REPORT OF BOARD OF CONSULTING ENGINEERS, PANAMA CANAL.


 Work on the canal was begun in 1881. In 1882 the force employed was 1,910, and in 1884 the average number for the year was 17,615, although the maximum was 19,243, in October. The aggregate of the numbers of those reported yearly as employed in the whole period is 86,812, or an average of 10,881 per year. By computation it is found that the total number treated for sickness during the eight years was 52,814. It is also found by reference to Tables 1 and 2, recently compiled (see Appendix 0), that the number of deaths of employees in the same period was 5,627, showing a rate of mortality among the sick of 10.62 per cent, and among the employed of 6.48 per cent. These important data, together with the recently compiled statistics for the city of Panama never yet published, are a very valuable contribution to our knowledge of the health conditions as they formerly existed on the Isthmus, not only during the activity of the old company but also for the years which have since elapsed, for the system of recording vital statistics instituted in 1881 has been continued to date.
 The methods adopted by the health authorities on the Isthmus twenty years ago for coinbating tropical diseases which caused great sickness and mortality were such as were deemed most effective by the sanitarians of the period. The French company erected fine hospitals of large capacity, with up-to-date equipment, and their physicians and nursing force were competent and efficient, but modern methods for preventing sickness were then unknown. The old company, a private corporation, had no power to compel observance of health ordinances by the resident population, or by their own employees. The local authorities and permanent residents of the Isthmus were immune to yellow fever, and the people and municipal authorities were indifferent. Yellow fever was believed to be due to a poison, ever present, to which a certain proportion of newcomers, especially Europeans, was expected to succumb, as they had always done. It was believed that the disease was contagious and that the malady was transmitted by personal contact with the sick or their excreta, and the preventive measures employed to protect the new arrivals consisted of attempts at isolation of the sick, as is now done with those afflicted with smallpox. 
 Malaria was believed to be caused by a miasma exhaled from the soil or by decaying vegetation, and it was accepted that newly upturned soil caused the disease to spread. As the name implies, the disease was believed to be due to bad air. But discoveries of the very greatest importance to the human race have put an end to these misconceptions, and malaria and yellow fever are no longer a mystery to science. The mosquito theory of the transmission of these two diseases is now generally accepted as the solution of the mystery by all the leading sanitarians and physicians.
 The knowledge of the discoveries of Reed, Lavaran, and Ross has been given world-wide publicity, and gradually has been accepted and acted upon in many parts of the world.
 The yellow-fever record.on the Isthmus since the United States took over the canal works is as follows: In May, 1904, there was 1 case; in June, 1; in July, 2; August, none; September, 1; October, 1; November, 3; December, 6; January, 1905, 18; February, 14; March, 11; April, 9; May, 33; June, 62; July, 42; August, 27; September, 7; October, 3; November, 5, one of which was. from a point 30 miles distant, making a total in the nineteen months of 246 cases. Of these, 84 terminated fatally, or about 34 per cent.
 Commenting upon these figures, Col. W. C. Gorgas, U. S. Army, the chief sanitary officer of the canal works at Panama, remarks in his October report as follows:
 I consider this (the October record) as indicating the near approach of the disappearance of the disease. * Panama has often in its past history been free from yellow fever, but the only disappearance was when there were no nonimmunes to contract it. At all times in its past history when there were nonimmunes here they had yellow fever as long as the nonimmunes remained. We had during October all the natural conditions favorable to this disease, a larger number of nonimmunes probably than had ever before been present on the Isthmus-in the neighborhood of 5,000-with a wet and hot month.
 Apparently, from the records, the season in Panama does not have much influence upon yellow fever. The weather in January is as favorable to the breeding of the Stegomyia as July, and the past records seem to show that if we have nonimmunes in Panama in December we will have as much fever as we would in July. It has altogether in the past depended upon the supply of nonimmune human beings. The only yellow-fever period when there was anything near to approximating as many nonimmunes on the Isthmus as we have at present was at the time during


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