Fig. 3.-Average gain in pounds of different groups of boys per year.

Fig. 4. Average gain in pounds of different groups of girls per year.

corresponding group, his height would have been 45.7 inches, a gain of 8.6 inches in this period of 42/12 years. His gain for a year would have been 12/50 of 8.6 inches, or 2.0 plus inches. In Chart 1 this figure was plotted. Similarly the gain was secured for other periods of the Bureau and the control series and plotted. With the Bureau curve as the standard the relative average gains of the tuberculous and control groups were studied. The tuberculous curve stands well above the control and the Bureau lines. The essential point to me appears to be how many of the tuberculous and control groups attained the Bureau

norm.

Chart 1 shows the average gain in inches per year of boys in the three series. In fourteen of twenty age periods, the tuberculous boys crosses the curve of the Bureau standard, while eleven of twenty of the controls did likewise. These groups represent 175 of 256 tuberculous males, or 68.35 per cent. gained as well or better than the Bureau standard; while a smaller number, 145 of 277 control boys, representing 52.34 per cent. reached or passed the norm. Thus it is apparent that the tuberculous boys attained the standard more often than the control boys.

Chart 2 indicates the comparative average gain per year in height of the girls of the three series. In thirteen of twenty-three age periods the tuberculous girls attained the norm (56.00 per cent.) while in seven of nineteen (37.00 per cent.) the control females were up to par. More than half of the tuberculous girls equalled or surpassed the Bureau standard, 143 of 252 or 56.74 per cent. In contrast, the control girls were normal in height gain in 34.71 per cent., 117 of 337 cases.

Thus the tuberculous girls, even as the boys, equalled the Bureau gain more frequently than the control. It is interesting to note that in the very much undernourished control and tuberculous series the boys gained uniformly more normally than the corresponding girls. This fact is in accordance with the common observation in normal children, that on the whole boys gain better and are taller than girls.

Chart 3 demonstrates the remarkable better gain of the tuberculous boys over the control series. In 76.95 per cent. of the cases (197 of 256) and in seventeen of twenty-six age groups the tuberculous males attained the standard weight gain. The control males were up to par in only six of twenty age groups, 20.21 per cent. for 50 of 277 cases. As for degree of pound gain, the tuberculous line rises markedly after the age of seven.

The tuberculous girls (Chart 4) did not as frequently attain the Bureau weight gain as did their brothers. In fifteen of twenty-six age groups there were 148 normals of 252 (58.73 per cent.) while the controls crossed the norm in eight of twenty-two age groups for a total of 113 of 337 observations, or 33.53 per cent. The tuberculous girl

gained in weight normally in 25.20 per cent. more instances. Here likewise the degree of weight gain is very marked from the age of seven on, in the tuberculous series.

The superiority in gain in height and weight per year of the tuberculous series has been plotted in Chart 5. The frequency of normal gain in height per year of the tuberculous child was 62.59 per cent. (318 and 508 observations) as contrasted with 42.67 per cent. (262 of 614 observations) for the control child. In 67.91 per cent. of the cases (345 of 508) the tuberculous child attained the Children's Bureau standard, while the control child did as well in but 27.52 per cent. (169 of 614).

Fig. 5.-Composite of boys and girls. The percentage of normal gain per year of observation in comparison with the children's bureau standard.

CONCLUSIONS

1. Using height and weight as the basis of comparison, tuberculous children more frequently attained the normal standard of gain than those of the control series.

2. Neither the entire tuberculous nor control series reached the Children's Bureau standard, represented as 100 per cent., although the tuberculous group more frequently approached it.

3. The superiority of the tuberculous over the control series in gain, I believe to be dependent on the improvement in sanitation, food, and the removal of defects.

4. The child with hilous or tracheobronchial gland tuberculosis in a group of children under-height and under-weight, when properly treated, will more often be the one to attain the normal gain. This observation, according to my experience, is equally applicable to cases seen in private practice.

