cated his observations of "The Motion of Roots in germinating Indian Corn." The chairman of the entomological sub-section, reviewing the growth of entomology in the United States, said that while forty years ago there were but ten working entomologists south of New York, the "Naturalists' Directory" for 1880 contains the names of four hundred and thirty-six entomologists. Professor Riley announced some novel views on the sudden appearances of the grasshopper pest, which seemed to indicate that he saw in them illustrations of the doctrine of evolution. A resolution was adopted disapproving the conferring of the degree of Ph. D. except after examination; and a committee was appointed to coöperate with the committee of the American Philological Association in addressing a memorial to the Boards of Trustees of all the colleges, asking them to discontinue the practice. The next meeting of the Association was appointed to be held at Montreal, August 23, 1882. The following-officers were elected for the ensuing year: President, Dr. J. W. Dawson, of Montreal, Canada; Permanent Secretary, Professor Putnam, of Cambridge, to continue; General Secretary, William Saunders, of London, Ontario; Assistant General Secretary, Professor J. Eastman, of Washington, D. C.; Vice-President and Chairman of Section A, Professor William Harkness, of Washington; Section B, Professor T. C. Mendenhall, of Columbus, Ohio. Treasurer, William S. Vaux, of Philadelphia. A new committee on Geological Survey was appointed, consisting of Professors Swallow, Proctor, James, Hull, Winchell, Kerr, and Orton, and Major Powell. Steps were taken during the meeting toward the organization of a distinct Association of American Geologists.
Physiological Effects of Compressed Air.—Professor C. M. Woodward, of Washington University, St. Louis, Missouri, has written a book on the St. Louis Bridge, and in it has devoted a chapter to the review of the affections which the men employed in sinking the piers of the bridge suffered from compressed air, and the theories that were proposed to account for the trouble. From advance sheets of this chapter kindly furnished by the author, we learn that no serious drawback was perceived to working four or even six hours consecutively in the air-chamber till the cutting-edge of the caisson of the east pier was nearly sixty feet below the surface of the river. From that time on the working-time was gradually shortened and the rests were made longer, till the 5th of February, at sixty-five feet, when the work-time was made three watches of two hours each, with two-hour rests. The first effect noticed upon the men was a muscular paralysis of the lower limbs, without pain, which would pass off in a day or two, but which became more difficult to subdue, more extended and painful, as the caisson was sunk deeper. It was joked about among the men at first, but became more serious by the middle of February, after which, the depth being seventy-six feet, severe cases became more frequent. The superintendent noticed the fact that the sick men were often thinly clad and poorly fed. At the end of March, several persons having died within a few days shortly after coming out of the excavations, Dr. A. Jaminet was appointed to take medical charge of the men and establish such regulations as in his judgment their well-being demanded. He had been a frequent visitor to the air-chamber, had noticed the men as they came out, and had observed that their appearance was pallid and cold; that in some the pulse was quick but somewhat weak, while with others it was as low as sixty, and that without exception the workmen complained of fatigue; also that the pulse always quickened on entering the air-chamber, though it soon fell to the normal rate, and even lower; that the number of respirations increased and a feeling of exhilaration came on in the air-chamber, and that the workmen sweated profusely during their stay in it, although the temperature was often below 60° Fahr. The air-lock was, as a rule, excessively warm when the pressure was increasing, and excessively cold when the pressure was diminishing. On the day the caisson touched the rock, when the pressure was forty-five pounds above the normal, Dr. Jaminet was conscious of a great loss of heat and a violent pain in his head while in the air-lock on his way out; he had much difficulty in getting to his carriage, and became partly