ing or decaying would produce this position. We know first of all that the pull is exerted by the muscles and tendons, and the reason why opisthotonos is the more commonly seen is that the muscles of the neck are strongest. In this spastic condition all the muscles of the body are intensely contracted and the more powerful muscles overcome the resistance of the weaker ones. It is interesting to observe in this connection that in the arm muscles of the male frog the pull of the strong flexors, used in the mating season for retaining the female, overcome the extensors and flex the arms into the attitude of embracing, while in the female frog the extensors overcome the flexors and the arms stick out straight, while in a spastic condition. Occasionally, however, as in pleurothotonos, the lateral muscles overcome the dorsal ones. Secondly the ligaments of the vertebral column are but slightly elastic, and I am sure it would puzzle Dr. Dean to furnish examples of opisthotonos caused by the action of the ligaments. If the ligaments did cause this phenomenon then the head should be pulled the other way, for the ventral ligaments drying first would overpower the dorsal ones. Sheep, cattle and horses are commonly seen dead in this position on the western plains, but no one can prove that the drying or rotting of the ligaments caused the attitude, while it is easily and daily proven that they died in a spastic condition, in opisthotonos.

Opisthotonos and its related phenomena can not be rightly regarded as a special form of disease, but rather as a result accompanying many forms of disease and poisoning. The Century Dictionary regards opisthotonos as a malady, but the word malady in medicine is almost meaningless.

Another important phase of the matter and a more difficult one to solve was suggested by Dr. Matthew. Vertebrate fossils are not always figured and studied in the positions in which they died. They are subject to so many disturbing agencies, wind, water and predatory animals, that we can not be sure that the position is really the one in which they died. Often the limbs and parts of the

body are shifted in preparing for museum exhibition. On this point, of course, no one can speak with more authority than can Dr. Matthew, but it occurs to me that a sufficient number of animals have been discovered in an undisturbed position to warrant the conclusion that some of the vertebrates preserved in the opisthotonos were the victims of disease. The beautiful skeleton of Steneosaurus bollensis in the U. S. National Museum, exhibits one of the most interesting examples of this known to the writer.

The point is still open to discussion. We need more evidence from the medical side as to the exact nature of opisthotonos, and from the paleontological side more exact observations by paleontologists of the positions in which the animals are preserved in the rocks. It will be with extreme interest that further discussion on this interesting topic, the antiquity of disease in all its phases, will be read.

COLLEGE OF MEDICINE, UNIVERSITY OF ILLINOIS, CHICAGO

ROY L. MOODIE

A CHINESE LAMP IN A YUCATAN MOUND

A RECENT publication of the United States Bureau of Ethnology is a report of Thomas W. F. Gann on the "Maya Indians of Southern Yucatan and Northern British Honduras.” Herein is given an interesting account of the people and a description of a series of mounds presenting very curious examples of the ancient Maya pottery and odd-shaped objects of obsidian. In one mound there was found near its surface a soapstone lamp which Mr. Gann recognizes as markedly unlike other objects of Maya fabrication. He says:

So widely does it differ from Maya standards that there can be but little doubt that it was introduced in post-Columbian days, probably very soon after the conquest. Another explanation which suggests itself is that the lamp was buried in the mound at a much later date (possibly during the troublous times of the Indian rebellions, between 1840 and 1850) by someone who wished to hide it temporarily, and that it had no connection with the original purpose of the mounds.

This latter conjecture is the correct one so far as its age is concerned. It is a modern Chinese lamp made in the vicinity of Canton. I give a rough sketch of one given to me in

1854 when I was a boy, for my cabinet of curiosities. It had been brought from Canton and was probably made by the same artisan who carved the lamp figured by Mr. Gann. In the Peabody Museum at Salem are two lamps of identical character and design. As there were probably no Chinese coolies in Yucatan fifty years ago is it not possible that some one buried the object within recent years to support the contention by some that the culture of Middle America was introduced from China! EDWARD S. MORSE

SALEM, MASS.,

August 27, 1919

QUOTATIONS

INDUSTRIAL FATIGUE AND SCIENTIFIC
MANAGEMENT

THE Industrial Fatigue Research Board was appointed at the end of 1917 by the Department of Scientific and Industrial Research to investigate the relations of the hours of labor and other conditions of employment to the production of fatigue having regard both to industrial efficiency and to the preservation of the health of workers. This board has recently issued two reports. One of these,

