the rational treatment to be noticeable; the question therefore naturally arises to which element in the treatment was the success due. My own opinion (as may be inferred from the above remarks) is, that the two mutually aid and accelerate each other, and that either part of the treatment, by itself, would not prove as speedily or thoroughly successful as when the two are combined.

2d. The connection of chorea with rheumatism, as first pointed out by Dr. COPLAND, and subsequently confirmed by the observations of Bright, BEGBIE, M. SEE, and others, is seen in two of these cases. [Compare the following article by Dr. ROGER.-ED. St. Louis Med. and Surg. Journal.] 3d. In two of the four cases the choreic movements were unilateral, one of the right, and the other of the left side. A large series of cases would not probably show so great a proportion of unilateral cases. The weight of testimony to be gathered from the books being, that while in the earlier stages the movements are more marked on one side than the other, subsequently the whole body is apt to become affected.

Lastly, there is to be observed the readiness with which the stomach accustoms itself to large and emetic doses of the zinc.

DANIEL SHEEHAN, æt. 11 years, came under my observation December 28, 1866. There was no positive history of any previous acute disease, but the boy had suffered during the winter and spring preceding from some of the symptoms of rheumatism. The irregular muscular movements came on very gradually, and were exclusively confined to the right side. They had existed in such degree as to attract the attention of the parents only for four months past. The movements were not unusually violent; and the case did not appear to be a formidable one as the lad was as well developed as could be expected in the condition of life to which he was subject. The bowels were not constipated but somewhat irregular; appetite fair but variable; heart beating heavily and somewhat tumultuously; apex displaced to the left, and the breadth of the organ increased one-half or three-quarters of an inch; sounds normal, except that the first was very much subdued; the movements cease during sleep.

The most explicit instructions were given as to the care of the patient, the regulation of his diet, exercise and habits, in a word, his whole plan of life, and I have reason to believe they were carried out as completely as could be under the circumstances. The sulphate of zinc was administered internally, commencing with one grain three times daily. This was increased gradually until the dose had reached ten grains, when decided amendment took place. The dose was once more increased to twelve grains, three times daily, at which point it was continued for a week, and the medication was then gradually but rapidly diminished. February 15th, although the patient was still under treatment, there was no indication of the disease, and on the 25th he was discharged. The heart's condition remained unchanged.

ALBERT SMITH, New York, æt. 5 years, was first seen by me February I. He had then well-marked general chorea. No antecedent disease. The patient is a bright-eyed, intelligent, well-nourished lad. The functions of the bowels, skin, and kidneys, are well performed. No indication of any cardiac disease, either functional or organic. The parents were inclined to think that much of his disability was due to habit. And my observations subsequently led me to the same opinion, as the lad could easily control the movements by an effort of the will. The movements were wholly confined to the muscles of the arms and face, the eyes espe

cially taking on a singularly mischievous appearance from the peculiar twinkling motion of the lids.

General treatment as in case I. The zinc was also administered internally, viz.: February 4th, 2 grains; 6th, 3 grains; 8th, 4 grains; 10th, 6 grains; 15th, 8 grains, per dose. At this time there was marked improvement, and in the course of the following week, no movements were perceptible which the child could not readily control. The medication was then stopped abruptly, but the disease returned, and during March the whole plan of treatment had to be again gone over. The amount of zinc was now pushed to 12 grains three times daily (March 20th to 25th), and withdrawn gradually. April 4th, the amount was 4 grains in each dose. April 10th, medication discontinued and patient discharged cured.

ELIZA KINNEY, N. Y., æt. 9 years, was brought to me, Feb. 5, 1867, suffering from general chorea of a very aggravated character. The case was acute, being of only two weeks' duration, and had followed an attack of inflammatory rheumatism. The movements were violent and very irregular; indeed, so excessive were they that the little patient could neither walk nor talk. The arms were thrown about in the wildest confusion; nothing could be held in the hand; the legs were flexed, extended or crossed in the most absurdly erratic manner; the tongue would be pro truded and suddenly withdrawn; the jaws would open and close with a vicious snap, and even the large muscles of the trunk participated in the movements. Distinct articulation was impossible, and only liquid food could be swallowed, and the patient, from loss of sleep and want of proper food, was rapidly losing strength. Altogether the case was the most violent one I have ever witnessed. Auscultation of the heart was unsatisfactory, as the excessive contortive movements interfered with the proper examination in this way.

