PUKNOI. 1X.TUUY TO APrLES. 



G. II. COONS AND GENEVIEVE GILLETTE. 



(Preliininaiy Note.) 



Injury t<» vegetation by fumes of various sorts has often been considered 

 in tlie literature of plant pathology, and in its l»roader aspects involves great 

 industrial oi)erations through the effects which the smoke from the industrial 

 plants have upon nearby vegetation. 



The investigation covered liy this pai)er concerns itself with a very 

 restricted phase of the fume-in.iury problem, and is most nearly connected 

 with the injury previously noted as coming from .Tar, "Tarvia,"' and other 

 coal tar products, such as are used for road building. 



The literature of "Tar" injury has recently been considered by Chivers', 

 and he has detailed expei'iments by which he was able to produce definite 

 injury to growing plants, such as begonia, ferns, wandering-jew, and gera- 

 niums, by subjecting them in the lalwratory to fumes from tarvia of various 

 grades. Chivers mentions the deposit upon the plants of an oily, greasy film, 

 and which was evidently associated with the injury to plants. 



The attention of French investigators had been called to injuries of this 

 type through the unthriftiness and death of trees along surfaced roads, anti 

 many articles have been written covering the subject. These are reviewed l»y 

 (Jatin- and others, and it is found that the bulk of the work presented lias 

 (concerned itself with the nature of the injury, the types of lesions, the varie 

 ties injured, etc. Little attempt has been made to determine tlie toxic com 

 ponents, since all the articles considered that the constituents of coal t.-ir were, 

 in general, more or less injurious. 



In tills regard the advance made has been little greater than the early 

 contribution of Oliver', who was .seeking the cause of the injury produced in 

 greenhouses by London fog.s— an injury associated with fogs in London, but 

 not found in fogs in the country. While assigning a ]iortion of the injury to 

 sulphite fumes, a part of the injury was believed to be caused by the tarry 

 constituents of smoke, and as corroboratory evidence, definite injury by 

 jihenol (crystals) and other aromatic compounds to foliage was demonstrated 

 by experiment. 



The problem of fume injury has many practical bearings. A popular 

 account of the injury to a rose fancier's choice collection through the burning 

 of a tar roof and the damage suit resulting, as given by G. T. Moore^ presents 

 an interesting turn to the iwssibilities of injury. Similarly the many luipub- 

 lished experiences in greenhouses, by use of tar paper in benches, or by 



21st Mieh. Acid. Sei. Rept., 1010. 