Ethel E. Osborne, M.Sc., on the output of women workers in relation to hours of work in shell-making, arrives at results for which previous investigations have prepared us. The investigations were concerned with the first operation to which the rough forging is subjected; it consists in cutting off the end portion of the forging to reduce it to the required length. It is considered the hardest work in shell-making, must be done rapidly, and entails constant changing of shells. For eighteen months the women doing this in the National Ordnance Factory worked on shifts of twelve hours' duration, with night and day work in alternate weeks. It then became evident that the hours were affecting the women adversely, and the shifts were shortened. Some time previously the machines had been changed to a type which considerably reduced the demands for violent physical exertion. The method in which the investigation was conducted is described at length, but we can only notice the chief general results. Under the earlier scheme the average number of hours worked was 55.85 a week, under the shortened scheme 35.65 a week. On the long hours system the average number of shells each operator turned out in an hour was 8.17; on the shortened shift it was 8.70. Study of the actual fraction of the total working time occupied in the automatic cutting of shells and in their handling respectively-the latter being a period in which speeding up was possible showed that the work accomplished in 100 minutes of the long hour system was carried out in 80.5 minutes of the short system

-a decrease of 19.5 per cent. in time. Taking the average hourly output of shells per hour of actual work as 100, the average hourly output of shells per hour in the factory under the long hour scheme was 85.43, and under the short hour scheme 92.41. The second part of the report is based on a study of actual hourly output; it shows a uniformly low efficiency in the last hour of the long shifts, whereas no such uniformity was to be observed in the case of the short shifts. In some instances there was no falling off at all. A comparison of the records of the same

worker's output for the long and short shifts respectively showed a lower hourly output during the later hours of the long shifts. The investigation afforded no evidence of a detrimental effect of night work in comparison with day work. The second report, by Dr. C. S. Myers, F.R.S., gives an account of a remarkable experiment carried out, with the consent of the workers, by Mr. Vincent Jobson, managing director of the Derwent Foundry Company, Derby. The first step was to analyze the various jobs in order to arrive at the best method, by the elimination of all superfluous movements. This involved the proper arrangement of the tools and materials, the establishment of standard sets of movements for the process, and the training of the men. When the system was not going the number of hours of work was reduced and a special system of payment devised. The result was an enormous increase of output in spite of the reduced hours of work. The increased output, combined with the diminished cost of production, has been beneficial to the firm and largely increased wages of the employees, without causing any increase in fatigue, but rather on the whole, apparently, a decrease.British Medical Journal.

SCIENTIFIC BOOKS

Mortality Statistics of Insured Wage Earners and Their Families. Experience of the Metropolitan Life Insurance Company Industrial Department, 1911 to 1916, in the United States and Canada. By Louis I. DUBLIN, Ph.D., Statistician, with the collaboration of EDWIN W. KOPF and GEORGE H. VAN BUREN. Pp. 397. New York, Metropolitan Life Insurance Company. 1919. This volume represents a painstaking and well-planned analysis of the 635,449 deaths which have occurred among the industrial policy holders of the Metropolitan Life Insurance Company in the years 1911 to 1916. Because of its great scope and wealth of detail it is of unique value to all who are interested in public health, as well as to physicians in their study of disease. The area covered by the data includes nearly all of the

states of the United States and the provinces of Canada. This geographic range is much greater than that of the Registration Area of the United States Bureau of the Census. The report presents a study of the mortality of industrial workers and their families. The data are classified according to color, age and sex. They comprise 54,000,000 years of life, of which 47,000,000 are white and 6,700,000 are black. Thus in addition to a presentation of the mortality experience of industrial workers as a whole, we have here a comparative study of the mortality of whites and blacks of the same economic status. Previous statistical comparisons of white and black mortality compared all whites to all blacks, ignoring their different social status, and the resultant effect of this on disease.

The mortality classification is that of the "International List of Causes of Death." This, while admitting of many imperfections, had to be used in order to render the statistics comparable with those of the Registration Area of the United States Census. The occupational classification follows the "Classified Index to Occupations." U. S. Bureau of the Census, 1910. The material was very carefully compiled, especial attention being given to the avoidance of clerical errors. The diagnoses of death, whenever they were doubtful, were controlled by follow-up letters to the physicians who had certified to the death. This resulted is a greatly increased accuracy of the statistics.

Some of the more important results of this study are worthy of mention. Among whites the mortality of males is much greater than that of females. Among negroes the male mortality is less than the female below the age of 25, with the exception of children from 1 to 4 years of age. After the twenty-fifth year the male mortality exceeds the female mortality, but the excess is moderate compared to that found in whites. Following the presentation of these general considerations, the authors proceed to a detailed analysis of the principal causes of death, giving the rates for the two races in the different age groups and sexes, as well as a comparison of the Metro

politan mortality with that of the Registration Area. Some of the more interesting facts which have been established by this study may be summarized.

