POPULAR MISCELLANY. 



861 



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 entomolo- 

 gFsts 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 grasshop- 

 per pest, which seemed to indicate that he 

 saw in them illustrations of the doctrine of 

 evolution. A resolution was adopted dis- 

 approving the conferring of the degree of 

 Ph. D. except after examination ; and a 

 committee was appointed to cooperate with 

 the committee of the American Philological 

 Association in addressing a memorial to the 

 Boards of Trustees of all the colleges, ask- 

 ing them to discontinue the practice. The 

 next meeting of the Association was ap- 

 pointed 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, Pro- 

 fessor 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 Geol- 



ogists. 



Physiological Effects of Compressed Air. 



Professor C. M. Woodward, of Wash- 

 ington University, St. Louis, Missouri, has 

 written a book on the St. Louis Bridge, 

 and in it has devoted a chapter to the re- 

 view of the affections which the men em- 

 ployed in sinking the piers of the bridge 

 suffered from compressed air, and the the- 

 ories 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 work- 

 ing-time was gradually shortened and the 

 rests were made longer, till the otb of Feb- 

 ruary, 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 sev- 

 enty-six feet, severe cases became more fre- 

 quent. The superintendent noticed the fact 

 that the sick men were often thinly clad 

 and poorly fed. At the end of March, sev- 

 eral persons having died within a few days 

 shortly after coming out of the excava- 

 tions, 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 fre- 

 quent 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 some- 

 what 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 nor- 

 mal rate, and even lower ; that the number 

 of respirations increased and a feeling of ex- 

 hilaration 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 con- 

 scious of a great loss of heat and a vio- 

 lent 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 