The same general plan of treatment was adopted as in the previous cases, and the directions as to the care of the patient were necessarily explicit on account of the gravity of the case, and yet from its rapid development it was fair to infer that so soon as an impression was made on the disease it would yield quite rapidly. And such proved to be the fact. The sulphate was carried only to 6 grains per dose in about 14 days, when there was a manifest amelioration of the symptoms. The amount was increased then to 8 grains per dose, at which point it was continued until the 25th of March, and then rapidly withdrawn, as the patient was entirely free from every evidence of the disease. I saw this patient again in October; there had been no return of the difficulty, and the patient was hardly recognizable, so great had been the change in her general appearance and condition. She had regained her flesh and strength and color; articulation was perfect, and all her functions were naturally performed. EMMA WITMEIER, N. Y., æt. 9 years, was brought to the hospital Dec. She had chorea confined to the left side, and not extreme in its characOne year previously she had typhus fever, and during convalescence from this there was a slight attack of chorea, which yielded readily to treatment, the nature of which was unknown to the mother. Three months previously the mother reports that she had pneumonia, though

2.

ter.

from an examination of the symptoms from which she suffered at that time I am disposed to question the correctness of this statement. Immediately following this illness the chorea manifested itself. The appetite was variable; digestion fairly well performed: bowels very irregular, but not much constipated.

The treatment was commenced as in the other cases, but after a few days the patient discontinued her visits. The result, therefore, can not be given. The case is reported here merely to show its unilateral character, and its connection with previous acute disease.

2.

The Relation of Chorca to Rheumatism in Children. By Dr. HENRI ROGER.

[Med.-Chir. Rundschau, Aug. 1867, from Ztsch. f. Pract. Heilk.]

From his numerous clinical investigations on the rheumatism of children and its manifestations, the author draws the following conclusions:

1. In reference to the rheumatism of children, as such :

Rheumatism occurs in youth much more frequently than is usually supposed. The new-born and infants at the breast are exempt from it, and from the third to the fifth year of age the disease occurs but exceptionally, but in "second childhood" it manifests itself almost as frequently as in adults. "Taking cold" is, as generally, in this age also the usual cause of acute articular rheumatism. Even the rheumatism in connection with scarlatina is almost always the result of cold; it has a peculiar character, is usually more limited, mostly confined to the neck and hands; moreover it is less severe, of shorter duration, and subject to less complication on the part of internal organs, although a rheumatico-scarlatinous endocarditis does occur. Acute wry-neck is as peculiar to children as lumbago to adults. Sometimes we meet with cerebral rheumatism in children, which occasionally can be mistaken for spinal meningitis. The extremely acute forms of articular rheumatism, as they are not rarely found in adults, are less frequently observed in children; in these the subacute form is the usual one. Complications, however, are just as frequent in children as in grown persons, and much more important and serious on account of the less resistance which the infantile organism offers. A very light rheumatism moderately affecting but one or two joints, nay even simple pains, in children be complicated by endo-pericarditis, which is sometimes fatal and always very serious. A simple and even light rheumatism, moreover, may in children be the starting-point of many other serious affections; thus, e. g., moderate pains in the ankle-joint may lead to congestion of the lungs, endocarditis, aortitis, and chorea, with mental alienation. As in adults, so also in children are the complications on the part of the heart the more frequent, to such extent that cardiac affections and acute rheumatism must be looked upon as in a measure connected and necessarily dependent upon one another; and that if a rheumatic child escapes the heart disease the first time, it will surely be subject to it in the

may