The mortality rate for pulmonary tuberculosis of the children of wage earners is not higher than that of children of the general population. This is all the more striking when we consider that about one half of the children in the Registration Area live in rural communities. The decline in the death rate from pulmonary tuberculosis during the years 1911 to 1916 is greater in the insured than in the general population. The mortality from organic heart disease is higher in wage earners than in the population at large, especially during the working ages. This higher rate persists to old age but to a less degree. Contrary to the general belief, there has been no increase in the death rate for organic heart disease in the period 1911 to 1916. Bright's disease too is a more frequent cause of death in the insured.

Accidents rank fifth in the causes of death. How serious this problem still is, and how great the field for prevention is, is shown by a comparison of the statistics of England and Wales with those of the United States. In 1913, that is before the war, the accident mortality for England and Wales for the ages from 35 to 45 was 62.4 per 100,000. In the United States it was 139.6 per 100,000 in the Registration Area and 154.3 per 100,000 in the insured males at the same ages. Industrial policy holders suffer from a higher accident rate at the ages where the occupational factor plays a part, and where too their death works the greatest hardship to their families. There has been little reduction in the accident rates in the six years under study. During the working years the suicide rate of male workers is greater than that of the general population. It is interesting to note that the colored rate is one half of the white rate. However the homicide rate for negro males is seven and a half times as great as for the entire group of insured wage earners. In the age period 25 to 34 it ranks next to pneumonia as a cause of death of negro males.

The study of the diseases incident to pregnancy and the puerperium is of the utmost importance. The statistics are based on the age group 15 to 45, the child-bearing period. In this age period these diseases cause more deaths than any class of disease except pulmonary tuberculosis. The rates are 66.1 per 100,000 for whites, and 82.3 per 100,000 for blacks. Puerperal sepsis caused 43 per cent, of all the deaths, albuminuria and convulsions 26.4 per cent. The figures for the Registration Area are almost the same. There has been some decline in the maternal death rate in the six years under study. The decline in the insured was 10.7 per cent., which was greater than that in the general population. The authors consider this a vindication of the Metropolitan Life Insurance Company's system of visiting nurses. These figures point out a very important field for preventive medicine.

The analysis of the cancer mortality rates for the period 1911 to 1916 is instructive, for it shows how unsafe it is to generalize. The necessity of considering age groups, the sex and race, as well as the site of the cancer, before drawing inferences as to the increase or decrease of cancer mortality is well brought out. The statistics of the Metropolitan Life Insurance Company show no definite increase in cancer mortality in the six years under study.

I have mentioned but a few of the valuable facts brought out in this volume. The authors are to be congratulated on having made an important and unique contribution to the study of the incidence of disease among wage earners, a study which will be of great assistance to all who labor for the prevention of disease, be they doctors, economists or social workers.

ERNST P. BOAS

SPECIAL ARTICLES

THE INTERACTION OF GRAVITATING AND

RADIANT FORCES1

1. Atmospheric Temperatures.-These relations are so interesting, not to say perplexing,

1 Advance note from a Report to the Carnegie Institution of Washington, D. C.

given environment. When M is on the right, or on the slightly warmer side of the region, m is deflected toward larger numbers y, of the scale. In the other case, the reading y is in smaller figures. The actual displacement of m is x=.1455 y in apparatus I; and x= .0214 y in apparatus II. The needle carrying m (balanced by an opposite m) pointed northsouth, the case being on this side of the large central laboratory pier. The basement wall is over 4 meters off on the east, and over 30 inches thick. This therefore receives solar radiation, directly or indirectly, in the morning.

Fig. 1, for instance, shows the direct reading, y of apparatus I, on July 31 and August 1, the mass M being passed alternately form east (larger reading) to west, at intervals of about an hour.

of the fact that the laboratory temperature is practically constant. It follows therefore that the ball M and the east wall reciprocate in their radiant exchanges, almost directly, in a way of which the room temperature gives no interpretable account.

On the top of Fig. 2 I have inserted the atmospheric temperatures kindly furnished by Meteorologist Charles S. Wood, of the Providence Station, U. S. W. B. It is obvious at a glance that the two groups of curves, those for Ay and that for external atmospheric temperature are of the same kind; but the Ay curves follow the temperature curve with a lag of one to three days. Whatever radiation falls on the outside of the east wall of the laboratory, shines in a subdued form on the ball M a few days later. In the dark room