RÉSUMÉ ON THE CIRCULATORY SYSTEM

LITERATURE OF 1920*

The electrocardiogram during the past year has become more extensively used, and more carefully studied. There are many points on which observers disagree, but certain fixed conclusions stand out clearly and its value in aiding diagnosis is undisputed. It is interesting to learn that in all of Paris Ribierre 1 knows of only two hospitals equipped for electrocardiography. To remedy this he suggests that medical societies in the smaller cities should acquire equipment to be loaned to the members.

Mann 2 describes his monocardiogram, which is an attempt to combine the graphs obtained in Leads I, II and III into a single curve. It is based on the fact that Lead II equals Lead III plus Lead I or the algebraic sum of the ordinates in Leads III and I at the same instant. By finding the location of the center of negativity at subsequent time intervals and connecting these points a curve is formed representing the cardiac cycle. This monocardiogram is a fusion of the three leads into a single curve by an algebraic reversal of the process by which the leads are obtained.

Hamburger studies the changes in the P wave, which represents the auricular complex. The physiologic P complex is an upright wave which results from auricular systole. It expresses the origin of the heart beat at the normal site of the impulse formation, and the passage of the wave through the auricular tissue in definite directions. Alterations in the height, direction and configuration are caused by abnormal auricular conditions. Twenty per cent. of the 300 electrocardiograph curves at the Michael Reese Hospital (Chicago) show an inverted P wave, usually in Lead III. The P wave may be inverted by vagus stimulation, by the impulse originating in the lower portion of the auricle, by force expiration, and by digitalis. The P wave may be

* Received for publication, Jan. 25, 1921.

1. Ribierre, P.: Méd. mod. 1:325 (March) 1920.

2. Mann, H.: Arch. Int. Med. 25:283 (March) 1920.

3. Hamburger, W. W.: Arch. Int. Med. 26:232 (Aug.) 1920.

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persistently inverted, or an inverted P wave may sometimes become upright with atropin. In auricular paroxysmal tachycardia the P wave is apt to be inverted. White analyzes a series of electrocardiograms in which the P wave is normal and the origin of the beat is not ectopic or, at least, if it be ectopic, it originates close to the normal pacemaker in the sinoauricular node. This is Galli's nomotopic (nomos custom, topos = place) type of paroxymal tachycardia, and it has a better prognosis than the usual paroxysmal tachycardia. When the pacemaker moves toward the ventricle there is a tendency toward shortening the P-R interval unless there is a simultaneous vagal stimulation, and the P wave is flattened and finally inverted. White includes in the series two electrocardiograms of sino-auricular heart block not due to digitalis. There are few electrocardiograms of similar conditions in the published records.

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Lewis and others, in a series of papers on flutter and fibrillation, have brought out a new conception of the arrangement of the muscles in the auricle, and of the path of the excitation wave through these muscles. Auricular flutter shows in the electrocardiogram rapid, contiguous waves uniform in extent and outline. The excitation wave passes through the auricle in a regular sequence from cycle to cycle, without any moment when all the muscle fibers are at rest, as they are in true diastole. The rates of conduction are slower than the rate with normal rhythm, and the direction of the wave of excitation after flutter is established has no relation to the point at which stimulation is applied. When the course is distinctly displayed it extends around the mouths of both the superior and inferior vena cava veins, probably in "a continuous circus movement in a natural ring of muscles existing in the intact heart." It may run either clockwise or counterclockwise. The auricular appendages and the sleeves of muscle on the great veins are supplied by excitation waves centrifugally from the body of the auricle-waves thrown off from the central path as the central wave revolves, so that the direction of the wave in these outlying paths is constant, and depends on the direction of movement in the central path. The basis of flutter is a "circus movement following a central path in the auricles." After long continued experimental flutter in dogs, there are slight variations in the path which Lewis classes as impure flutter. Experimentally, the processes of auricular flutter, impure flutter and auricular fibrillation are linked as parts of a whole complex.

4. White, P. D.: Arch. Int. Med. 25:420 (April) 1920.

5. Lewis, Th.: Heart 7:127, 131, 247, 293 (April, Aug.) 1920.