It may be considered as established that the death rate from tuberculosis among silk-mill operatives is distinctly high as compared with the average rate for factory industries in general. There is a strong presumption, moreover, that conditions in the industry itself are partly responsible, although these conditions have not been identified. Whatever the effect of factors directly involved in manufacturing processes, it is certain that various collateral factors, such as nationality, personal habits, and living conditions, have an important influence.

Whatever the cause of this high mortality from tuberculosis among silk workers may be, it calls for most serious study in order to locate the responsibility and, so far as possible, remove or minimize the cause.

In view of the rather general disposition among writers on industrial hygiene to attribute a high occurrence of tuberculosis to factory dust, it is worth emphasizing the fact, already pointed out, that the silk manufacturing industry is exceptionally free from dust hazards, except perhaps in the plush and velvet mills. Yet, on the whole, the tuberculosis death rate among silk-mill operatives is rather higher than that for workers in cotton and wool mills, where dust is characteristic of certain processes.

Special studies of health conditions in the silk industry in Italy, under the direction of the Department of Industry and Labor, show a similar high mortality from tuberculosis, particularly for the younger age groups. This has been attributed by one writer1 to the fact that children go to work at so early an age in the silk industry in Italy that they are unable to stand the strain of the work and the unsatisfactory ventilation in the factories. This, the report stated, tends to bring on an anæmic condition which later results in tuberculosis.

In the United States, the laws of most of the states in which the silk industry is conducted aim to protect children from working while too young, and also prescribe their hours of work. It should be remembered, however, that the proportion of young persons working in the silk industry is higher than in most factory industries, and higher than in the other textile industries. It may be that this has a bearing on the high incidence of tuberculosis among silk workers later in life.

'Dott. Luigi Carozzi. "Contributo allo Studio delle Condizione IgienicoSanitarie nella Trattura della Seta." Bulletin of the Department of Industry and Labor. Anno IV.N. 7-8 Rome. 1913.

ACCIDENT HAZARD

The accident rate in the silk industry is distinctly low. Thus, in the Pennsylvania Rate Manual,' the silk manufacturing industry takes a rate of 25 cents per $100 of payroll as against 55 cents for cotton and wool spinning and weaving, and $1.05 for wool combing, and much higher rates in many other industries.

CONCLUSIONS AS TO HEALTH

The evidence necessary for satisfactory conclusions as to the health of silk-mill workers under different hours-ofwork schedules is not in existence. As already noted, there was the same absence of records as in the cotton and wool industries. No morbidity statistics are gathered by the Government, and even the Census mortality statistics by occupation are limited. Special effort was made to see whether information was contained in literature on the subject which would permit of valid conclusions. Here, again, the same paucity of information was developed.2

There is no doubt that the mortality from tuberculosis among silk-mill workers is high; it is somewhat higher

The following table shows the rates for various industries as quoted in the Pennsylvania Rate Manual.

Pulp manufacturing, sulphur process, no saw or barking mills

2.75

Wool separating (chemical)

3.00

Blast furnace operatives

3.50

Saw and barking mills

3.75

Thus, in Diseases of Occupation and Vocational Hygiene, by Kober and Hanson, covering nearly 900 pages, the only reference to the silk industry noted in the index is a brief reference to the use of chemicals in the manufacture of artificial silk.

than the rate for the wool and cotton manufacturing industries which, in turn, show a higher rate than the general average for all factory industries combined.

With the exception of tuberculosis, however, health conditions among silk-mill workers, so far as these can be judged by mortality statistics, compare favorably with those in other factory industries.

The National Industrial Conference Board, in the summer of 1918, secured the co-operation of a substantial number of establishments for the keeping of careful records of absenteeism in industry over a 24-day period which would show not only the total amount of time lost but also the cause. It is hoped to present a report on the results of this study in the near future. In the meantime a similar record is being kept for another 24-day period which will reflect conditions at the end of the winter. It should be understood that these records will throw little light on the effect of hours of work on health. Probably in most cases there has been no change in work-hours between the periods for which these absence records were kept. In any case it would be necessary to have records covering a much longer time before any safe conclusions could be drawn as to the effect of a single factor such as a change in hours of work.

It is hoped, however, that the keeping of these records for specific periods may lead to keeping permanent records by these establishments, and may encourage other employers to adopt a similar policy. Until such careful records of the amount and causes of absenteeism are kept by a large number of industrial establishments, it will be practically impossible to present valid conclusions as to the effect of hours of work or any other single factor on the health of industrial workers.

Appendix

The following table epitomizes the important data submitted by those establishments which reported the effects on output accompanying reduction in work-hours. For convenience, the information is assembled by hourgroups and the establishments classified according to the effect on production.

In examining the data given in the column "Change in Rates of Wages," the distinction between rates of wages and total wages must be kept clearly in mind. The statement that there was no change in piece or hourly rates when hours were shortened means that weekly earnings were reduced for dayworkers, and for pieceworkers also unless these increased their output. Likewise an increase in efficiency as shown by an increased hourly output does not necessarily mean that total output was maintained.