278 NEBRASKA STATE HORTICULTURAL SOCIETY. 



INJURIOUS EFFECTS OF ILLUMINATING GAS UPON GREENHOUSE 



PLANTS. 



BY E. MKAB WIIXOX, PROFESSOR OF AGRICULTURAL BOTANY, UNIVERSITY OF 



NEBRASKA. 



The presence of such modern necessities as gas, electric lights, sewers 

 and pavements places many an obstacle in the way of any attempt to 

 grow plants with success in our cities. The stretching of wires for tele- 

 phone, telegraph and lighting purposes too often involves the serious 

 cutting away of the larger branches of our shade trees, while leaks from 

 gas and sewer pipes often are responsible for the death of trees along 

 streets and in private grounds. It is often a question whether it pays 

 to try to grow trees along city streets in open competition with all these 

 unfavorable factors. 



Professor Stone of the Massachusetts Experiment Station has given 

 this matter considerable attention and recently said: "The death of many 

 trees can be referred to illuminating gas. If a leak occurs in the pipe, 

 the gas escapes very readily into the soil, especially if it is porous, and 

 when it comes in contact with the roots they are asphyxiated, and the 

 result to the tree manifests itself very quickly. The symptoms of gas 

 poisoning are most generally a sudden falling of the leaves, a deadened 

 appearance of the bark, due to the collapse of the cambium or living 

 layer, brought about by the asphyxiation of the roots, which results in 

 the rapid death of the tree. In mild instances of poisoning the effect 

 shows only upon one side of the tree, but in general the tree seldom 

 escapes death. We have observed many single trees killed by gas on the 

 private grounds of city residences, without the owner ever surmising 

 what the trouble was; and this last summer we had an opportunity to 

 examine whole rows of native trees which had died by gas asphyxiation. 

 Some of the trees which we observed were at a distance of fifty feet 

 from the nearest gas main, while others succumbed when not nearer than 

 one hundred feet to the leak in the pipes." 



" The injurious effects of the gases or fumes from smelter plants of 

 various types upon vegetation and even animals have received much at- 

 tention in Europe from chemists and plant pathologists. In this country 

 the investigations of Haywood and others have shown the nature of the 

 injuries involved and suggested certain possible remedial or rather pre- 

 ventive measures which could be applied at the smelter which might 

 largely do away with this type of nuisance. In some of these cases large 

 areas are rendered unfit for agriculture and streams may become polluted 

 with such injurious chemicals that it becomes unwise to use such water 

 for purposes of irrigation. Sediments containing arsenic may settle upon 

 grass at some distance from the smelter and thus cattle grazing be made 

 dangerous — in some cases such grass cannot with safety be cut and em- 

 ployed for hay. 



