NEW VORK 



EFFECT OF ILLUMINATING GAS AND ETHYLENE 

 UPON FLOWERING CARNATIONS 



CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY Il6 



William Crocker and Lee I. Knight 



(with FOUR figures) 



i . Historical 



As early as 1864 observations were recorded on the effect of 

 illuminating gas on vegetation. Girardin (i) called attention to the 

 phenomena of gas injury to trees as reported from various places in 

 Rouen, Berlin, Hamburg, Hanover, etc. He especially investigated 

 injury done to Italian poplars which had come into use as shade 

 trees along the highways. He made a chemical analysis of samples 

 of soil taken three feet from leaks in the gas pipes, and found inflam- 

 mable oil as well as sulfur and ammonia compounds present 

 R. Virchow (2) expressed an opinion that coal gas is especially 

 injurious to vegetation. Kny (3) was one of the first to test the 

 injury experimentally. He used three sound trees in the Berlin 

 Botanical Garden, each about twenty years old — one maple and two 

 lindens. Gas pipes were carefully laid 84°™ deep and the gas used 

 was freed of sulfuretted hydrogen. The two pipes were laid in a 

 circle about the maple, and four burners were attached at a distance 

 of n8 cm from the trunk. Near each linden tree were two burners, 

 IIO cm f rom the trunks. The gas escape was measured daily. 



(1) Maple received daily 12 .9 cubic meters 



(2) First linden 11. 7 cubic meters 



(3) Second linden 1.6 cubic meters 



The experiment was begun July 7 and lasted for (1) and (2) a half- 

 year, for (3) a full year. First a Euonymus (E. europea) near the 

 maple died, then the maple lost its leaves (September 1). At the 

 same time an elm near by showed injury. September 30 the first 

 linden showed signs of injury. On October 12 the first linden lost 

 ~- its leaves, and on October 19 the second, while other lindens in the 

 er> garden were yet green. An examination of roots one-half inch in 

 ^ diameter showed a blue coloration extending out from the middle 

 »— < 259] [Botanical Gazette, vol. 46 



